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/*
* AVS2-P2/IEEE1857.4 video parser.
* Copyright (c) 2018 Huiwen Ren <hwrenx@gmail.com>
*
* 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 "libavutil/avutil.h"
#include "avs2.h"
#include "get_bits.h"
#include "parser.h"
static int avs2_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size)
{
int pic_found = pc->frame_start_found;
uint32_t state = pc->state;
int cur = 0;
if (!pic_found) {
for (; cur < buf_size; ++cur) {
state = (state << 8) | buf[cur];
if ((state & 0xFFFFFF00) == 0x100 && AVS2_ISPIC(buf[cur])) {
cur++;
pic_found = 1;
break;
}
}
}
if (pic_found) {
if (!buf_size)
return END_NOT_FOUND;
for (; cur < buf_size; cur++) {
state = (state << 8) | buf[cur];
if ((state & 0xFFFFFF00) == 0x100 && AVS2_ISUNIT(buf[cur])) {
pc->frame_start_found = 0;
pc->state = -1;
return cur - 3;
}
}
}
pc->frame_start_found = pic_found;
pc->state = state;
return END_NOT_FOUND;
}
static void parse_avs2_seq_header(AVCodecParserContext *s, const uint8_t *buf,
int buf_size, AVCodecContext *avctx)
{
GetBitContext gb;
int profile, level;
int width, height;
int chroma, sample_precision, encoding_precision = 1;
// sample_precision and encoding_precision is 3 bits
static const uint8_t precision[8] = { 0, 8, 10 };
unsigned aspect_ratio;
unsigned frame_rate_code;
int low_delay;
av_unused int ret;
// update buf_size_min if parse more deeper
const int buf_size_min = 15;
if (buf_size < buf_size_min)
return;
ret = init_get_bits8(&gb, buf, buf_size_min);
av_assert1(ret >= 0);
s->key_frame = 1;
s->pict_type = AV_PICTURE_TYPE_I;
profile = get_bits(&gb, 8);
level = get_bits(&gb, 8);
// progressive_sequence u(1)
// field_coded_sequence u(1)
skip_bits(&gb, 2);
width = get_bits(&gb, 14);
height = get_bits(&gb, 14);
chroma = get_bits(&gb, 2);
sample_precision = get_bits(&gb, 3);
if (profile == AVS2_PROFILE_MAIN10)
encoding_precision = get_bits(&gb, 3);
aspect_ratio = get_bits(&gb, 4);
frame_rate_code = get_bits(&gb, 4);
// bit_rate_lower u(18)
// marker_bit f(1)
// bit_rate_upper u(12)
skip_bits(&gb, 31);
low_delay = get_bits(&gb, 1);
s->width = width;
s->height = height;
s->coded_width = FFALIGN(width, 8);
s->coded_height = FFALIGN(height, 8);
avctx->framerate.num =
ff_avs2_frame_rate_tab[frame_rate_code].num;
avctx->framerate.den =
ff_avs2_frame_rate_tab[frame_rate_code].den;
avctx->has_b_frames = FFMAX(avctx->has_b_frames, !low_delay);
av_log(avctx, AV_LOG_DEBUG,
"AVS2 parse seq HDR: profile %x, level %x, "
"width %d, height %d, "
"chroma %d, sample_precision %d bits, encoding_precision %d bits, "
"aspect_ratio 0x%x, framerate %d/%d, low_delay %d\n",
profile, level,
width, height,
chroma, precision[sample_precision], precision[encoding_precision],
aspect_ratio, avctx->framerate.num, avctx->framerate.den, low_delay);
}
static void parse_avs2_units(AVCodecParserContext *s, const uint8_t *buf,
int buf_size, AVCodecContext *avctx)
{
if (buf_size < 5)
return;
if (!(buf[0] == 0x0 && buf[1] == 0x0 && buf[2] == 0x1))
return;
switch (buf[3]) {
case AVS2_SEQ_START_CODE:
parse_avs2_seq_header(s, buf + 4, buf_size - 4, avctx);
return;
case AVS2_INTRA_PIC_START_CODE:
s->key_frame = 1;
s->pict_type = AV_PICTURE_TYPE_I;
return;
case AVS2_INTER_PIC_START_CODE:
s->key_frame = 0;
if (buf_size > 9) {
int pic_code_type = buf[8] & 0x3;
if (pic_code_type == 1)
s->pict_type = AV_PICTURE_TYPE_P;
else if (pic_code_type == 3)
s->pict_type = AV_PICTURE_TYPE_S;
else
s->pict_type = AV_PICTURE_TYPE_B;
}
return;
}
}
static int avs2_parse(AVCodecParserContext *s, AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
ParseContext *pc = s->priv_data;
int next;
if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
next = buf_size;
} else {
next = avs2_find_frame_end(pc, buf, buf_size);
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
}
parse_avs2_units(s, buf, buf_size, avctx);
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
const AVCodecParser ff_avs2_parser = {
.codec_ids = { AV_CODEC_ID_AVS2 },
.priv_data_size = sizeof(ParseContext),
.parser_parse = avs2_parse,
.parser_close = ff_parse_close,
};
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