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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  libavcodec/wmaprodec.c
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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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/**
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 * @brief frame specific decoder context for a single channel
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 */
127
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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/**
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 *@brief helper function to print the most important members of the context
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 *@param s context
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 */
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static void av_cold dump_context(WMAProDecodeCtx *s)
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{
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#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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{
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    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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258
    return 0;
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}
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/**
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 *@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;
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    int num_possible_block_sizes;
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    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 = SAMPLE_FMT_FLT;
280

    
281
    if (avctx->extradata_size >= 18) {
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        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++)
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            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;
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    }
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 */
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    s->packet_loss = 1;
301
    s->len_prefix  = (s->decode_flags & 0x40);
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303
    if (!s->len_prefix) {
304
        av_log_ask_for_sample(avctx, "no length prefix\n");
305
        return AVERROR_INVALIDDATA;
306
    }
307

    
308
    /** get frame len */
309
    s->samples_per_frame = 1 << ff_wma_get_frame_len_bits(avctx->sample_rate,
310
                                                          3, s->decode_flags);
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312
    /** init previous block len */
313
    for (i = 0; i < avctx->channels; i++)
314
        s->channel[i].prev_block_len = s->samples_per_frame;
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316
    /** subframe info */
317
    log2_max_num_subframes       = ((s->decode_flags & 0x38) >> 3);
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    s->max_num_subframes         = 1 << log2_max_num_subframes;
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    if (s->max_num_subframes == 16)
320
        s->max_subframe_len_bit = 1;
321
    s->subframe_len_bits = av_log2(log2_max_num_subframes) + 1;
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323
    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;
325
    s->dynamic_range_compression = (s->decode_flags & 0x80);
326

    
327
    if (s->max_num_subframes > MAX_SUBFRAMES) {
328
        av_log(avctx, AV_LOG_ERROR, "invalid number of subframes %i\n",
329
               s->max_num_subframes);
330
        return AVERROR_INVALIDDATA;
331
    }
332

    
333
    s->num_channels = avctx->channels;
334

    
335
    /** extract lfe channel position */
336
    s->lfe_channel = -1;
337

    
338
    if (channel_mask & 8) {
339
        unsigned int mask;
340
        for (mask = 1; mask < 16; mask <<= 1) {
341
            if (channel_mask & mask)
342
                ++s->lfe_channel;
343
        }
344
    }
345

    
346
    if (s->num_channels < 0) {
347
        av_log(avctx, AV_LOG_ERROR, "invalid number of channels %d\n", s->num_channels);
348
        return AVERROR_INVALIDDATA;
349
    } else if (s->num_channels > WMAPRO_MAX_CHANNELS) {
350
        av_log_ask_for_sample(avctx, "unsupported number of channels\n");
351
        return AVERROR_PATCHWELCOME;
352
    }
353

    
354
    INIT_VLC_STATIC(&sf_vlc, SCALEVLCBITS, HUFF_SCALE_SIZE,
355
                    scale_huffbits, 1, 1,
356
                    scale_huffcodes, 2, 2, 616);
357

    
358
    INIT_VLC_STATIC(&sf_rl_vlc, VLCBITS, HUFF_SCALE_RL_SIZE,
359
                    scale_rl_huffbits, 1, 1,
360
                    scale_rl_huffcodes, 4, 4, 1406);
361

    
362
    INIT_VLC_STATIC(&coef_vlc[0], VLCBITS, HUFF_COEF0_SIZE,
363
                    coef0_huffbits, 1, 1,
364
                    coef0_huffcodes, 4, 4, 2108);
365

    
366
    INIT_VLC_STATIC(&coef_vlc[1], VLCBITS, HUFF_COEF1_SIZE,
367
                    coef1_huffbits, 1, 1,
368
                    coef1_huffcodes, 4, 4, 3912);
369

    
370
    INIT_VLC_STATIC(&vec4_vlc, VLCBITS, HUFF_VEC4_SIZE,
371
                    vec4_huffbits, 1, 1,
372
                    vec4_huffcodes, 2, 2, 604);
373

    
374
    INIT_VLC_STATIC(&vec2_vlc, VLCBITS, HUFF_VEC2_SIZE,
375
                    vec2_huffbits, 1, 1,
376
                    vec2_huffcodes, 2, 2, 562);
377

    
378
    INIT_VLC_STATIC(&vec1_vlc, VLCBITS, HUFF_VEC1_SIZE,
379
                    vec1_huffbits, 1, 1,
380
                    vec1_huffcodes, 2, 2, 562);
381

    
382
    /** calculate number of scale factor bands and their offsets
383
        for every possible block size */
384
    for (i = 0; i < num_possible_block_sizes; i++) {
385
        int subframe_len = s->samples_per_frame >> i;
386
        int x;
387
        int band = 1;
388

    
389
        s->sfb_offsets[i][0] = 0;
390

    
391
        for (x = 0; x < MAX_BANDS-1 && s->sfb_offsets[i][band - 1] < subframe_len; x++) {
392
            int offset = (subframe_len * 2 * critical_freq[x])
393
                          / s->avctx->sample_rate + 2;
394
            offset &= ~3;
395
            if (offset > s->sfb_offsets[i][band - 1])
396
                s->sfb_offsets[i][band++] = offset;
397
        }
398
        s->sfb_offsets[i][band - 1] = subframe_len;
399
        s->num_sfb[i]               = band - 1;
400
    }
401

    
402

    
403
    /** Scale factors can be shared between blocks of different size
404
        as every block has a different scale factor band layout.
405
        The matrix sf_offsets is needed to find the correct scale factor.
406
     */
407

    
408
    for (i = 0; i < num_possible_block_sizes; i++) {
409
        int b;
410
        for (b = 0; b < s->num_sfb[i]; b++) {
411
            int x;
412
            int offset = ((s->sfb_offsets[i][b]
413
                           + s->sfb_offsets[i][b + 1] - 1) << i) >> 1;
414
            for (x = 0; x < num_possible_block_sizes; x++) {
415
                int v = 0;
416
                while (s->sfb_offsets[x][v + 1] << x < offset)
417
                    ++v;
418
                s->sf_offsets[i][x][b] = v;
419
            }
420
        }
421
    }
422

    
423
    /** init MDCT, FIXME: only init needed sizes */
424
    for (i = 0; i < WMAPRO_BLOCK_SIZES; i++)
425
        ff_mdct_init(&s->mdct_ctx[i], BLOCK_MIN_BITS+1+i, 1,
426
                     1.0 / (1 << (BLOCK_MIN_BITS + i - 1))
427
                     / (1 << (s->bits_per_sample - 1)));
428

    
429
    /** init MDCT windows: simple sinus window */
430
    for (i = 0; i < WMAPRO_BLOCK_SIZES; i++) {
431
        const int win_idx = WMAPRO_BLOCK_MAX_BITS - i;
432
        ff_init_ff_sine_windows(win_idx);
433
        s->windows[WMAPRO_BLOCK_SIZES - i - 1] = ff_sine_windows[win_idx];
434
    }
435

