1
0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2024-12-07 11:13:41 +02:00
FFmpeg/libavcodec/tta.c
Justin Ruggles 5778299c7e ttadec: fix last frame handling when seeking
Using a frame count, as is done currently, does not work at all with
seeking. Instead, when the number of samples in the final frame has
been decoded, we check if only the 32-bit CRC is remaining. If so, we
assume that it is the final frame.

There is no longer a need to keep total_frames in TTAContext.
2012-12-22 14:45:35 -05:00

485 lines
14 KiB
C

/*
* TTA (The Lossless True Audio) decoder
* Copyright (c) 2006 Alex Beregszaszi
*
* 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
*/
/**
* @file
* TTA (The Lossless True Audio) decoder
* @see http://www.true-audio.com/
* @see http://tta.corecodec.org/
* @author Alex Beregszaszi
*/
#define BITSTREAM_READER_LE
//#define DEBUG
#include <limits.h>
#include "avcodec.h"
#include "get_bits.h"
#include "internal.h"
#include "libavutil/crc.h"
#define FORMAT_SIMPLE 1
#define FORMAT_ENCRYPTED 2
#define MAX_ORDER 16
typedef struct TTAFilter {
int32_t shift, round, error;
int32_t qm[MAX_ORDER];
int32_t dx[MAX_ORDER];
int32_t dl[MAX_ORDER];
} TTAFilter;
typedef struct TTARice {
uint32_t k0, k1, sum0, sum1;
} TTARice;
typedef struct TTAChannel {
int32_t predictor;
TTAFilter filter;
TTARice rice;
} TTAChannel;
typedef struct TTAContext {
AVCodecContext *avctx;
AVFrame frame;
GetBitContext gb;
const AVCRC *crc_table;
int format, channels, bps;
unsigned data_length;
int frame_length, last_frame_length;
int32_t *decode_buffer;
TTAChannel *ch_ctx;
} TTAContext;
static const uint32_t shift_1[] = {
0x00000001, 0x00000002, 0x00000004, 0x00000008,
0x00000010, 0x00000020, 0x00000040, 0x00000080,
0x00000100, 0x00000200, 0x00000400, 0x00000800,
0x00001000, 0x00002000, 0x00004000, 0x00008000,
0x00010000, 0x00020000, 0x00040000, 0x00080000,
0x00100000, 0x00200000, 0x00400000, 0x00800000,
0x01000000, 0x02000000, 0x04000000, 0x08000000,
0x10000000, 0x20000000, 0x40000000, 0x80000000,
0x80000000, 0x80000000, 0x80000000, 0x80000000,
0x80000000, 0x80000000, 0x80000000, 0x80000000
};
static const uint32_t * const shift_16 = shift_1 + 4;
static const int32_t ttafilter_configs[4] = {
10,
9,
10,
12
};
static void ttafilter_init(TTAFilter *c, int32_t shift) {
memset(c, 0, sizeof(TTAFilter));
c->shift = shift;
c->round = shift_1[shift-1];
// c->round = 1 << (shift - 1);
}
// FIXME: copy paste from original
static inline void memshl(register int32_t *a, register int32_t *b) {
*a++ = *b++;
*a++ = *b++;
*a++ = *b++;
*a++ = *b++;
*a++ = *b++;
*a++ = *b++;
*a++ = *b++;
*a = *b;
}
static inline void ttafilter_process(TTAFilter *c, int32_t *in)
{
register int32_t *dl = c->dl, *qm = c->qm, *dx = c->dx, sum = c->round;
if (!c->error) {
sum += *dl++ * *qm, qm++;
sum += *dl++ * *qm, qm++;
sum += *dl++ * *qm, qm++;
sum += *dl++ * *qm, qm++;
sum += *dl++ * *qm, qm++;
