[FFmpeg-cvslog] wmall: Working bitstream parser
Andreas Öman
git at videolan.org
Mon Oct 24 15:58:50 CEST 2011
ffmpeg | branch: master | Andreas Öman <andreas at lonelycoder.com> | Thu Mar 3 09:31:34 2011 +0100| [123b1fac5c0a18061d7fa9a7869e537e81d16506] | committer: Michael Niedermayer
wmall: Working bitstream parser
(cherry picked from commit 929822111bc10fdf19ca66b7ed09e0ebf802878b)
Signed-off-by: Michael Niedermayer <michaelni at gmx.at>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=123b1fac5c0a18061d7fa9a7869e537e81d16506
---
libavcodec/Makefile | 1 +
libavcodec/allcodecs.c | 1 +
libavcodec/wmalosslessdec.c | 1170 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 1172 insertions(+), 0 deletions(-)
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index d90bcac..8e18255 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -428,6 +428,7 @@ OBJS-$(CONFIG_VP6_DECODER) += vp6.o vp56.o vp56data.o vp56dsp.o \
OBJS-$(CONFIG_VP8_DECODER) += vp8.o vp8dsp.o vp56rac.o
OBJS-$(CONFIG_VQA_DECODER) += vqavideo.o
OBJS-$(CONFIG_WAVPACK_DECODER) += wavpack.o
+OBJS-$(CONFIG_WMALOSSLESS_DECODER) += wmalosslessdec.o wma.o
OBJS-$(CONFIG_WMAPRO_DECODER) += wmaprodec.o wma.o
OBJS-$(CONFIG_WMAV1_DECODER) += wmadec.o wma.o aactab.o
OBJS-$(CONFIG_WMAV1_ENCODER) += wmaenc.o wma.o aactab.o
diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c
index fb63038..2417382 100644
--- a/libavcodec/allcodecs.c
+++ b/libavcodec/allcodecs.c
@@ -296,6 +296,7 @@ void avcodec_register_all(void)
REGISTER_DECODER (VMDAUDIO, vmdaudio);
REGISTER_ENCDEC (VORBIS, vorbis);
REGISTER_DECODER (WAVPACK, wavpack);
+ REGISTER_DECODER (WMALOSSLESS, wmalossless);
REGISTER_DECODER (WMAPRO, wmapro);
REGISTER_ENCDEC (WMAV1, wmav1);
REGISTER_ENCDEC (WMAV2, wmav2);
diff --git a/libavcodec/wmalosslessdec.c b/libavcodec/wmalosslessdec.c
new file mode 100644
index 0000000..7e8acf3
--- /dev/null
+++ b/libavcodec/wmalosslessdec.c
@@ -0,0 +1,1170 @@
+/*
+ * Wmall compatible decoder
+ * Copyright (c) 2007 Baptiste Coudurier, Benjamin Larsson, Ulion
+ * Copyright (c) 2008 - 2011 Sascha Sommer, Benjamin Larsson
+ * Copyright (c) 2011 Andreas Öman
+ *
+ * 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
+ * @brief wmall decoder implementation
+ * Wmall 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 wmall 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 wmall 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 wmall 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 wmall 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 "dsputil.h"
+#include "wma.h"
+
+/** current decoder limitations */
+#define WMALL_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 WMALL_BLOCK_MIN_BITS 6 ///< log2 of min block size
+#define WMALL_BLOCK_MAX_BITS 12 ///< log2 of max block size
+#define WMALL_BLOCK_MAX_SIZE (1 << WMALL_BLOCK_MAX_BITS) ///< maximum block size
+#define WMALL_BLOCK_SIZES (WMALL_BLOCK_MAX_BITS - WMALL_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 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
+ uint16_t num_vec_coeffs; ///< number of vector coded coefficients
+ DECLARE_ALIGNED(16, float, out)[WMALL_BLOCK_MAX_SIZE + WMALL_BLOCK_MAX_SIZE / 2]; ///< output buffer
+} WmallChannelCtx;
+
+/**
+ * @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[WMALL_MAX_CHANNELS*WMALL_MAX_CHANNELS];
+ float* channel_data[WMALL_MAX_CHANNELS]; ///< transformation coefficients
+} WmallChannelGrp;
+
+/**
+ * @brief main decoder context