    
436
    /** calculate subwoofer cutoff values */
437
    for (i = 0; i < num_possible_block_sizes; i++) {
438
        int block_size = s->samples_per_frame >> i;
439
        int cutoff = (440*block_size + 3 * (s->avctx->sample_rate >> 1) - 1)
440
                     / s->avctx->sample_rate;
441
        s->subwoofer_cutoffs[i] = av_clip(cutoff, 4, block_size);
442
    }
443

    
444
    /** calculate sine values for the decorrelation matrix */
445
    for (i = 0; i < 33; i++)
446
        sin64[i] = sin(i*M_PI / 64.0);
447

    
448
    if (avctx->debug & FF_DEBUG_BITSTREAM)
449
        dump_context(s);
450

    
451
    avctx->channel_layout = channel_mask;
452
    return 0;
453
}
454

    
455
/**
456
 *@brief Decode the subframe length.
457
 *@param s context
458
 *@param offset sample offset in the frame
459
 *@return decoded subframe length on success, < 0 in case of an error
460
 */
461
static int decode_subframe_length(WMAProDecodeCtx *s, int offset)
462
{
463
    int frame_len_shift = 0;
464
    int subframe_len;
465

    
466
    /** no need to read from the bitstream when only one length is possible */
467
    if (offset == s->samples_per_frame - s->min_samples_per_subframe)
468
        return s->min_samples_per_subframe;
469

    
470
    /** 1 bit indicates if the subframe is of maximum length */
471
    if (s->max_subframe_len_bit) {
472
        if (get_bits1(&s->gb))
473
            frame_len_shift = 1 + get_bits(&s->gb, s->subframe_len_bits-1);
474
    } else
475
        frame_len_shift = get_bits(&s->gb, s->subframe_len_bits);
476

    
477
    subframe_len = s->samples_per_frame >> frame_len_shift;
478

    
479
    /** sanity check the length */
480
    if (subframe_len < s->min_samples_per_subframe ||
481
        subframe_len > s->samples_per_frame) {
482
        av_log(s->avctx, AV_LOG_ERROR, "broken frame: subframe_len %i\n",
483
               subframe_len);
484
        return AVERROR_INVALIDDATA;
485
    }
486
    return subframe_len;
487
}
488

    
489
/**
490
 *@brief Decode how the data in the frame is split into subframes.
491
 *       Every WMA frame contains the encoded data for a fixed number of
492
 *       samples per channel. The data for every channel might be split
493
 *       into several subframes. This function will reconstruct the list of
494
 *       subframes for every channel.
495
 *
496
 *       If the subframes are not evenly split, the algorithm estimates the
497
 *       channels with the lowest number of total samples.
498
 *       Afterwards, for each of these channels a bit is read from the
499
 *       bitstream that indicates if the channel contains a subframe with the
500
 *       next subframe size that is going to be read from the bitstream or not.
501
 *       If a channel contains such a subframe, the subframe size gets added to
502
 *       the channel's subframe list.
503
 *       The algorithm repeats these steps until the frame is properly divided
504
 *       between the individual channels.
505
 *
506
 *@param s context
507
 *@return 0 on success, < 0 in case of an error
508
 */
509
static int decode_tilehdr(WMAProDecodeCtx *s)
510
{
511
    uint16_t num_samples[WMAPRO_MAX_CHANNELS];        /** sum of samples for all currently known subframes of a channel */
512
    uint8_t  contains_subframe[WMAPRO_MAX_CHANNELS];  /** flag indicating if a channel contains the current subframe */
513
    int channels_for_cur_subframe = s->num_channels;  /** number of channels that contain the current subframe */
514
    int fixed_channel_layout = 0;                     /** flag indicating that all channels use the same subframe offsets and sizes */
515
    int min_channel_len = 0;                          /** smallest sum of samples (channels with this length will be processed first) */
516
    int c;
517

    
518
    /* Should never consume more than 3073 bits (256 iterations for the
519
     * while loop when always the minimum amount of 128 samples is substracted
520
     * from missing samples in the 8 channel case).
521
     * 1 + BLOCK_MAX_SIZE * MAX_CHANNELS / BLOCK_MIN_SIZE * (MAX_CHANNELS  + 4)
522
     */
523

    
524
    /** reset tiling information */
525
    for (c = 0; c < s->num_channels; c++)
526
        s->channel[c].num_subframes = 0;
527

    
528
    memset(num_samples, 0, sizeof(num_samples));
529

    
530
    if (s->max_num_subframes == 1 || get_bits1(&s->gb))
531
        fixed_channel_layout = 1;
532

    
533
    /** loop until the frame data is split between the subframes */
534
    do {
535
        int subframe_len;
536

    
537
        /** check which channels contain the subframe */
538
        for (c = 0; c < s->num_channels; c++) {
539
            if (num_samples[c] == min_channel_len) {
540
                if (fixed_channel_layout || channels_for_cur_subframe == 1 ||
541
                   (min_channel_len == s->samples_per_frame - s->min_samples_per_subframe))
542
                    contains_subframe[c] = 1;
543
                else
544
                    contains_subframe[c] = get_bits1(&s->gb);
545
            } else
546
                contains_subframe[c] = 0;
547
        }
548

    
549
        /** get subframe length, subframe_len == 0 is not allowed */
550
        if ((subframe_len = decode_subframe_length(s, min_channel_len)) <= 0)
551
            return AVERROR_INVALIDDATA;
552

    
553
        /** add subframes to the individual channels and find new min_channel_len */
554
        min_channel_len += subframe_len;
555
        for (c = 0; c < s->num_channels; c++) {
556
            WMAProChannelCtx* chan = &s->channel[c];
557

    
558
            if (contains_subframe[c]) {
559
                if (chan->num_subframes >= MAX_SUBFRAMES) {
560
                    av_log(s->avctx, AV_LOG_ERROR,
561
                           "broken frame: num subframes > 31\n");
562
                    return AVERROR_INVALIDDATA;
563
                }
564
                chan->subframe_len[chan->num_subframes] = subframe_len;
565
                num_samples[c] += subframe_len;
566
                ++chan->num_subframes;
567
                if (num_samples[c] > s->samples_per_frame) {
568
                    av_log(s->avctx, AV_LOG_ERROR, "broken frame: "
569
                           "channel len > samples_per_frame\n");
570
                    return AVERROR_INVALIDDATA;
571
                }
572
            } else if (num_samples[c] <= min_channel_len) {
573
                if (num_samples[c] < min_channel_len) {
574
                    channels_for_cur_subframe = 0;
575
                    min_channel_len = num_samples[c];
576
                }
577
                ++channels_for_cur_subframe;
578
            }
579
        }
580
    } while (min_channel_len < s->samples_per_frame);
581

    
582
    for (c = 0; c < s->num_channels; c++) {
583
        int i;
584
        int offset = 0;
585
        for (i = 0; i < s->channel[c].num_subframes; i++) {
586
            dprintf(s->avctx, "frame[%i] channel[%i] subframe[%i]"
587
                    " len %i\n", s->frame_num, c, i,
588
                    s->channel[c].subframe_len[i]);
589
            s->channel[c].subframe_offset[i] = offset;
590
            offset += s->channel[c].subframe_len[i];
591
        }
592
    }
593

