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/*
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 * Wmapro compatible decoder
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 * Copyright (c) 2007 Baptiste Coudurier, Benjamin Larsson, Ulion
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 * Copyright (c) 2008 - 2009 Sascha Sommer, Benjamin Larsson
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * @brief wmapro decoder implementation
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 * Wmapro is an MDCT based codec comparable to wma standard or AAC.
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 * The decoding therefore consists of the following steps:
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 * - bitstream decoding
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 * - reconstruction of per-channel data
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 * - rescaling and inverse quantization
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 * - IMDCT
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 * - windowing and overlapp-add
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 *
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 * The compressed wmapro bitstream is split into individual packets.
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 * Every such packet contains one or more wma frames.
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 * The compressed frames may have a variable length and frames may
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 * cross packet boundaries.
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 * Common to all wmapro frames is the number of samples that are stored in
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 * a frame.
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 * The number of samples and a few other decode flags are stored
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 * as extradata that has to be passed to the decoder.
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 *
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 * The wmapro frames themselves are again split into a variable number of
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 * subframes. Every subframe contains the data for 2^N time domain samples
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 * where N varies between 7 and 12.
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 *
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 * Example wmapro bitstream (in samples):
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 *
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 * ||   packet 0           || packet 1 || packet 2      packets
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 * ---------------------------------------------------
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 * || frame 0      || frame 1       || frame 2    ||    frames
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 * ---------------------------------------------------
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 * ||   |      |   ||   |   |   |   ||            ||    subframes of channel 0
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 * ---------------------------------------------------
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 * ||      |   |   ||   |   |   |   ||            ||    subframes of channel 1
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 * ---------------------------------------------------
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 *
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 * The frame layouts for the individual channels of a wma frame does not need
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 * to be the same.
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 *
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 * However, if the offsets and lengths of several subframes of a frame are the
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 * same, the subframes of the channels can be grouped.
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 * Every group may then use special coding techniques like M/S stereo coding
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 * to improve the compression ratio. These channel transformations do not
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 * need to be applied to a whole subframe. Instead, they can also work on
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 * individual scale factor bands (see below).
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 * The coefficients that carry the audio signal in the frequency domain
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 * are transmitted as huffman-coded vectors with 4, 2 and 1 elements.
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 * In addition to that, the encoder can switch to a runlevel coding scheme
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 * by transmitting subframe_length / 128 zero coefficients.
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 *
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 * Before the audio signal can be converted to the time domain, the
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 * coefficients have to be rescaled and inverse quantized.
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 * A subframe is therefore split into several scale factor bands that get
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 * scaled individually.
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 * Scale factors are submitted for every frame but they might be shared
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 * between the subframes of a channel. Scale factors are initially DPCM-coded.
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 * Once scale factors are shared, the differences are transmitted as runlevel
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 * codes.
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 * Every subframe length and offset combination in the frame layout shares a
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 * common quantization factor that can be adjusted for every channel by a
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 * modifier.
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 * After the inverse quantization, the coefficients get processed by an IMDCT.
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 * The resulting values are then windowed with a sine window and the first half
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 * of the values are added to the second half of the output from the previous
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 * subframe in order to reconstruct the output samples.
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 */
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#include "avcodec.h"
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#include "internal.h"
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#include "get_bits.h"
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#include "put_bits.h"
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#include "wmaprodata.h"
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#include "dsputil.h"
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#include "wma.h"
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/** current decoder limitations */
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#define WMAPRO_MAX_CHANNELS    8                             ///< max number of handled channels
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#define MAX_SUBFRAMES  32                                    ///< max number of subframes per channel
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#define MAX_BANDS      29                                    ///< max number of scale factor bands
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#define MAX_FRAMESIZE  32768                                 ///< maximum compressed frame size
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#define WMAPRO_BLOCK_MAX_BITS 12                                           ///< log2 of max block size
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#define WMAPRO_BLOCK_MAX_SIZE (1 << WMAPRO_BLOCK_MAX_BITS)                 ///< maximum block size
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#define WMAPRO_BLOCK_SIZES    (WMAPRO_BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1) ///< possible block sizes
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#define VLCBITS            9
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#define SCALEVLCBITS       8
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#define VEC4MAXDEPTH    ((HUFF_VEC4_MAXBITS+VLCBITS-1)/VLCBITS)
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#define VEC2MAXDEPTH    ((HUFF_VEC2_MAXBITS+VLCBITS-1)/VLCBITS)
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#define VEC1MAXDEPTH    ((HUFF_VEC1_MAXBITS+VLCBITS-1)/VLCBITS)
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#define SCALEMAXDEPTH   ((HUFF_SCALE_MAXBITS+SCALEVLCBITS-1)/SCALEVLCBITS)
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#define SCALERLMAXDEPTH ((HUFF_SCALE_RL_MAXBITS+VLCBITS-1)/VLCBITS)
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static VLC              sf_vlc;           ///< scale factor DPCM vlc
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static VLC              sf_rl_vlc;        ///< scale factor run length vlc
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static VLC              vec4_vlc;         ///< 4 coefficients per symbol
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static VLC              vec2_vlc;         ///< 2 coefficients per symbol
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static VLC              vec1_vlc;         ///< 1 coefficient per symbol
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static VLC              coef_vlc[2];      ///< coefficient run length vlc codes
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static float            sin64[33];        ///< sinus table for decorrelation
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124
/**
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 * @brief frame specific decoder context for a single channel
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 */
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typedef struct {
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    int16_t  prev_block_len;                          ///< length of the previous block
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    uint8_t  transmit_coefs;
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    uint8_t  num_subframes;
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    uint16_t subframe_len[MAX_SUBFRAMES];             ///< subframe length in samples
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    uint16_t subframe_offset[MAX_SUBFRAMES];          ///< subframe positions in the current frame
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    uint8_t  cur_subframe;                            ///< current subframe number
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    uint16_t decoded_samples;                         ///< number of already processed samples
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    uint8_t  grouped;                                 ///< channel is part of a group
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    int      quant_step;                              ///< quantization step for the current subframe
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    int8_t   reuse_sf;                                ///< share scale factors between subframes
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    int8_t   scale_factor_step;                       ///< scaling step for the current subframe
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    int      max_scale_factor;                        ///< maximum scale factor for the current subframe
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    int      saved_scale_factors[2][MAX_BANDS];       ///< resampled and (previously) transmitted scale factor values
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    int8_t   scale_factor_idx;                        ///< index for the transmitted scale factor values (used for resampling)
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    int*     scale_factors;                           ///< pointer to the scale factor values used for decoding
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    uint8_t  table_idx;                               ///< index in sf_offsets for the scale factor reference block
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    float*   coeffs;                                  ///< pointer to the subframe decode buffer
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    DECLARE_ALIGNED(16, float, out)[WMAPRO_BLOCK_MAX_SIZE + WMAPRO_BLOCK_MAX_SIZE / 2]; ///< output buffer
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} WMAProChannelCtx;
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/**
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 * @brief channel group for channel transformations
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 */
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typedef struct {
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    uint8_t num_channels;                                     ///< number of channels in the group
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    int8_t  transform;                                        ///< transform on / off
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    int8_t  transform_band[MAX_BANDS];                        ///< controls if the transform is enabled for a certain band
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    float   decorrelation_matrix[WMAPRO_MAX_CHANNELS*WMAPRO_MAX_CHANNELS];
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    float*  channel_data[WMAPRO_MAX_CHANNELS];                ///< transformation coefficients
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} WMAProChannelGrp;
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/**
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 * @brief main decoder context
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 */
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typedef struct WMAProDecodeCtx {
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    /* generic decoder variables */
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    AVCodecContext*  avctx;                         ///< codec context for av_log
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    DSPContext       dsp;                           ///< accelerated DSP functions
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    uint8_t          frame_data[MAX_FRAMESIZE +
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                      FF_INPUT_BUFFER_PADDING_SIZE];///< compressed frame data
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    PutBitContext    pb;                            ///< context for filling the frame_data buffer
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    FFTContext       mdct_ctx[WMAPRO_BLOCK_SIZES];  ///< MDCT context per block size
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    DECLARE_ALIGNED(16, float, tmp)[WMAPRO_BLOCK_MAX_SIZE]; ///< IMDCT output buffer
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    float*           windows[WMAPRO_BLOCK_SIZES];   ///< windows for the different block sizes
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    /* frame size dependent frame information (set during initialization) */
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    uint32_t         decode_flags;                  ///< used compression features
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    uint8_t          len_prefix;                    ///< frame is prefixed with its length
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    uint8_t          dynamic_range_compression;     ///< frame contains DRC data
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    uint8_t          bits_per_sample;               ///< integer audio sample size for the unscaled IMDCT output (used to scale to [-1.0, 1.0])
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    uint16_t         samples_per_frame;             ///< number of samples to output
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    uint16_t         log2_frame_size;
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    int8_t           num_channels;                  ///< number of channels in the stream (same as AVCodecContext.num_channels)
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    int8_t           lfe_channel;                   ///< lfe channel index
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    uint8_t          max_num_subframes;
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    uint8_t          subframe_len_bits;             ///< number of bits used for the subframe length
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    uint8_t          max_subframe_len_bit;          ///< flag indicating that the subframe is of maximum size when the first subframe length bit is 1
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    uint16_t         min_samples_per_subframe;
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    int8_t           num_sfb[WMAPRO_BLOCK_SIZES];   ///< scale factor bands per block size
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    int16_t          sfb_offsets[WMAPRO_BLOCK_SIZES][MAX_BANDS];                    ///< scale factor band offsets (multiples of 4)
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    int8_t           sf_offsets[WMAPRO_BLOCK_SIZES][WMAPRO_BLOCK_SIZES][MAX_BANDS]; ///< scale factor resample matrix
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    int16_t          subwoofer_cutoffs[WMAPRO_BLOCK_SIZES]; ///< subwoofer cutoff values
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    /* packet decode state */
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    GetBitContext    pgb;                           ///< bitstream reader context for the packet
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    uint8_t          packet_offset;                 ///< frame offset in the packet
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    uint8_t          packet_sequence_number;        ///< current packet number
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    int              num_saved_bits;                ///< saved number of bits
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    int              frame_offset;                  ///< frame offset in the bit reservoir
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    int              subframe_offset;               ///< subframe offset in the bit reservoir
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    uint8_t          packet_loss;                   ///< set in case of bitstream error
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    uint8_t          packet_done;                   ///< set when a packet is fully decoded
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    /* frame decode state */
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    uint32_t         frame_num;                     ///< current frame number (not used for decoding)
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    GetBitContext    gb;                            ///< bitstream reader context
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    int              buf_bit_size;                  ///< buffer size in bits
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    float*           samples;                       ///< current samplebuffer pointer
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    float*           samples_end;                   ///< maximum samplebuffer pointer
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    uint8_t          drc_gain;                      ///< gain for the DRC tool
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    int8_t           skip_frame;                    ///< skip output step
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    int8_t           parsed_all_subframes;          ///< all subframes decoded?
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    /* subframe/block decode state */
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    int16_t          subframe_len;                  ///< current subframe length
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    int8_t           channels_for_cur_subframe;     ///< number of channels that contain the subframe
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    int8_t           channel_indexes_for_cur_subframe[WMAPRO_MAX_CHANNELS];
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    int8_t           num_bands;                     ///< number of scale factor bands
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    int16_t*         cur_sfb_offsets;               ///< sfb offsets for the current block
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    uint8_t          table_idx;                     ///< index for the num_sfb, sfb_offsets, sf_offsets and subwoofer_cutoffs tables
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    int8_t           esc_len;                       ///< length of escaped coefficients
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    uint8_t          num_chgroups;                  ///< number of channel groups
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    WMAProChannelGrp chgroup[WMAPRO_MAX_CHANNELS];  ///< channel group information
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    WMAProChannelCtx channel[WMAPRO_MAX_CHANNELS];  ///< per channel data
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} WMAProDecodeCtx;
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226

