generic-library/ffmpeg
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity
ca411fc1d3
ffmpeg/libavcodec/wmalosslessdec.c
Michael Niedermayer d65d834731 wmalosslessdec: Reset put bit buffer when num_saved_bits is reset. 
Fixes CVE-2012-2799

CC:libav-stable@libav.org

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Anton Khirnov <anton@khirnov.net>
2012-09-29 19:17:38 +02:00

1300 lines
47 KiB
C
Raw Blame History

/*
* Windows Media Audio Lossless decoder
* Copyright (c) 2007 Baptiste Coudurier, Benjamin Larsson, Ulion
* Copyright (c) 2008 - 2011 Sascha Sommer, Benjamin Larsson
* Copyright (c) 2011 Andreas Öman
* Copyright (c) 2011 - 2012 Mashiat Sarker Shakkhar
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/attributes.h"
#include "libavutil/avassert.h"
#include "avcodec.h"
#include "internal.h"
#include "get_bits.h"
#include "put_bits.h"
#include "wma.h"
#include "wma_common.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 MAX_ORDER 256
#define WMALL_BLOCK_MIN_BITS 6 ///< log2 of min block size
#define WMALL_BLOCK_MAX_BITS 14 ///< 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
/**
* @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_offsets[MAX_SUBFRAMES]; ///< subframe positions in the current frame
uint8_t cur_subframe; ///< current subframe number
uint16_t decoded_samples; ///< number of already processed samples
int quant_step; ///< quantization step for the current subframe
int transient_counter; ///< number of transient samples from the beginning of the transient zone
} WmallChannelCtx;
/**
* @brief main decoder context
*/
typedef struct WmallDecodeCtx {
/* generic decoder variables */
AVCodecContext *avctx;
AVFrame frame;
uint8_t frame_data[MAX_FRAMESIZE + FF_INPUT_BUFFER_PADDING_SIZE]; ///< compressed frame data
PutBitContext pb; ///< context for filling the frame_data buffer
/* frame size dependent frame information (set during initialization) */
uint32_t decode_flags; ///< used compression features
int len_prefix; ///< frame is prefixed with its length
int 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;
/* 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; ///< offset to the frame 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
int16_t *samples_16[WMALL_MAX_CHANNELS]; ///< current samplebuffer pointer (16-bit)
int32_t *samples_32[WMALL_MAX_CHANNELS]; ///< current samplebuffer pointer (24-bit)
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];
WmallChannelCtx channel[WMALL_MAX_CHANNELS]; ///< per channel data
// WMA Lossless-specific
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;
int64_t acfilter_coeffs[16];
int acfilter_prevvalues[2][16];
int8_t mclms_order;
int8_t mclms_scaling;
int16_t mclms_coeffs[128];
int16_t mclms_coeffs_cur[4];
int16_t mclms_prevvalues[WMALL_MAX_CHANNELS * 2 * 32];
int16_t mclms_updates[WMALL_MAX_CHANNELS * 2 * 32];
int mclms_recent;
int movave_scaling;
int quant_stepsize;
struct {
int order;
int scaling;
int coefsend;
int bitsend;
int16_t coefs[MAX_ORDER];
int16_t lms_prevvalues[MAX_ORDER * 2];
int16_t lms_updates[MAX_ORDER * 2];
int recent;
} cdlms[2][9];
int cdlms_ttl[2];
int bV3RTM;
int is_channel_coded[2];
int update_speed[2];
int transient[2];
int transient_pos[2];
int seekable_tile;
int ave_sum[2];
int channel_residues[2][WMALL_BLOCK_MAX_SIZE];
int lpc_coefs[2][40];
int lpc_order;
int lpc_scaling;
int lpc_intbits;
int channel_coeffs[2][WMALL_BLOCK_MAX_SIZE];
} WmallDecodeCtx;
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, log2_max_num_subframes;
s->avctx = avctx;
init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE);
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);
if (s->bits_per_sample == 16)
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
else if (s->bits_per_sample == 24) {
avctx->sample_fmt = AV_SAMPLE_FMT_S32;
av_log_missing_feature(avctx, "bit-depth higher than 16", 0);
return AVERROR_PATCHWELCOME;
} else {
av_log(avctx, AV_LOG_ERROR, "Unknown bit-depth: %d\n",