    
594
    return 0;
595
}
596

    
597
/**
598
 *@brief Calculate a decorrelation matrix from the bitstream parameters.
599
 *@param s codec context
600
 *@param chgroup channel group for which the matrix needs to be calculated
601
 */
602
static void decode_decorrelation_matrix(WMAProDecodeCtx *s,
603
                                        WMAProChannelGrp *chgroup)
604
{
605
    int i;
606
    int offset = 0;
607
    int8_t rotation_offset[WMAPRO_MAX_CHANNELS * WMAPRO_MAX_CHANNELS];
608
    memset(chgroup->decorrelation_matrix, 0, s->num_channels *
609
           s->num_channels * sizeof(*chgroup->decorrelation_matrix));
610

    
611
    for (i = 0; i < chgroup->num_channels * (chgroup->num_channels - 1) >> 1; i++)
612
        rotation_offset[i] = get_bits(&s->gb, 6);
613

    
614
    for (i = 0; i < chgroup->num_channels; i++)
615
        chgroup->decorrelation_matrix[chgroup->num_channels * i + i] =
616
            get_bits1(&s->gb) ? 1.0 : -1.0;
617

    
618
    for (i = 1; i < chgroup->num_channels; i++) {
619
        int x;
620
        for (x = 0; x < i; x++) {
621
            int y;
622
            for (y = 0; y < i + 1; y++) {
623
                float v1 = chgroup->decorrelation_matrix[x * chgroup->num_channels + y];
624
                float v2 = chgroup->decorrelation_matrix[i * chgroup->num_channels + y];
625
                int n = rotation_offset[offset + x];
626
                float sinv;
627
                float cosv;
628

    
629
                if (n < 32) {
630
                    sinv = sin64[n];
631
                    cosv = sin64[32 - n];
632
                } else {
633
                    sinv =  sin64[64 -  n];
634
                    cosv = -sin64[n  - 32];
635
                }
636

    
637
                chgroup->decorrelation_matrix[y + x * chgroup->num_channels] =
638
                                               (v1 * sinv) - (v2 * cosv);
639
                chgroup->decorrelation_matrix[y + i * chgroup->num_channels] =
640
                                               (v1 * cosv) + (v2 * sinv);
641
            }
642
        }
643
        offset += i;
644
    }
645
}
646

    
647
/**
648
 *@brief Decode channel transformation parameters
649
 *@param s codec context
650
 *@return 0 in case of success, < 0 in case of bitstream errors
651
 */
652
static int decode_channel_transform(WMAProDecodeCtx* s)
653
{
654
    int i;
655
    /* should never consume more than 1921 bits for the 8 channel case
656
     * 1 + MAX_CHANNELS * (MAX_CHANNELS + 2 + 3 * MAX_CHANNELS * MAX_CHANNELS
657
     * + MAX_CHANNELS + MAX_BANDS + 1)
658
     */
659

    
660
    /** in the one channel case channel transforms are pointless */
661
    s->num_chgroups = 0;
662
    if (s->num_channels > 1) {
663
        int remaining_channels = s->channels_for_cur_subframe;
664

    
665
        if (get_bits1(&s->gb)) {
666
            av_log_ask_for_sample(s->avctx,
667
                                  "unsupported channel transform bit\n");
668
            return AVERROR_INVALIDDATA;
669
        }
670

    
671
        for (s->num_chgroups = 0; remaining_channels &&
672
             s->num_chgroups < s->channels_for_cur_subframe; s->num_chgroups++) {
673
            WMAProChannelGrp* chgroup = &s->chgroup[s->num_chgroups];
674
            float** channel_data = chgroup->channel_data;
675
            chgroup->num_channels = 0;
676
            chgroup->transform = 0;
677

    
678
            /** decode channel mask */
679
            if (remaining_channels > 2) {
680
                for (i = 0; i < s->channels_for_cur_subframe; i++) {
681
                    int channel_idx = s->channel_indexes_for_cur_subframe[i];
682
                    if (!s->channel[channel_idx].grouped
683
                        && get_bits1(&s->gb)) {
684
                        ++chgroup->num_channels;
685
                        s->channel[channel_idx].grouped = 1;
686
                        *channel_data++ = s->channel[channel_idx].coeffs;
687
                    }
688
                }
689
            } else {
690
                chgroup->num_channels = remaining_channels;
691
                for (i = 0; i < s->channels_for_cur_subframe; i++) {
692
                    int channel_idx = s->channel_indexes_for_cur_subframe[i];
693
                    if (!s->channel[channel_idx].grouped)
694
                        *channel_data++ = s->channel[channel_idx].coeffs;
695
                    s->channel[channel_idx].grouped = 1;
696
                }
697
            }
698

    
699
            /** decode transform type */
700
            if (chgroup->num_channels == 2) {
701
                if (get_bits1(&s->gb)) {
702
                    if (get_bits1(&s->gb)) {
703
                        av_log_ask_for_sample(s->avctx,
704
                                              "unsupported channel transform type\n");
705
                    }
706
                } else {
707
                    chgroup->transform = 1;
708
                    if (s->num_channels == 2) {
709
                        chgroup->decorrelation_matrix[0] =  1.0;
710
                        chgroup->decorrelation_matrix[1] = -1.0;
711
                        chgroup->decorrelation_matrix[2] =  1.0;
712
                        chgroup->decorrelation_matrix[3] =  1.0;
713
                    } else {
714
                        /** cos(pi/4) */
715
                        chgroup->decorrelation_matrix[0] =  0.70703125;
716
                        chgroup->decorrelation_matrix[1] = -0.70703125;
717
                        chgroup->decorrelation_matrix[2] =  0.70703125;
718
                        chgroup->decorrelation_matrix[3] =  0.70703125;
719
                    }
720
                }
721
            } else if (chgroup->num_channels > 2) {
722
                if (get_bits1(&s->gb)) {
723
                    chgroup->transform = 1;
724
                    if (get_bits1(&s->gb)) {
725
                        decode_decorrelation_matrix(s, chgroup);
726
                    } else {
727
                        /** FIXME: more than 6 coupled channels not supported */
728
                        if (chgroup->num_channels > 6) {
729
                            av_log_ask_for_sample(s->avctx,
730
                                                  "coupled channels > 6\n");
731
                        } else {
732
                            memcpy(chgroup->decorrelation_matrix,
733
                                   default_decorrelation[chgroup->num_channels],
734
                                   chgroup->num_channels * chgroup->num_channels *
735
                                   sizeof(*chgroup->decorrelation_matrix));
736
                        }
737
                    }
738
                }
739
            }
740