sum += *dl++ * *qm, qm++;
sum += *dl++ * *qm, qm++;
sum += *dl++ * *qm, qm++;
dx += 8;
} else if(c->error < 0) {
sum += *dl++ * (*qm -= *dx++), qm++;
sum += *dl++ * (*qm -= *dx++), qm++;
sum += *dl++ * (*qm -= *dx++), qm++;
sum += *dl++ * (*qm -= *dx++), qm++;
sum += *dl++ * (*qm -= *dx++), qm++;
sum += *dl++ * (*qm -= *dx++), qm++;
sum += *dl++ * (*qm -= *dx++), qm++;
sum += *dl++ * (*qm -= *dx++), qm++;
} else {
sum += *dl++ * (*qm += *dx++), qm++;
sum += *dl++ * (*qm += *dx++), qm++;
sum += *dl++ * (*qm += *dx++), qm++;
sum += *dl++ * (*qm += *dx++), qm++;
sum += *dl++ * (*qm += *dx++), qm++;
sum += *dl++ * (*qm += *dx++), qm++;
sum += *dl++ * (*qm += *dx++), qm++;
sum += *dl++ * (*qm += *dx++), qm++;
}
*(dx-0) = ((*(dl-1) >> 30) | 1) << 2;
*(dx-1) = ((*(dl-2) >> 30) | 1) << 1;
*(dx-2) = ((*(dl-3) >> 30) | 1) << 1;
*(dx-3) = ((*(dl-4) >> 30) | 1);
c->error = *in;
*in += (sum >> c->shift);
*dl = *in;
*(dl-1) = *dl - *(dl-1);
*(dl-2) = *(dl-1) - *(dl-2);
*(dl-3) = *(dl-2) - *(dl-3);
memshl(c->dl, c->dl + 1);
memshl(c->dx, c->dx + 1);
}
static void rice_init(TTARice *c, uint32_t k0, uint32_t k1)
{
c->k0 = k0;
c->k1 = k1;
c->sum0 = shift_16[k0];
c->sum1 = shift_16[k1];
}
static int tta_get_unary(GetBitContext *gb)
{
int ret = 0;
// count ones
while (get_bits_left(gb) > 0 && get_bits1(gb))
ret++;
return ret;
}
static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size)
{
uint32_t crc, CRC;
CRC = AV_RL32(buf + buf_size);
crc = av_crc(s->crc_table, 0xFFFFFFFFU, buf, buf_size);
if (CRC != (crc ^ 0xFFFFFFFFU)) {
av_log(s->avctx, AV_LOG_ERROR, "CRC error\n");
return AVERROR_INVALIDDATA;
}
return 0;
}
static av_cold int tta_decode_init(AVCodecContext * avctx)
{
TTAContext *s = avctx->priv_data;
int total_frames;
s->avctx = avctx;
// 30bytes includes a seektable with one frame
if (avctx->extradata_size < 30)
return -1;
init_get_bits(&s->gb, avctx->extradata, avctx->extradata_size * 8);
if (show_bits_long(&s->gb, 32) == AV_RL32("TTA1"))
{
if (avctx->err_recognition & AV_EF_CRCCHECK) {
s->crc_table = av_crc_get_table(AV_CRC_32_IEEE_LE);
tta_check_crc(s, avctx->extradata, 18);
}
/* signature */
skip_bits_long(&s->gb, 32);
s->format = get_bits(&s->gb, 16);
if (s->format > 2) {
av_log(s->avctx, AV_LOG_ERROR, "Invalid format\n");
return -1;
}
if (s->format == FORMAT_ENCRYPTED) {
av_log_missing_feature(s->avctx, "Encrypted TTA", 0);
return AVERROR_PATCHWELCOME;
}
avctx->channels = s->channels = get_bits(&s->gb, 16);
avctx->bits_per_coded_sample = get_bits(&s->gb, 16);
s->bps = (avctx->bits_per_coded_sample + 7) / 8;
avctx->sample_rate = get_bits_long(&s->gb, 32);
s->data_length = get_bits_long(&s->gb, 32);
skip_bits_long(&s->gb, 32); // CRC32 of header
if (s->channels == 0) {
av_log(s->avctx, AV_LOG_ERROR, "Invalid number of channels\n");
return AVERROR_INVALIDDATA;
} else if (avctx->sample_rate == 0) {
av_log(s->avctx, AV_LOG_ERROR, "Invalid samplerate\n");