    
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/**
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 *@brief helper function to print the most important members of the context
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 *@param s context
230
 */
231
static void av_cold dump_context(WMAProDecodeCtx *s)
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{
233
#define PRINT(a, b)     av_log(s->avctx, AV_LOG_DEBUG, " %s = %d\n", a, b);
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#define PRINT_HEX(a, b) av_log(s->avctx, AV_LOG_DEBUG, " %s = %x\n", a, b);
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    PRINT("ed sample bit depth", s->bits_per_sample);
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    PRINT_HEX("ed decode flags", s->decode_flags);
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    PRINT("samples per frame",   s->samples_per_frame);
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    PRINT("log2 frame size",     s->log2_frame_size);
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    PRINT("max num subframes",   s->max_num_subframes);
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    PRINT("len prefix",          s->len_prefix);
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    PRINT("num channels",        s->num_channels);
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}
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/**
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 *@brief Uninitialize the decoder and free all resources.
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 *@param avctx codec context
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 *@return 0 on success, < 0 otherwise
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 */
250
static av_cold int decode_end(AVCodecContext *avctx)
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{
252
    WMAProDecodeCtx *s = avctx->priv_data;
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    int i;
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    for (i = 0; i < WMAPRO_BLOCK_SIZES; i++)
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        ff_mdct_end(&s->mdct_ctx[i]);
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    return 0;
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}
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261
/**
262
 *@brief Initialize the decoder.
263
 *@param avctx codec context
264
 *@return 0 on success, -1 otherwise
265
 */
266
static av_cold int decode_init(AVCodecContext *avctx)
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{
268
    WMAProDecodeCtx *s = avctx->priv_data;
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    uint8_t *edata_ptr = avctx->extradata;
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    unsigned int channel_mask;
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    int i;
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    int log2_max_num_subframes;
273
    int num_possible_block_sizes;
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275
    s->avctx = avctx;
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    dsputil_init(&s->dsp, avctx);
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    init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE);
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279
    avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
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281
    if (avctx->extradata_size >= 18) {
282
        s->decode_flags    = AV_RL16(edata_ptr+14);
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        channel_mask       = AV_RL32(edata_ptr+2);
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        s->bits_per_sample = AV_RL16(edata_ptr);
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        /** dump the extradata */
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        for (i = 0; i < avctx->extradata_size; i++)
287
            dprintf(avctx, "[%x] ", avctx->extradata[i]);
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        dprintf(avctx, "\n");
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290
    } else {
291
        av_log_ask_for_sample(avctx, "Unknown extradata size\n");
292
        return AVERROR_INVALIDDATA;
293
    }
294

    
295
    /** generic init */
296
    s->log2_frame_size = av_log2(avctx->block_align) + 4;
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298
    /** frame info */
299
    s->skip_frame  = 1; /* skip first frame */
300
    s->packet_loss = 1;
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    s->len_prefix  = (s->decode_flags & 0x40);
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303
    /** get frame len */
304
    s->samples_per_frame = 1 << ff_wma_get_frame_len_bits(avctx->sample_rate,
305
                                                          3, s->decode_flags);
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307
    /** init previous block len */
308
    for (i = 0; i < avctx->channels; i++)
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        s->channel[i].prev_block_len = s->samples_per_frame;
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311
    /** subframe info */
312
    log2_max_num_subframes       = ((s->decode_flags & 0x38) >> 3);
313
    s->max_num_subframes         = 1 << log2_max_num_subframes;
314
    if (s->max_num_subframes == 16 || s->max_num_subframes == 4)
315
        s->max_subframe_len_bit = 1;
316
    s->subframe_len_bits = av_log2(log2_max_num_subframes) + 1;
317

    
318
    num_possible_block_sizes     = log2_max_num_subframes + 1;
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    s->min_samples_per_subframe  = s->samples_per_frame / s->max_num_subframes;
320
    s->dynamic_range_compression = (s->decode_flags & 0x80);
321

    
322
    if (s->max_num_subframes > MAX_SUBFRAMES) {
323
        av_log(avctx, AV_LOG_ERROR, "invalid number of subframes %i\n",
324
               s->max_num_subframes);
325
        return AVERROR_INVALIDDATA;
326
    }
327

    
328
    s->num_channels = avctx->channels;
329

    
330
    /** extract lfe channel position */
331
    s->lfe_channel = -1;
332

    
333
    if (channel_mask & 8) {
334
        unsigned int mask;
335
        for (mask = 1; mask < 16; mask <<= 1) {
336
            if (channel_mask & mask)
337
                ++s->lfe_channel;
338
        }
339
    }
340

    
341
    if (s->num_channels < 0) {
342
        av_log(avctx, AV_LOG_ERROR, "invalid number of channels %d\n", s->num_channels);
343
        return AVERROR_INVALIDDATA;
344
    } else if (s->num_channels > WMAPRO_MAX_CHANNELS) {
345
        av_log_ask_for_sample(avctx, "unsupported number of channels\n");
346
        return AVERROR_PATCHWELCOME;
347
    }
348

    
349
    INIT_VLC_STATIC(&sf_vlc, SCALEVLCBITS, HUFF_SCALE_SIZE,
350
                    scale_huffbits, 1, 1,
351
                    scale_huffcodes, 2, 2, 616);
352

    
353
    INIT_VLC_STATIC(&sf_rl_vlc, VLCBITS, HUFF_SCALE_RL_SIZE,
354
                    scale_rl_huffbits, 1, 1,
355
                    scale_rl_huffcodes, 4, 4, 1406);
356

    
357
    INIT_VLC_STATIC(&coef_vlc[0], VLCBITS, HUFF_COEF0_SIZE,
358
                    coef0_huffbits, 1, 1,
359
                    coef0_huffcodes, 4, 4, 2108);
360