    
741
            /** decode transform on / off */
742
            if (chgroup->transform) {
743
                if (!get_bits1(&s->gb)) {
744
                    int i;
745
                    /** transform can be enabled for individual bands */
746
                    for (i = 0; i < s->num_bands; i++) {
747
                        chgroup->transform_band[i] = get_bits1(&s->gb);
748
                    }
749
                } else {
750
                    memset(chgroup->transform_band, 1, s->num_bands);
751
                }
752
            }
753
            remaining_channels -= chgroup->num_channels;
754
        }
755
    }
756
    return 0;
757
}
758

    
759
/**
760
 *@brief Extract the coefficients from the bitstream.
761
 *@param s codec context
762
 *@param c current channel number
763
 *@return 0 on success, < 0 in case of bitstream errors
764
 */
765
static int decode_coeffs(WMAProDecodeCtx *s, int c)
766
{
767
    /* Integers 0..15 as single-precision floats.  The table saves a
768
       costly int to float conversion, and storing the values as
769
       integers allows fast sign-flipping. */
770
    static const int fval_tab[16] = {
771
        0x00000000, 0x3f800000, 0x40000000, 0x40400000,
772
        0x40800000, 0x40a00000, 0x40c00000, 0x40e00000,
773
        0x41000000, 0x41100000, 0x41200000, 0x41300000,
774
        0x41400000, 0x41500000, 0x41600000, 0x41700000,
775
    };
776
    int vlctable;
777
    VLC* vlc;
778
    WMAProChannelCtx* ci = &s->channel[c];
779
    int rl_mode = 0;
780
    int cur_coeff = 0;
781
    int num_zeros = 0;
782
    const uint16_t* run;
783
    const float* level;
784

    
785
    dprintf(s->avctx, "decode coefficients for channel %i\n", c);
786

    
787
    vlctable = get_bits1(&s->gb);
788
    vlc = &coef_vlc[vlctable];
789

    
790
    if (vlctable) {
791
        run = coef1_run;
792
        level = coef1_level;
793
    } else {
794
        run = coef0_run;
795
        level = coef0_level;
796
    }
797

    
798
    /** decode vector coefficients (consumes up to 167 bits per iteration for
799
      4 vector coded large values) */
800
    while (!rl_mode && cur_coeff + 3 < s->subframe_len) {
801
        int vals[4];
802
        int i;
803
        unsigned int idx;
804

    
805
        idx = get_vlc2(&s->gb, vec4_vlc.table, VLCBITS, VEC4MAXDEPTH);
806

    
807
        if (idx == HUFF_VEC4_SIZE - 1) {
808
            for (i = 0; i < 4; i += 2) {
809
                idx = get_vlc2(&s->gb, vec2_vlc.table, VLCBITS, VEC2MAXDEPTH);
810
                if (idx == HUFF_VEC2_SIZE - 1) {
811
                    int v0, v1;
812
                    v0 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
813
                    if (v0 == HUFF_VEC1_SIZE - 1)
814
                        v0 += ff_wma_get_large_val(&s->gb);
815
                    v1 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH);
816
                    if (v1 == HUFF_VEC1_SIZE - 1)
817
                        v1 += ff_wma_get_large_val(&s->gb);
818
                    ((float*)vals)[i  ] = v0;
819
                    ((float*)vals)[i+1] = v1;
820
                } else {
821
                    vals[i]   = fval_tab[symbol_to_vec2[idx] >> 4 ];
822
                    vals[i+1] = fval_tab[symbol_to_vec2[idx] & 0xF];
823
                }
824
            }
825
        } else {
826
            vals[0] = fval_tab[ symbol_to_vec4[idx] >> 12      ];
827
            vals[1] = fval_tab[(symbol_to_vec4[idx] >> 8) & 0xF];
828
            vals[2] = fval_tab[(symbol_to_vec4[idx] >> 4) & 0xF];
829
            vals[3] = fval_tab[ symbol_to_vec4[idx]       & 0xF];
830
        }
831

    
832
        /** decode sign */
833
        for (i = 0; i < 4; i++) {
834
            if (vals[i]) {
835
                int sign = get_bits1(&s->gb) - 1;
836
                *(uint32_t*)&ci->coeffs[cur_coeff] = vals[i] ^ sign<<31;
837
                num_zeros = 0;
838
            } else {
839
                ci->coeffs[cur_coeff] = 0;
840
                /** switch to run level mode when subframe_len / 128 zeros
841
                    were found in a row */
842
                rl_mode |= (++num_zeros > s->subframe_len >> 8);
843
            }
844
            ++cur_coeff;
845
        }
846
    }
847

    
848
    /** decode run level coded coefficients */
849
    if (rl_mode) {
850
        memset(&ci->coeffs[cur_coeff], 0,
851
               sizeof(*ci->coeffs) * (s->subframe_len - cur_coeff));
852
        if (ff_wma_run_level_decode(s->avctx, &s->gb, vlc,
853
                                    level, run, 1, ci->coeffs,
854
                                    cur_coeff, s->subframe_len,
855
                                    s->subframe_len, s->esc_len, 0))
856
            return AVERROR_INVALIDDATA;
857
    }
858

    
859
    return 0;
860
}
861

    
862
/**
863
 *@brief Extract scale factors from the bitstream.
864
 *@param s codec context
865
 *@return 0 on success, < 0 in case of bitstream errors
866
 */
867
static int decode_scale_factors(WMAProDecodeCtx* s)
868
{
869
    int i;
870

    
871
    /** should never consume more than 5344 bits
872
     *  MAX_CHANNELS * (1 +  MAX_BANDS * 23)
873
     */
874

    
875
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
876
        int c = s->channel_indexes_for_cur_subframe[i];
877
        int* sf;
878
        int* sf_end;
879
        s->channel[c].scale_factors = s->channel[c].saved_scale_factors[!s->channel[c].scale_factor_idx];
880
        sf_end = s->channel[c].scale_factors + s->num_bands;
881

    
882
        /** resample scale factors for the new block size
883
         *  as the scale factors might need to be resampled several times
884
         *  before some  new values are transmitted, a backup of the last
885
         *  transmitted scale factors is kept in saved_scale_factors
886
         */
887
        if (s->channel[c].reuse_sf) {
888
            const int8_t* sf_offsets = s->sf_offsets[s->table_idx][s->channel[c].table_idx];
889
            int b;
890
            for (b = 0; b < s->num_bands; b++)
891
                s->channel[c].scale_factors[b] =
892
                    s->channel[c].saved_scale_factors[s->channel[c].scale_factor_idx][*sf_offsets++];
893
        }
894

    
895
        if (!s->channel[c].cur_subframe || get_bits1(&s->gb)) {
896

    
897
            if (!s->channel[c].reuse_sf) {
898
                int val;
899
                /** decode DPCM coded scale factors */
900
                s->channel[c].scale_factor_step = get_bits(&s->gb, 2) + 1;
901
                val = 45 / s->channel[c].scale_factor_step;
902
                for (sf = s->channel[c].scale_factors; sf < sf_end; sf++) {
903
                    val += get_vlc2(&s->gb, sf_vlc.table, SCALEVLCBITS, SCALEMAXDEPTH) - 60;
904
                    *sf = val;
905
                }
906
            } else {
907
                int i;
908
                /** run level decode differences to the resampled factors */
909
                for (i = 0; i < s->num_bands; i++) {
910
                    int idx;
911
                    int skip;
912
                    int val;
913
                    int sign;
914

