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/*
* 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
* This bitstream filter splits VP9 superframes into packets containing
* just one frame.
*/
#include <stddef.h>
#include "avcodec.h"
#include "bsf.h"
#include "bitstream.h"
#include "bytestream.h"
typedef struct VP9SFSplitContext {
AVPacket *buffer_pkt;
int nb_frames;
int next_frame;
size_t next_frame_offset;
int sizes[8];
} VP9SFSplitContext;
static int vp9_superframe_split_filter(AVBSFContext *ctx, AVPacket *out)
{
VP9SFSplitContext *s = ctx->priv_data;
AVPacket *in;
int i, j, ret, marker;
int is_superframe = !!s->buffer_pkt;
if (!s->buffer_pkt) {
ret = ff_bsf_get_packet(ctx, &s->buffer_pkt);
if (ret < 0)
return ret;
in = s->buffer_pkt;
marker = in->data[in->size - 1];
if ((marker & 0xe0) == 0xc0) {
int length_size = 1 + ((marker >> 3) & 0x3);
int nb_frames = 1 + (marker & 0x7);
int idx_size = 2 + nb_frames * length_size;
if (in->size >= idx_size && in->data[in->size - idx_size] == marker) {
GetByteContext bc;
int total_size = 0;
bytestream2_init(&bc, in->data + in->size + 1 - idx_size,
nb_frames * length_size);
for (i = 0; i < nb_frames; i++) {
int frame_size = 0;
for (j = 0; j < length_size; j++)
frame_size |= bytestream2_get_byte(&bc) << (j * 8);
total_size += frame_size;
if (total_size > in->size - idx_size) {
av_log(ctx, AV_LOG_ERROR,
"Invalid frame size in a superframe: %d\n", frame_size);
ret = AVERROR(EINVAL);
goto fail;
}
s->sizes[i] = frame_size;
}
s->nb_frames = nb_frames;
s->next_frame = 0;
s->next_frame_offset = 0;
is_superframe = 1;
}
}
}
if (is_superframe) {
BitstreamContext bc;
int profile, invisible = 0;
ret = av_packet_ref(out, s->buffer_pkt);
if (ret < 0)
goto fail;
out->data += s->next_frame_offset;
out->size = s->sizes[s->next_frame];
s->next_frame_offset += out->size;
s->next_frame++;
if (s->next_frame >= s->nb_frames)
av_packet_free(&s->buffer_pkt);
ret = bitstream_init8(&bc, out->data, out->size);
if (ret < 0)
goto fail;
bitstream_read(&bc, 2); // frame_marker
profile = bitstream_read(&bc, 1);
profile |= bitstream_read(&bc, 1) << 1;
if (profile == 3)
bitstream_read(&bc, 1);
if (!bitstream_read(&bc, 1)) {
bitstream_read(&bc, 1);
invisible = !bitstream_read(&bc, 1);
}
if (invisible)
out->pts = AV_NOPTS_VALUE;
} else {
av_packet_move_ref(out, s->buffer_pkt);
av_packet_free(&s->buffer_pkt);
}
return 0;
fail:
av_packet_free(&s->buffer_pkt);
return ret;
}
static void vp9_superframe_split_uninit(AVBSFContext *ctx)
{
VP9SFSplitContext *s = ctx->priv_data;
av_packet_free(&s->buffer_pkt);
}
const AVBitStreamFilter ff_vp9_superframe_split_bsf = {
.name = "vp9_superframe_split",
.priv_data_size = sizeof(VP9SFSplitContext),
.close = vp9_superframe_split_uninit,
.filter = vp9_superframe_split_filter,
.codec_ids = (const enum AVCodecID []){ AV_CODEC_ID_VP9, AV_CODEC_ID_NONE },
};
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