    
361
    INIT_VLC_STATIC(&coef_vlc[1], VLCBITS, HUFF_COEF1_SIZE,
362
                    coef1_huffbits, 1, 1,
363
                    coef1_huffcodes, 4, 4, 3912);
364

    
365
    INIT_VLC_STATIC(&vec4_vlc, VLCBITS, HUFF_VEC4_SIZE,
366
                    vec4_huffbits, 1, 1,
367
                    vec4_huffcodes, 2, 2, 604);
368

    
369
    INIT_VLC_STATIC(&vec2_vlc, VLCBITS, HUFF_VEC2_SIZE,
370
                    vec2_huffbits, 1, 1,
371
                    vec2_huffcodes, 2, 2, 562);
372

    
373
    INIT_VLC_STATIC(&vec1_vlc, VLCBITS, HUFF_VEC1_SIZE,
374
                    vec1_huffbits, 1, 1,
375
                    vec1_huffcodes, 2, 2, 562);
376

    
377
    /** calculate number of scale factor bands and their offsets
378
        for every possible block size */
379
    for (i = 0; i < num_possible_block_sizes; i++) {
380
        int subframe_len = s->samples_per_frame >> i;
381
        int x;
382
        int band = 1;
383

    
384
        s->sfb_offsets[i][0] = 0;
385

    
386
        for (x = 0; x < MAX_BANDS-1 && s->sfb_offsets[i][band - 1] < subframe_len; x++) {
387
            int offset = (subframe_len * 2 * critical_freq[x])
388
                          / s->avctx->sample_rate + 2;
389
            offset &= ~3;
390
            if (offset > s->sfb_offsets[i][band - 1])
391
                s->sfb_offsets[i][band++] = offset;
392
        }
393
        s->sfb_offsets[i][band - 1] = subframe_len;
394
        s->num_sfb[i]               = band - 1;
395
    }
396

    
397

    
398
    /** Scale factors can be shared between blocks of different size
399
        as every block has a different scale factor band layout.
400
        The matrix sf_offsets is needed to find the correct scale factor.
401
     */
402

    
403
    for (i = 0; i < num_possible_block_sizes; i++) {
404
        int b;
405
        for (b = 0; b < s->num_sfb[i]; b++) {
406
            int x;
407
            int offset = ((s->sfb_offsets[i][b]
408
                           + s->sfb_offsets[i][b + 1] - 1) << i) >> 1;
409
            for (x = 0; x < num_possible_block_sizes; x++) {
410
                int v = 0;
411
                while (s->sfb_offsets[x][v + 1] << x < offset)
412
                    ++v;
413
                s->sf_offsets[i][x][b] = v;
414
            }
415
        }
416
    }
417

    
418
    /** init MDCT, FIXME: only init needed sizes */
419
    for (i = 0; i < WMAPRO_BLOCK_SIZES; i++)
420
        ff_mdct_init(&s->mdct_ctx[i], BLOCK_MIN_BITS+1+i, 1,
421
                     1.0 / (1 << (BLOCK_MIN_BITS + i - 1))
422
                     / (1 << (s->bits_per_sample - 1)));
423

    
424
    /** init MDCT windows: simple sinus window */
425
    for (i = 0; i < WMAPRO_BLOCK_SIZES; i++) {
426
        const int win_idx = WMAPRO_BLOCK_MAX_BITS - i;
427
        ff_init_ff_sine_windows(win_idx);
428
        s->windows[WMAPRO_BLOCK_SIZES - i - 1] = ff_sine_windows[win_idx];
429
    }
430

    
431
    /** calculate subwoofer cutoff values */
432
    for (i = 0; i < num_possible_block_sizes; i++) {
433
        int block_size = s->samples_per_frame >> i;
434
        int cutoff = (440*block_size + 3 * (s->avctx->sample_rate >> 1) - 1)
435
                     / s->avctx->sample_rate;
436
        s->subwoofer_cutoffs[i] = av_clip(cutoff, 4, block_size);
437
    }
438

    
439
    /** calculate sine values for the decorrelation matrix */
440
    for (i = 0; i < 33; i++)
441
        sin64[i] = sin(i*M_PI / 64.0);
442

    
443
    if (avctx->debug & FF_DEBUG_BITSTREAM)
444
        dump_context(s);
445

    
446
    avctx->channel_layout = channel_mask;
447
    return 0;
448
}
449

    
450
/**
451
 *@brief Decode the subframe length.
452
 *@param s context
453
 *@param offset sample offset in the frame
454
 *@return decoded subframe length on success, < 0 in case of an error
455
 */
456
static int decode_subframe_length(WMAProDecodeCtx *s, int offset)
457
{
458
    int frame_len_shift = 0;
459
    int subframe_len;
460

    
461
    /** no need to read from the bitstream when only one length is possible */
462
    if (offset == s->samples_per_frame - s->min_samples_per_subframe)
463
        return s->min_samples_per_subframe;
464

    
465
    /** 1 bit indicates if the subframe is of maximum length */
466
    if (s->max_subframe_len_bit) {
467
        if (get_bits1(&s->gb))
468
            frame_len_shift = 1 + get_bits(&s->gb, s->subframe_len_bits-1);
469
    } else
470
        frame_len_shift = get_bits(&s->gb, s->subframe_len_bits);
471

    
472
    subframe_len = s->samples_per_frame >> frame_len_shift;
473

    
474
    /** sanity check the length */
475
    if (subframe_len < s->min_samples_per_subframe ||
476
        subframe_len > s->samples_per_frame) {
477
        av_log(s->avctx, AV_LOG_ERROR, "broken frame: subframe_len %i\n",
478
               subframe_len);
479
        return AVERROR_INVALIDDATA;
480
    }
481
    return subframe_len;
482
}
483

    
484
/**
485
 *@brief Decode how the data in the frame is split into subframes.
486
 *       Every WMA frame contains the encoded data for a fixed number of
487
 *       samples per channel. The data for every channel might be split
488
 *       into several subframes. This function will reconstruct the list of
489
 *       subframes for every channel.
490
 *
491
 *       If the subframes are not evenly split, the algorithm estimates the
492
 *       channels with the lowest number of total samples.
493
 *       Afterwards, for each of these channels a bit is read from the
494
 *       bitstream that indicates if the channel contains a subframe with the
495
 *       next subframe size that is going to be read from the bitstream or not.
496
 *       If a channel contains such a subframe, the subframe size gets added to
497
 *       the channel's subframe list.
498
 *       The algorithm repeats these steps until the frame is properly divided
499
 *       between the individual channels.
500
 *
501
 *@param s context
502
 *@return 0 on success, < 0 in case of an error
503
 */
504
static int decode_tilehdr(WMAProDecodeCtx *s)
505
{
506
    uint16_t num_samples[WMAPRO_MAX_CHANNELS];        /**< sum of samples for all currently known subframes of a channel */
507
    uint8_t  contains_subframe[WMAPRO_MAX_CHANNELS];  /**< flag indicating if a channel contains the current subframe */
508
    int channels_for_cur_subframe = s->num_channels;  /**< number of channels that contain the current subframe */
509
    int fixed_channel_layout = 0;                     /**< flag indicating that all channels use the same subframe offsets and sizes */
510
    int min_channel_len = 0;                          /**< smallest sum of samples (channels with this length will be processed first) */
511
    int c;
512

    
513
    /* Should never consume more than 3073 bits (256 iterations for the
514
     * while loop when always the minimum amount of 128 samples is substracted
515
     * from missing samples in the 8 channel case).
516
     * 1 + BLOCK_MAX_SIZE * MAX_CHANNELS / BLOCK_MIN_SIZE * (MAX_CHANNELS  + 4)
517
     */
518

    
519
    /** reset tiling information */
520
    for (c = 0; c < s->num_channels; c++)
521
        s->channel[c].num_subframes = 0;
522

    
523
    memset(num_samples, 0, sizeof(num_samples));
524

    
525
    if (s->max_num_subframes == 1 || get_bits1(&s->gb))
526
        fixed_channel_layout = 1;
527

    
528
    /** loop until the frame data is split between the subframes */
529
    do {
530
        int subframe_len;
531

    
532
        /** check which channels contain the subframe */
533
        for (c = 0; c < s->num_channels; c++) {
534
            if (num_samples[c] == min_channel_len) {
535
                if (fixed_channel_layout || channels_for_cur_subframe == 1 ||
536
                   (min_channel_len == s->samples_per_frame - s->min_samples_per_subframe))
537
                    contains_subframe[c] = 1;
538
                else
539
                    contains_subframe[c] = get_bits1(&s->gb);
540
            } else
541
                contains_subframe[c] = 0;
542
        }
543

    
544
        /** get subframe length, subframe_len == 0 is not allowed */
545
        if ((subframe_len = decode_subframe_length(s, min_channel_len)) <= 0)
546
            return AVERROR_INVALIDDATA;
547