    
915
                    idx = get_vlc2(&s->gb, sf_rl_vlc.table, VLCBITS, SCALERLMAXDEPTH);
916

    
917
                    if (!idx) {
918
                        uint32_t code = get_bits(&s->gb, 14);
919
                        val  =  code >> 6;
920
                        sign = (code & 1) - 1;
921
                        skip = (code & 0x3f) >> 1;
922
                    } else if (idx == 1) {
923
                        break;
924
                    } else {
925
                        skip = scale_rl_run[idx];
926
                        val  = scale_rl_level[idx];
927
                        sign = get_bits1(&s->gb)-1;
928
                    }
929

    
930
                    i += skip;
931
                    if (i >= s->num_bands) {
932
                        av_log(s->avctx, AV_LOG_ERROR,
933
                               "invalid scale factor coding\n");
934
                        return AVERROR_INVALIDDATA;
935
                    }
936
                    s->channel[c].scale_factors[i] += (val ^ sign) - sign;
937
                }
938
            }
939
            /** swap buffers */
940
            s->channel[c].scale_factor_idx = !s->channel[c].scale_factor_idx;
941
            s->channel[c].table_idx = s->table_idx;
942
            s->channel[c].reuse_sf  = 1;
943
        }
944

    
945
        /** calculate new scale factor maximum */
946
        s->channel[c].max_scale_factor = s->channel[c].scale_factors[0];
947
        for (sf = s->channel[c].scale_factors + 1; sf < sf_end; sf++) {
948
            s->channel[c].max_scale_factor =
949
                FFMAX(s->channel[c].max_scale_factor, *sf);
950
        }
951

    
952
    }
953
    return 0;
954
}
955

    
956
/**
957
 *@brief Reconstruct the individual channel data.
958
 *@param s codec context
959
 */
960
static void inverse_channel_transform(WMAProDecodeCtx *s)
961
{
962
    int i;
963

    
964
    for (i = 0; i < s->num_chgroups; i++) {
965
        if (s->chgroup[i].transform) {
966
            float data[WMAPRO_MAX_CHANNELS];
967
            const int num_channels = s->chgroup[i].num_channels;
968
            float** ch_data = s->chgroup[i].channel_data;
969
            float** ch_end = ch_data + num_channels;
970
            const int8_t* tb = s->chgroup[i].transform_band;
971
            int16_t* sfb;
972

    
973
            /** multichannel decorrelation */
974
            for (sfb = s->cur_sfb_offsets;
975
                 sfb < s->cur_sfb_offsets + s->num_bands; sfb++) {
976
                int y;
977
                if (*tb++ == 1) {
978
                    /** multiply values with the decorrelation_matrix */
979
                    for (y = sfb[0]; y < FFMIN(sfb[1], s->subframe_len); y++) {
980
                        const float* mat = s->chgroup[i].decorrelation_matrix;
981
                        const float* data_end = data + num_channels;
982
                        float* data_ptr = data;
983
                        float** ch;
984

    
985
                        for (ch = ch_data; ch < ch_end; ch++)
986
                            *data_ptr++ = (*ch)[y];
987

    
988
                        for (ch = ch_data; ch < ch_end; ch++) {
989
                            float sum = 0;
990
                            data_ptr = data;
991
                            while (data_ptr < data_end)
992
                                sum += *data_ptr++ * *mat++;
993

    
994
                            (*ch)[y] = sum;
995
                        }
996
                    }
997
                } else if (s->num_channels == 2) {
998
                    int len = FFMIN(sfb[1], s->subframe_len) - sfb[0];
999
                    s->dsp.vector_fmul_scalar(ch_data[0] + sfb[0],
1000
                                              ch_data[0] + sfb[0],
1001
                                              181.0 / 128, len);
1002
                    s->dsp.vector_fmul_scalar(ch_data[1] + sfb[0],
1003
                                              ch_data[1] + sfb[0],
1004
                                              181.0 / 128, len);
1005
                }
1006
            }
1007
        }
1008
    }
1009
}
1010

    
1011
/**
1012
 *@brief Apply sine window and reconstruct the output buffer.
1013
 *@param s codec context
1014
 */
1015
static void wmapro_window(WMAProDecodeCtx *s)
1016
{
1017
    int i;
1018
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
1019
        int c = s->channel_indexes_for_cur_subframe[i];
1020
        float* window;
1021
        int winlen = s->channel[c].prev_block_len;
1022
        float* start = s->channel[c].coeffs - (winlen >> 1);
1023

    
1024
        if (s->subframe_len < winlen) {
1025
            start += (winlen - s->subframe_len) >> 1;
1026
            winlen = s->subframe_len;
1027
        }
1028

    
1029
        window = s->windows[av_log2(winlen) - BLOCK_MIN_BITS];
1030

    
1031
        winlen >>= 1;
1032

    
1033
        s->dsp.vector_fmul_window(start, start, start + winlen,
1034
                                  window, 0, winlen);
1035

    
1036
        s->channel[c].prev_block_len = s->subframe_len;
1037
    }
1038
}
1039

    
1040
/**
1041
 *@brief Decode a single subframe (block).
1042
 *@param s codec context
1043
 *@return 0 on success, < 0 when decoding failed
1044
 */
1045
static int decode_subframe(WMAProDecodeCtx *s)
1046
{
1047
    int offset = s->samples_per_frame;
1048
    int subframe_len = s->samples_per_frame;
1049
    int i;
1050
    int total_samples   = s->samples_per_frame * s->num_channels;
1051
    int transmit_coeffs = 0;
1052
    int cur_subwoofer_cutoff;
1053

    
1054
    s->subframe_offset = get_bits_count(&s->gb);
1055

    
1056
    /** reset channel context and find the next block offset and size
1057
        == the next block of the channel with the smallest number of
1058
        decoded samples
1059
    */
1060
    for (i = 0; i < s->num_channels; i++) {
1061
        s->channel[i].grouped = 0;
1062
        if (offset > s->channel[i].decoded_samples) {
1063
            offset = s->channel[i].decoded_samples;
1064
            subframe_len =
1065
                s->channel[i].subframe_len[s->channel[i].cur_subframe];
1066
        }
1067
    }
1068

    
1069
    dprintf(s->avctx,
1070
            "processing subframe with offset %i len %i\n", offset, subframe_len);
1071

    
1072
    /** get a list of all channels that contain the estimated block */
1073
    s->channels_for_cur_subframe = 0;
1074
    for (i = 0; i < s->num_channels; i++) {
1075
        const int cur_subframe = s->channel[i].cur_subframe;
1076
        /** substract already processed samples */
1077
        total_samples -= s->channel[i].decoded_samples;
1078