return AVERROR_INVALIDDATA;
}
switch(s->bps) {
case 2:
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
avctx->bits_per_raw_sample = 16;
break;
case 3:
avctx->sample_fmt = AV_SAMPLE_FMT_S32;
avctx->bits_per_raw_sample = 24;
break;
default:
av_log(avctx, AV_LOG_ERROR, "Invalid/unsupported sample format.\n");
return AVERROR_INVALIDDATA;
}
// prevent overflow
if (avctx->sample_rate > 0x7FFFFFu) {
av_log(avctx, AV_LOG_ERROR, "sample_rate too large\n");
return AVERROR(EINVAL);
}
s->frame_length = 256 * avctx->sample_rate / 245;
s->last_frame_length = s->data_length % s->frame_length;
total_frames = s->data_length / s->frame_length +
(s->last_frame_length ? 1 : 0);
av_log(s->avctx, AV_LOG_DEBUG, "format: %d chans: %d bps: %d rate: %d block: %d\n",
s->format, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate,
avctx->block_align);
av_log(s->avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n",
s->data_length, s->frame_length, s->last_frame_length, total_frames);
// FIXME: seek table
if (avctx->extradata_size <= 26 || total_frames > INT_MAX / 4 ||
avctx->extradata_size - 26 < total_frames * 4)
av_log(avctx, AV_LOG_WARNING, "Seek table missing or too small\n");
else if (avctx->err_recognition & AV_EF_CRCCHECK) {
if (tta_check_crc(s, avctx->extradata + 22, total_frames * 4))
return AVERROR_INVALIDDATA;
}
skip_bits_long(&s->gb, 32 * total_frames);
skip_bits_long(&s->gb, 32); // CRC32 of seektable
if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){
av_log(avctx, AV_LOG_ERROR, "frame_length too large\n");
return -1;
}
if (s->bps == 2) {
s->decode_buffer = av_mallocz(sizeof(int32_t)*s->frame_length*s->channels);
if (!s->decode_buffer)
return AVERROR(ENOMEM);
}
s->ch_ctx = av_malloc(avctx->channels * sizeof(*s->ch_ctx));
if (!s->ch_ctx) {
av_freep(&s->decode_buffer);
return AVERROR(ENOMEM);
}
} else {
av_log(avctx, AV_LOG_ERROR, "Wrong extradata present\n");
return -1;
}
avcodec_get_frame_defaults(&s->frame);
avctx->coded_frame = &s->frame;
return 0;
}
static int tta_decode_frame(AVCodecContext *avctx, void *data,
int *got_frame_ptr, AVPacket *avpkt)
{
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
TTAContext *s = avctx->priv_data;
int i, ret;
int cur_chan = 0, framelen = s->frame_length;
int32_t *p;
if (avctx->err_recognition & AV_EF_CRCCHECK) {
if (buf_size < 4 || tta_check_crc(s, buf, buf_size - 4))
return AVERROR_INVALIDDATA;
}
init_get_bits(&s->gb, buf, buf_size*8);
/* get output buffer */
s->frame.nb_samples = framelen;
if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
return ret;
}
// decode directly to output buffer for 24-bit sample format
if (s->bps == 3)
s->decode_buffer = (int32_t *)s->frame.data[0];
// init per channel states
for (i = 0; i < s->channels; i++) {
s->ch_ctx[i].predictor = 0;
ttafilter_init(&s->ch_ctx[i].filter, ttafilter_configs[s->bps-1]);
rice_init(&s->ch_ctx[i].rice, 10, 10);
}
i = 0;