    
548
        /** add subframes to the individual channels and find new min_channel_len */
549
        min_channel_len += subframe_len;
550
        for (c = 0; c < s->num_channels; c++) {
551
            WMAProChannelCtx* chan = &s->channel[c];
552

    
553
            if (contains_subframe[c]) {
554
                if (chan->num_subframes >= MAX_SUBFRAMES) {
555
                    av_log(s->avctx, AV_LOG_ERROR,
556
                           "broken frame: num subframes > 31\n");
557
                    return AVERROR_INVALIDDATA;
558
                }
559
                chan->subframe_len[chan->num_subframes] = subframe_len;
560
                num_samples[c] += subframe_len;
561
                ++chan->num_subframes;
562
                if (num_samples[c] > s->samples_per_frame) {
563
                    av_log(s->avctx, AV_LOG_ERROR, "broken frame: "
564
                           "channel len > samples_per_frame\n");
565
                    return AVERROR_INVALIDDATA;
566
                }
567
            } else if (num_samples[c] <= min_channel_len) {
568
                if (num_samples[c] < min_channel_len) {
569
                    channels_for_cur_subframe = 0;
570
                    min_channel_len = num_samples[c];
571
                }
572
                ++channels_for_cur_subframe;
573
            }
574
        }
575
    } while (min_channel_len < s->samples_per_frame);
576

    
577
    for (c = 0; c < s->num_channels; c++) {
578
        int i;
579
        int offset = 0;
580
        for (i = 0; i < s->channel[c].num_subframes; i++) {
581
            dprintf(s->avctx, "frame[%i] channel[%i] subframe[%i]"
582
                    " len %i\n", s->frame_num, c, i,
583
                    s->channel[c].subframe_len[i]);
584
            s->channel[c].subframe_offset[i] = offset;
585
            offset += s->channel[c].subframe_len[i];
586
        }
587
    }
588

    
589
    return 0;
590
}
591

    
592
/**
593
 *@brief Calculate a decorrelation matrix from the bitstream parameters.
594
 *@param s codec context
595
 *@param chgroup channel group for which the matrix needs to be calculated
596
 */
597
static void decode_decorrelation_matrix(WMAProDecodeCtx *s,
598
                                        WMAProChannelGrp *chgroup)
599
{
600
    int i;
601
    int offset = 0;
602
    int8_t rotation_offset[WMAPRO_MAX_CHANNELS * WMAPRO_MAX_CHANNELS];
603
    memset(chgroup->decorrelation_matrix, 0, s->num_channels *
604
           s->num_channels * sizeof(*chgroup->decorrelation_matrix));
605

    
606
    for (i = 0; i < chgroup->num_channels * (chgroup->num_channels - 1) >> 1; i++)
607
        rotation_offset[i] = get_bits(&s->gb, 6);
608

    
609
    for (i = 0; i < chgroup->num_channels; i++)
610
        chgroup->decorrelation_matrix[chgroup->num_channels * i + i] =
611
            get_bits1(&s->gb) ? 1.0 : -1.0;
612

    
613
    for (i = 1; i < chgroup->num_channels; i++) {
614
        int x;
615
        for (x = 0; x < i; x++) {
616
            int y;
617
            for (y = 0; y < i + 1; y++) {
618
                float v1 = chgroup->decorrelation_matrix[x * chgroup->num_channels + y];
619
                float v2 = chgroup->decorrelation_matrix[i * chgroup->num_channels + y];
620
                int n = rotation_offset[offset + x];
621
                float sinv;
622
                float cosv;
623

    
624
                if (n < 32) {
625
                    sinv = sin64[n];
626
                    cosv = sin64[32 - n];
627
                } else {
628
                    sinv =  sin64[64 -  n];
629
                    cosv = -sin64[n  - 32];
630
                }
631

    
632
                chgroup->decorrelation_matrix[y + x * chgroup->num_channels] =
633
                                               (v1 * sinv) - (v2 * cosv);
634
                chgroup->decorrelation_matrix[y + i * chgroup->num_channels] =
635
                                               (v1 * cosv) + (v2 * sinv);
636
            }
637
        }
638
        offset += i;
639
    }
640
}
641

    
642
/**
643
 *@brief Decode channel transformation parameters
644
 *@param s codec context
645
 *@return 0 in case of success, < 0 in case of bitstream errors
646
 */
647
static int decode_channel_transform(WMAProDecodeCtx* s)
648
{
649
    int i;
650
    /* should never consume more than 1921 bits for the 8 channel case
651
     * 1 + MAX_CHANNELS * (MAX_CHANNELS + 2 + 3 * MAX_CHANNELS * MAX_CHANNELS
652
     * + MAX_CHANNELS + MAX_BANDS + 1)
653
     */
654

    
655
    /** in the one channel case channel transforms are pointless */
656
    s->num_chgroups = 0;
657
    if (s->num_channels > 1) {
658
        int remaining_channels = s->channels_for_cur_subframe;
659

    
660
        if (get_bits1(&s->gb)) {
661
            av_log_ask_for_sample(s->avctx,
662
                                  "unsupported channel transform bit\n");
663
            return AVERROR_INVALIDDATA;
664
        }
665

    
666
        for (s->num_chgroups = 0; remaining_channels &&
667
             s->num_chgroups < s->channels_for_cur_subframe; s->num_chgroups++) {
668
            WMAProChannelGrp* chgroup = &s->chgroup[s->num_chgroups];
669
            float** channel_data = chgroup->channel_data;
670
            chgroup->num_channels = 0;
671
            chgroup->transform = 0;
672

    
673
            /** decode channel mask */
674
            if (remaining_channels > 2) {
675
                for (i = 0; i < s->channels_for_cur_subframe; i++) {
676
                    int channel_idx = s->channel_indexes_for_cur_subframe[i];
677
                    if (!s->channel[channel_idx].grouped
678
                        && get_bits1(&s->gb)) {
679
                        ++chgroup->num_channels;
680
                        s->channel[channel_idx].grouped = 1;
681
                        *channel_data++ = s->channel[channel_idx].coeffs;
682
                    }
683
                }
684
            } else {
685
                chgroup->num_channels = remaining_channels;
686
                for (i = 0; i < s->channels_for_cur_subframe; i++) {
687
                    int channel_idx = s->channel_indexes_for_cur_subframe[i];
688
                    if (!s->channel[channel_idx].grouped)
689
                        *channel_data++ = s->channel[channel_idx].coeffs;
690
                    s->channel[channel_idx].grouped = 1;
691
                }
692
            }
693

    
694
            /** decode transform type */
695
            if (chgroup->num_channels == 2) {
696
                if (get_bits1(&s->gb)) {
697
                    if (get_bits1(&s->gb)) {
698
                        av_log_ask_for_sample(s->avctx,
699
                                              "unsupported channel transform type\n");
700
                    }
701
                } else {
702
                    chgroup->transform = 1;
703
                    if (s->num_channels == 2) {
704
                        chgroup->decorrelation_matrix[0] =  1.0;
705
                        chgroup->decorrelation_matrix[1] = -1.0;
706
                        chgroup->decorrelation_matrix[2] =  1.0;
707
                        chgroup->decorrelation_matrix[3] =  1.0;
708
                    } else {
709
                        /** cos(pi/4) */
710
                        chgroup->decorrelation_matrix[0] =  0.70703125;
711
                        chgroup->decorrelation_matrix[1] = -0.70703125;
712
                        chgroup->decorrelation_matrix[2] =  0.70703125;
713
                        chgroup->decorrelation_matrix[3] =  0.70703125;
714
                    }
715
                }
716
            } else if (chgroup->num_channels > 2) {
717
                if (get_bits1(&s->gb)) {
718
                    chgroup->transform = 1;
719
                    if (get_bits1(&s->gb)) {
720
                        decode_decorrelation_matrix(s, chgroup);
721
                    } else {
722
                        /** FIXME: more than 6 coupled channels not supported */
723
                        if (chgroup->num_channels > 6) {
724
                            av_log_ask_for_sample(s->avctx,
725
                                                  "coupled channels > 6\n");
726
                        } else {
727
                            memcpy(chgroup->decorrelation_matrix,
728
                                   default_decorrelation[chgroup->num_channels],
729
                                   chgroup->num_channels * chgroup->num_channels *
730
                                   sizeof(*chgroup->decorrelation_matrix));
731
                        }
732
                    }
733
                }
734
            }
735

    
736
            /** decode transform on / off */
737
            if (chgroup->transform) {
738
                if (!get_bits1(&s->gb)) {
739
                    int i;
740
                    /** transform can be enabled for individual bands */
741
                    for (i = 0; i < s->num_bands; i++) {
742
                        chgroup->transform_band[i] = get_bits1(&s->gb);
743
                    }
744
                } else {
745
                    memset(chgroup->transform_band, 1, s->num_bands);
746
                }
747
            }
748
            remaining_channels -= chgroup->num_channels;
749
        }
750
    }
751
    return 0;
752
}
753

