ffmpeg / libavcodec / wmaprodec.c @ 5d6e4c16
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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 021101301 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 perchannel data

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*  rescaling and inverse quantization

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*  IMDCT

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*  windowing and overlappadd

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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 huffmancoded 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 DPCMcoded.

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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+VLCBITS1)/VLCBITS) 
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#define VEC2MAXDEPTH ((HUFF_VEC2_MAXBITS+VLCBITS1)/VLCBITS) 
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#define VEC1MAXDEPTH ((HUFF_VEC1_MAXBITS+VLCBITS1)/VLCBITS) 
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#define SCALEMAXDEPTH ((HUFF_SCALE_MAXBITS+SCALEVLCBITS1)/SCALEVLCBITS) 
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#define SCALERLMAXDEPTH ((HUFF_SCALE_RL_MAXBITS+VLCBITS1)/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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*/

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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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/**

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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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*/

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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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return 0; 
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} 
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/**

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*@brief Initialize the decoder.

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*@param avctx codec context

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*@return 0 on success, 1 otherwise

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*/

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static av_cold int decode_init(AVCodecContext *avctx) 
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{ 
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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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avctx>sample_fmt = AV_SAMPLE_FMT_FLT; 
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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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} else {

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av_log_ask_for_sample(avctx, "Unknown extradata size\n");

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return AVERROR_INVALIDDATA;

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} 
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/** generic init */

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s>log2_frame_size = av_log2(avctx>block_align) + 4;

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/** frame info */

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s>skip_frame = 1; /* skip first frame */ 
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s>packet_loss = 1;

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s>len_prefix = (s>decode_flags & 0x40);

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if (!s>len_prefix) {

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av_log_ask_for_sample(avctx, "no length prefix\n");

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return AVERROR_INVALIDDATA;

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} 
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/** get frame len */

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s>samples_per_frame = 1 << ff_wma_get_frame_len_bits(avctx>sample_rate,

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3, s>decode_flags);

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/** init previous block len */

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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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/** subframe info */

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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) 
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s>max_subframe_len_bit = 1;

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s>subframe_len_bits = av_log2(log2_max_num_subframes) + 1;

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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; 
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s>dynamic_range_compression = (s>decode_flags & 0x80);

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if (s>max_num_subframes > MAX_SUBFRAMES) {

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av_log(avctx, AV_LOG_ERROR, "invalid number of subframes %i\n",

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s>max_num_subframes); 
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return AVERROR_INVALIDDATA;

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} 
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s>num_channels = avctx>channels; 
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/** extract lfe channel position */

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s>lfe_channel = 1;

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if (channel_mask & 8) { 
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unsigned int mask; 
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for (mask = 1; mask < 16; mask <<= 1) { 
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if (channel_mask & mask)

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++s>lfe_channel; 
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} 
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} 
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if (s>num_channels < 0) { 
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av_log(avctx, AV_LOG_ERROR, "invalid number of channels %d\n", s>num_channels);

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return AVERROR_INVALIDDATA;

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} else if (s>num_channels > WMAPRO_MAX_CHANNELS) { 
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av_log_ask_for_sample(avctx, "unsupported number of channels\n");

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return AVERROR_PATCHWELCOME;

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} 
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INIT_VLC_STATIC(&sf_vlc, SCALEVLCBITS, HUFF_SCALE_SIZE, 
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scale_huffbits, 1, 1, 
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scale_huffcodes, 2, 2, 616); 
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INIT_VLC_STATIC(&sf_rl_vlc, VLCBITS, HUFF_SCALE_RL_SIZE, 
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scale_rl_huffbits, 1, 1, 
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scale_rl_huffcodes, 4, 4, 1406); 
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INIT_VLC_STATIC(&coef_vlc[0], VLCBITS, HUFF_COEF0_SIZE,