+ */
+typedef struct WmallDecodeCtx {
+ /* 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[WMALL_BLOCK_SIZES]; ///< MDCT context per block size
+ DECLARE_ALIGNED(16, float, tmp)[WMALL_BLOCK_MAX_SIZE]; ///< IMDCT output buffer
+ float* windows[WMALL_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[WMALL_BLOCK_SIZES]; ///< scale factor bands per block size
+ int16_t sfb_offsets[WMALL_BLOCK_SIZES][MAX_BANDS]; ///< scale factor band offsets (multiples of 4)
+ int8_t sf_offsets[WMALL_BLOCK_SIZES][WMALL_BLOCK_SIZES][MAX_BANDS]; ///< scale factor resample matrix
+ int16_t subwoofer_cutoffs[WMALL_BLOCK_SIZES]; ///< subwoofer cutoff values
+
+ /* packet decode state */
+ GetBitContext pgb; ///< bitstream reader context for the packet
+ int next_packet_start; ///< start offset of the next wma packet in the demuxer 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[WMALL_MAX_CHANNELS];
+ int8_t num_bands; ///< number of scale factor bands
+ int8_t transmit_num_vec_coeffs; ///< number of vector coded coefficients is part of the bitstream
+ 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
+ WmallChannelGrp chgroup[WMALL_MAX_CHANNELS]; ///< channel group information
+
+ WmallChannelCtx channel[WMALL_MAX_CHANNELS]; ///< per channel data
+
+ // WMA lossless
+
+ uint8_t do_arith_coding;
+ uint8_t do_ac_filter;
+ uint8_t do_inter_ch_decorr;
+ uint8_t do_mclms;
+ uint8_t do_lpc;
+
+ int8_t acfilter_order;
+ int8_t acfilter_scaling;
+ int acfilter_coeffs[16];
+
+ int8_t mclms_order;
+ int8_t mclms_scaling;
+ int16_t mclms_coeffs[128];
+ int16_t mclms_coeffs_cur[4];
+
+ int movave_scaling;
+ int quant_stepsize;
+
+ struct {
+ int order;
+ int scaling;
+ int coefsend;
+ int bitsend;
+ int16_t coefs[256];
+ } cdlms[2][9];
+
+
+ int cdlms_ttl[2];
+
+ int bV3RTM;
+
+ int is_channel_coded[2];
+
+ int transient[2];
+ int transient_pos[2];
+ int seekable_tile;
+
+ int ave_sum[2];
+
+ int channel_residues[2][2048];
+
+
+ int lpc_coefs[2][40];
+ int lpc_order;
+ int lpc_scaling;
+ int lpc_intbits;
+
+ int channel_coeffs[2][2048];
+
+} WmallDecodeCtx;
+
+
+#undef dprintf
+#define dprintf(pctx, ...) av_log(pctx, AV_LOG_DEBUG, __VA_ARGS__)
+
+
+/**
+ *@brief helper function to print the most important members of the context
+ *@param s context
+ */
+static void av_cold dump_context(WmallDecodeCtx *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)
+{
+ WmallDecodeCtx *s = avctx->priv_data;
+ int i;
+
+ for (i = 0; i < WMALL_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)
+{
+ WmallDecodeCtx *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 = AV_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);
+
+ /** 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;
+ s->max_subframe_len_bit = 0;
+ 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);
+
+ s->bV3RTM = s->decode_flags & 0x100;
+
+ 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 > WMALL_MAX_CHANNELS) {
+ av_log_ask_for_sample(avctx, "unsupported number of channels\n");
+ return AVERROR_PATCHWELCOME;
+ }
+
+ 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(WmallDecodeCtx *s, int offset)
+{
+ int frame_len_ratio;
+ int subframe_len, 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;
+
+ len = av_log2(s->max_num_subframes - 1) + 1;
+ frame_len_ratio = get_bits(&s->gb, len);
+
+ subframe_len = s->min_samples_per_subframe * (frame_len_ratio + 1);
+
+ /** 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(WmallDecodeCtx *s)