s->bits_per_sample);
return AVERROR_INVALIDDATA;
}
/* dump the extradata */
for (i = 0; i < avctx->extradata_size; i++)
av_dlog(avctx, "[%x] ", avctx->extradata[i]);
av_dlog(avctx, "\n");
} else {
av_log_ask_for_sample(avctx, "Unsupported 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);
av_assert0(s->samples_per_frame <= WMALL_BLOCK_MAX_SIZE);
/* 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;
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;
}
avcodec_get_frame_defaults(&s->frame);
avctx->coded_frame = &s->frame;
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, 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] = { 0 }; /* 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, tile_aligned;
/* reset tiling information */
for (c = 0; c < s->num_channels; c++)
s->channel[c].num_subframes = 0;
tile_aligned = get_bits1(&s->gb);
if (s->max_num_subframes == 1 || tile_aligned)
fixed_channel_layout = 1;
/* loop until the frame data is split between the subframes */
do {
int subframe_len, in_use = 0;
/* 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] = in_use = 1;
} else {
if (get_bits1(&s->gb))
contains_subframe[c] = in_use = 1;
}
} else
contains_subframe[c] = 0;
}
if (!in_use) {
av_log(s->avctx, AV_LOG_ERROR,
"Found empty subframe\n");
return AVERROR_INVALIDDATA;
}
/* 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, offset = 0;
for (i = 0; i < s->channel[c].num_subframes; i++) {
s->channel[c].subframe_offsets[i] = offset;
offset += s->channel[c].subframe_len[i];
}
}
return 0;
}
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] = (s->acfilter_scaling ?
get_bits(&s->gb, s->acfilter_scaling) : 0) + 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)) {
int i, send_coef_bits;
int cbits = av_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 int 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;
if (s->cdlms[c][i].order > MAX_ORDER) {
av_log(s->avctx, AV_LOG_ERROR,
"Order[%d][%d] %d > max (%d), not supported\n",
c, i, s->cdlms[c][i].order, MAX_ORDER);
s->cdlms[0][0].order = 0;
return AVERROR_INVALIDDATA;
}
}
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 - s->cdlms[c][i].scaling - 2;
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;
}
}
}
return 0;
}
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->transient_pos[ch])
s->transient[ch] = 0;
s->channel[ch].transient_counter =
FFMAX(s->channel[ch].transient_counter, s->samples_per_frame / 2);
} else if (s->channel[ch].transient_counter)
s->transient[ch] = 1;
if (s->seekable_tile) {
ave_mean = get_bits(&s->gb, s->bits_per_sample);
s->ave_sum[ch] = ave_mean << (s->movave_scaling + 1);
}
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 (get_bits_left(&s->gb) <= 0)
return -1;
}
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);
if (ave_mean <= 1)
residue = quo;
else {
rem_bits = av_ceil_log2(ave_mean);
rem = rem_bits ? get_bits_long(&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;
}
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);
}
static void clear_codec_buffers(WmallDecodeCtx *s)
{
int ich, ilms;
memset(s->acfilter_coeffs, 0, sizeof(s->acfilter_coeffs));
memset(s->acfilter_prevvalues, 0, sizeof(s->acfilter_prevvalues));
memset(s->lpc_coefs, 0, sizeof(s->lpc_coefs));
memset(s->mclms_coeffs, 0, sizeof(s->mclms_coeffs));
memset(s->mclms_coeffs_cur, 0, sizeof(s->mclms_coeffs_cur));
memset(s->mclms_prevvalues, 0, sizeof(s->mclms_prevvalues));
memset(s->mclms_updates, 0, sizeof(s->mclms_updates));
for (ich = 0; ich < s->num_channels; ich++) {
for (ilms = 0; ilms < s->cdlms_ttl[ich]; ilms++) {
memset(s->cdlms[ich][ilms].coefs, 0,
sizeof(s->cdlms[ich][ilms].coefs));
memset(s->cdlms[ich][ilms].lms_prevvalues, 0,
sizeof(s->cdlms[ich][ilms].lms_prevvalues));
memset(s->cdlms[ich][ilms].lms_updates, 0,
sizeof(s->cdlms[ich][ilms].lms_updates));
}
s->ave_sum[ich] = 0;
}
}
/**
* @brief Reset filter parameters and transient area at new seekable tile.