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coef0_huffbits, 1, 1, 
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coef0_huffcodes, 4, 4, 2108); 
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INIT_VLC_STATIC(&coef_vlc[1], VLCBITS, HUFF_COEF1_SIZE,

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coef1_huffbits, 1, 1, 
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coef1_huffcodes, 4, 4, 3912); 
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INIT_VLC_STATIC(&vec4_vlc, VLCBITS, HUFF_VEC4_SIZE, 
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vec4_huffbits, 1, 1, 
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vec4_huffcodes, 2, 2, 604); 
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INIT_VLC_STATIC(&vec2_vlc, VLCBITS, HUFF_VEC2_SIZE, 
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vec2_huffbits, 1, 1, 
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vec2_huffcodes, 2, 2, 562); 
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INIT_VLC_STATIC(&vec1_vlc, VLCBITS, HUFF_VEC1_SIZE, 
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vec1_huffbits, 1, 1, 
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vec1_huffcodes, 2, 2, 562); 
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/** calculate number of scale factor bands and their offsets

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for every possible block size */

384 
for (i = 0; i < num_possible_block_sizes; i++) { 
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int subframe_len = s>samples_per_frame >> i;

386 
int x;

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int band = 1; 
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s>sfb_offsets[i][0] = 0; 
390  
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for (x = 0; x < MAX_BANDS1 && s>sfb_offsets[i][band  1] < subframe_len; x++) { 
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int offset = (subframe_len * 2 * critical_freq[x]) 
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/ s>avctx>sample_rate + 2;

394 
offset &= ~3;

395 
if (offset > s>sfb_offsets[i][band  1]) 
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s>sfb_offsets[i][band++] = offset; 
397 
} 
398 
s>sfb_offsets[i][band  1] = subframe_len;

399 
s>num_sfb[i] = band  1;

400 
} 
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/** Scale factors can be shared between blocks of different size

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as every block has a different scale factor band layout.

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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 */

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for (i = 0; i < num_possible_block_sizes; i++) { 
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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_bits1); 
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 singleprecision floats. The table saves a

768 
costly int to float conversion, and storing the values as

769 
integers allows fast signflipping. */

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 overlappadd */

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 
// FIXME should create/use a DSP function here

1355 
while (iptr < iend) {

1356 
*ptr = *iptr++; 
1357 
ptr += incr; 
1358 
} 
1359  
1360 
/** reuse second half of the IMDCT output for the next frame */

1361 
memcpy(&s>channel[i].out[0],

1362 
&s>channel[i].out[s>samples_per_frame], 
1363 
s>samples_per_frame * sizeof(*s>channel[i].out) >> 1); 
1364 
} 
1365  
1366 
if (s>skip_frame) {

1367 
s>skip_frame = 0;

1368 
} else

1369 
s>samples += s>num_channels * s>samples_per_frame; 
1370  
1371 
if (len != (get_bits_count(gb)  s>frame_offset) + 2) { 
1372 
/** FIXME: not sure if this is always an error */

1373 
av_log(s>avctx, AV_LOG_ERROR, "frame[%i] would have to skip %i bits\n",

1374 
s>frame_num, len  (get_bits_count(gb)  s>frame_offset)  1);

1375 
s>packet_loss = 1;

1376 
return 0; 
1377 
} 
1378  
1379 
/** skip the rest of the frame data */

1380 
skip_bits_long(gb, len  (get_bits_count(gb)  s>frame_offset)  1);

1381  
1382 
/** decode trailer bit */

1383 
more_frames = get_bits1(gb); 
1384  
1385 
++s>frame_num; 
1386 
return more_frames;

1387 
} 
1388  
1389 
/**

1390 
*@brief Calculate remaining input buffer length.

1391 
*@param s codec context

1392 
*@param gb bitstream reader context

1393 
*@return remaining size in bits

1394 
*/

1395 
static int remaining_bits(WMAProDecodeCtx *s, GetBitContext *gb) 
1396 
{ 
1397 
return s>buf_bit_size  get_bits_count(gb);

1398 
} 
1399  
1400 
/**

1401 
*@brief Fill the bit reservoir with a (partial) frame.

