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Diffstat (limited to 'apps/codecs/libwmapro/wmaprodec.c')
| -rw-r--r-- | apps/codecs/libwmapro/wmaprodec.c | 1578 |
1 files changed, 1578 insertions, 0 deletions
diff --git a/apps/codecs/libwmapro/wmaprodec.c b/apps/codecs/libwmapro/wmaprodec.c new file mode 100644 index 0000000000..82f1b3623b --- /dev/null +++ b/apps/codecs/libwmapro/wmaprodec.c @@ -0,0 +1,1578 @@ +/* + * Wmapro compatible decoder + * Copyright (c) 2007 Baptiste Coudurier, Benjamin Larsson, Ulion + * Copyright (c) 2008 - 2009 Sascha Sommer, Benjamin Larsson + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file libavcodec/wmaprodec.c + * @brief wmapro decoder implementation + * Wmapro is an MDCT based codec comparable to wma standard or AAC. + * The decoding therefore consists of the following steps: + * - bitstream decoding + * - reconstruction of per-channel data + * - rescaling and inverse quantization + * - IMDCT + * - windowing and overlapp-add + * + * The compressed wmapro bitstream is split into individual packets. + * Every such packet contains one or more wma frames. + * The compressed frames may have a variable length and frames may + * cross packet boundaries. + * Common to all wmapro frames is the number of samples that are stored in + * a frame. + * The number of samples and a few other decode flags are stored + * as extradata that has to be passed to the decoder. + * + * The wmapro frames themselves are again split into a variable number of + * subframes. Every subframe contains the data for 2^N time domain samples + * where N varies between 7 and 12. + * + * Example wmapro bitstream (in samples): + * + * || packet 0 || packet 1 || packet 2 packets + * --------------------------------------------------- + * || frame 0 || frame 1 || frame 2 || frames + * --------------------------------------------------- + * || | | || | | | || || subframes of channel 0 + * --------------------------------------------------- + * || | | || | | | || || subframes of channel 1 + * --------------------------------------------------- + * + * The frame layouts for the individual channels of a wma frame does not need + * to be the same. + * + * However, if the offsets and lengths of several subframes of a frame are the + * same, the subframes of the channels can be grouped. + * Every group may then use special coding techniques like M/S stereo coding + * to improve the compression ratio. These channel transformations do not + * need to be applied to a whole subframe. Instead, they can also work on + * individual scale factor bands (see below). + * The coefficients that carry the audio signal in the frequency domain + * are transmitted as huffman-coded vectors with 4, 2 and 1 elements. + * In addition to that, the encoder can switch to a runlevel coding scheme + * by transmitting subframe_length / 128 zero coefficients. + * + * Before the audio signal can be converted to the time domain, the + * coefficients have to be rescaled and inverse quantized. + * A subframe is therefore split into several scale factor bands that get + * scaled individually. + * Scale factors are submitted for every frame but they might be shared + * between the subframes of a channel. Scale factors are initially DPCM-coded. + * Once scale factors are shared, the differences are transmitted as runlevel + * codes. + * Every subframe length and offset combination in the frame layout shares a + * common quantization factor that can be adjusted for every channel by a + * modifier. + * After the inverse quantization, the coefficients get processed by an IMDCT. + * The resulting values are then windowed with a sine window and the first half + * of the values are added to the second half of the output from the previous + * subframe in order to reconstruct the output samples. + */ + +#include "avcodec.h" +#include "internal.h" +#include "get_bits.h" +#include "put_bits.h" +#include "wmaprodata.h" +#include "dsputil.h" +#include "wma.h" + +/** current decoder limitations */ +#define WMAPRO_MAX_CHANNELS 8 ///< max number of handled channels +#define MAX_SUBFRAMES 32 ///< max number of subframes per channel +#define MAX_BANDS 29 ///< max number of scale factor bands +#define MAX_FRAMESIZE 32768 ///< maximum compressed frame size + +#define WMAPRO_BLOCK_MAX_BITS 12 ///< log2 of max block size +#define WMAPRO_BLOCK_MAX_SIZE (1 << WMAPRO_BLOCK_MAX_BITS) ///< maximum block size +#define WMAPRO_BLOCK_SIZES (WMAPRO_BLOCK_MAX_BITS - BLOCK_MIN_BITS + 1) ///< possible block sizes + + +#define VLCBITS 9 +#define SCALEVLCBITS 8 +#define VEC4MAXDEPTH ((HUFF_VEC4_MAXBITS+VLCBITS-1)/VLCBITS) +#define VEC2MAXDEPTH ((HUFF_VEC2_MAXBITS+VLCBITS-1)/VLCBITS) +#define VEC1MAXDEPTH ((HUFF_VEC1_MAXBITS+VLCBITS-1)/VLCBITS) +#define SCALEMAXDEPTH ((HUFF_SCALE_MAXBITS+SCALEVLCBITS-1)/SCALEVLCBITS) +#define SCALERLMAXDEPTH ((HUFF_SCALE_RL_MAXBITS+VLCBITS-1)/VLCBITS) + +static VLC sf_vlc; ///< scale factor DPCM vlc +static VLC sf_rl_vlc; ///< scale factor run length vlc +static VLC vec4_vlc; ///< 4 coefficients per symbol +static VLC vec2_vlc; ///< 2 coefficients per symbol +static VLC vec1_vlc; ///< 1 coefficient per symbol +static VLC coef_vlc[2]; ///< coefficient run length vlc codes +static float sin64[33]; ///< sinus table for decorrelation + +/** + * @brief frame specific decoder context for a single channel + */ +typedef struct { + int16_t prev_block_len; ///< length of the previous block + uint8_t transmit_coefs; + uint8_t num_subframes; + uint16_t subframe_len[MAX_SUBFRAMES]; ///< subframe length in samples + uint16_t subframe_offset[MAX_SUBFRAMES]; ///< subframe positions in the current frame + uint8_t cur_subframe; ///< current subframe number + uint16_t decoded_samples; ///< number of already processed samples + uint8_t grouped; ///< channel is part of a group + int quant_step; ///< quantization step for the current subframe + int8_t reuse_sf; ///< share scale factors between subframes + int8_t scale_factor_step; ///< scaling step for the current subframe + int max_scale_factor; ///< maximum scale factor for the current subframe + int saved_scale_factors[2][MAX_BANDS]; ///< resampled and (previously) transmitted scale factor values + int8_t scale_factor_idx; ///< index for the transmitted scale factor values (used for resampling) + int* scale_factors; ///< pointer