*/
static void reset_codec(WmallDecodeCtx *s)
{
int ich, ilms;
s->mclms_recent = s->mclms_order * s->num_channels;
for (ich = 0; ich < s->num_channels; ich++) {
for (ilms = 0; ilms < s->cdlms_ttl[ich]; ilms++)
s->cdlms[ich][ilms].recent = s->cdlms[ich][ilms].order;
/* first sample of a seekable subframe is considered as the starting of
a transient area which is samples_per_frame samples long */
s->channel[ich].transient_counter = s->samples_per_frame;
s->transient[ich] = 1;
s->transient_pos[ich] = 0;
}
}
static void mclms_update(WmallDecodeCtx *s, int icoef, int *pred)
{
int i, j, ich, pred_error;
int order = s->mclms_order;
int num_channels = s->num_channels;
int range = 1 << (s->bits_per_sample - 1);
for (ich = 0; ich < num_channels; ich++) {
pred_error = s->channel_residues[ich][icoef] - pred[ich];
if (pred_error > 0) {
for (i = 0; i < order * num_channels; i++)
s->mclms_coeffs[i + ich * order * num_channels] +=
s->mclms_updates[s->mclms_recent + i];
for (j = 0; j < ich; j++) {
if (s->channel_residues[j][icoef] > 0)
s->mclms_coeffs_cur[ich * num_channels + j] += 1;
else if (s->channel_residues[j][icoef] < 0)
s->mclms_coeffs_cur[ich * num_channels + j] -= 1;
}
} else if (pred_error < 0) {
for (i = 0; i < order * num_channels; i++)
s->mclms_coeffs[i + ich * order * num_channels] -=
s->mclms_updates[s->mclms_recent + i];
for (j = 0; j < ich; j++) {
if (s->channel_residues[j][icoef] > 0)
s->mclms_coeffs_cur[ich * num_channels + j] -= 1;
else if (s->channel_residues[j][icoef] < 0)
s->mclms_coeffs_cur[ich * num_channels + j] += 1;
}
}
}
for (ich = num_channels - 1; ich >= 0; ich--) {
s->mclms_recent--;
s->mclms_prevvalues[s->mclms_recent] = s->channel_residues[ich][icoef];
if (s->channel_residues[ich][icoef] > range - 1)
s->mclms_prevvalues[s->mclms_recent] = range - 1;
else if (s->channel_residues[ich][icoef] < -range)
s->mclms_prevvalues[s->mclms_recent] = -range;
s->mclms_updates[s->mclms_recent] = 0;
if (s->channel_residues[ich][icoef] > 0)
s->mclms_updates[s->mclms_recent] = 1;
else if (s->channel_residues[ich][icoef] < 0)
s->mclms_updates[s->mclms_recent] = -1;
}
if (s->mclms_recent == 0) {
memcpy(&s->mclms_prevvalues[order * num_channels],
s->mclms_prevvalues,
2 * order * num_channels);
memcpy(&s->mclms_updates[order * num_channels],
s->mclms_updates,
2 * order * num_channels);
s->mclms_recent = num_channels * order;
}
}
static void mclms_predict(WmallDecodeCtx *s, int icoef, int *pred)
{
int ich, i;
int order = s->mclms_order;
int num_channels = s->num_channels;
for (ich = 0; ich < num_channels; ich++) {
pred[ich] = 0;
if (!s->is_channel_coded[ich])
continue;
for (i = 0; i < order * num_channels; i++)
pred[ich] += s->mclms_prevvalues[i + s->mclms_recent] *
s->mclms_coeffs[i + order * num_channels * ich];
for (i = 0; i < ich; i++)
pred[ich] += s->channel_residues[i][icoef] *
s->mclms_coeffs_cur[i + num_channels * ich];
pred[ich] += 1 << s->mclms_scaling - 1;
pred[ich] >>= s->mclms_scaling;
s->channel_residues[ich][icoef] += pred[ich];
}
}
static void revert_mclms(WmallDecodeCtx *s, int tile_size)
{
int icoef, pred[WMALL_MAX_CHANNELS] = { 0 };
for (icoef = 0; icoef < tile_size; icoef++) {
mclms_predict(s, icoef, pred);
mclms_update(s, icoef, pred);
}
}
static int lms_predict(WmallDecodeCtx *s, int ich, int ilms)
{
int pred = 0, icoef;
int recent = s->cdlms[ich][ilms].recent;