1402 
*@param s codec context

1403 
*@param gb bitstream reader context

1404 
*@param len length of the partial frame

1405 
*@param append decides wether to reset the buffer or not

1406 
*/

1407 
static void save_bits(WMAProDecodeCtx *s, GetBitContext* gb, int len, 
1408 
int append)

1409 
{ 
1410 
int buflen;

1411  
1412 
/** when the frame data does not need to be concatenated, the input buffer

1413 
is resetted and additional bits from the previous frame are copyed

1414 
and skipped later so that a fast byte copy is possible */

1415  
1416 
if (!append) {

1417 
s>frame_offset = get_bits_count(gb) & 7;

1418 
s>num_saved_bits = s>frame_offset; 
1419 
init_put_bits(&s>pb, s>frame_data, MAX_FRAMESIZE); 
1420 
} 
1421  
1422 
buflen = (s>num_saved_bits + len + 8) >> 3; 
1423  
1424 
if (len <= 0  buflen > MAX_FRAMESIZE) { 
1425 
av_log_ask_for_sample(s>avctx, "input buffer too small\n");

1426 
s>packet_loss = 1;

1427 
return;

1428 
} 
1429  
1430 
s>num_saved_bits += len; 
1431 
if (!append) {

1432 
ff_copy_bits(&s>pb, gb>buffer + (get_bits_count(gb) >> 3),

1433 
s>num_saved_bits); 
1434 
} else {

1435 
int align = 8  (get_bits_count(gb) & 7); 
1436 
align = FFMIN(align, len); 
1437 
put_bits(&s>pb, align, get_bits(gb, align)); 
1438 
len = align; 
1439 
ff_copy_bits(&s>pb, gb>buffer + (get_bits_count(gb) >> 3), len);

1440 
} 
1441 
skip_bits_long(gb, len); 
1442  
1443 
{ 
1444 
PutBitContext tmp = s>pb; 
1445 
flush_put_bits(&tmp); 
1446 
} 
1447  
1448 
init_get_bits(&s>gb, s>frame_data, s>num_saved_bits); 
1449 
skip_bits(&s>gb, s>frame_offset); 
1450 
} 
1451  
1452 
/**

1453 
*@brief Decode a single WMA packet.

1454 
*@param avctx codec context

1455 
*@param data the output buffer

1456 
*@param data_size number of bytes that were written to the output buffer

1457 
*@param avpkt input packet

1458 
*@return number of bytes that were read from the input buffer

1459 
*/

1460 
static int decode_packet(AVCodecContext *avctx, 
1461 
void *data, int *data_size, AVPacket* avpkt) 
1462 
{ 
1463 
WMAProDecodeCtx *s = avctx>priv_data; 
1464 
GetBitContext* gb = &s>pgb; 
1465 
const uint8_t* buf = avpkt>data;

1466 
int buf_size = avpkt>size;

1467 
int num_bits_prev_frame;

1468 
int packet_sequence_number;

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

1472 
*data_size = 0;

1473  
1474 
if (s>packet_done  s>packet_loss) {

1475 
s>packet_done = 0;

1476 
s>buf_bit_size = buf_size << 3;

1477  
1478 
/** sanity check for the buffer length */

1479 
if (buf_size < avctx>block_align)

1480 
return 0; 
1481  
1482 
buf_size = avctx>block_align; 
1483  
1484 
/** parse packet header */

1485 
init_get_bits(gb, buf, s>buf_bit_size); 
1486 
packet_sequence_number = get_bits(gb, 4);

1487 
skip_bits(gb, 2);

1488  
1489 
/** get number of bits that need to be added to the previous frame */

1490 
num_bits_prev_frame = get_bits(gb, s>log2_frame_size); 
1491 
dprintf(avctx, "packet[%d]: nbpf %x\n", avctx>frame_number,