+{
+ uint16_t num_samples[WMALL_MAX_CHANNELS]; /**< sum of samples for all currently known subframes of a channel */
+ uint8_t contains_subframe[WMALL_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 subfra2me 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++) {
+ WmallChannelCtx* 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(%d) > samples_per_frame(%d)\n",
+ num_samples[c], s->samples_per_frame);
+ 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++) {
+ s->channel[c].subframe_offset[i] = offset;
+ offset += s->channel[c].subframe_len[i];
+ }
+ }
+
+ return 0;
+}
+
+
+static int my_log2(unsigned int i)
+{
+ unsigned int iLog2 = 0;
+ while ((i >> iLog2) > 1)
+ iLog2++;
+ return iLog2;
+}
+
+
+/**
+ *
+ */
+static void decode_ac_filter(WmallDecodeCtx *s)
+{
+ int i;
+ s->acfilter_order = get_bits(&s->gb, 4) + 1;
+ s->acfilter_scaling = get_bits(&s->gb, 4);
+
+ for(i = 0; i < s->acfilter_order; i++) {
+ s->acfilter_coeffs[i] = get_bits(&s->gb, s->acfilter_scaling) + 1;
+ }
+}
+
+
+/**
+ *
+ */
+static void decode_mclms(WmallDecodeCtx *s)
+{
+ s->mclms_order = (get_bits(&s->gb, 4) + 1) * 2;
+ s->mclms_scaling = get_bits(&s->gb, 4);
+ if(get_bits1(&s->gb)) {
+ // mclms_send_coef
+ int i;
+ int send_coef_bits;
+ int cbits = av_log2(s->mclms_scaling + 1);
+ assert(cbits == my_log2(s->mclms_scaling + 1));
+ if(1 << cbits < s->mclms_scaling + 1)
+ cbits++;
+
+ send_coef_bits = (cbits ? get_bits(&s->gb, cbits) : 0) + 2;
+
+ for(i = 0; i < s->mclms_order * s->num_channels * s->num_channels; i++) {
+ s->mclms_coeffs[i] = get_bits(&s->gb, send_coef_bits);
+ }
+
+ for(i = 0; i < s->num_channels; i++) {
+ int c;
+ for(c = 0; c < i; c++) {
+ s->mclms_coeffs_cur[i * s->num_channels + c] = get_bits(&s->gb, send_coef_bits);
+ }
+ }
+ }
+}
+
+
+/**
+ *
+ */
+static void decode_cdlms(WmallDecodeCtx *s)
+{
+ int c, i;
+ int cdlms_send_coef = get_bits1(&s->gb);
+
+ for(c = 0; c < s->num_channels; c++) {
+ s->cdlms_ttl[c] = get_bits(&s->gb, 3) + 1;
+ for(i = 0; i < s->cdlms_ttl[c]; i++) {
+ s->cdlms[c][i].order = (get_bits(&s->gb, 7) + 1) * 8;
+ }
+
+ for(i = 0; i < s->cdlms_ttl[c]; i++) {
+ s->cdlms[c][i].scaling = get_bits(&s->gb, 4);
+ }
+
+ if(cdlms_send_coef) {
+ for(i = 0; i < s->cdlms_ttl[c]; i++) {
+ int cbits, shift_l, shift_r, j;
+ cbits = av_log2(s->cdlms[c][i].order);
+ if(1 << cbits < s->cdlms[c][i].order)
+ cbits++;
+ s->cdlms[c][i].coefsend = get_bits(&s->gb, cbits) + 1;
+
+ cbits = av_log2(s->cdlms[c][i].scaling + 1);
+ if(1 << cbits < s->cdlms[c][i].scaling + 1)
+ cbits++;
+
+ s->cdlms[c][i].bitsend = get_bits(&s->gb, cbits) + 2;
+ shift_l = 32 - s->cdlms[c][i].bitsend;
+ shift_r = 32 - 2 - s->cdlms[c][i].scaling;
+ for(j = 0; j < s->cdlms[c][i].coefsend; j++) {
+ s->cdlms[c][i].coefs[j] =
+ (get_bits(&s->gb, s->cdlms[c][i].bitsend) << shift_l) >> shift_r;
+ }
+ }
+ }
+ }
+}
+
+/**
+ *
+ */
+static int decode_channel_residues(WmallDecodeCtx *s, int ch, int tile_size)
+{
+ int i = 0;
+ unsigned int ave_mean;
+ s->transient[ch] = get_bits1(&s->gb);
+ if(s->transient[ch])
+ s->transient_pos[ch] = get_bits(&s->gb, av_log2(tile_size));
+
+ if(s->seekable_tile) {
+ ave_mean = get_bits(&s->gb, s->bits_per_sample);
+ s->ave_sum[ch] = ave_mean << (s->movave_scaling + 1);
+// s->ave_sum[ch] *= 2;
+ }
+
+ if(s->seekable_tile) {
+ if(s->do_inter_ch_decorr)
+ s->channel_residues[ch][0] = get_sbits(&s->gb, s->bits_per_sample + 1);
+ else
+ s->channel_residues[ch][0] = get_sbits(&s->gb, s->bits_per_sample);