    
1079
        /** and count if there are multiple subframes that match our profile */
1080
        if (offset == s->channel[i].decoded_samples &&
1081
            subframe_len == s->channel[i].subframe_len[cur_subframe]) {
1082
            total_samples -= s->channel[i].subframe_len[cur_subframe];
1083
            s->channel[i].decoded_samples +=
1084
                s->channel[i].subframe_len[cur_subframe];
1085
            s->channel_indexes_for_cur_subframe[s->channels_for_cur_subframe] = i;
1086
            ++s->channels_for_cur_subframe;
1087
        }
1088
    }
1089

    
1090
    /** check if the frame will be complete after processing the
1091
        estimated block */
1092
    if (!total_samples)
1093
        s->parsed_all_subframes = 1;
1094

    
1095

    
1096
    dprintf(s->avctx, "subframe is part of %i channels\n",
1097
            s->channels_for_cur_subframe);
1098

    
1099
    /** calculate number of scale factor bands and their offsets */
1100
    s->table_idx         = av_log2(s->samples_per_frame/subframe_len);
1101
    s->num_bands         = s->num_sfb[s->table_idx];
1102
    s->cur_sfb_offsets   = s->sfb_offsets[s->table_idx];
1103
    cur_subwoofer_cutoff = s->subwoofer_cutoffs[s->table_idx];
1104

    
1105
    /** configure the decoder for the current subframe */
1106
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
1107
        int c = s->channel_indexes_for_cur_subframe[i];
1108

    
1109
        s->channel[c].coeffs = &s->channel[c].out[(s->samples_per_frame >> 1)
1110
                                                  + offset];
1111
    }
1112

    
1113
    s->subframe_len = subframe_len;
1114
    s->esc_len = av_log2(s->subframe_len - 1) + 1;
1115

    
1116
    /** skip extended header if any */
1117
    if (get_bits1(&s->gb)) {
1118
        int num_fill_bits;
1119
        if (!(num_fill_bits = get_bits(&s->gb, 2))) {
1120
            int len = get_bits(&s->gb, 4);
1121
            num_fill_bits = get_bits(&s->gb, len) + 1;
1122
        }
1123

    
1124
        if (num_fill_bits >= 0) {
1125
            if (get_bits_count(&s->gb) + num_fill_bits > s->num_saved_bits) {
1126
                av_log(s->avctx, AV_LOG_ERROR, "invalid number of fill bits\n");
1127
                return AVERROR_INVALIDDATA;
1128
            }
1129

    
1130
            skip_bits_long(&s->gb, num_fill_bits);
1131
        }
1132
    }
1133

    
1134
    /** no idea for what the following bit is used */
1135
    if (get_bits1(&s->gb)) {
1136
        av_log_ask_for_sample(s->avctx, "reserved bit set\n");
1137
        return AVERROR_INVALIDDATA;
1138
    }
1139

    
1140

    
1141
    if (decode_channel_transform(s) < 0)
1142
        return AVERROR_INVALIDDATA;
1143

    
1144

    
1145
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
1146
        int c = s->channel_indexes_for_cur_subframe[i];
1147
        if ((s->channel[c].transmit_coefs = get_bits1(&s->gb)))
1148
            transmit_coeffs = 1;
1149
    }
1150

    
1151
    if (transmit_coeffs) {
1152
        int step;
1153
        int quant_step = 90 * s->bits_per_sample >> 4;
1154
        if ((get_bits1(&s->gb))) {
1155
            /** FIXME: might change run level mode decision */
1156
            av_log_ask_for_sample(s->avctx, "unsupported quant step coding\n");
1157
            return AVERROR_INVALIDDATA;
1158
        }
1159
        /** decode quantization step */
1160
        step = get_sbits(&s->gb, 6);
1161
        quant_step += step;
1162
        if (step == -32 || step == 31) {
1163
            const int sign = (step == 31) - 1;
1164
            int quant = 0;
1165
            while (get_bits_count(&s->gb) + 5 < s->num_saved_bits &&
1166
                   (step = get_bits(&s->gb, 5)) == 31) {
1167
                quant += 31;
1168
            }
1169
            quant_step += ((quant + step) ^ sign) - sign;
1170
        }
1171
        if (quant_step < 0) {
1172
            av_log(s->avctx, AV_LOG_DEBUG, "negative quant step\n");
1173
        }
1174

    
1175
        /** decode quantization step modifiers for every channel */
1176

    
1177
        if (s->channels_for_cur_subframe == 1) {
1178
            s->channel[s->channel_indexes_for_cur_subframe[0]].quant_step = quant_step;
1179
        } else {
1180
            int modifier_len = get_bits(&s->gb, 3);
1181
            for (i = 0; i < s->channels_for_cur_subframe; i++) {
1182
                int c = s->channel_indexes_for_cur_subframe[i];
1183
                s->channel[c].quant_step = quant_step;
1184
                if (get_bits1(&s->gb)) {
1185
                    if (modifier_len) {
1186
                        s->channel[c].quant_step += get_bits(&s->gb, modifier_len) + 1;
1187
                    } else
1188
                        ++s->channel[c].quant_step;
1189
                }
1190
            }
1191
        }
1192

    
1193
        /** decode scale factors */
1194
        if (decode_scale_factors(s) < 0)
1195
            return AVERROR_INVALIDDATA;
1196
    }
1197

    
1198
    dprintf(s->avctx, "BITSTREAM: subframe header length was %i\n",
1199
            get_bits_count(&s->gb) - s->subframe_offset);
1200

    
1201
    /** parse coefficients */
1202
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
1203
        int c = s->channel_indexes_for_cur_subframe[i];
1204
        if (s->channel[c].transmit_coefs &&
1205
            get_bits_count(&s->gb) < s->num_saved_bits) {
1206
            decode_coeffs(s, c);
1207
        } else
1208
            memset(s->channel[c].coeffs, 0,
1209
                   sizeof(*s->channel[c].coeffs) * subframe_len);
1210
    }
1211

    
1212
    dprintf(s->avctx, "BITSTREAM: subframe length was %i\n",
1213
            get_bits_count(&s->gb) - s->subframe_offset);
1214

    
1215
    if (transmit_coeffs) {
1216
        /** reconstruct the per channel data */
1217
        inverse_channel_transform(s);
1218
        for (i = 0; i < s->channels_for_cur_subframe; i++) {
1219
            int c = s->channel_indexes_for_cur_subframe[i];
1220
            const int* sf = s->channel[c].scale_factors;
1221
            int b;
1222

    
1223
            if (c == s->lfe_channel)
1224
                memset(&s->tmp[cur_subwoofer_cutoff], 0, sizeof(*s->tmp) *
1225
                       (subframe_len - cur_subwoofer_cutoff));
1226

    
1227
            /** inverse quantization and rescaling */
1228
            for (b = 0; b < s->num_bands; b++) {
1229
                const int end = FFMIN(s->cur_sfb_offsets[b+1], s->subframe_len);
1230
                const int exp = s->channel[c].quant_step -
1231
                            (s->channel[c].max_scale_factor - *sf++) *
1232
                            s->channel[c].scale_factor_step;
1233
                const float quant = pow(10.0, exp / 20.0);
1234
                int start = s->cur_sfb_offsets[b];
1235
                s->dsp.vector_fmul_scalar(s->tmp + start,
1236
                                          s->channel[c].coeffs + start,
1237
                                          quant, end - start);
1238
            }
1239