for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++)
pred += s->cdlms[ich][ilms].coefs[icoef] *
s->cdlms[ich][ilms].lms_prevvalues[icoef + recent];
return pred;
}
static void lms_update(WmallDecodeCtx *s, int ich, int ilms,
int input, int residue)
{
int icoef;
int recent = s->cdlms[ich][ilms].recent;
int range = 1 << s->bits_per_sample - 1;
if (residue < 0) {
for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++)
s->cdlms[ich][ilms].coefs[icoef] -=
s->cdlms[ich][ilms].lms_updates[icoef + recent];
} else if (residue > 0) {
for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++)
s->cdlms[ich][ilms].coefs[icoef] +=
s->cdlms[ich][ilms].lms_updates[icoef + recent];
}
if (recent)
recent--;
else {
memcpy(&s->cdlms[ich][ilms].lms_prevvalues[s->cdlms[ich][ilms].order],
s->cdlms[ich][ilms].lms_prevvalues,
2 * s->cdlms[ich][ilms].order);
memcpy(&s->cdlms[ich][ilms].lms_updates[s->cdlms[ich][ilms].order],
s->cdlms[ich][ilms].lms_updates,
2 * s->cdlms[ich][ilms].order);
recent = s->cdlms[ich][ilms].order - 1;
}
s->cdlms[ich][ilms].lms_prevvalues[recent] = av_clip(input, -range, range - 1);
if (!input)
s->cdlms[ich][ilms].lms_updates[recent] = 0;
else if (input < 0)
s->cdlms[ich][ilms].lms_updates[recent] = -s->update_speed[ich];
else
s->cdlms[ich][ilms].lms_updates[recent] = s->update_speed[ich];
s->cdlms[ich][ilms].lms_updates[recent + (s->cdlms[ich][ilms].order >> 4)] >>= 2;
s->cdlms[ich][ilms].lms_updates[recent + (s->cdlms[ich][ilms].order >> 3)] >>= 1;
s->cdlms[ich][ilms].recent = recent;
}
static void use_high_update_speed(WmallDecodeCtx *s, int ich)
{
int ilms, recent, icoef;
for (ilms = s->cdlms_ttl[ich] - 1; ilms >= 0; ilms--) {
recent = s->cdlms[ich][ilms].recent;
if (s->update_speed[ich] == 16)
continue;
if (s->bV3RTM) {
for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++)
s->cdlms[ich][ilms].lms_updates[icoef + recent] *= 2;
} else {
for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++)
s->cdlms[ich][ilms].lms_updates[icoef] *= 2;
}
}
s->update_speed[ich] = 16;
}
static void use_normal_update_speed(WmallDecodeCtx *s, int ich)
{
int ilms, recent, icoef;
for (ilms = s->cdlms_ttl[ich] - 1; ilms >= 0; ilms--) {
recent = s->cdlms[ich][ilms].recent;
if (s->update_speed[ich] == 8)
continue;
if (s->bV3RTM)
for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++)
s->cdlms[ich][ilms].lms_updates[icoef + recent] /= 2;
else
for (icoef = 0; icoef < s->cdlms[ich][ilms].order; icoef++)
s->cdlms[ich][ilms].lms_updates[icoef] /= 2;
}
s->update_speed[ich] = 8;
}
static void revert_cdlms(WmallDecodeCtx *s, int ch,
int coef_begin, int coef_end)
{
int icoef, pred, ilms, num_lms, residue, input;
num_lms = s->cdlms_ttl[ch];
for (ilms = num_lms - 1; ilms >= 0; ilms--) {
for (icoef = coef_begin; icoef < coef_end; icoef++) {
pred = 1 << (s->cdlms[ch][ilms].scaling - 1);
residue = s->channel_residues[ch][icoef];
pred += lms_predict(s, ch, ilms);
input = residue + (pred >> s->cdlms[ch][ilms].scaling);
lms_update(s, ch, ilms, input, residue);
s->channel_residues[ch][icoef] = input;
}
}
}
static void revert_inter_ch_decorr(WmallDecodeCtx *s, int tile_size)
{
if (s->num_channels != 2)
return;
else if (s->is_channel_coded[0] || s->is_channel_coded[1]) {
int icoef;
for (icoef = 0; icoef < tile_size; icoef++) {
s->channel_residues[0][icoef] -= s->channel_residues[1][icoef] >> 1;