    
754
/**
755
 *@brief Extract the coefficients from the bitstream.
756
 *@param s codec context
757
 *@param c current channel number
758
 *@return 0 on success, < 0 in case of bitstream errors
759
 */
760
static int decode_coeffs(WMAProDecodeCtx *s, int c)
761
{
762
    /* Integers 0..15 as single-precision floats.  The table saves a
763
       costly int to float conversion, and storing the values as
764
       integers allows fast sign-flipping. */
765
    static const int fval_tab[16] = {
766
        0x00000000, 0x3f800000, 0x40000000, 0x40400000,
767
        0x40800000, 0x40a00000, 0x40c00000, 0x40e00000,
768
        0x41000000, 0x41100000, 0x41200000, 0x41300000,
769
        0x41400000, 0x41500000, 0x41600000, 0x41700000,
770
    };
771
    int vlctable;
772
    VLC* vlc;
773
    WMAProChannelCtx* ci = &s->channel[c];
774
    int rl_mode = 0;
775
    int cur_coeff = 0;
776
    int num_zeros = 0;
777
    const uint16_t* run;
778
    const float* level;
779

    
780
    dprintf(s->avctx, "decode coefficients for channel %i\n", c);
781

    
782
    vlctable = get_bits1(&s->gb);
783
    vlc = &coef_vlc[vlctable];
784

    
785
    if (vlctable) {
786
        run = coef1_run;
787
        level = coef1_level;
788
    } else {
789
        run = coef0_run;
790
        level = coef0_level;
791
    }
792

    
793
    /** decode vector coefficients (consumes up to 167 bits per iteration for
794
      4 vector coded large values) */
795
    while (!rl_mode && cur_coeff + 3 < s->subframe_len) {
796
        int vals[4];
797
        int i;
798
        unsigned int idx;
799

    
800
        idx = get_vlc2(&s->gb, vec4_vlc.table, VLCBITS, VEC4MAXDEPTH);
801

    
802
        if (idx == HUFF_VEC4_SIZE - 1) {
803
            for (i = 0; i < 4; i += 2) {
804
                idx = get_vlc2(&s->gb, vec2_vlc.table, VLCBITS, VEC2MAXDEPTH);
805
                if (idx == HUFF_VEC2_SIZE - 1) {
806
                    int v0, v1;
807
                    v0 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
808
                    if (v0 == HUFF_VEC1_SIZE - 1)
809
                        v0 += ff_wma_get_large_val(&s->gb);
810
                    v1 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
811
                    if (v1 == HUFF_VEC1_SIZE - 1)
812
                        v1 += ff_wma_get_large_val(&s->gb);
813
                    ((float*)vals)[i  ] = v0;
814
                    ((float*)vals)[i+1] = v1;
815
                } else {
816
                    vals[i]   = fval_tab[symbol_to_vec2[idx] >> 4 ];
817
                    vals[i+1] = fval_tab[symbol_to_vec2[idx] & 0xF];
818
                }
819
            }
820
        } else {
821
            vals[0] = fval_tab[ symbol_to_vec4[idx] >> 12      ];
822
            vals[1] = fval_tab[(symbol_to_vec4[idx] >> 8) & 0xF];
823
            vals[2] = fval_tab[(symbol_to_vec4[idx] >> 4) & 0xF];
824
            vals[3] = fval_tab[ symbol_to_vec4[idx]       & 0xF];
825
        }
826

    
827
        /** decode sign */
828
        for (i = 0; i < 4; i++) {
829
            if (vals[i]) {
830
                int sign = get_bits1(&s->gb) - 1;
831
                *(uint32_t*)&ci->coeffs[cur_coeff] = vals[i] ^ sign<<31;
832
                num_zeros = 0;
833
            } else {
834
                ci->coeffs[cur_coeff] = 0;
835
                /** switch to run level mode when subframe_len / 128 zeros
836
                    were found in a row */
837
                rl_mode |= (++num_zeros > s->subframe_len >> 8);
838
            }
839
            ++cur_coeff;
840
        }
841
    }
842

    
843
    /** decode run level coded coefficients */
844
    if (rl_mode) {
845
        memset(&ci->coeffs[cur_coeff], 0,
846
               sizeof(*ci->coeffs) * (s->subframe_len - cur_coeff));
847
        if (ff_wma_run_level_decode(s->avctx, &s->gb, vlc,
848
                                    level, run, 1, ci->coeffs,
849
                                    cur_coeff, s->subframe_len,
850
                                    s->subframe_len, s->esc_len, 0))
851
            return AVERROR_INVALIDDATA;
852
    }
853

    
854
    return 0;
855
}
856

    
857
/**
858
 *@brief Extract scale factors from the bitstream.
859
 *@param s codec context
860
 *@return 0 on success, < 0 in case of bitstream errors
861
 */
862
static int decode_scale_factors(WMAProDecodeCtx* s)
863
{
864
    int i;
865

    
866
    /** should never consume more than 5344 bits
867
     *  MAX_CHANNELS * (1 +  MAX_BANDS * 23)
868
     */
869

    
870
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
871
        int c = s->channel_indexes_for_cur_subframe[i];
872
        int* sf;
873
        int* sf_end;
874
        s->channel[c].scale_factors = s->channel[c].saved_scale_factors[!s->channel[c].scale_factor_idx];
875
        sf_end = s->channel[c].scale_factors + s->num_bands;
876

    
877
        /** resample scale factors for the new block size
878
         *  as the scale factors might need to be resampled several times
879
         *  before some  new values are transmitted, a backup of the last
880
         *  transmitted scale factors is kept in saved_scale_factors
881
         */
882
        if (s->channel[c].reuse_sf) {
883
            const int8_t* sf_offsets = s->sf_offsets[s->table_idx][s->channel[c].table_idx];
884
            int b;
885
            for (b = 0; b < s->num_bands; b++)
886
                s->channel[c].scale_factors[b] =
887
                    s->channel[c].saved_scale_factors[s->channel[c].scale_factor_idx][*sf_offsets++];
888
        }
889

    
890
        if (!s->channel[c].cur_subframe || get_bits1(&s->gb)) {
891

    
892
            if (!s->channel[c].reuse_sf) {
893
                int val;
894
                /** decode DPCM coded scale factors */
895
                s->channel[c].scale_factor_step = get_bits(&s->gb, 2) + 1;
896
                val = 45 / s->channel[c].scale_factor_step;
897
                for (sf = s->channel[c].scale_factors; sf < sf_end; sf++) {
898
                    val += get_vlc2(&s->gb, sf_vlc.table, SCALEVLCBITS, SCALEMAXDEPTH) - 60;
899
                    *sf = val;
900
                }
901
            } else {
902
                int i;
903
                /** run level decode differences to the resampled factors */
904
                for (i = 0; i < s->num_bands; i++) {
905
                    int idx;
906
                    int skip;
907
                    int val;
908
                    int sign;
909

    
910
                    idx = get_vlc2(&s->gb, sf_rl_vlc.table, VLCBITS, SCALERLMAXDEPTH);
911

    
912
                    if (!idx) {
913
                        uint32_t code = get_bits(&s->gb, 14);
914
                        val  =  code >> 6;
915
                        sign = (code & 1) - 1;
916
                        skip = (code & 0x3f) >> 1;
917
                    } else if (idx == 1) {
918
                        break;
919
                    } else {
920
                        skip = scale_rl_run[idx];
921
                        val  = scale_rl_level[idx];
922
                        sign = get_bits1(&s->gb)-1;
923
                    }
924

    
925
                    i += skip;
926
                    if (i >= s->num_bands) {
927
                        av_log(s->avctx, AV_LOG_ERROR,
928
                               "invalid scale factor coding\n");
929
                        return AVERROR_INVALIDDATA;
930
                    }
931
                    s->channel[c].scale_factors[i] += (val ^ sign) - sign;
932
                }
933
            }
934
            /** swap buffers */
935
            s->channel[c].scale_factor_idx = !s->channel[c].scale_factor_idx;
936
            s->channel[c].table_idx = s->table_idx;
937
            s->channel[c].reuse_sf  = 1;
938
        }
939

    
940
        /** calculate new scale factor maximum */
941
        s->channel[c].max_scale_factor = s->channel[c].scale_factors[0];
942
        for (sf = s->channel[c].scale_factors + 1; sf < sf_end; sf++) {
943
            s->channel[c].max_scale_factor =
944
                FFMAX(s->channel[c].max_scale_factor, *sf);
945
        }
946

    
947
    }
948
    return 0;
949
}
950

    
951
/**
952
 *@brief Reconstruct the individual channel data.
953
 *@param s codec context
954
 */
955
static void inverse_channel_transform(WMAProDecodeCtx *s)
956
{
957
    int i;
958