to the scale factor values used for decoding + uint8_t table_idx; ///< index in sf_offsets for the scale factor reference block + float* coeffs; ///< pointer to the subframe decode buffer + DECLARE_ALIGNED(16, float, out)[WMAPRO_BLOCK_MAX_SIZE + WMAPRO_BLOCK_MAX_SIZE / 2]; ///< output buffer +} WMAProChannelCtx; + +/** + * @brief channel group for channel transformations + */ +typedef struct { + uint8_t num_channels; ///< number of channels in the group + int8_t transform; ///< transform on / off + int8_t transform_band[MAX_BANDS]; ///< controls if the transform is enabled for a certain band + float decorrelation_matrix[WMAPRO_MAX_CHANNELS*WMAPRO_MAX_CHANNELS]; + float* channel_data[WMAPRO_MAX_CHANNELS]; ///< transformation coefficients +} WMAProChannelGrp; + +/** + * @brief main decoder context + */ +typedef struct WMAProDecodeCtx { + /* generic decoder variables */ + AVCodecContext* avctx; ///< codec context for av_log + DSPContext dsp; ///< accelerated DSP functions + uint8_t frame_data[MAX_FRAMESIZE + + FF_INPUT_BUFFER_PADDING_SIZE];///< compressed frame data + PutBitContext pb; ///< context for filling the frame_data buffer + FFTContext mdct_ctx[WMAPRO_BLOCK_SIZES]; ///< MDCT context per block size + DECLARE_ALIGNED(16, float, tmp)[WMAPRO_BLOCK_MAX_SIZE]; ///< IMDCT output buffer + float* windows[WMAPRO_BLOCK_SIZES]; ///< windows for the different block sizes + + /* frame size dependent frame information (set during initialization) */ + uint32_t decode_flags; ///< used compression features + uint8_t len_prefix; ///< frame is prefixed with its length + uint8_t dynamic_range_compression; ///< frame contains DRC data + uint8_t bits_per_sample; ///< integer audio sample size for the unscaled IMDCT output (used to scale to [-1.0, 1.0]) + uint16_t samples_per_frame; ///< number of samples to output + uint16_t log2_frame_size; + int8_t num_channels; ///< number of channels in the stream (same as AVCodecContext.num_channels) + int8_t lfe_channel; ///< lfe channel index + uint8_t max_num_subframes; + uint8_t subframe_len_bits; ///< number of bits used for the subframe length + uint8_t max_subframe_len_bit; ///< flag indicating that the subframe is of maximum size when the first subframe length bit is 1 + uint16_t min_samples_per_subframe; + int8_t num_sfb[WMAPRO_BLOCK_SIZES]; ///< scale factor bands per block size + int16_t sfb_offsets[WMAPRO_BLOCK_SIZES][MAX_BANDS]; ///< scale factor band offsets (multiples of 4) + int8_t sf_offsets[WMAPRO_BLOCK_SIZES][WMAPRO_BLOCK_SIZES][MAX_BANDS]; ///< scale factor resample matrix + int16_t subwoofer_cutoffs[WMAPRO_BLOCK_SIZES]; ///< subwoofer cutoff values + + /* packet decode state */ + GetBitContext pgb; ///< bitstream reader context for the packet + uint8_t packet_offset; ///< frame offset in the packet + uint8_t packet_sequence_number; ///< current packet number + int num_saved_bits; ///< saved number of bits + int frame_offset; ///< frame offset in the bit reservoir + int subframe_offset; ///< subframe offset in the bit reservoir + uint8_t packet_loss; ///< set in case of bitstream error + uint8_t packet_done; ///< set when a packet is fully decoded + + /* frame decode state */ + uint32_t frame_num; ///< current frame number (not used for decoding) + GetBitContext gb; ///< bitstream reader context + int buf_bit_size; ///< buffer size in bits + float* samples; ///< current samplebuffer pointer + float* samples_end; ///< maximum samplebuffer pointer + uint8_t drc_gain; ///< gain for the DRC tool + int8_t skip_frame; ///< skip output step + int8_t parsed_all_subframes; ///< all subframes decoded? + + /* subframe/block decode state */ + int16_t subframe_len; ///< current subframe length + int8_t channels_for_cur_subframe; ///< number of channels that contain the subframe + int8_t channel_indexes_for_cur_subframe[WMAPRO_MAX_CHANNELS]; + int8_t num_bands; ///< number of scale factor bands + int16_t* cur_sfb_offsets; ///< sfb offsets for the current block + uint8_t table_idx; ///< index for the num_sfb, sfb_offsets, sf_offsets and subwoofer_cutoffs tables + int8_t esc_len; ///< length of escaped coefficients + + uint8_t num_chgroups; ///< number of channel groups + WMAProChannelGrp chgroup[WMAPRO_MAX_CHANNELS]; ///< channel group information + + WMAProChannelCtx channel[WMAPRO_MAX_CHANNELS]; ///< per channel data +} WMAProDecodeCtx; + + +/** + *@brief helper function to print the most important members of the context + *@param s context + */ +static void av_cold dump_context(WMAProDecodeCtx *s) +{ +#define PRINT(a, b) av_log(s->avctx, AV_LOG_DEBUG, " %s = %d\n", a, b); +#define PRINT_HEX(a, b) av_log(s->avctx, AV_LOG_DEBUG, " %s = %x\n", a, b); + + PRINT("ed sample bit depth", s->bits_per_sample); + PRINT_HEX("ed decode flags", s->decode_flags); + PRINT("samples per frame", s->samples_per_frame); + PRINT("log2 frame size", s->log2_frame_size); + PRINT("max num subframes", s->max_num_subframes); + PRINT("len prefix", s->len_prefix); + PRINT("num channels", s->num_channels); +} + +/** + *@brief Uninitialize the decoder and free all resources. + *@param avctx codec context + *@return 0 on success, < 0 otherwise + */ +static av_cold int decode_end(AVCodecContext *avctx) +{ + WMAProDecodeCtx *s = avctx->priv_data; + int i; + + for (i = 0; i < WMAPRO_BLOCK_SIZES; i++) + ff_mdct_end(&s->mdct_ctx[i]); + + return 0; +} + +/** + *@brief Initialize the decoder. + *@param avctx codec context + *@return 0 on success, -1 otherwise + */ +static av_cold int decode_init(AVCodecContext *avctx) +{ + WMAProDecodeCtx *s = avctx->priv_data; + uint8_t *edata_ptr = avctx->extradata; + unsigned int channel_mask; + int i; + int log2_max_num_subframes; + int num_possible_block_sizes; + + s->avctx = avctx; + dsputil_init(&s->dsp, avctx); + init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE); + + avctx->sample_fmt = SAMPLE_FMT_FLT; + + if (avctx->extradata_size >= 18) { + s->decode_flags = AV_RL16(edata_ptr+14); + channel_mask = AV_RL32(edata_ptr+2); + s->bits_per_sample = AV_RL16(edata_ptr); + /** dump the extradata */ + for (i = 0; i < avctx->extradata_size; i++) + dprintf(avctx, "[%x] ", avctx->extradata[i]); + dprintf(avctx, "\n"); + + } else { + av_log_ask_for_sample(avctx, "Unknown extradata size\n"); + return AVERROR_INVALIDDATA; + } + + /** generic init */ + s->log2_frame_size = av_log2(avctx->block_align) + 4; + + /** frame info */ + s->skip_frame = 1; /** skip first frame */ + s->packet_loss = 1; + s->len_prefix = (s->decode_flags & 0x40); + + if (!s->len_prefix) { + av_log_ask_for_sample(avctx, "no length prefix\n"); + return AVERROR_INVALIDDATA; + } + + /** get frame len */ + s->samples_per_frame = 1 << ff_wma_get_frame_len_bits(avctx->sample_rate, + 3, s->decode_flags); + + /** init previous block len */ + for (i = 0; i < avctx->channels; i++) + s->channel[i].prev_block_len = s->samples_per_frame; + + /** subframe info */ + log2_max_num_subframes = ((s->decode_flags & 0x38) >> 3); + s->max_num_subframes = 1 << log2_max_num_subframes; + if (s->max_num_subframes == 16) + s->max_subframe_len_bit = 1; + s->subframe_len_bits = av_log2(log2_max_num_subframes) + 1; + + num_possible_block_sizes = log2_max_num_subframes + 1; + s->min_samples_per_subframe = s->samples_per_frame / s->max_num_subframes; + s->dynamic_range_compression = (s->decode_flags & 0x80); + + if (s->max_num_subframes > MAX_SUBFRAMES) { + av_log(avctx, AV_LOG_ERROR, "invalid number of subframes %i\n", + s->max_num_subframes); + return AVERROR_INVALIDDATA; + } + + s->num_channels = avctx->channels; + + /** extract lfe channel position */ + s->lfe_channel = -1; + + if (channel_mask & 8) { + unsigned int mask; + for (mask = 1; mask < 16; mask <<= 1) { + if (channel_mask & mask) + ++s->lfe_channel; + } + } + + if (s->num_channels < 0) { + av_log(avctx, AV_LOG_ERROR, "invalid number of channels %d\n", s->num_channels); + return AVERROR_INVALIDDATA; + } else if (s->num_channels > WMAPRO_MAX_CHANNELS) { + av_log_ask_for_sample(avctx, "unsupported number of channels\n"); + return AVERROR_PATCHWELCOME; + } + + INIT_VLC_STATIC(&sf_vlc, SCALEVLCBITS, HUFF_SCALE_SIZE, + scale_huffbits, 1, 1, + scale_huffcodes, 2, 2, 616); + + INIT_VLC_STATIC(&sf_rl_vlc, VLCBITS, HUFF_SCALE_RL_SIZE, + scale_rl_huffbits, 1, 1, + scale_rl_huffcodes, 4, 4, 1406); + + INIT_VLC_STATIC(&coef_vlc[0], VLCBITS, HUFF_COEF0_SIZE, + coef0_huffbits, 1, 1, + coef0_huffcodes, 4, 4, 2108); + + INIT_VLC_STATIC(&coef_vlc[1], VLCBITS, HUFF_COEF1_SIZE, + coef1_huffbits, 1, 1, + coef1_huffcodes, 4, 4, 3912); + + INIT_VLC_STATIC(&vec4_vlc, VLCBITS, HUFF_VEC4_SIZE, + vec4_huffbits, 1, 1, + vec4_huffcodes, 2, 2, 604); + + INIT_VLC_STATIC(&vec2_vlc, VLCBITS, HUFF_VEC2_SIZE, + vec2_huffbits, 1, 1, + vec2_huffcodes, 2, 2, 562); + + INIT_VLC_STATIC(&vec1_vlc, VLCBITS, HUFF_VEC1_SIZE, + vec1_huffbits, 1, 1, + vec1_huffcodes, 2, 2, 562); + + /** calculate number of scale factor bands and their offsets + for every possible block size */ + for (i = 0; i < num_possible_block_sizes; i++) { + int subframe_len = s->samples_per_frame >> i; + int x; + int band = 1; + + s->sfb_offsets[i][0] = 0; + + for (x = 0; x < MAX_BANDS-1 && s->sfb_offsets[i][band - 1] < subframe_len; x++) { + int offset = (subframe_len * 2 * critical_freq[x]) + / s->avctx->sample_rate + 2; + offset &= ~3; + if (offset > s->sfb_offsets[i][band - 1]) + s->sfb_offsets[i][band++] = offset; + } + s->sfb_offsets[i][band - 1] = subframe_len; + s->num_sfb[i] = band - 1; + } + + + /** Scale factors can be shared between blocks of different size + as every block has a different scale factor band layout. + The matrix sf_offsets is needed to find the correct scale factor. + */ + + for (i = 0; i < num_possible_block_sizes; i++) { + int b; + for (b = 0; b < s->num_sfb[i]; b++) { + int x; + int offset = ((s->sfb_offsets[i][b] + + s->sfb_offsets[i][b + 1] - 1) << i) >> 1; + for (x = 0; x < num_possible_block_sizes; x++) { + int v = 0; + while (s->sfb_offsets[x][v + 1] << x < offset) + ++v; + s->sf_offsets[i][x][b] = v; + } + } + } + + /** init MDCT, FIXME: only init needed sizes */ + for (i = 0; i < WMAPRO_BLOCK_SIZES; i++) + ff_mdct_init(&s->mdct_ctx[i], BLOCK_MIN_BITS+1+i, 1, + 1.0 / (1 << (BLOCK_MIN_BITS + i - 1)) + / (1 << (s->bits_per_sample - 1))); + + /** init MDCT windows: simple sinus window */ + for (i = 0; i < WMAPRO_BLOCK_SIZES; i++) { + const int win_idx = WMAPRO_BLOCK_MAX_BITS - i; + ff_init_ff_sine_windows(win_idx); + s->windows[WMAPRO_BLOCK_SIZES - i - 1] = ff_sine_windows[win_idx]; + } + + /** calculate subwoofer cutoff values */ + for (i = 0; i < num_possible_block_sizes; i++) { + int block_size = s->samples_per_frame >> i; + int cutoff = (440*block_size + 3 * (s->avctx->sample_rate >> 1) - 1) + / s->avctx->sample_rate; + s->subwoofer_cutoffs[i] = av_clip(cutoff, 4, block_size); + } + + /** calculate sine values for the decorrelation matrix */ + for (i = 0; i < 33; i++) + sin64[i] = sin(i*M_PI / 64.0); + + if (avctx->debug & FF_DEBUG_BITSTREAM) + dump_context(s); + + avctx->channel_layout = channel_mask; + return 0; +} + +/** + *@brief Decode the subframe length. + *@param s context + *@param offset sample offset in the frame + *@return decoded subframe length on success, < 0 in case of an error + */ +static int decode_subframe_length(WMAProDecodeCtx *s, int offset) +{ + int frame_len_shift = 0; + int subframe_len; + + /** no need to read from the bitstream when only one length is possible */ + if (offset == s->samples_per_frame - s->min_samples_per_subframe) + return s->min_samples_per_subframe; + + /** 1 bit indicates if the subframe is of maximum length */ + if (s->max_subframe_len_bit) { + if (get_bits1(&s->gb)) + frame_len_shift = 1 + get_bits(&s->gb, s->subframe_len_bits-1); + } else + frame_len_shift = get_bits(&s->gb, s->subframe_len_bits); + + subframe_len = s->samples_per_frame >> frame_len_shift; + + /** sanity check the length */ + if (subframe_len < s->min_samples_per_subframe || + subframe_len > s->samples_per_frame) { + av_log(s->avctx, AV_LOG_ERROR, "broken frame: subframe_len %i\n", + subframe_len); + return AVERROR_INVALIDDATA; + } + return subframe_len; +} + +/** + *@brief Decode how the data in the frame is split into subframes. + * Every WMA frame contains the encoded data for a fixed number of + * samples per channel. The data for every channel might be split + * into several subframes. This function will reconstruct the list of + * subframes for every channel. + * + * If the subframes are not evenly split, the algorithm estimates the + * channels with the lowest number of total samples. + * Afterwards, for each of these channels a bit is read from the + * bitstream that indicates if the channel