s->channel_residues[1][icoef] += s->channel_residues[0][icoef];
}
}
}
static void revert_acfilter(WmallDecodeCtx *s, int tile_size)
{
int ich, pred, i, j;
int64_t *filter_coeffs = s->acfilter_coeffs;
int scaling = s->acfilter_scaling;
int order = s->acfilter_order;
for (ich = 0; ich < s->num_channels; ich++) {
int *prevvalues = s->acfilter_prevvalues[ich];
for (i = 0; i < order; i++) {
pred = 0;
for (j = 0; j < order; j++) {
if (i <= j)
pred += filter_coeffs[j] * prevvalues[j - i];
else
pred += s->channel_residues[ich][i - j - 1] * filter_coeffs[j];
}
pred >>= scaling;
s->channel_residues[ich][i] += pred;
}
for (i = order; i < tile_size; i++) {
pred = 0;
for (j = 0; j < order; j++)
pred += s->channel_residues[ich][i - j - 1] * filter_coeffs[j];
pred >>= scaling;
s->channel_residues[ich][i] += pred;
}
for (j = 0; j < order; j++)
prevvalues[j] = s->channel_residues[ich][tile_size - j - 1];
}
}
static int decode_subframe(WmallDecodeCtx *s)
{
int offset = s->samples_per_frame;
int subframe_len = s->samples_per_frame;
int total_samples = s->samples_per_frame * s->num_channels;
int i, j, rawpcm_tile, padding_zeroes, res;
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++) {
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;
/* subtract 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) {
clear_codec_buffers(s);
s->do_arith_coding = get_bits1(&s->gb);
if (s->do_arith_coding) {
av_log_missing_feature(s->avctx, "arithmetic coding", 1);
return AVERROR_PATCHWELCOME;
}
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);
if ((res = decode_cdlms(s)) < 0)
return res;
s->movave_scaling = get_bits(&s->gb, 3);
s->quant_stepsize = get_bits(&s->gb, 8) + 1;
reset_codec(s);
} else if (!s->cdlms[0][0].order) {
av_log(s->avctx, AV_LOG_DEBUG,
"Waiting for seekable tile\n");
s->frame.nb_samples = 0;
return -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);
av_log_ask_for_sample(s->avctx, "Inverse LPC filter not "
"implemented. Expect wrong output.\n");
}
} 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;
if (bits <= 0) {
av_log(s->avctx, AV_LOG_ERROR,
"Invalid number of padding bits in raw PCM tile\n");
return AVERROR_INVALIDDATA;
}
av_dlog(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);
} else {
for (i = 0; i < s->num_channels; i++)
if (s->is_channel_coded[i]) {
decode_channel_residues(s, i, subframe_len);
if (s->seekable_tile)
use_high_update_speed(s, i);
else
use_normal_update_speed(s, i);
revert_cdlms(s, i, 0, subframe_len);
} else {
memset(s->channel_residues[i], 0, sizeof(**s->channel_residues) * subframe_len);
}
}
if (s->do_mclms)
revert_mclms(s, subframe_len);
if (s->do_inter_ch_decorr)
revert_inter_ch_decorr(s, subframe_len);
if (s->do_ac_filter)
revert_acfilter(s, subframe_len);
/* Dequantize */
if (s->quant_stepsize != 1)
for (i = 0; i < s->num_channels; i++)
for (j = 0; j < subframe_len; j++)
s->channel_residues[i][j] *= s->quant_stepsize;
/* Write to proper output buffer depending on bit-depth */
for (i = 0; i < s->channels_for_cur_subframe; i++) {
int c = s->channel_indexes_for_cur_subframe[i];
int subframe_len = s->channel[c].subframe_len[s->channel[c].cur_subframe];
for (j = 0; j < subframe_len; j++) {
if (s->bits_per_sample == 16) {
*s->samples_16[c] = (int16_t) s->channel_residues[c][j] << padding_zeroes;