    
959
    for (i = 0; i < s->num_chgroups; i++) {
960
        if (s->chgroup[i].transform) {
961
            float data[WMAPRO_MAX_CHANNELS];
962
            const int num_channels = s->chgroup[i].num_channels;
963
            float** ch_data = s->chgroup[i].channel_data;
964
            float** ch_end = ch_data + num_channels;
965
            const int8_t* tb = s->chgroup[i].transform_band;
966
            int16_t* sfb;
967

    
968
            /** multichannel decorrelation */
969
            for (sfb = s->cur_sfb_offsets;
970
                 sfb < s->cur_sfb_offsets + s->num_bands; sfb++) {
971
                int y;
972
                if (*tb++ == 1) {
973
                    /** multiply values with the decorrelation_matrix */
974
                    for (y = sfb[0]; y < FFMIN(sfb[1], s->subframe_len); y++) {
975
                        const float* mat = s->chgroup[i].decorrelation_matrix;
976
                        const float* data_end = data + num_channels;
977
                        float* data_ptr = data;
978
                        float** ch;
979

    
980
                        for (ch = ch_data; ch < ch_end; ch++)
981
                            *data_ptr++ = (*ch)[y];
982

    
983
                        for (ch = ch_data; ch < ch_end; ch++) {
984
                            float sum = 0;
985
                            data_ptr = data;
986
                            while (data_ptr < data_end)
987
                                sum += *data_ptr++ * *mat++;
988

    
989
                            (*ch)[y] = sum;
990
                        }
991
                    }
992
                } else if (s->num_channels == 2) {
993
                    int len = FFMIN(sfb[1], s->subframe_len) - sfb[0];
994
                    s->dsp.vector_fmul_scalar(ch_data[0] + sfb[0],
995
                                              ch_data[0] + sfb[0],
996
                                              181.0 / 128, len);
997
                    s->dsp.vector_fmul_scalar(ch_data[1] + sfb[0],
998
                                              ch_data[1] + sfb[0],
999
                                              181.0 / 128, len);
1000
                }
1001
            }
1002
        }
1003
    }
1004
}
1005

    
1006
/**
1007
 *@brief Apply sine window and reconstruct the output buffer.
1008
 *@param s codec context
1009
 */
1010
static void wmapro_window(WMAProDecodeCtx *s)
1011
{
1012
    int i;
1013
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
1014
        int c = s->channel_indexes_for_cur_subframe[i];
1015
        float* window;
1016
        int winlen = s->channel[c].prev_block_len;
1017
        float* start = s->channel[c].coeffs - (winlen >> 1);
1018

    
1019
        if (s->subframe_len < winlen) {
1020
            start += (winlen - s->subframe_len) >> 1;
1021
            winlen = s->subframe_len;
1022
        }
1023

    
1024
        window = s->windows[av_log2(winlen) - BLOCK_MIN_BITS];
1025

    
1026
        winlen >>= 1;
1027

    
1028
        s->dsp.vector_fmul_window(start, start, start + winlen,
1029
                                  window, 0, winlen);
1030

    
1031
        s->channel[c].prev_block_len = s->subframe_len;
1032
    }
1033
}
1034

    
1035
/**
1036
 *@brief Decode a single subframe (block).
1037
 *@param s codec context
1038
 *@return 0 on success, < 0 when decoding failed
1039
 */
1040
static int decode_subframe(WMAProDecodeCtx *s)
1041
{
1042
    int offset = s->samples_per_frame;
1043
    int subframe_len = s->samples_per_frame;
1044
    int i;
1045
    int total_samples   = s->samples_per_frame * s->num_channels;
1046
    int transmit_coeffs = 0;
1047
    int cur_subwoofer_cutoff;
1048

    
1049
    s->subframe_offset = get_bits_count(&s->gb);
1050

    
1051
    /** reset channel context and find the next block offset and size
1052
        == the next block of the channel with the smallest number of
1053
        decoded samples
1054
    */
1055
    for (i = 0; i < s->num_channels; i++) {
1056
        s->channel[i].grouped = 0;
1057
        if (offset > s->channel[i].decoded_samples) {
1058
            offset = s->channel[i].decoded_samples;
1059
            subframe_len =
1060
                s->channel[i].subframe_len[s->channel[i].cur_subframe];
1061
        }
1062
    }
1063

    
1064
    dprintf(s->avctx,
1065
            "processing subframe with offset %i len %i\n", offset, subframe_len);
1066

    
1067
    /** get a list of all channels that contain the estimated block */
1068
    s->channels_for_cur_subframe = 0;
1069
    for (i = 0; i < s->num_channels; i++) {
1070
        const int cur_subframe = s->channel[i].cur_subframe;
1071
        /** substract already processed samples */
1072
        total_samples -= s->channel[i].decoded_samples;
1073

    
1074
        /** and count if there are multiple subframes that match our profile */
1075
        if (offset == s->channel[i].decoded_samples &&
1076
            subframe_len == s->channel[i].subframe_len[cur_subframe]) {
1077
            total_samples -= s->channel[i].subframe_len[cur_subframe];
1078
            s->channel[i].decoded_samples +=
1079
                s->channel[i].subframe_len[cur_subframe];
1080
            s->channel_indexes_for_cur_subframe[s->channels_for_cur_subframe] = i;
1081
            ++s->channels_for_cur_subframe;
1082
        }
1083
    }
1084

    
1085
    /** check if the frame will be complete after processing the
1086
        estimated block */
1087
    if (!total_samples)
1088
        s->parsed_all_subframes = 1;
1089

    
1090

    
1091
    dprintf(s->avctx, "subframe is part of %i channels\n",
1092
            s->channels_for_cur_subframe);
1093

    
1094
    /** calculate number of scale factor bands and their offsets */
1095
    s->table_idx         = av_log2(s->samples_per_frame/subframe_len);
1096
    s->num_bands         = s->num_sfb[s->table_idx];
1097
    s->cur_sfb_offsets   = s->sfb_offsets[s->table_idx];
1098
    cur_subwoofer_cutoff = s->subwoofer_cutoffs[s->table_idx];
1099

    
1100
    /** configure the decoder for the current subframe */
1101
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
1102
        int c = s->channel_indexes_for_cur_subframe[i];
1103

    
1104
        s->channel[c].coeffs = &s->channel[c].out[(s->samples_per_frame >> 1)
1105
                                                  + offset];
1106
    }
1107

    
1108
    s->subframe_len = subframe_len;
1109
    s->esc_len = av_log2(s->subframe_len - 1) + 1;
1110

    
1111
    /** skip extended header if any */
1112
    if (get_bits1(&s->gb)) {
1113
        int num_fill_bits;
1114
        if (!(num_fill_bits = get_bits(&s->gb, 2))) {
1115
            int len = get_bits(&s->gb, 4);
1116
            num_fill_bits = get_bits(&s->gb, len) + 1;
1117
        }
1118

    
1119
        if (num_fill_bits >= 0) {
1120
            if (get_bits_count(&s->gb) + num_fill_bits > s->num_saved_bits) {
1121
                av_log(s->avctx, AV_LOG_ERROR, "invalid number of fill bits\n");
1122
                return AVERROR_INVALIDDATA;
1123
            }
1124

    
1125
            skip_bits_long(&s->gb, num_fill_bits);
1126
        }
1127
    }
1128

    
1129
    /** no idea for what the following bit is used */
1130
    if (get_bits1(&s->gb)) {
1131
        av_log_ask_for_sample(s->avctx, "reserved bit set\n");
1132
        return AVERROR_INVALIDDATA;
1133
    }
1134

    
1135

    
1136
    if (decode_channel_transform(s) < 0)
1137
        return AVERROR_INVALIDDATA;
1138

    
1139

    
1140
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
1141
        int c = s->channel_indexes_for_cur_subframe[i];
1142
        if ((s->channel[c].transmit_coefs = get_bits1(&s->gb)))
1143
            transmit_coeffs = 1;
1144
    }
1145

    
1146
    if (transmit_coeffs) {
1147
        int step;
1148
        int quant_step = 90 * s->bits_per_sample >> 4;
1149
        if ((get_bits1(&s->gb))) {
1150
            /** FIXME: might change run level mode decision */
1151
            av_log_ask_for_sample(s->avctx, "unsupported quant step coding\n");
1152
            return AVERROR_INVALIDDATA;
1153
        }
1154
        /** decode quantization step */
1155
        step = get_sbits(&s->gb, 6);
1156
        quant_step += step;
1157
        if (step == -32 || step == 31) {
1158
            const int sign = (step == 31) - 1;
1159
            int quant = 0;
1160
            while (get_bits_count(&s->gb) + 5 < s->num_saved_bits &&
1161
                   (step = get_bits(&s->gb, 5)) == 31) {
1162
                quant += 31;
1163
            }
1164
            quant_step += ((quant + step) ^ sign) - sign;
1165
        }
1166
        if (quant_step < 0) {
1167
            av_log(s->avctx, AV_LOG_DEBUG, "negative quant step\n");
1168
        }
1169