for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) {
int32_t *predictor = &s->ch_ctx[cur_chan].predictor;
TTAFilter *filter = &s->ch_ctx[cur_chan].filter;
TTARice *rice = &s->ch_ctx[cur_chan].rice;
uint32_t unary, depth, k;
int32_t value;
unary = tta_get_unary(&s->gb);
if (unary == 0) {
depth = 0;
k = rice->k0;
} else {
depth = 1;
k = rice->k1;
unary--;
}
if (get_bits_left(&s->gb) < k) {
ret = AVERROR_INVALIDDATA;
goto error;
}
if (k) {
if (k > MIN_CACHE_BITS) {
ret = AVERROR_INVALIDDATA;
goto error;
}
value = (unary << k) + get_bits(&s->gb, k);
} else
value = unary;
// FIXME: copy paste from original
switch (depth) {
case 1:
rice->sum1 += value - (rice->sum1 >> 4);
if (rice->k1 > 0 && rice->sum1 < shift_16[rice->k1])
rice->k1--;
else if(rice->sum1 > shift_16[rice->k1 + 1])
rice->k1++;
value += shift_1[rice->k0];
default:
rice->sum0 += value - (rice->sum0 >> 4);
if (rice->k0 > 0 && rice->sum0 < shift_16[rice->k0])
rice->k0--;
else if(rice->sum0 > shift_16[rice->k0 + 1])
rice->k0++;
}
// extract coded value
*p = 1 + ((value >> 1) ^ ((value & 1) - 1));
// run hybrid filter
ttafilter_process(filter, p);
// fixed order prediction
#define PRED(x, k) (int32_t)((((uint64_t)x << k) - x) >> k)
switch (s->bps) {
case 1: *p += PRED(*predictor, 4); break;
case 2:
case 3: *p += PRED(*predictor, 5); break;
case 4: *p += *predictor; break;
}
*predictor = *p;
// flip channels
if (cur_chan < (s->channels-1))
cur_chan++;
else {
// decorrelate in case of multiple channels
if (s->channels > 1) {
int32_t *r = p - 1;
for (*p += *r / 2; r > p - s->channels; r--)
*r = *(r + 1) - *r;
}
cur_chan = 0;
i++;
// check for last frame
if (i == s->last_frame_length && get_bits_left(&s->gb) / 8 == 4) {
s->frame.nb_samples = framelen = s->last_frame_length;
break;
}
}
}
align_get_bits(&s->gb);
if (get_bits_left(&s->gb) < 32) {
ret = AVERROR_INVALIDDATA;
goto error;
}
skip_bits_long(&s->gb, 32); // frame crc
// convert to output buffer
if (s->bps == 2) {
int16_t *samples = (int16_t *)s->frame.data[0];
for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++)
*samples++ = *p;
} else {
// shift samples for 24-bit sample format
int32_t *samples = (int32_t *)s->frame.data[0];
for (i = 0; i < framelen * s->channels; i++)
*samples++ <<= 8;
// reset decode buffer
s->decode_buffer = NULL;
}
*got_frame_ptr = 1;
*(AVFrame *)data = s->frame;
return buf_size;
error:
// reset decode buffer
if (s->bps == 3)
s->decode_buffer = NULL;
return ret;
}
static av_cold int tta_decode_close(AVCodecContext *avctx) {
TTAContext *s = avctx->priv_data;
av_free(s->decode_buffer);
av_freep(&s->ch_ctx);
return 0;
}
AVCodec ff_tta_decoder = {
.name = "tta",
.type = AVMEDIA_TYPE_AUDIO,
.id = AV_CODEC_ID_TTA,
.priv_data_size = sizeof(TTAContext),
.init = tta_decode_init,
.close = tta_decode_close,
.decode = tta_decode_frame,
.capabilities = CODEC_CAP_DR1,
.long_name = NULL_IF_CONFIG_SMALL("TTA (True Audio)"),
};