contains a subframe with the + * next subframe size that is going to be read from the bitstream or not. + * If a channel contains such a subframe, the subframe size gets added to + * the channel's subframe list. + * The algorithm repeats these steps until the frame is properly divided + * between the individual channels. + * + *@param s context + *@return 0 on success, < 0 in case of an error + */ +static int decode_tilehdr(WMAProDecodeCtx *s) +{ + uint16_t num_samples[WMAPRO_MAX_CHANNELS]; /** sum of samples for all currently known subframes of a channel */ + uint8_t contains_subframe[WMAPRO_MAX_CHANNELS]; /** flag indicating if a channel contains the current subframe */ + int channels_for_cur_subframe = s->num_channels; /** number of channels that contain the current subframe */ + int fixed_channel_layout = 0; /** flag indicating that all channels use the same subframe offsets and sizes */ + int min_channel_len = 0; /** smallest sum of samples (channels with this length will be processed first) */ + int c; + + /* Should never consume more than 3073 bits (256 iterations for the + * while loop when always the minimum amount of 128 samples is substracted + * from missing samples in the 8 channel case). + * 1 + BLOCK_MAX_SIZE * MAX_CHANNELS / BLOCK_MIN_SIZE * (MAX_CHANNELS + 4) + */ + + /** reset tiling information */ + for (c = 0; c < s->num_channels; c++) + s->channel[c].num_subframes = 0; + + memset(num_samples, 0, sizeof(num_samples)); + + if (s->max_num_subframes == 1 || get_bits1(&s->gb)) + fixed_channel_layout = 1; + + /** loop until the frame data is split between the subframes */ + do { + int subframe_len; + + /** check which channels contain the subframe */ + for (c = 0; c < s->num_channels; c++) { + if (num_samples[c] == min_channel_len) { + if (fixed_channel_layout || channels_for_cur_subframe == 1 || + (min_channel_len == s->samples_per_frame - s->min_samples_per_subframe)) + contains_subframe[c] = 1; + else + contains_subframe[c] = get_bits1(&s->gb); + } else + contains_subframe[c] = 0; + } + + /** get subframe length, subframe_len == 0 is not allowed */ + if ((subframe_len = decode_subframe_length(s, min_channel_len)) <= 0) + return AVERROR_INVALIDDATA; + + /** add subframes to the individual channels and find new min_channel_len */ + min_channel_len += subframe_len; + for (c = 0; c < s->num_channels; c++) { + WMAProChannelCtx* chan = &s->channel[c]; + + if (contains_subframe[c]) { + if (chan->num_subframes >= MAX_SUBFRAMES) { + av_log(s->avctx, AV_LOG_ERROR, + "broken frame: num subframes > 31\n"); + return AVERROR_INVALIDDATA; + } + chan->subframe_len[chan->num_subframes] = subframe_len; + num_samples[c] += subframe_len; + ++chan->num_subframes; + if (num_samples[c] > s->samples_per_frame) { + av_log(s->avctx, AV_LOG_ERROR, "broken frame: " + "channel len > samples_per_frame\n"); + return AVERROR_INVALIDDATA; + } + } else if (num_samples[c] <= min_channel_len) { + if (num_samples[c] < min_channel_len) { + channels_for_cur_subframe = 0; + min_channel_len = num_samples[c]; + } + ++channels_for_cur_subframe; + } + } + } while (min_channel_len < s->samples_per_frame); + + for (c = 0; c < s->num_channels; c++) { + int i; + int offset = 0; + for (i = 0; i < s->channel[c].num_subframes; i++) { + dprintf(s->avctx, "frame[%i] channel[%i] subframe[%i]" + " len %i\n", s->frame_num, c, i, + s->channel[c].subframe_len[i]); + s->channel[c].subframe_offset[i] = offset; + offset += s->channel[c].subframe_len[i]; + } + } + + return 0; +} + +/** + *@brief Calculate a decorrelation matrix from the bitstream parameters. + *@param s codec context + *@param chgroup channel group for which the matrix needs to be calculated + */ +static void decode_decorrelation_matrix(WMAProDecodeCtx *s, + WMAProChannelGrp *chgroup) +{ + int i; + int offset = 0; + int8_t rotation_offset[WMAPRO_MAX_CHANNELS * WMAPRO_MAX_CHANNELS]; + memset(chgroup->decorrelation_matrix, 0, s->num_channels * + s->num_channels * sizeof(*chgroup->decorrelation_matrix)); + + for (i = 0; i < chgroup->num_channels * (chgroup->num_channels - 1) >> 1; i++) + rotation_offset[i] = get_bits(&s->gb, 6); + + for (i = 0; i < chgroup->num_channels; i++) + chgroup->decorrelation_matrix[chgroup->num_channels * i + i] = + get_bits1(&s->gb) ? 1.0 : -1.0; + + for (i = 1; i < chgroup->num_channels; i++) { + int x; + for (x = 0; x < i; x++) { + int y; + for (y = 0; y < i + 1; y++) { + float v1 = chgroup->decorrelation_matrix[x * chgroup->num_channels + y]; + float v2 = chgroup->decorrelation_matrix[i * chgroup->num_channels + y]; + int n = rotation_offset[offset + x]; + float sinv; + float cosv; + + if (n < 32) { + sinv = sin64[n]; + cosv = sin64[32 - n]; + } else { + sinv = sin64[64 - n]; + cosv = -sin64[n - 32]; + } + + chgroup->decorrelation_matrix[y + x * chgroup->num_channels] = + (v1 * sinv) - (v2 * cosv); + chgroup->decorrelation_matrix[y + i * chgroup->num_channels] = + (v1 * cosv) + (v2 * sinv); + } + } + offset += i; + } +} + +/** + *@brief Decode channel transformation parameters + *@param s codec context + *@return 0 in case of success, < 0 in case of bitstream errors + */ +static int decode_channel_transform(WMAProDecodeCtx* s) +{ + int i; + /* should never consume more than 1921 bits for the 8 channel case + * 1 + MAX_CHANNELS * (MAX_CHANNELS + 2 + 3 * MAX_CHANNELS * MAX_CHANNELS + * + MAX_CHANNELS + MAX_BANDS + 1) + */ + + /** in the one channel case channel transforms are pointless */ + s->num_chgroups = 0; + if (s->num_channels > 1) { + int remaining_channels = s->channels_for_cur_subframe; + + if (get_bits1(&s->gb)) { + av_log_ask_for_sample(s->avctx, + "unsupported channel transform bit\n"); + return AVERROR_INVALIDDATA; + } + + for (s->num_chgroups = 0; remaining_channels && + s->num_chgroups < s->channels_for_cur_subframe; s->num_chgroups++) { + WMAProChannelGrp* chgroup = &s->chgroup[s->num_chgroups]; + float** channel_data = chgroup->channel_data; + chgroup->num_channels = 0; + chgroup->transform = 0; + + /** decode channel mask */ + if (remaining_channels > 2) { + for (i = 0; i < s->channels_for_cur_subframe; i++) { + int channel_idx = s->channel_indexes_for_cur_subframe[i]; + if (!s->channel[channel_idx].grouped + && get_bits1(&s->gb)) { + ++chgroup->num_channels; + s->channel[channel_idx].grouped = 1; + *channel_data++ = s->channel[channel_idx].coeffs; + } + } + } else { + chgroup->num_channels = remaining_channels; + for (i = 0; i < s->channels_for_cur_subframe; i++) { + int channel_idx = s->channel_indexes_for_cur_subframe[i]; + if (!s->channel[channel_idx].grouped) + *channel_data++ = s->channel[channel_idx].coeffs; + s->channel[channel_idx].grouped = 1; + } + } + + /** decode transform type */ + if (chgroup->num_channels == 2) { + if (get_bits1(&s->gb)) { + if (get_bits1(&s->gb)) { + av_log_ask_for_sample(s->avctx, + "unsupported channel transform type\n"); + } + } else { + chgroup->transform = 1; + if (s->num_channels == 2) { + chgroup->decorrelation_matrix[0] = 1.0; + chgroup->decorrelation_matrix[1] = -1.0; + chgroup->decorrelation_matrix[2] = 1.0; + chgroup->decorrelation_matrix[3] = 1.0; + } else { + /** cos(pi/4) */ + chgroup->decorrelation_matrix[0] = 0.70703125; + chgroup->decorrelation_matrix[1] = -0.70703125; + chgroup->decorrelation_matrix[2] = 0.70703125; + chgroup->decorrelation_matrix[3] = 0.70703125; + } + } + } else if (chgroup->num_channels > 2) { + if (get_bits1(&s->gb)) { + chgroup->transform = 1; + if (get_bits1(&s->gb)) { + decode_decorrelation_matrix(s, chgroup); + } else { + /** FIXME: more than 6 coupled channels not supported */ + if (chgroup->num_channels > 6) { + av_log_ask_for_sample(s->avctx, + "coupled channels > 6\n"); + } else { + memcpy(chgroup->decorrelation_matrix, + default_decorrelation[chgroup->num_channels], + chgroup->num_channels * chgroup->num_channels * + sizeof(*chgroup->decorrelation_matrix)); + } + } + } + } + + /** decode transform on / off */ + if (chgroup->transform) { + if (!get_bits1(&s->gb)) { + int i; + /** transform can be enabled for individual bands */ + for (i = 0; i < s->num_bands; i++) { + chgroup->transform_band[i] = get_bits1(&s->gb); + } + } else { + memset(chgroup->transform_band, 1, s->num_bands); + } + } + remaining_channels -= chgroup->num_channels; + } + } + return 0; +} + +/** + *@brief Extract the coefficients from the bitstream. + *@param s codec context + *@param c current channel number + *@return 0 on success, < 0 in case of bitstream errors + */ +static int decode_coeffs(WMAProDecodeCtx *s, int c) +{ + /* Integers 0..15 as single-precision floats. The table saves a + costly int to float conversion, and storing the values as + integers allows fast sign-flipping. */ + static const int fval_tab[16] = { + 0x00000000, 0x3f800000, 0x40000000, 0x40400000, + 0x40800000, 0x40a00000, 0x40c00000, 0x40e00000, + 0x41000000, 0x41100000, 0x41200000, 0x41300000, + 0x41400000, 0x41500000, 0x41600000, 0x41700000, + }; + int vlctable; + VLC* vlc; + WMAProChannelCtx* ci = &s->channel[c]; + int rl_mode = 0; + int cur_coeff = 0; + int num_zeros = 0; + const uint16_t* run; + const float* level; + + dprintf(s->avctx, "decode coefficients for channel %i\n", c); + + vlctable = get_bits1(&s->gb); + vlc = &coef_vlc[vlctable]; + + if (vlctable) { + run = coef1_run; + level = coef1_level; + } else { + run = coef0_run; + level = coef0_level; + } + + /** decode vector coefficients (consumes up to 167 bits per iteration for + 4 vector coded large values) */ + while (!rl_mode && cur_coeff + 3 < s->subframe_len) { + int vals[4]; + int i; + unsigned int idx; + + idx = get_vlc2(&s->gb, vec4_vlc.table, VLCBITS, VEC4MAXDEPTH); + + if (idx == HUFF_VEC4_SIZE - 1) { + for (i = 0; i < 4; i += 2) { + idx = get_vlc2(&s->gb, vec2_vlc.table, VLCBITS, VEC2MAXDEPTH); + if (idx == HUFF_VEC2_SIZE - 1) { + int v0, v1; + v0 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH); + if (v0 == HUFF_VEC1_SIZE - 1) + v0 += ff_wma_get_large_val(&s->gb); + v1 = get_vlc2(&s->gb, vec1_vlc.table, VLCBITS, VEC1MAXDEPTH); + if (v1 == HUFF_VEC1_SIZE - 1) + v1 += ff_wma_get_large_val(&s->gb); + ((float*)vals)[i ] = v0; + ((float*)vals)[i+1] = v1; + } else { + vals[i] = fval_tab[symbol_to_vec2[idx] >> 4 ]; + vals[i+1] = fval_tab[symbol_to_vec2[idx] & 0xF]; + } + } + } else { + vals[0] = fval_tab[ symbol_to_vec4[idx] >> 12 ]; + vals[1] = fval_tab[(symbol_to_vec4[idx] >> 8) & 0xF]; + vals[2] = fval_tab[(symbol_to_vec4[idx] >> 4) & 0xF]; + vals[3] = fval_tab[ symbol_to_vec4[idx] & 0xF]; + } + + /** decode sign */ + for (i = 0; i < 4; i++) { + if (vals[i]) { + int sign = get_bits1(&s->gb) - 1; + *(uint32_t*)&ci->coeffs[cur_coeff] = vals[i] ^ sign<<31; + num_zeros = 0; + } else { + ci->coeffs[cur_coeff] = 0; + /** switch to run level mode when subframe_len / 128 zeros + were found in a row */ + rl_mode |= (++num_zeros > s->subframe_len >> 8); + } + ++cur_coeff; + } + } + + /** decode run level coded coefficients */ + if (rl_mode) { + memset(&ci->coeffs[cur_coeff], 0, + sizeof(*ci->coeffs) * (s->subframe_len - cur_coeff)); + if (ff_wma_run_level_decode(s->avctx, &s->gb, vlc, + level, run, 1, ci->coeffs, + cur_coeff, s->subframe_len, + s->subframe_len, s->esc_len, 0)) + return AVERROR_INVALIDDATA; + } + + return 0; +} + +/** + *@brief Extract scale factors from the bitstream. + *@param s codec context + *@return 0 on success, < 0 in case of bitstream errors + */ +static int decode_scale_factors(WMAProDecodeCtx* s) +{ + int i; + + /** should never consume more than 5344 bits + * MAX_CHANNELS * (1 + MAX_BANDS * 23) + */ + + for (i = 0; i < s->channels_for_cur_subframe; i++) { + int c = s->channel_indexes_for_cur_subframe[i]; + int* sf; + int* sf_end; + s->channel[c].scale_factors = s->channel[c].saved_scale_factors[!s->channel[c].scale_factor_idx]; + sf_end = s->channel[c].scale_factors + s->num_bands; + + /** resample scale factors for the new block size + * as the scale factors might need to be resampled several times + * before some new values are transmitted, a backup of the last + * transmitted scale factors is kept in saved_scale_factors + */ + if (s->channel[c].reuse_sf) { + const int8_t* sf_offsets = s->sf_offsets[s->table_idx][s->channel[c].table_idx]; + int b; + for (b = 0; b < s->num_bands; b++) + s->channel[c].scale_factors[b] = + s->channel[c].saved_scale_factors[s->channel[c].scale_factor_idx][*sf_offsets++]; + } + + if (!s->channel[c].cur_subframe || get_bits1(&s->gb)) { + + if (!s->channel[c].reuse_sf) { + int val; + /** decode DPCM coded scale factors */ + s->channel[c].scale_factor_step = get_bits(&s->gb, 2) + 1; + val = 45 / s->channel[c].scale_factor_step; + for (sf = s->channel[c].scale_factors; sf < sf_end; sf++) { + val += get_vlc2(&s->gb, sf_vlc.table, SCALEVLCBITS, SCALEMAXDEPTH) - 60; + *sf = val; + } + } else { + int i; + /** run level decode differences to the resampled factors */ + for (i = 0; i < s->num_bands; i++) { + int idx; + int skip; + int val; + int sign; + + idx = get_vlc2(&s->gb, sf_rl_vlc.table, VLCBITS, SCALERLMAXDEPTH); + + if (!idx) { + uint32_t code = get_bits(&s->gb, 14); + val = code >> 6; + sign = (code & 1) - 1; + skip = (code & 0x3f) >> 1; + } else if (idx == 1) { + break; + } else { + skip = scale_rl_run[idx]; + val = scale_rl_level[idx]; + sign = get_bits1(&s->gb)-1; + } + + i += skip; + if (i >= s->num_bands) { + av_log(s->avctx, AV_LOG_ERROR, + "invalid scale factor coding\n"); + return AVERROR_INVALIDDATA; + } + s->channel[c].scale_factors[i] += (val ^ sign) - sign; + } + } + /** swap buffers */ + s->channel[c].scale_factor_idx = !s->channel[c].scale_factor_idx; + s->channel[c].table_idx = s->table_idx; + s->channel[c].reuse_sf = 1; + } + + /** calculate new scale factor maximum */ + s->channel[c].max_scale_factor = s->channel[c].scale_factors[0]; + for (sf = s->channel[c].scale_factors + 1; sf < sf_end; sf++) { + s->channel[c].max_scale_factor = + FFMAX(s->channel[c].max_scale_factor, *sf); + } + + } + return 0; +} + +/** + *@brief Reconstruct the individual channel data. + *@param s codec context + */ +static void inverse_channel_transform(WMAProDecodeCtx *s) +{ + int i; + + for (i = 0; i < s->num_chgroups; i++) { + if (s->chgroup[i].transform) { + float data[WMAPRO_MAX_CHANNELS]; + const int num_channels = s->chgroup[i].num_channels; + float** ch_data = s->chgroup[i].channel_data; + float** ch_end = ch_data + num_channels; + const int8_t* tb = s->chgroup[i].transform_band; + int16_t* sfb; + + /** multichannel decorrelation */ + for (sfb = s->cur_sfb_offsets; + sfb < s->cur_sfb_offsets + s->num_bands; sfb++) { + int y; + if (*tb++ == 1) { + /** multiply values with the decorrelation_matrix */ + for (y = sfb[0]; y < FFMIN(sfb[1], s->subframe_len); y++) { + const float* mat = s->chgroup[i].decorrelation_matrix; + const float* data_end = data + num_channels; + float* data_ptr = data; + float** ch; + + for (ch = ch_data; ch < ch_end; ch++) + *data_ptr++ = (*ch)[y]; + + for (ch = ch_data; ch < ch_end; ch++) { + float sum = 0; + data_ptr = data; + while (data_ptr < data_end) + sum += *data_ptr++ * *mat++; + + (*ch)[y] = sum; + } + } + } else if (s->num_channels == 2) { + int len = FFMIN(sfb[1], s->subframe_len) - sfb[0]; + s->dsp.vector_fmul_scalar(ch_data[0] + sfb[0], + ch_data[0] + sfb[0], + 181.0 / 128, len); + s->dsp.vector_fmul_scalar(ch_data[1] + sfb[0], + ch_data[1] + sfb[0], + 181.0 / 128, len); + } + } + } + } +} + +/** + *@brief Apply sine window and reconstruct the output buffer. + *@param s codec context + */ +static void wmapro_window(WMAProDecodeCtx *s) +{ + int i; + for (i = 0; i < s->channels_for_cur_subframe; i++) { + int c = s->channel_indexes_for_cur_subframe[i]; + float* window; + int winlen = s->channel[c].prev_block_len; + float* start = s->channel[c].coeffs - (winlen >> 1); + + if (s->subframe_len < winlen) { + start += (winlen - s->subframe_len) >> 1; + winlen = s->subframe_len; + } + + window = s->windows[av_log2(winlen) - BLOCK_MIN_BITS]; + + winlen >>= 1; + + s->dsp.vector_fmul_window(start, start, start + winlen, + window, 0, winlen); + + s->channel[c].prev_block_len = s->subframe_len; + } +} + +/** + *@brief Decode a single subframe (block). + *@param s codec context + *@return 0 on success, < 0 when decoding failed + */ +static int decode_subframe(WMAProDecodeCtx *s) +{ + int offset = s->samples_per_frame; + int subframe_len = s->samples_per_frame; + int i; + int total_samples = s->samples_per_frame * s->num_channels; + int transmit_coeffs = 0; + int cur_subwoofer_cutoff; + + s->subframe_offset = get_bits_count(&s->gb); + + /** reset channel context and find the next block offset and size + == the next block of the channel with the smallest number of + decoded samples + */ + for (i = 0; i < s->num_channels; i++) { + s->channel[i].grouped = 0; + if (offset > s->channel[i].decoded_samples) { + offset = s->channel[i].decoded_samples; + subframe_len = + s->channel[i].subframe_len[s->channel[i].cur_subframe]; + } + } + + dprintf(s->avctx, + "processing subframe with offset %i len %i\n", offset, subframe_len); + + /** get a list of all channels that contain the estimated block */ + s->channels_for_cur_subframe = 0; + for (i = 0; i < s->num_channels; i++) { + const int cur_subframe = s->channel[i].cur_subframe; + /** substract already processed samples */ + total_samples -= s->channel[i].decoded_samples; + + /** and count if there are multiple subframes that match our profile */ + if (offset == s->channel[i].decoded_samples && + subframe_len == s->channel[i].subframe_len[cur_subframe]) { + total_samples -= s->channel[i].subframe_len[cur_subframe]; + s->channel[i].decoded_samples += + s->channel[i].subframe_len[cur_subframe]; + s->channel_indexes_for_cur_subframe[s->channels_for_cur_subframe] = i; + ++s->channels_for_cur_subframe; + } + } + + /** check if the frame will be complete after processing the + estimated block */ + if (!total_samples) + s->parsed_all_subframes = 1; + + + dprintf(s->avctx, "subframe is part of %i channels\n", + s->channels_for_cur_subframe); + + /** calculate number of scale factor bands and their offsets */ + s->table_idx = av_log2(s->samples_per_frame/subframe_len); + s->num_bands = s->num_sfb[s->table_idx]; + s->cur_sfb_offsets = s->sfb_offsets[s->table_idx]; + cur_subwoofer_cutoff = s->subwoofer_cutoffs[s->table_idx]; + + /** configure the decoder for the current subframe */ + for (i = 0; i < s->channels_for_cur_subframe; i++) { + int c = s->channel_indexes_for_cur_subframe[i]; + + s->channel[c].coeffs = &s->channel[c].out[(s->samples_per_frame >> 1) + + offset]; + } + + s->subframe_len = subframe_len; + s->esc_len = av_log2(s->subframe_len - 1) + 1; + + /** skip extended header if any */ + if (get_bits1(&s->gb)) { + int num_fill_bits; + if (!