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ffmpeg/libavcodec/dca_parser.c
Andreas Rheinhardt 3afb41655e avcodec/dca: Unavpriv dca_sample_rates 
Said table is 64 bytes long and exported so that it can be used both
in libavcodec and libavformat. This commit stops doing so and instead
duplicates it for shared builds, because the overhead of exporting the
symbol is bigger than 64 bytes. It consists of the length of the name of
the symbol (2x24 bytes), two entries in .dynsym (2x24 bytes), two
entries for symbol version (2x2 bytes), one hash value in the exporting
library (4 bytes) in addition to one entry in the importing library's
.got and .rela.dyn (8 + 24 bytes).
(The above numbers are for a Linux/GNU/Elf system; the numbers for other
platforms may be different.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-01-04 13:16:49 +01:00

353 lines
11 KiB
C
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/*
* DCA parser
* Copyright (C) 2004 Gildas Bazin
* Copyright (C) 2004 Benjamin Zores
* Copyright (C) 2006 Benjamin Larsson
* Copyright (C) 2007 Konstantin Shishkov
*
* 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
*/
#include "dca.h"
#include "dca_core.h"
#include "dca_exss.h"
#include "dca_lbr.h"
#include "dca_syncwords.h"
#include "get_bits.h"
#include "parser.h"
typedef struct DCAParseContext {
ParseContext pc;
uint32_t lastmarker;
int size;
int framesize;
unsigned int startpos;
DCAExssParser exss;
unsigned int sr_code;
} DCAParseContext;
#define IS_CORE_MARKER(state) \
(((state & 0xFFFFFFFFF0FF) == (((uint64_t)DCA_SYNCWORD_CORE_14B_LE << 16) | 0xF007)) || \
((state & 0xFFFFFFFFFFF0) == (((uint64_t)DCA_SYNCWORD_CORE_14B_BE << 16) | 0x07F0)) || \
((state & 0xFFFFFFFF00FC) == (((uint64_t)DCA_SYNCWORD_CORE_LE << 16) | 0x00FC)) || \
((state & 0xFFFFFFFFFC00) == (((uint64_t)DCA_SYNCWORD_CORE_BE << 16) | 0xFC00)))
#define IS_EXSS_MARKER(state) ((state & 0xFFFFFFFF) == DCA_SYNCWORD_SUBSTREAM)
#define IS_MARKER(state) (IS_CORE_MARKER(state) || IS_EXSS_MARKER(state))
#define CORE_MARKER(state) ((state >> 16) & 0xFFFFFFFF)
#define EXSS_MARKER(state) (state & 0xFFFFFFFF)
#define STATE_LE(state) (((state & 0xFF00FF00) >> 8) | ((state & 0x00FF00FF) << 8))
#define STATE_14(state) (((state & 0x3FFF0000) >> 8) | ((state & 0x00003FFF) >> 6))
#define CORE_FRAMESIZE(state) (((state >> 4) & 0x3FFF) + 1)
#define EXSS_FRAMESIZE(state) ((state & 0x2000000000) ? \
((state >> 5) & 0xFFFFF) + 1 : \
((state >> 13) & 0x0FFFF) + 1)
/**
* Find the end of the current frame in the bitstream.