    
1170
        /** decode quantization step modifiers for every channel */
1171

    
1172
        if (s->channels_for_cur_subframe == 1) {
1173
            s->channel[s->channel_indexes_for_cur_subframe[0]].quant_step = quant_step;
1174
        } else {
1175
            int modifier_len = get_bits(&s->gb, 3);
1176
            for (i = 0; i < s->channels_for_cur_subframe; i++) {
1177
                int c = s->channel_indexes_for_cur_subframe[i];
1178
                s->channel[c].quant_step = quant_step;
1179
                if (get_bits1(&s->gb)) {
1180
                    if (modifier_len) {
1181
                        s->channel[c].quant_step += get_bits(&s->gb, modifier_len) + 1;
1182
                    } else
1183
                        ++s->channel[c].quant_step;
1184
                }
1185
            }
1186
        }
1187

    
1188
        /** decode scale factors */
1189
        if (decode_scale_factors(s) < 0)
1190
            return AVERROR_INVALIDDATA;
1191
    }
1192

    
1193
    dprintf(s->avctx, "BITSTREAM: subframe header length was %i\n",
1194
            get_bits_count(&s->gb) - s->subframe_offset);
1195

    
1196
    /** parse coefficients */
1197
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
1198
        int c = s->channel_indexes_for_cur_subframe[i];
1199
        if (s->channel[c].transmit_coefs &&
1200
            get_bits_count(&s->gb) < s->num_saved_bits) {
1201
            decode_coeffs(s, c);
1202
        } else
1203
            memset(s->channel[c].coeffs, 0,
1204
                   sizeof(*s->channel[c].coeffs) * subframe_len);
1205
    }
1206

    
1207
    dprintf(s->avctx, "BITSTREAM: subframe length was %i\n",
1208
            get_bits_count(&s->gb) - s->subframe_offset);
1209

    
1210
    if (transmit_coeffs) {
1211
        /** reconstruct the per channel data */
1212
        inverse_channel_transform(s);
1213
        for (i = 0; i < s->channels_for_cur_subframe; i++) {
1214
            int c = s->channel_indexes_for_cur_subframe[i];
1215
            const int* sf = s->channel[c].scale_factors;
1216
            int b;
1217

    
1218
            if (c == s->lfe_channel)
1219
                memset(&s->tmp[cur_subwoofer_cutoff], 0, sizeof(*s->tmp) *
1220
                       (subframe_len - cur_subwoofer_cutoff));
1221

    
1222
            /** inverse quantization and rescaling */
1223
            for (b = 0; b < s->num_bands; b++) {
1224
                const int end = FFMIN(s->cur_sfb_offsets[b+1], s->subframe_len);
1225
                const int exp = s->channel[c].quant_step -
1226
                            (s->channel[c].max_scale_factor - *sf++) *
1227
                            s->channel[c].scale_factor_step;
1228
                const float quant = pow(10.0, exp / 20.0);
1229
                int start = s->cur_sfb_offsets[b];
1230
                s->dsp.vector_fmul_scalar(s->tmp + start,
1231
                                          s->channel[c].coeffs + start,
1232
                                          quant, end - start);
1233
            }
1234

    
1235
            /** apply imdct (ff_imdct_half == DCTIV with reverse) */
1236
            ff_imdct_half(&s->mdct_ctx[av_log2(subframe_len) - BLOCK_MIN_BITS],
1237
                          s->channel[c].coeffs, s->tmp);
1238
        }
1239
    }
1240

    
1241
    /** window and overlapp-add */
1242
    wmapro_window(s);
1243

    
1244
    /** handled one subframe */
1245
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
1246
        int c = s->channel_indexes_for_cur_subframe[i];
1247
        if (s->channel[c].cur_subframe >= s->channel[c].num_subframes) {
1248
            av_log(s->avctx, AV_LOG_ERROR, "broken subframe\n");
1249
            return AVERROR_INVALIDDATA;
1250
        }
1251
        ++s->channel[c].cur_subframe;
1252
    }
1253

    
1254
    return 0;
1255
}
1256

    
1257
/**
1258
 *@brief Decode one WMA frame.
1259
 *@param s codec context
1260
 *@return 0 if the trailer bit indicates that this is the last frame,
1261
 *        1 if there are additional frames
1262
 */
1263
static int decode_frame(WMAProDecodeCtx *s)
1264
{
1265
    GetBitContext* gb = &s->gb;
1266
    int more_frames = 0;
1267
    int len = 0;
1268
    int i;
1269

    
1270
    /** check for potential output buffer overflow */
1271
    if (s->num_channels * s->samples_per_frame > s->samples_end - s->samples) {
1272
        /** return an error if no frame could be decoded at all */
1273
        av_log(s->avctx, AV_LOG_ERROR,
1274
               "not enough space for the output samples\n");
1275
        s->packet_loss = 1;
1276
        return 0;
1277
    }
1278

    
1279
    /** get frame length */
1280
    if (s->len_prefix)
1281
        len = get_bits(gb, s->log2_frame_size);
1282

    
1283
    dprintf(s->avctx, "decoding frame with length %x\n", len);
1284

    
1285
    /** decode tile information */
1286
    if (decode_tilehdr(s)) {
1287
        s->packet_loss = 1;
1288
        return 0;
1289
    }
1290

    
1291
    /** read postproc transform */
1292
    if (s->num_channels > 1 && get_bits1(gb)) {
1293
        av_log_ask_for_sample(s->avctx, "Unsupported postproc transform found\n");
1294
        s->packet_loss = 1;
1295
        return 0;
1296
    }
1297

    
1298
    /** read drc info */
1299
    if (s->dynamic_range_compression) {
1300
        s->drc_gain = get_bits(gb, 8);
1301
        dprintf(s->avctx, "drc_gain %i\n", s->drc_gain);
1302
    }
1303

    
1304
    /** no idea what these are for, might be the number of samples
1305
        that need to be skipped at the beginning or end of a stream */
1306
    if (get_bits1(gb)) {
1307
        int skip;
1308

    
1309
        /** usually true for the first frame */
1310
        if (get_bits1(gb)) {
1311
            skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
1312
            dprintf(s->avctx, "start skip: %i\n", skip);
1313
        }
1314

    
1315
        /** sometimes true for the last frame */
1316
        if (get_bits1(gb)) {
1317
            skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
1318
            dprintf(s->avctx, "end skip: %i\n", skip);
1319
        }
1320

    
1321
    }
1322

    
1323
    dprintf(s->avctx, "BITSTREAM: frame header length was %i\n",
1324
            get_bits_count(gb) - s->frame_offset);
1325

    
1326
    /** reset subframe states */
1327
    s->parsed_all_subframes = 0;
1328
    for (i = 0; i < s->num_channels; i++) {
1329
        s->channel[i].decoded_samples = 0;
1330
        s->channel[i].cur_subframe    = 0;
1331
        s->channel[i].reuse_sf        = 0;
1332
    }
1333

    
1334
    /** decode all subframes */
1335
    while (!s->parsed_all_subframes) {
1336
        if (decode_subframe(s) < 0) {
1337
            s->packet_loss = 1;
1338
            return 0;
1339
        }
1340
    }
1341

    
1342
    /** interleave samples and write them to the output buffer */
1343
    for (i = 0; i < s->num_channels; i++) {
1344
        float* ptr  = s->samples + i;
1345
        int incr = s->num_channels;
1346
        float* iptr = s->channel[i].out;
1347
        float* iend = iptr + s->samples_per_frame;
1348

    
1349
        // FIXME should create/use a DSP function here
1350
        while (iptr < iend) {
1351
            *ptr = *iptr++;
1352
            ptr += incr;
1353
        }
1354

    
1355
        /** reuse second half of the IMDCT output for the next frame */
1356
        memcpy(&s->channel[i].out[0],
1357
               &s->channel[i].out[s->samples_per_frame],
1358
               s->samples_per_frame * sizeof(*s->channel[i].out) >> 1);
1359
    }
1360

    
1361
    if (s->skip_frame) {
1362
        s->skip_frame = 0;
1363
    } else
1364
        s->samples += s->num_channels * s->samples_per_frame;
1365

    
1366
    if (s->len_prefix) {
1367
        if (len != (get_bits_count(gb) - s->frame_offset) + 2) {
1368
            /** FIXME: not sure if this is always an error */
1369
            av_log(s->avctx, AV_LOG_ERROR,
1370
                   "frame[%i] would have to skip %i bits\n", s->frame_num,
1371
                   len - (get_bits_count(gb) - s->frame_offset) - 1);
1372
            s->packet_loss = 1;
1373
            return 0;
1374
        }
1375

    
1376
        /** skip the rest of the frame data */
1377
        skip_bits_long(gb, len - (get_bits_count(gb) - s->frame_offset) - 1);
1378
    } else {
1379
        while (get_bits_count(gb) < s->num_saved_bits && get_bits1(gb) == 0) {
1380
        }
1381
    }
1382