s->samples_16[c] += s->num_channels;
} else {
*s->samples_32[c] = s->channel_residues[c][j] << padding_zeroes;
s->samples_32[c] += s->num_channels;
}
}
}
/* 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, len = 0, i, ret;
s->frame.nb_samples = s->samples_per_frame;
if ((ret = s->avctx->get_buffer(s->avctx, &s->frame)) < 0) {
/* 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 ret;
}
for (i = 0; i < s->num_channels; i++) {
s->samples_16[i] = (int16_t *)s->frame.data[0] + i;
s->samples_32[i] = (int32_t *)s->frame.data[0] + i;
}
/* 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 av_unused skip;
/* usually true for the first frame */
if (get_bits1(gb)) {
skip = get_bits(gb, av_log2(s->samples_per_frame * 2));
av_dlog(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));
av_dlog(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;
}
/* decode all subframes */
while (!s->parsed_all_subframes) {
if (decode_subframe(s) < 0) {
s->packet_loss = 1;
return 0;
}
}
av_dlog(s->avctx, "Frame done\n");
if (s->skip_frame)
s->skip_frame = 0;
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);
}
/* 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 whether to reset the buffer or not
*/
static void save_bits(WmallDecodeCtx *s, GetBitContext* gb, int len,
int append)
{
int buflen;
PutBitContext tmp;
/* when the frame data does not need to be concatenated, the input buffer
is reset and additional bits from the previous frame are copied
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);
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);
}
static int decode_packet(AVCodecContext *avctx, void *data, int *got_frame_ptr,
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, packet_sequence_number, spliced_packet;
s->frame.nb_samples = 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);
skip_bits(gb, 1); // Skip seekable_frame_in_packet, currently ununused
spliced_packet = get_bits1(gb);
if (spliced_packet)
av_log_missing_feature(avctx, "Bitstream splicing", 1);
/* 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 (num_bits_prev_frame < remaining_packet_bits && !s->packet_loss)
decode_frame(s);
} else if (s->num_saved_bits - s->frame_offset) {
av_dlog(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;
init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE);
}
} 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);
}
*(AVFrame *)data = s->frame;
*got_frame_ptr = s->frame.nb_samples > 0;
s->packet_offset = get_bits_count(gb) & 7;
return (s->packet_loss) ? AVERROR_INVALIDDATA : get_bits_count(gb) >> 3;
}
static void flush(AVCodecContext *avctx)
{
WmallDecodeCtx *s = avctx->priv_data;
s->packet_loss = 1;
s->packet_done = 0;
s->num_saved_bits = 0;
s->frame_offset = 0;
s->next_packet_start = 0;
s->cdlms[0][0].order = 0;
s->frame.nb_samples = 0;
init_put_bits(&s->pb, s->frame_data, MAX_FRAMESIZE);
}
AVCodec ff_wmalossless_decoder = {
.name = "wmalossless",
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_WMALOSSLESS,
.priv_data_size = sizeof(WmallDecodeCtx),
.init = decode_init,
.decode = decode_packet,
.flush = flush,
.capabilities = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1 | CODEC_CAP_DELAY,
.long_name = NULL_IF_CONFIG_SMALL("Windows Media Audio Lossless"),
};
Reference in New Issue View Git Blame Copy Permalink