(num_fill_bits = get_bits(&s->gb, 2))) { + int len = get_bits(&s->gb, 4); + num_fill_bits = get_bits(&s->gb, len) + 1; + } + + if (num_fill_bits >= 0) { + if (get_bits_count(&s->gb) + num_fill_bits > s->num_saved_bits) { + av_log(s->avctx, AV_LOG_ERROR, "invalid number of fill bits\n"); + return AVERROR_INVALIDDATA; + } + + skip_bits_long(&s->gb, num_fill_bits); + } + } + + /** no idea for what the following bit is used */ + if (get_bits1(&s->gb)) { + av_log_ask_for_sample(s->avctx, "reserved bit set\n"); + return AVERROR_INVALIDDATA; + } + + + if (decode_channel_transform(s) < 0) + return AVERROR_INVALIDDATA; + + + for (i = 0; i < s->channels_for_cur_subframe; i++) { + int c = s->channel_indexes_for_cur_subframe[i]; + if ((s->channel[c].transmit_coefs = get_bits1(&s->gb))) + transmit_coeffs = 1; + } + + if (transmit_coeffs) { + int step; + int quant_step = 90 * s->bits_per_sample >> 4; + if ((get_bits1(&s->gb))) { + /** FIXME: might change run level mode decision */ + av_log_ask_for_sample(s->avctx, "unsupported quant step coding\n"); + return AVERROR_INVALIDDATA; + } + /** decode quantization step */ + step = get_sbits(&s->gb, 6); + quant_step += step; + if (step == -32 || step == 31) { + const int sign = (step == 31) - 1; + int quant = 0; + while (get_bits_count(&s->gb) + 5 < s->num_saved_bits && + (step = get_bits(&s->gb, 5)) == 31) { + quant += 31; + } + quant_step += ((quant + step) ^ sign) - sign; + } + if (quant_step < 0) { + av_log(s->avctx, AV_LOG_DEBUG, "negative quant step\n"); + } + + /** decode quantization step modifiers for every channel */ + + if (s->channels_for_cur_subframe == 1) { + s->channel[s->channel_indexes_for_cur_subframe[0]].quant_step = quant_step; + } else { + int modifier_len = get_bits(&s->gb, 3); + for (i = 0; i < s->channels_for_cur_subframe; i++) { + int c = s->channel_indexes_for_cur_subframe[i]; + s->channel[c].quant_step = quant_step; + if (get_bits1(&s->gb)) { + if (modifier_len) { + s->channel[c].quant_step += get_bits(&s->gb, modifier_len) + 1; + } else + ++s->channel[c].quant_step; + } + } + } + + /** decode scale factors */ + if (decode_scale_factors(s) < 0) + return AVERROR_INVALIDDATA; + } + + dprintf(s->avctx, "BITSTREAM: subframe header length was %i\n", + get_bits_count(&s->gb) - s->subframe_offset); + + /** parse coefficients */ + for (i = 0; i < s->channels_for_cur_subframe; i++) { + int c = s->channel_indexes_for_cur_subframe[i]; + if (s->channel[c].transmit_coefs && + get_bits_count(&s->gb) < s->num_saved_bits) { + decode_coeffs(s, c); + } else + memset(s->channel[c].coeffs, 0, + sizeof(*s->channel[c].coeffs) * subframe_len); + } + + dprintf(s->avctx, "BITSTREAM: subframe length was %i\n", + get_bits_count(&s->gb) - s->subframe_offset); + + if (transmit_coeffs) { + /** reconstruct the per channel data */ + inverse_channel_transform(s); + for (i = 0; i < s->channels_for_cur_subframe; i++) { + int c = s->channel_indexes_for_cur_subframe[i]; + const int* sf = s->channel[c].scale_factors; + int b; + + if (c == s->lfe_channel) + memset(&s->tmp[cur_subwoofer_cutoff], 0, sizeof(*s->tmp) * + (subframe_len - cur_subwoofer_cutoff)); + + /** inverse quantization and rescaling */ + for (b = 0; b < s->num_bands; b++) { + const int end = FFMIN(s->cur_sfb_offsets[b+1], s->subframe_len); + const int exp = s->channel[c].quant_step - + (s->channel[c].max_scale_factor - *sf++) * + s->channel[c].scale_factor_step; + const float quant = pow(10.0, exp / 20.0); + int start = s->cur_sfb_offsets[b]; + s->dsp.vector_fmul_scalar(s->tmp + start, + s->channel[c].coeffs + start, + quant, end - start); + } + + /** apply imdct (ff_imdct_half == DCTIV with reverse) */ + ff_imdct_half(&s->mdct_ctx[av_log2(subframe_len) - BLOCK_MIN_BITS], + s->channel[c].coeffs, s->tmp); + } + } + + /** window and overlapp-add */ + wmapro_window(s); + + /** handled one subframe */ + for (i = 0; i < s->channels_for_cur_subframe; i++) { + int c = s->channel_indexes_for_cur_subframe[i]; + if (s->channel[c].cur_subframe >= s->channel[c].num_subframes) { + av_log(s->avctx, AV_LOG_ERROR, "broken subframe\n"); + return AVERROR_INVALIDDATA; + } + ++s->channel[c].cur_subframe; + } + + return 0; +} + +/** + *@brief Decode one WMA frame. + *@param s codec context + *@return 0 if the trailer bit indicates that this is the last frame, + * 1 if there are additional frames + */ +static int decode_frame(WMAProDecodeCtx *s) +{ + GetBitContext* gb = &s->gb; + int more_frames = 0; + int len = 0; + int i; + + /** check for potential output buffer overflow */ + if (s->num_channels * s->samples_per_frame > s->samples_end - s->samples) { + /** return an error if no frame could be decoded at all */ + av_log(s->avctx, AV_LOG_ERROR, + "not enough space for the output samples\n"); + s->packet_loss = 1; + return 0; + } + + /** get frame length */ + if (s->len_prefix) + len = get_bits(gb, s->log2_frame_size); + + dprintf(s->avctx, "decoding frame with length %x\n", len); + + /** decode tile information */ + if (decode_tilehdr(s)) { + s->packet_loss = 1; + return 0; + } + + /** read postproc transform */ + if (s->num_channels > 1 && get_bits1(gb)) { + av_log_ask_for_sample(s->avctx, "Unsupported postproc transform found\n"); + s->packet_loss = 1; + return 0; + } + + /** read drc info */ + if (s->dynamic_range_compression) { + s->drc_gain = get_bits(gb, 8); + dprintf(s->avctx, "drc_gain %i\n", s->drc_gain); + } + + /** no idea what these are for, might be the number of samples + that need to be skipped at the beginning or end of a stream */ + if (get_bits1(gb)) { + int skip; + + /** usually true for the first frame */ + if (get_bits1(gb)) { + skip = get_bits(gb, av_log2(s->samples_per_frame * 2)); + dprintf(s->avctx, "start skip: %i\n", skip); + } + + /** sometimes true for the last frame */ + if (get_bits1(gb)) { + skip = get_bits(gb, av_log2(s->samples_per_frame * 2)); + dprintf(s->avctx, "end skip: %i\n", skip); + } + + } + + dprintf(s->avctx, "BITSTREAM: frame header length was %i\n", + get_bits_count(gb) - s->frame_offset); + + /** reset subframe states */ + s->parsed_all_subframes = 0; + for (i = 0; i < s->num_channels; i++) { + s->channel[i].decoded_samples = 0; + s->channel[i].cur_subframe = 0; + s->channel[i].reuse_sf = 0; + } + + /** decode all subframes */ + while (!s->parsed_all_subframes) { + if (decode_subframe(s) < 0) { + s->packet_loss = 1; + return 0; + } + } + + /** interleave samples and write them to the output buffer */ + for (i = 0; i < s->num_channels; i++) { + float* ptr = s->samples + i; + int incr = s->num_channels; + float* iptr = s->channel[i].out; + float* iend = iptr + s->samples_per_frame; + + while (iptr < iend) { + *ptr = av_clipf(*iptr++, -1.0, 