+ i++;
+ }
+ for(; i < tile_size; i++) {
+ int quo = 0, rem, rem_bits, residue;
+ while(get_bits1(&s->gb))
+ quo++;
+ if(quo >= 32)
+ quo += get_bits_long(&s->gb, get_bits(&s->gb, 5) + 1);
+
+ ave_mean = (s->ave_sum[ch] + (1 << s->movave_scaling)) >> (s->movave_scaling + 1);
+ rem_bits = av_ceil_log2(ave_mean);
+ rem = rem_bits ? get_bits(&s->gb, rem_bits) : 0;
+ residue = (quo << rem_bits) + rem;
+
+ s->ave_sum[ch] = residue + s->ave_sum[ch] - (s->ave_sum[ch] >> s->movave_scaling);
+
+ if(residue & 1)
+ residue = -(residue >> 1) - 1;
+ else
+ residue = residue >> 1;
+ s->channel_residues[ch][i] = residue;
+
+// dprintf(s->avctx, "%5d: %5d %10d %12d %12d %5d %-16d %04x\n",i, quo, ave_mean, s->ave_sum[ch], rem, rem_bits, s->channel_residues[ch][i], show_bits(&s->gb, 16));
+ }
+
+ return 0;
+
+}
+
+
+/**
+ *
+ */
+static void
+decode_lpc(WmallDecodeCtx *s)
+{
+ int ch, i, cbits;
+ s->lpc_order = get_bits(&s->gb, 5) + 1;
+ s->lpc_scaling = get_bits(&s->gb, 4);
+ s->lpc_intbits = get_bits(&s->gb, 3) + 1;
+ cbits = s->lpc_scaling + s->lpc_intbits;
+ for(ch = 0; ch < s->num_channels; ch++) {
+ for(i = 0; i < s->lpc_order; i++) {
+ s->lpc_coefs[ch][i] = get_sbits(&s->gb, cbits);
+ }
+ }
+}
+
+
+
+/**
+ *@brief Decode a single subframe (block).
+ *@param s codec context
+ *@return 0 on success, < 0 when decoding failed
+ */
+static int decode_subframe(WmallDecodeCtx *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 rawpcm_tile;
+ int padding_zeroes;
+
+ 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];
+ }
+ }
+
+ /** 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;
+
+
+ s->seekable_tile = get_bits1(&s->gb);
+ if(s->seekable_tile) {
+ s->do_arith_coding = get_bits1(&s->gb);
+ if(s->do_arith_coding) {
+ dprintf(s->avctx, "do_arith_coding == 1");
+ abort();
+ }
+ s->do_ac_filter = get_bits1(&s->gb);
+ s->do_inter_ch_decorr = get_bits1(&s->gb);
+ s->do_mclms = get_bits1(&s->gb);
+
+ if(s->do_ac_filter)
+ decode_ac_filter(s);
+
+ if(s->do_mclms)
+ decode_mclms(s);
+
+ decode_cdlms(s);
+ s->movave_scaling = get_bits(&s->gb, 3);
+ s->quant_stepsize = get_bits(&s->gb, 8) + 1;
+ }
+
+ rawpcm_tile = get_bits1(&s->gb);
+
+ for(i = 0; i < s->num_channels; i++) {
+ s->is_channel_coded[i] = 1;
+ }
+
+ if(!rawpcm_tile) {
+
+ for(i = 0; i < s->num_channels; i++) {
+ s->is_channel_coded[i] = get_bits1(&s->gb);
+ }
+
+ if(s->bV3RTM) {
+ // LPC
+ s->do_lpc = get_bits1(&s->gb);
+ if(s->do_lpc) {
+ decode_lpc(s);
+ }
+ } else {
+ s->do_lpc = 0;
+ }
+ }
+
+
+ if(get_bits1(&s->gb)) {
+ padding_zeroes = get_bits(&s->gb, 5);
+ } else {
+ padding_zeroes = 0;
+ }
+
+ if(rawpcm_tile) {
+
+ int bits = s->bits_per_sample - padding_zeroes;
+ int j;
+ dprintf(s->avctx, "RAWPCM %d bits per sample. total %d bits, remain=%d\n", bits,
+ bits * s->num_channels * subframe_len, get_bits_count(&s->gb));
+ for(i = 0; i < s->num_channels; i++) {
+ for(j = 0; j < subframe_len; j++) {
+ s->channel_coeffs[i][j] = get_sbits(&s->gb, bits);
+// dprintf(s->avctx, "PCM[%d][%d] = 0x%04x\n", i, j, s->channel_coeffs[i][j]);
+ }
+ }
+ } else {
+ for(i = 0; i < s->num_channels; i++)
+ if(s->is_channel_coded[i])
+ decode_channel_residues(s, i, subframe_len);
+ }
+
+ /** 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(WmallDecodeCtx *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);
+
+ /** decode tile information */
+ if (decode_tilehdr(s)) {
+ s->packet_loss = 1;
+ return 0;
+ }
+
+ /** read drc info */