    
1383
    /** decode trailer bit */
1384
    more_frames = get_bits1(gb);
1385

    
1386
    ++s->frame_num;
1387
    return more_frames;
1388
}
1389

    
1390
/**
1391
 *@brief Calculate remaining input buffer length.
1392
 *@param s codec context
1393
 *@param gb bitstream reader context
1394
 *@return remaining size in bits
1395
 */
1396
static int remaining_bits(WMAProDecodeCtx *s, GetBitContext *gb)
1397
{
1398
    return s->buf_bit_size - get_bits_count(gb);
1399
}
1400

    
1401
/**
1402
 *@brief Fill the bit reservoir with a (partial) frame.
1403
 *@param s codec context
1404
 *@param gb bitstream reader context
1405
 *@param len length of the partial frame
1406
 *@param append decides wether to reset the buffer or not
1407
 */
1408
static void save_bits(WMAProDecodeCtx *s, GetBitContext* gb, int len,
1409
                      int append)
1410
{
1411
    int buflen;
1412

    
1413
    /** when the frame data does not need to be concatenated, the input buffer
1414
        is resetted and additional bits from the previous frame are copyed
1415
        and skipped later so that a fast byte copy is possible */
1416

    
1417
    if (!append) {
1418
        s->frame_offset = get_bits_count(gb) & 7;
1419
        s->num_saved_bits = s->frame_offset;
1420
        init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE);
1421
    }
1422

    
1423
    buflen = (s->num_saved_bits + len + 8) >> 3;
1424

    
1425
    if (len <= 0 || buflen > MAX_FRAMESIZE) {
1426
        av_log_ask_for_sample(s->avctx, "input buffer too small\n");
1427
        s->packet_loss = 1;
1428
        return;
1429
    }
1430

    
1431
    s->num_saved_bits += len;
1432
    if (!append) {
1433
        ff_copy_bits(&s->pb, gb->buffer + (get_bits_count(gb) >> 3),
1434
                     s->num_saved_bits);
1435
    } else {
1436
        int align = 8 - (get_bits_count(gb) & 7);
1437
        align = FFMIN(align, len);
1438
        put_bits(&s->pb, align, get_bits(gb, align));
1439
        len -= align;
1440
        ff_copy_bits(&s->pb, gb->buffer + (get_bits_count(gb) >> 3), len);
1441
    }
1442
    skip_bits_long(gb, len);
1443

    
1444
    {
1445
        PutBitContext tmp = s->pb;
1446
        flush_put_bits(&tmp);
1447
    }
1448

    
1449
    init_get_bits(&s->gb, s->frame_data, s->num_saved_bits);
1450
    skip_bits(&s->gb, s->frame_offset);
1451
}
1452

    
1453
/**
1454
 *@brief Decode a single WMA packet.
1455
 *@param avctx codec context
1456
 *@param data the output buffer
1457
 *@param data_size number of bytes that were written to the output buffer
1458
 *@param avpkt input packet
1459
 *@return number of bytes that were read from the input buffer
1460
 */
1461
static int decode_packet(AVCodecContext *avctx,
1462
                         void *data, int *data_size, AVPacket* avpkt)
1463
{
1464
    WMAProDecodeCtx *s = avctx->priv_data;
1465
    GetBitContext* gb  = &s->pgb;
1466
    const uint8_t* buf = avpkt->data;
1467
    int buf_size       = avpkt->size;
1468
    int num_bits_prev_frame;
1469
    int packet_sequence_number;
1470

    
1471
    s->samples       = data;
1472
    s->samples_end   = (float*)((int8_t*)data + *data_size);
1473
    *data_size = 0;
1474

    
1475
    if (s->packet_done || s->packet_loss) {
1476
        s->packet_done = 0;
1477
        s->buf_bit_size = buf_size << 3;
1478

    
1479
        /** sanity check for the buffer length */
1480
        if (buf_size < avctx->block_align)
1481
            return 0;
1482

    
1483
        buf_size = avctx->block_align;
1484

    
1485
        /** parse packet header */
1486
        init_get_bits(gb, buf, s->buf_bit_size);
1487
        packet_sequence_number = get_bits(gb, 4);
1488
        skip_bits(gb, 2);
1489

    
1490
        /** get number of bits that need to be added to the previous frame */
1491
        num_bits_prev_frame = get_bits(gb, s->log2_frame_size);
1492
        dprintf(avctx, "packet[%d]: nbpf %x\n", avctx->frame_number,
1493
                num_bits_prev_frame);
1494

    
1495
        /** check for packet loss */
1496
        if (!s->packet_loss &&
1497
            ((s->packet_sequence_number + 1) & 0xF) != packet_sequence_number) {
1498
            s->packet_loss = 1;
1499
            av_log(avctx, AV_LOG_ERROR, "Packet loss detected! seq %x vs %x\n",
1500
                   s->packet_sequence_number, packet_sequence_number);
1501
        }
1502
        s->packet_sequence_number = packet_sequence_number;
1503

    
1504
        if (num_bits_prev_frame > 0) {
1505
            /** append the previous frame data to the remaining data from the
1506
                previous packet to create a full frame */
1507
            save_bits(s, gb, num_bits_prev_frame, 1);
1508
            dprintf(avctx, "accumulated %x bits of frame data\n",
1509
                    s->num_saved_bits - s->frame_offset);
1510

    
1511
            /** decode the cross packet frame if it is valid */
1512
            if (!s->packet_loss)
1513
                decode_frame(s);
1514
        } else if (s->num_saved_bits - s->frame_offset) {
1515
            dprintf(avctx, "ignoring %x previously saved bits\n",
1516
                    s->num_saved_bits - s->frame_offset);
1517
        }
1518

    
1519
        if (s->packet_loss) {
1520
            /** reset number of saved bits so that the decoder
1521
                does not start to decode incomplete frames in the
1522
                s->len_prefix == 0 case */
1523
            s->num_saved_bits = 0;
1524
            s->packet_loss = 0;
1525
        }
1526

    
1527
    } else {
1528
        int frame_size;
1529
        s->buf_bit_size = avpkt->size << 3;
1530
        init_get_bits(gb, avpkt->data, s->buf_bit_size);
1531
        skip_bits(gb, s->packet_offset);
1532
        if (s->len_prefix && remaining_bits(s, gb) > s->log2_frame_size &&
1533
            (frame_size = show_bits(gb, s->log2_frame_size)) &&
1534
            frame_size <= remaining_bits(s, gb)) {
1535
            save_bits(s, gb, frame_size, 0);
1536
            s->packet_done = !decode_frame(s);
1537
        } else if (!s->len_prefix
1538
                   && s->num_saved_bits > get_bits_count(&s->gb)) {
1539
            /** when the frames do not have a length prefix, we don't know
1540
                the compressed length of the individual frames
1541
                however, we know what part of a new packet belongs to the
1542
                previous frame
1543
                therefore we save the incoming packet first, then we append
1544
                the "previous frame" data from the next packet so that
1545
                we get a buffer that only contains full frames */
1546
            s->packet_done = !decode_frame(s);
1547
        } else
1548
            s->packet_done = 1;
1549
    }
1550

    
1551
    if (s->packet_done && !s->packet_loss &&
1552
        remaining_bits(s, gb) > 0) {
1553
        /** save the rest of the data so that it can be decoded
1554
            with the next packet */
1555
        save_bits(s, gb, remaining_bits(s, gb), 0);
1556
    }
1557

    
1558
    *data_size = (int8_t *)s->samples - (int8_t *)data;
1559
    s->packet_offset = get_bits_count(gb) & 7;
1560

    
1561
    return (s->packet_loss) ? AVERROR_INVALIDDATA : get_bits_count(gb) >> 3;
1562
}
1563

    
1564
/**
1565
 *@brief Clear decoder buffers (for seeking).
1566
 *@param avctx codec context
1567
 */
1568
static void flush(AVCodecContext *avctx)
1569
{
1570
    WMAProDecodeCtx *s = avctx->priv_data;
1571
    int i;
1572
    /** reset output buffer as a part of it is used during the windowing of a
1573
        new frame */
1574
    for (i = 0; i < s->num_channels; i++)
1575
        memset(s->channel[i].out, 0, s->samples_per_frame *
1576
               sizeof(*s->channel[i].out));
1577
    s->packet_loss = 1;
1578
}
1579

    
1580

    
1581
/**
1582
 *@brief wmapro decoder
1583
 */
1584
AVCodec wmapro_decoder = {
1585
    "wmapro",
1586
    AVMEDIA_TYPE_AUDIO,
1587
    CODEC_ID_WMAPRO,
1588
    sizeof(WMAProDecodeCtx),
1589
    decode_init,
1590
    NULL,
1591
    decode_end,
1592
    decode_packet,
1593
    .capabilities = CODEC_CAP_SUBFRAMES,
1594
    .flush= flush,
1595
    .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 9 Professional"),
1596
};