1492 
num_bits_prev_frame); 
1493  
1494 
/** check for packet loss */

1495 
if (!s>packet_loss &&

1496 
((s>packet_sequence_number + 1) & 0xF) != packet_sequence_number) { 
1497 
s>packet_loss = 1;

1498 
av_log(avctx, AV_LOG_ERROR, "Packet loss detected! seq %x vs %x\n",

1499 
s>packet_sequence_number, packet_sequence_number); 
1500 
} 
1501 
s>packet_sequence_number = packet_sequence_number; 
1502  
1503 
if (num_bits_prev_frame > 0) { 
1504 
/** append the previous frame data to the remaining data from the

1505 
previous packet to create a full frame */

1506 
save_bits(s, gb, num_bits_prev_frame, 1);

1507 
dprintf(avctx, "accumulated %x bits of frame data\n",

1508 
s>num_saved_bits  s>frame_offset); 
1509  
1510 
/** decode the cross packet frame if it is valid */

1511 
if (!s>packet_loss)

1512 
decode_frame(s); 
1513 
} else if (s>num_saved_bits  s>frame_offset) { 
1514 
dprintf(avctx, "ignoring %x previously saved bits\n",

1515 
s>num_saved_bits  s>frame_offset); 
1516 
} 
1517  
1518 
s>packet_loss = 0;

1519  
1520 
} else {

1521 
int frame_size;

1522 
s>buf_bit_size = avpkt>size << 3;

1523 
init_get_bits(gb, avpkt>data, s>buf_bit_size); 
1524 
skip_bits(gb, s>packet_offset); 
1525 
if (remaining_bits(s, gb) > s>log2_frame_size &&

1526 
(frame_size = show_bits(gb, s>log2_frame_size)) && 
1527 
frame_size <= remaining_bits(s, gb)) { 
1528 
save_bits(s, gb, frame_size, 0);

1529 
s>packet_done = !decode_frame(s); 
1530 
} else

1531 
s>packet_done = 1;

1532 
} 
1533  
1534 
if (s>packet_done && !s>packet_loss &&

1535 
remaining_bits(s, gb) > 0) {

1536 
/** save the rest of the data so that it can be decoded

1537 
with the next packet */

1538 
save_bits(s, gb, remaining_bits(s, gb), 0);

1539 
} 
1540  
1541 
*data_size = (int8_t *)s>samples  (int8_t *)data; 
1542 
s>packet_offset = get_bits_count(gb) & 7;

1543  
1544 
return (s>packet_loss) ? AVERROR_INVALIDDATA : get_bits_count(gb) >> 3; 
1545 
} 
1546  
1547 
/**

1548 
*@brief Clear decoder buffers (for seeking).

1549 
*@param avctx codec context

1550 
*/

1551 
static void flush(AVCodecContext *avctx) 
1552 
{ 
1553 
WMAProDecodeCtx *s = avctx>priv_data; 
1554 
int i;

1555 
/** reset output buffer as a part of it is used during the windowing of a

1556 
new frame */

1557 
for (i = 0; i < s>num_channels; i++) 
1558 
memset(s>channel[i].out, 0, s>samples_per_frame *

1559 
sizeof(*s>channel[i].out));

1560 
s>packet_loss = 1;

1561 
} 
1562  
1563  
1564 
/**

1565 
*@brief wmapro decoder

1566 
*/

1567 
AVCodec wmapro_decoder = { 
1568 
"wmapro",

1569 
AVMEDIA_TYPE_AUDIO, 
1570 
CODEC_ID_WMAPRO, 
1571 
sizeof(WMAProDecodeCtx),

1572 
decode_init, 
1573 
NULL,

1574 
decode_end, 
1575 
decode_packet, 
1576 
.capabilities = CODEC_CAP_SUBFRAMES, 
1577 
.flush= flush, 
1578 
.long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 9 Professional"),

1579 
}; 