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/*
* VP9 compatible video decoder
*
* Copyright (C) 2013 Ronald S. Bultje <rsbultje gmail com>
* Copyright (C) 2013 Clément Bœsch <u pkh me>
*
* 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/intreadwrite.h"
#include "parser.h"
typedef struct VP9ParseContext {
int n_frames; // 1-8
int size[8];
} VP9ParseContext;
static void parse_frame(AVCodecParserContext *ctx, const uint8_t *buf, int size)
{
if (buf[0] & 0x4) {
ctx->pict_type = AV_PICTURE_TYPE_P;
ctx->key_frame = 0;
} else {
ctx->pict_type = AV_PICTURE_TYPE_I;
ctx->key_frame = 1;
}
}
static int parse(AVCodecParserContext *ctx,
AVCodecContext *avctx,
const uint8_t **out_data, int *out_size,
const uint8_t *data, int size)
{
VP9ParseContext *s = ctx->priv_data;
int full_size = size;
int marker;
if (size <= 0) {
*out_size = 0;
*out_data = data;
return 0;
}
if (s->n_frames > 0) {
*out_data = data;
*out_size = s->size[--s->n_frames];
parse_frame(ctx, *out_data, *out_size);
return s->n_frames > 0 ? *out_size : size /* i.e. include idx tail */;
}
marker = data[size - 1];
if ((marker & 0xe0) == 0xc0) {
int nbytes = 1 + ((marker >> 3) & 0x3);
int n_frames = 1 + (marker & 0x7), idx_sz = 2 + n_frames * nbytes;
if (size >= idx_sz && data[size - idx_sz] == marker) {
const uint8_t *idx = data + size + 1 - idx_sz;
int first = 1;
switch (nbytes) {
#define case_n(a, rd) \
case a: \
while (n_frames--) { \
unsigned sz = rd; \
idx += a; \
if (sz > size) { \
s->n_frames = 0; \
*out_size = size; \
*out_data = data; \
av_log(avctx, AV_LOG_ERROR, \
"Superframe packet size too big: %u > %d\n", \
sz, size); \
return full_size; \
} \
if (first) { \
first = 0; \
*out_data = data; \
*out_size = sz; \
s->n_frames = n_frames; \
} else { \
s->size[n_frames] = sz; \
} \
data += sz; \
size -= sz; \
} \
parse_frame(ctx, *out_data, *out_size); \
return *out_size
case_n(1, *idx);
case_n(2, AV_RL16(idx));
case_n(3, AV_RL24(idx));
case_n(4, AV_RL32(idx));
}
}
}
*out_data = data;
*out_size = size;
parse_frame(ctx, data, size);
return size;
}
AVCodecParser ff_vp9_parser = {
.codec_ids = { AV_CODEC_ID_VP9 },
.priv_data_size = sizeof(VP9ParseContext),
.parser_parse = parse,
};
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