32767.0 / 32768.0); + ptr += incr; + } + + /** reuse second half of the IMDCT output for the next frame */ + memcpy(&s->channel[i].out[0], + &s->channel[i].out[s->samples_per_frame], + s->samples_per_frame * sizeof(*s->channel[i].out) >> 1); + } + + if (s->skip_frame) { + s->skip_frame = 0; + } else + s->samples += s->num_channels * s->samples_per_frame; + + if (len != (get_bits_count(gb) - s->frame_offset) + 2) { + /** FIXME: not sure if this is always an error */ + av_log(s->avctx, AV_LOG_ERROR, "frame[%i] would have to skip %i bits\n", + s->frame_num, len - (get_bits_count(gb) - s->frame_offset) - 1); + s->packet_loss = 1; + return 0; + } + + /** skip the rest of the frame data */ + skip_bits_long(gb, len - (get_bits_count(gb) - s->frame_offset) - 1); + + /** decode trailer bit */ + more_frames = get_bits1(gb); + + ++s->frame_num; + return more_frames; +} + +/** + *@brief Calculate remaining input buffer length. + *@param s codec context + *@param gb bitstream reader context + *@return remaining size in bits + */ +static int remaining_bits(WMAProDecodeCtx *s, GetBitContext *gb) +{ + return s->buf_bit_size - get_bits_count(gb); +} + +/** + *@brief Fill the bit reservoir with a (partial) frame. + *@param s codec context + *@param gb bitstream reader context + *@param len length of the partial frame + *@param append decides wether to reset the buffer or not + */ +static void save_bits(WMAProDecodeCtx *s, GetBitContext* gb, int len, + int append) +{ + int buflen; + + /** when the frame data does not need to be concatenated, the input buffer + is resetted and additional bits from the previous frame are copyed + and skipped later so that a fast byte copy is possible */ + + if (!append) { + s->frame_offset = get_bits_count(gb) & 7; + s->num_saved_bits = s->frame_offset; + init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE); + } + + buflen = (s->num_saved_bits + len + 8) >> 3; + + if (len <= 0 || buflen > MAX_FRAMESIZE) { + av_log_ask_for_sample(s->avctx, "input buffer too small\n"); + s->packet_loss = 1; + return; + } + + s->num_saved_bits += len; + if (!append) { + ff_copy_bits(&s->pb, gb->buffer + (get_bits_count(gb) >> 3), + s->num_saved_bits); + } else { + int align = 8 - (get_bits_count(gb) & 7); + align = FFMIN(align, len); + put_bits(&s->pb, align, get_bits(gb, align)); + len -= align; + ff_copy_bits(&s->pb, gb->buffer + (get_bits_count(gb) >> 3), len); + } + skip_bits_long(gb, len); + + { + PutBitContext tmp = s->pb; + flush_put_bits(&tmp); + } + + init_get_bits(&s->gb, s->frame_data, s->num_saved_bits); + skip_bits(&s->gb, s->frame_offset); +} + +/** + *@brief Decode a single WMA packet. + *@param avctx codec context + *@param data the output buffer + *@param data_size number of bytes that were written to the output buffer + *@param avpkt input packet + *@return number of bytes that were read from the input buffer + */ +static int decode_packet(AVCodecContext *avctx, + void *data, int *data_size, AVPacket* avpkt) +{ + WMAProDecodeCtx *s = avctx->priv_data; + GetBitContext* gb = &s->pgb; + const uint8_t* buf = avpkt->data; + int buf_size = avpkt->size; + int num_bits_prev_frame; + int packet_sequence_number; + + s->samples = data; + s->samples_end = (float*)((int8_t*)data + *data_size); + *data_size = 0; + + if (s->packet_done || s->packet_loss) { + s->packet_done = 0; + s->buf_bit_size = buf_size << 3; + + /** sanity check for the buffer length */ + if (buf_size < avctx->block_align) + return 0; + + buf_size = avctx->block_align; + + /** parse packet header */ + init_get_bits(gb, buf, s->buf_bit_size); + packet_sequence_number = get_bits(gb, 4); + skip_bits(gb, 2); + + /** get number of bits that need to be added to the previous frame */ + num_bits_prev_frame = get_bits(gb, s->log2_frame_size); + dprintf(avctx, "packet[%d]: nbpf %x\n", avctx->frame_number, + num_bits_prev_frame); + + /** check for packet loss */ + if (!s->packet_loss && + ((s->packet_sequence_number + 1) & 0xF) != packet_sequence_number) { + s->packet_loss = 1; + av_log(avctx, AV_LOG_ERROR, "Packet loss detected! seq %x vs %x\n", + s->packet_sequence_number, packet_sequence_number); + } + s->packet_sequence_number = packet_sequence_number; + + if (num_bits_prev_frame > 0) { + /** append the previous frame data to the remaining data from the + previous packet to create a full frame */ + save_bits(s, gb, num_bits_prev_frame, 1); + dprintf(avctx, "accumulated %x bits of frame data\n", + s->num_saved_bits - s->frame_offset); + + /** decode the cross packet frame if it is valid */ + if (!s->packet_loss) + decode_frame(s); + } else if (s->num_saved_bits - s->frame_offset) { + dprintf(avctx, "ignoring %x previously saved bits\n", + s->num_saved_bits - s->frame_offset); + } + + s->packet_loss = 0; + + } else { + int frame_size; + s->buf_bit_size = avpkt->size << 3; + init_get_bits(gb, avpkt->data, s->buf_bit_size); + skip_bits(gb, s->packet_offset); + if (remaining_bits(s, gb) > s->log2_frame_size && + (frame_size = show_bits(gb, s->log2_frame_size)) && + frame_size <= remaining_bits(s, gb)) { + save_bits(s, gb, frame_size, 0); + s->packet_done = !decode_frame(s); + } else + s->packet_done = 1; + } + + if (s->packet_done && !s->packet_loss && + remaining_bits(s, gb) > 0) { + /** save the rest of the data so that it can be decoded + with the next packet */ + save_bits(s, gb, remaining_bits(s, gb), 0); + } + + *data_size = (int8_t *)s->samples - (int8_t *)data; + s->packet_offset = get_bits_count(gb) & 7; + + return (s->packet_loss) ? AVERROR_INVALIDDATA : get_bits_count(gb) >> 3; +} + +/** + *@brief Clear decoder buffers (for seeking). + *@param avctx codec context + */ +static void flush(AVCodecContext *avctx) +{ + WMAProDecodeCtx *s = avctx->priv_data; + int i; + /** reset output buffer as a part of it is used during the windowing of a + new frame */ + for (i = 0; i < s->num_channels; i++) + memset(s->channel[i].out, 0, s->samples_per_frame * + sizeof(*s->channel[i].out)); + s->packet_loss = 1; +} + + +/** + *@brief wmapro decoder + */ +AVCodec wmapro_decoder = { + "wmapro", + AVMEDIA_TYPE_AUDIO, + CODEC_ID_WMAPRO, + sizeof(WMAProDecodeCtx), + decode_init, + NULL, + decode_end, + decode_packet, + .capabilities = CODEC_CAP_SUBFRAMES, + .flush= flush, + .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 9 Professional"), +}; |