    
1240
            /** apply imdct (ff_imdct_half == DCTIV with reverse) */
1241
            ff_imdct_half(&s->mdct_ctx[av_log2(subframe_len) - BLOCK_MIN_BITS],
1242
                          s->channel[c].coeffs, s->tmp);
1243
        }
1244
    }
1245

    
1246
    /** window and overlapp-add */
1247
    wmapro_window(s);
1248

    
1249
    /** handled one subframe */
1250
    for (i = 0; i < s->channels_for_cur_subframe; i++) {
1251
        int c = s->channel_indexes_for_cur_subframe[i];
1252
        if (s->channel[c].cur_subframe >= s->channel[c].num_subframes) {
1253
            av_log(s->avctx, AV_LOG_ERROR, "broken subframe\n");
1254
            return AVERROR_INVALIDDATA;
1255
        }
1256
        ++s->channel[c].cur_subframe;
1257
    }
1258

    
1259
    return 0;
1260
}
1261

    
1262
/**
1263
 *@brief Decode one WMA frame.
1264
 *@param s codec context
1265
 *@return 0 if the trailer bit indicates that this is the last frame,
1266
 *        1 if there are additional frames
1267
 */
1268
static int decode_frame(WMAProDecodeCtx *s)
1269
{
1270
    GetBitContext* gb = &s->gb;
1271
    int more_frames = 0;
1272
    int len = 0;
1273
    int i;
1274

    
1275
    /** check for potential output buffer overflow */
1276
    if (s->num_channels * s->samples_per_frame > s->samples_end - s->samples) {
1277
        /** return an error if no frame could be decoded at all */
1278
        av_log(s->avctx, AV_LOG_ERROR,
1279
               "not enough space for the output samples\n");
1280
        s->packet_loss = 1;
1281
        return 0;
1282
    }
1283

    
1284
    /** get frame length */
1285
    if (s->len_prefix)
1286
        len = get_bits(gb, s->log2_frame_size);
1287

    
1288
    dprintf(s->avctx, "decoding frame with length %x\n", len);
1289

    
1290
    /** decode tile information */
1291
    if (decode_tilehdr(s)) {
1292
        s->packet_loss = 1;
1293
        return 0;
1294
    }
1295

    
1296
    /** read postproc transform */
1297
    if (s->num_channels > 1 && get_bits1(gb)) {
1298
        av_log_ask_for_sample(s->avctx, "Unsupported postproc transform found\n");
1299
        s->packet_loss = 1;
1300
        return 0;
1301
    }
1302

    
1303
    /** read drc info */
1304
    if (s->dynamic_range_compression) {
1305
        s->drc_gain = get_bits(gb, 8);
1306
        dprintf(s->avctx, "drc_gain %i\n", s->drc_gain);
1307
    }
1308

    
1309
    /** no idea what these are for, might be the number of samples
1310
        that need to be skipped at the beginning or end of a stream */
1311
    if (get_bits1(gb)) {
1312
        int skip;
1313

    
1314
        /** usually true for the first frame */
1315
        if (get_bits1(gb)) {
1316
            skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
1317
            dprintf(s->avctx, "start skip: %i\n", skip);
1318
        }
1319

    
1320
        /** sometimes true for the last frame */
1321
        if (get_bits1(gb)) {
1322
            skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
1323
            dprintf(s->avctx, "end skip: %i\n", skip);
1324
        }
1325

    
1326
    }
1327

    
1328
    dprintf(s->avctx, "BITSTREAM: frame header length was %i\n",
1329
            get_bits_count(gb) - s->frame_offset);
1330

    
1331
    /** reset subframe states */
1332
    s->parsed_all_subframes = 0;
1333
    for (i = 0; i < s->num_channels; i++) {
1334
        s->channel[i].decoded_samples = 0;
1335
        s->channel[i].cur_subframe    = 0;
1336
        s->channel[i].reuse_sf        = 0;
1337
    }
1338

    
1339
    /** decode all subframes */
1340
    while (!s->parsed_all_subframes) {
1341
        if (decode_subframe(s) < 0) {
1342
            s->packet_loss = 1;
1343
            return 0;
1344
        }
1345
    }
1346

    
1347
    /** interleave samples and write them to the output buffer */
1348
    for (i = 0; i < s->num_channels; i++) {
1349
        float* ptr  = s->samples + i;
1350
        int incr = s->num_channels;
1351
        float* iptr = s->channel[i].out;
1352
        float* iend = iptr + s->samples_per_frame;
1353

    
1354
        while (iptr < iend) {
1355
            *ptr = av_clipf(*iptr++, -1.0, 32767.0 / 32768.0);
1356
            ptr += incr;
1357
        }
1358

    
1359
        /** reuse second half of the IMDCT output for the next frame */
1360
        memcpy(&s->channel[i].out[0],
1361
               &s->channel[i].out[s->samples_per_frame],
1362
               s->samples_per_frame * sizeof(*s->channel[i].out) >> 1);
1363
    }
1364

    
1365
    if (s->skip_frame) {
1366
        s->skip_frame = 0;
1367
    } else
1368
        s->samples += s->num_channels * s->samples_per_frame;
1369

    
1370
    if (len != (get_bits_count(gb) - s->frame_offset) + 2) {
1371
        /** FIXME: not sure if this is always an error */
1372
        av_log(s->avctx, AV_LOG_ERROR, "frame[%i] would have to skip %i bits\n",
1373
               s->frame_num, len - (get_bits_count(gb) - s->frame_offset) - 1);
1374
        s->packet_loss = 1;
1375
        return 0;
1376
    }
1377

    
1378
    /** skip the rest of the frame data */
1379
    skip_bits_long(gb, len - (get_bits_count(gb) - s->frame_offset) - 1);
1380

    
1381
    /** decode trailer bit */
1382
    more_frames = get_bits1(gb);
1383

    
1384
    ++s->frame_num;
1385
    return more_frames;
1386
}
1387

    
1388
/**
1389
 *@brief Calculate remaining input buffer length.
1390
 *@param s codec context
1391
 *@param gb bitstream reader context
1392
 *@return remaining size in bits
1393
 */
1394
static int remaining_bits(WMAProDecodeCtx *s, GetBitContext *gb)
1395
{
1396
    return s->buf_bit_size - get_bits_count(gb);
1397
}
1398

    
1399
/**
1400
 *@brief Fill the bit reservoir with a (partial) frame.
1401
 *@param s codec context
1402
 *@param gb bitstream reader context
1403
 *@param len length of the partial frame
1404
 *@param append decides wether to reset the buffer or not
1405
 */
1406
static void save_bits(WMAProDecodeCtx *s, GetBitContext* gb, int len,
1407
                      int append)
1408
{
1409
    int buflen;
1410

    
1411
    /** when the frame data does not need to be concatenated, the input buffer
1412
        is resetted and additional bits from the previous frame are copyed
1413
        and skipped later so that a fast byte copy is possible */
1414