* @return the position of the first byte of the next frame, or -1
*/
static int dca_find_frame_end(DCAParseContext *pc1, const uint8_t *buf,
int buf_size)
{
int start_found, size, i;
uint64_t state;
ParseContext *pc = &pc1->pc;
start_found = pc->frame_start_found;
state = pc->state64;
size = pc1->size;
i = 0;
if (!start_found) {
for (; i < buf_size; i++) {
size++;
state = (state << 8) | buf[i];
if (IS_MARKER(state) &&
(!pc1->lastmarker ||
pc1->lastmarker == CORE_MARKER(state) ||
pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM)) {
if (!pc1->lastmarker)
pc1->startpos = IS_EXSS_MARKER(state) ? size - 4 : size - 6;
if (IS_EXSS_MARKER(state))
pc1->lastmarker = EXSS_MARKER(state);
else
pc1->lastmarker = CORE_MARKER(state);
start_found = 1;
size = 0;
i++;
break;
}
}
}
if (start_found) {
for (; i < buf_size; i++) {
size++;
state = (state << 8) | buf[i];
if (start_found == 1) {
switch (pc1->lastmarker) {
case DCA_SYNCWORD_CORE_BE:
if (size == 2) {
pc1->framesize = CORE_FRAMESIZE(state);
start_found = 2;
}
break;
case DCA_SYNCWORD_CORE_LE:
if (size == 2) {
pc1->framesize = CORE_FRAMESIZE(STATE_LE(state));
start_found = 4;
}
break;
case DCA_SYNCWORD_CORE_14B_BE:
if (size == 4) {
pc1->framesize = CORE_FRAMESIZE(STATE_14(state));
start_found = 4;
}
break;
case DCA_SYNCWORD_CORE_14B_LE:
if (size == 4) {
pc1->framesize = CORE_FRAMESIZE(STATE_14(STATE_LE(state)));
start_found = 4;
}
break;
case DCA_SYNCWORD_SUBSTREAM:
if (size == 6) {
pc1->framesize = EXSS_FRAMESIZE(state);
start_found = 4;
}
break;
default:
av_assert0(0);
}
continue;
}
if (start_found == 2 && IS_EXSS_MARKER(state) &&
pc1->framesize <= size + 2) {
pc1->framesize = size + 2;
start_found = 3;
continue;
}
if (start_found == 3) {
if (size == pc1->framesize + 4) {
pc1->framesize += EXSS_FRAMESIZE(state);
start_found = 4;
}
continue;
}
if (pc1->framesize > size)
continue;
if (IS_MARKER(state) &&
(pc1->lastmarker == CORE_MARKER(state) ||
pc1->lastmarker == DCA_SYNCWORD_SUBSTREAM)) {
pc->frame_start_found = 0;
pc->state64 = -1;
pc1->size = 0;
return IS_EXSS_MARKER(state) ? i - 3 : i - 5;
}
}
}
pc->frame_start_found = start_found;
pc->state64 = state;
pc1->size = size;
return END_NOT_FOUND;
}
static av_cold int dca_parse_init(AVCodecParserContext *s)
{
DCAParseContext *pc1 = s->priv_data;
pc1->lastmarker = 0;
pc1->sr_code = -1;
return 0;
}
static int dca_parse_params(DCAParseContext *pc1, const uint8_t *buf,
int buf_size, int *duration, int *sample_rate,
int *profile)
{
DCAExssAsset *asset = &pc1->exss.assets[0];
GetBitContext gb;
DCACoreFrameHeader h;
uint8_t hdr[DCA_CORE_FRAME_HEADER_SIZE + AV_INPUT_BUFFER_PADDING_SIZE] = { 0 };
int ret, frame_size;
if (buf_size < DCA_CORE_FRAME_HEADER_SIZE)
return AVERROR_INVALIDDATA;
if (AV_RB32(buf) == DCA_SYNCWORD_SUBSTREAM) {
if ((ret = ff_dca_exss_parse(&pc1->exss, buf, buf_size)) < 0)
return ret;
if (asset->extension_mask & DCA_EXSS_LBR) {
if ((ret = init_get_bits8(&gb, buf + asset->lbr_offset, asset->lbr_size)) < 0)
return ret;
if (get_bits_long(&gb, 32) != DCA_SYNCWORD_LBR)
return AVERROR_INVALIDDATA;
switch (get_bits(&gb, 8)) {
case DCA_LBR_HEADER_DECODER_INIT:
pc1->sr_code = get_bits(&gb, 8);
case DCA_LBR_HEADER_SYNC_ONLY:
break;
default:
return AVERROR_INVALIDDATA;
}
if (pc1->sr_code >= FF_ARRAY_ELEMS(ff_dca_sampling_freqs))
return AVERROR_INVALIDDATA;
*sample_rate = ff_dca_sampling_freqs[pc1->sr_code];
*duration = 1024 << ff_dca_freq_ranges[pc1->sr_code];
*profile = FF_PROFILE_DTS_EXPRESS;
return 0;
}
if (asset->extension_mask & DCA_EXSS_XLL) {
int nsamples_log2;
if ((ret = init_get_bits8(&gb, buf + asset->xll_offset, asset->xll_size)) < 0)
return ret;
if (get_bits_long(&gb, 32) != DCA_SYNCWORD_XLL)
return AVERROR_INVALIDDATA;
if (get_bits(&gb, 4))
return AVERROR_INVALIDDATA;
skip_bits(&gb, 8);
skip_bits_long(&gb, get_bits(&gb, 5) + 1);
skip_bits(&gb, 4);
nsamples_log2 = get_bits(&gb, 4) + get_bits(&gb, 4);
if (nsamples_log2 > 24)
return AVERROR_INVALIDDATA;
*sample_rate = asset->max_sample_rate;
*duration = (1 + (*sample_rate > 96000)) << nsamples_log2;
*profile = FF_PROFILE_DTS_HD_MA;
return 0;
}
return AVERROR_INVALIDDATA;
}
if ((ret = avpriv_dca_convert_bitstream(buf, DCA_CORE_FRAME_HEADER_SIZE,
hdr, DCA_CORE_FRAME_HEADER_SIZE)) < 0)
return ret;
if (avpriv_dca_parse_core_frame_header(&h, hdr, ret) < 0)
return AVERROR_INVALIDDATA;
*duration = h.npcmblocks * DCA_PCMBLOCK_SAMPLES;
*sample_rate = ff_dca_sample_rates[h.sr_code];
if (*profile != FF_PROFILE_UNKNOWN)
return 0;
*profile = FF_PROFILE_DTS;
if (h.ext_audio_present) {
switch (h.ext_audio_type) {
case DCA_EXT_AUDIO_XCH:
case DCA_EXT_AUDIO_XXCH:
*profile = FF_PROFILE_DTS_ES;
break;
case DCA_EXT_AUDIO_X96:
*profile = FF_PROFILE_DTS_96_24;
break;
}
}
frame_size = FFALIGN(h.frame_size, 4);
if (buf_size - 4 < frame_size)
return 0;
buf += frame_size;
buf_size -= frame_size;
if (AV_RB32(buf) != DCA_SYNCWORD_SUBSTREAM)
return 0;
if (ff_dca_exss_parse(&pc1->exss, buf, buf_size) < 0)
return 0;
if (asset->extension_mask & DCA_EXSS_XLL)
*profile = FF_PROFILE_DTS_HD_MA;
else if (asset->extension_mask & (DCA_EXSS_XBR | DCA_EXSS_XXCH | DCA_EXSS_X96))
*profile = FF_PROFILE_DTS_HD_HRA;
return 0;
}
static int dca_parse(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
DCAParseContext *pc1 = s->priv_data;
ParseContext *pc = &pc1->pc;
int next, duration, sample_rate;
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
} else {
next = dca_find_frame_end(pc1, buf, buf_size);
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
/* skip initial padding */
if (buf_size > pc1->startpos) {
buf += pc1->startpos;
buf_size -= pc1->startpos;
}
pc1->startpos = 0;
}
/* read the duration and sample rate from the frame header */
if (!dca_parse_params(pc1, buf, buf_size, &duration, &sample_rate, &avctx->profile)) {
if (!avctx->sample_rate)
avctx->sample_rate = sample_rate;
s->duration = av_rescale(duration, avctx->sample_rate, sample_rate);
} else
s->duration = 0;
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
const AVCodecParser ff_dca_parser = {
.codec_ids = { AV_CODEC_ID_DTS },
.priv_data_size = sizeof(DCAParseContext),
.parser_init = dca_parse_init,
.parser_parse = dca_parse,
.parser_close = ff_parse_close,
};
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