mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-07 11:13:41 +02:00
211 lines
6.2 KiB
C
211 lines
6.2 KiB
C
/*
|
|
* 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 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 "parser.h"
|
|
#include "dca.h"
|
|
#include "dca_parser.h"
|
|
#include "get_bits.h"
|
|
#include "put_bits.h"
|
|
|
|
typedef struct DCAParseContext {
|
|
ParseContext pc;
|
|
uint32_t lastmarker;
|
|
int size;
|
|
int framesize;
|
|
int hd_pos;
|
|
} DCAParseContext;
|
|
|
|
#define IS_MARKER(state, i, buf, buf_size) \
|
|
((state == DCA_MARKER_14B_LE && (i < buf_size-2) && (buf[i+1] & 0xF0) == 0xF0 && buf[i+2] == 0x07) \
|
|
|| (state == DCA_MARKER_14B_BE && (i < buf_size-2) && buf[i+1] == 0x07 && (buf[i+2] & 0xF0) == 0xF0) \
|
|
|| state == DCA_MARKER_RAW_LE || state == DCA_MARKER_RAW_BE)
|
|
|
|
/**
|
|
* 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, i;
|
|
uint32_t state;
|
|
ParseContext *pc = &pc1->pc;
|
|
|
|
start_found = pc->frame_start_found;
|
|
state = pc->state;
|
|
|
|
i = 0;
|
|
if (!start_found) {
|
|
for (i = 0; i < buf_size; i++) {
|
|
state = (state << 8) | buf[i];
|
|
if (IS_MARKER(state, i, buf, buf_size)) {
|
|
if (pc1->lastmarker && state == pc1->lastmarker) {
|
|
start_found = 1;
|
|
break;
|
|
} else if (!pc1->lastmarker) {
|
|
start_found = 1;
|
|
pc1->lastmarker = state;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (start_found) {
|
|
for (; i < buf_size; i++) {
|
|
pc1->size++;
|
|
state = (state << 8) | buf[i];
|
|
if (state == DCA_HD_MARKER && !pc1->hd_pos)
|
|
pc1->hd_pos = pc1->size;
|
|
if (state == pc1->lastmarker && IS_MARKER(state, i, buf, buf_size)) {
|
|
if(pc1->framesize > pc1->size)
|
|
continue;
|
|
if(!pc1->framesize){
|
|
pc1->framesize = pc1->hd_pos ? pc1->hd_pos : pc1->size;
|
|
}
|
|
pc->frame_start_found = 0;
|
|
pc->state = -1;
|
|
pc1->size = 0;
|
|
return i - 3;
|
|
}
|
|
}
|
|
}
|
|
pc->frame_start_found = start_found;
|
|
pc->state = state;
|
|
return END_NOT_FOUND;
|
|
}
|
|
|
|
static av_cold int dca_parse_init(AVCodecParserContext * s)
|
|
{
|
|
DCAParseContext *pc1 = s->priv_data;
|
|
|
|
pc1->lastmarker = 0;
|
|
return 0;
|
|
}
|
|
|
|
int ff_dca_convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst,
|
|
int max_size)
|
|
{
|
|
uint32_t mrk;
|
|
int i, tmp;
|
|
const uint16_t *ssrc = (const uint16_t *) src;
|
|
uint16_t *sdst = (uint16_t *) dst;
|
|
PutBitContext pb;
|
|
|
|
if ((unsigned) src_size > (unsigned) max_size)
|
|
src_size = max_size;
|
|
|
|
mrk = AV_RB32(src);
|
|
switch (mrk) {
|
|
case DCA_MARKER_RAW_BE:
|
|
memcpy(dst, src, src_size);
|
|
return src_size;
|
|
case DCA_MARKER_RAW_LE:
|
|
for (i = 0; i < (src_size + 1) >> 1; i++)
|
|
*sdst++ = av_bswap16(*ssrc++);
|
|
return src_size;
|
|
case DCA_MARKER_14B_BE:
|
|
case DCA_MARKER_14B_LE:
|
|
init_put_bits(&pb, dst, max_size);
|
|
for (i = 0; i < (src_size + 1) >> 1; i++, src += 2) {
|
|
tmp = ((mrk == DCA_MARKER_14B_BE) ? AV_RB16(src) : AV_RL16(src)) & 0x3FFF;
|
|
put_bits(&pb, 14, tmp);
|
|
}
|
|
flush_put_bits(&pb);
|
|
return (put_bits_count(&pb) + 7) >> 3;
|
|
default:
|
|
return AVERROR_INVALIDDATA;
|
|
}
|
|
}
|
|
|
|
static int dca_parse_params(const uint8_t *buf, int buf_size, int *duration,
|
|
int *sample_rate)
|
|
{
|
|
GetBitContext gb;
|
|
uint8_t hdr[12 + FF_INPUT_BUFFER_PADDING_SIZE] = { 0 };
|
|
int ret, sample_blocks, sr_code;
|
|
|
|
if (buf_size < 12)
|
|
return AVERROR_INVALIDDATA;
|
|
|
|
if ((ret = ff_dca_convert_bitstream(buf, 12, hdr, 12)) < 0)
|
|
return ret;
|
|
|
|
init_get_bits(&gb, hdr, 96);
|
|
|
|
skip_bits_long(&gb, 39);
|
|
sample_blocks = get_bits(&gb, 7) + 1;
|
|
if (sample_blocks < 8)
|
|
return AVERROR_INVALIDDATA;
|
|
*duration = 256 * (sample_blocks / 8);
|
|
|
|
skip_bits(&gb, 20);
|
|
sr_code = get_bits(&gb, 4);
|
|
*sample_rate = avpriv_dca_sample_rates[sr_code];
|
|
if (*sample_rate == 0)
|
|
return AVERROR_INVALIDDATA;
|
|
|
|
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;
|
|
}
|
|
}
|
|
|
|
/* read the duration and sample rate from the frame header */
|
|
if (!dca_parse_params(buf, buf_size, &duration, &sample_rate)) {
|
|
s->duration = duration;
|
|
avctx->sample_rate = sample_rate;
|
|
} else
|
|
s->duration = 0;
|
|
|
|
*poutbuf = buf;
|
|
*poutbuf_size = buf_size;
|
|
return next;
|
|
}
|
|
|
|
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,
|
|
};
|