    
1415
    if (!append) {
1416
        s->frame_offset = get_bits_count(gb) & 7;
1417
        s->num_saved_bits = s->frame_offset;
1418
        init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE);
1419
    }
1420

    
1421
    buflen = (s->num_saved_bits + len + 8) >> 3;
1422

    
1423
    if (len <= 0 || buflen > MAX_FRAMESIZE) {
1424
        av_log_ask_for_sample(s->avctx, "input buffer too small\n");
1425
        s->packet_loss = 1;
1426
        return;
1427
    }
1428

    
1429
    s->num_saved_bits += len;
1430
    if (!append) {
1431
        ff_copy_bits(&s->pb, gb->buffer + (get_bits_count(gb) >> 3),
1432
                     s->num_saved_bits);
1433
    } else {
1434
        int align = 8 - (get_bits_count(gb) & 7);
1435
        align = FFMIN(align, len);
1436
        put_bits(&s->pb, align, get_bits(gb, align));
1437
        len -= align;
1438
        ff_copy_bits(&s->pb, gb->buffer + (get_bits_count(gb) >> 3), len);
1439
    }
1440
    skip_bits_long(gb, len);
1441

    
1442
    {
1443
        PutBitContext tmp = s->pb;
1444
        flush_put_bits(&tmp);
1445
    }
1446

    
1447
    init_get_bits(&s->gb, s->frame_data, s->num_saved_bits);
1448
    skip_bits(&s->gb, s->frame_offset);
1449
}
1450

    
1451
/**
1452
 *@brief Decode a single WMA packet.
1453
 *@param avctx codec context
1454
 *@param data the output buffer
1455
 *@param data_size number of bytes that were written to the output buffer
1456
 *@param avpkt input packet
1457
 *@return number of bytes that were read from the input buffer
1458
 */
1459
static int decode_packet(AVCodecContext *avctx,
1460
                         void *data, int *data_size, AVPacket* avpkt)
1461
{
1462
    WMAProDecodeCtx *s = avctx->priv_data;
1463
    GetBitContext* gb  = &s->pgb;
1464
    const uint8_t* buf = avpkt->data;
1465
    int buf_size       = avpkt->size;
1466
    int num_bits_prev_frame;
1467
    int packet_sequence_number;
1468

    
1469
    s->samples       = data;
1470
    s->samples_end   = (float*)((int8_t*)data + *data_size);
1471
    *data_size = 0;
1472

    
1473
    if (s->packet_done || s->packet_loss) {
1474
        s->packet_done = 0;
1475
        s->buf_bit_size = buf_size << 3;
1476

    
1477
        /** sanity check for the buffer length */
1478
        if (buf_size < avctx->block_align)
1479
            return 0;
1480

    
1481
        buf_size = avctx->block_align;
1482

    
1483
        /** parse packet header */
1484
        init_get_bits(gb, buf, s->buf_bit_size);
1485
        packet_sequence_number = get_bits(gb, 4);
1486
        skip_bits(gb, 2);
1487

    
1488
        /** get number of bits that need to be added to the previous frame */
1489
        num_bits_prev_frame = get_bits(gb, s->log2_frame_size);
1490
        dprintf(avctx, "packet[%d]: nbpf %x\n", avctx->frame_number,
1491
                num_bits_prev_frame);
1492

    
1493
        /** check for packet loss */
1494
        if (!s->packet_loss &&
1495
            ((s->packet_sequence_number + 1) & 0xF) != packet_sequence_number) {
1496
            s->packet_loss = 1;
1497
            av_log(avctx, AV_LOG_ERROR, "Packet loss detected! seq %x vs %x\n",
1498
                   s->packet_sequence_number, packet_sequence_number);
1499
        }
1500
        s->packet_sequence_number = packet_sequence_number;
1501

    
1502
        if (num_bits_prev_frame > 0) {
1503
            /** append the previous frame data to the remaining data from the
1504
                previous packet to create a full frame */
1505
            save_bits(s, gb, num_bits_prev_frame, 1);
1506
            dprintf(avctx, "accumulated %x bits of frame data\n",
1507
                    s->num_saved_bits - s->frame_offset);
1508

    
1509
            /** decode the cross packet frame if it is valid */
1510
            if (!s->packet_loss)
1511
                decode_frame(s);
1512
        } else if (s->num_saved_bits - s->frame_offset) {
1513
            dprintf(avctx, "ignoring %x previously saved bits\n",
1514
                    s->num_saved_bits - s->frame_offset);
1515
        }
1516

    
1517
        s->packet_loss = 0;
1518

    
1519
    } else {
1520
        int frame_size;
1521
        s->buf_bit_size = avpkt->size << 3;
1522
        init_get_bits(gb, avpkt->data, s->buf_bit_size);
1523
        skip_bits(gb, s->packet_offset);
1524
        if (remaining_bits(s, gb) > s->log2_frame_size &&
1525
            (frame_size = show_bits(gb, s->log2_frame_size)) &&
1526
            frame_size <= remaining_bits(s, gb)) {
1527
            save_bits(s, gb, frame_size, 0);
1528
            s->packet_done = !decode_frame(s);
1529
        } else
1530
            s->packet_done = 1;
1531
    }
1532

    
1533
    if (s->packet_done && !s->packet_loss &&
1534
        remaining_bits(s, gb) > 0) {
1535
        /** save the rest of the data so that it can be decoded
1536
            with the next packet */
1537
        save_bits(s, gb, remaining_bits(s, gb), 0);
1538
    }
1539

    
1540
    *data_size = (int8_t *)s->samples - (int8_t *)data;
1541
    s->packet_offset = get_bits_count(gb) & 7;
1542

    
1543
    return (s->packet_loss) ? AVERROR_INVALIDDATA : get_bits_count(gb) >> 3;
1544
}
1545

    
1546
/**
1547
 *@brief Clear decoder buffers (for seeking).
1548
 *@param avctx codec context
1549
 */
1550
static void flush(AVCodecContext *avctx)
1551
{
1552
    WMAProDecodeCtx *s = avctx->priv_data;
1553
    int i;
1554
    /** reset output buffer as a part of it is used during the windowing of a
1555
        new frame */
1556
    for (i = 0; i < s->num_channels; i++)
1557
        memset(s->channel[i].out, 0, s->samples_per_frame *
1558
               sizeof(*s->channel[i].out));
1559
    s->packet_loss = 1;
1560
}
1561

    
1562

    
1563
/**
1564
 *@brief wmapro decoder
1565
 */
1566
AVCodec wmapro_decoder = {
1567
    "wmapro",
1568
    AVMEDIA_TYPE_AUDIO,
1569
    CODEC_ID_WMAPRO,
1570
    sizeof(WMAProDecodeCtx),
1571
    decode_init,
1572
    NULL,
1573
    decode_end,
1574
    decode_packet,
1575
    .capabilities = CODEC_CAP_SUBFRAMES,
1576
    .flush= flush,
1577
    .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 9 Professional"),
1578
};