+ if (s->dynamic_range_compression) {
+ s->drc_gain = get_bits(gb, 8);
+ }
+
+ /** 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);
+ }
+
+ }
+
+ /** 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;
+ }
+ }
+
+ dprintf(s->avctx, "Frame done\n");
+
+ if (s->skip_frame) {
+ s->skip_frame = 0;
+ } else
+ s->samples += s->num_channels * s->samples_per_frame;
+
+ if (s->len_prefix) {
+ 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);
+ } else {
+/*
+ while (get_bits_count(gb) < s->num_saved_bits && get_bits1(gb) == 0) {
+ dprintf(s->avctx, "skip1\n");
+ }
+*/
+ }
+
+ /** 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(WmallDecodeCtx *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(WmallDecodeCtx *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) {
+ avpriv_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;
+ avpriv_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)
+{
+ WmallDecodeCtx *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;
+
+ /** sanity check for the buffer length */
+ if (buf_size < avctx->block_align)
+ return 0;
+
+ s->next_packet_start = buf_size - avctx->block_align;
+ buf_size = avctx->block_align;
+ s->buf_bit_size = buf_size << 3;
+
+ /** parse packet header */
+ init_get_bits(gb, buf, s->buf_bit_size);
+ packet_sequence_number = get_bits(gb, 4);
+ int seekable_frame_in_packet = get_bits1(gb);
+ int spliced_packet = get_bits1(gb);
+
+ /** get number of bits that need to be added to the previous frame */
+ num_bits_prev_frame = get_bits(gb, s->log2_frame_size);
+
+ /** 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) {
+ int remaining_packet_bits = s->buf_bit_size - get_bits_count(gb);
+ if (num_bits_prev_frame >= remaining_packet_bits) {
+ num_bits_prev_frame = remaining_packet_bits;
+ s->packet_done = 1;
+ }
+
+ /** 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);
+
+ /** 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);
+ }
+
+ if (s->packet_loss) {
+ /** reset number of saved bits so that the decoder
+ does not start to decode incomplete frames in the
+ s->len_prefix == 0 case */
+ s->num_saved_bits = 0;
+ s->packet_loss = 0;
+ }
+
+ } else {
+ int frame_size;
+
+ s->buf_bit_size = (avpkt->size - s->next_packet_start) << 3;
+ init_get_bits(gb, avpkt->data, s->buf_bit_size);
+ skip_bits(gb, s->packet_offset);
+
+ if (s->len_prefix && 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 if (!s->len_prefix
+ && s->num_saved_bits > get_bits_count(&s->gb)) {
+ /** when the frames do not have a length prefix, we don't know
+ the compressed length of the individual frames
+ however, we know what part of a new packet belongs to the
+ previous frame
+ therefore we save the incoming packet first, then we append
+ the "previous frame" data from the next packet so that
+ we get a buffer that only contains full frames */
+ 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 = 0; // (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)
+{
+ WmallDecodeCtx *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 wmall decoder
+ */
+AVCodec ff_wmalossless_decoder = {
+ "wmalossless",
+ AVMEDIA_TYPE_AUDIO,
+ CODEC_ID_WMALOSSLESS,
+ sizeof(WmallDecodeCtx),
+ decode_init,
+ NULL,
+ decode_end,
+ decode_packet,
+ .capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_EXPERIMENTAL,
+ .flush= flush,
+ .long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio 9 Lossless"),
+};
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