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/*
* RAW EVC video demuxer
*
* Copyright (c) 2021 Dawid Kozinski <d.kozinski@samsung.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 "libavcodec/evc.h"
#include "libavcodec/bsf.h"
#include "libavutil/opt.h"
#include "avformat.h"
#include "avio_internal.h"
#include "evc.h"
#include "internal.h"
#define RAW_PACKET_SIZE 1024
typedef struct EVCDemuxContext {
const AVClass *class;
AVRational framerate;
AVBSFContext *bsf;
} EVCDemuxContext;
#define DEC AV_OPT_FLAG_DECODING_PARAM
#define OFFSET(x) offsetof(EVCDemuxContext, x)
static const AVOption evc_options[] = {
{ "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, DEC},
{ NULL },
};
#undef OFFSET
static const AVClass evc_demuxer_class = {
.class_name = "EVC Annex B demuxer",
.item_name = av_default_item_name,
.option = evc_options,
.version = LIBAVUTIL_VERSION_INT,
};
static int annexb_probe(const AVProbeData *p)
{
int nalu_type;
size_t nalu_size;
int got_sps = 0, got_pps = 0, got_idr = 0, got_nonidr = 0;
const unsigned char *bits = p->buf;
int bytes_to_read = p->buf_size;
while (bytes_to_read > EVC_NALU_LENGTH_PREFIX_SIZE) {
nalu_size = evc_read_nal_unit_length(bits, EVC_NALU_LENGTH_PREFIX_SIZE);
if (nalu_size == 0) break;
bits += EVC_NALU_LENGTH_PREFIX_SIZE;
bytes_to_read -= EVC_NALU_LENGTH_PREFIX_SIZE;
if(bytes_to_read < nalu_size) break;
nalu_type = evc_get_nalu_type(bits, bytes_to_read);
if (nalu_type == EVC_SPS_NUT)
got_sps++;
else if (nalu_type == EVC_PPS_NUT)
got_pps++;
else if (nalu_type == EVC_IDR_NUT )
got_idr++;
else if (nalu_type == EVC_NOIDR_NUT)
got_nonidr++;
bits += nalu_size;
bytes_to_read -= nalu_size;
}
if (got_sps && got_pps && (got_idr || got_nonidr > 3))
return AVPROBE_SCORE_EXTENSION + 1; // 1 more than .mpg
return 0;
}
static int evc_read_header(AVFormatContext *s)
{
AVStream *st;
FFStream *sti;
const AVBitStreamFilter *filter = av_bsf_get_by_name("evc_frame_merge");
EVCDemuxContext *c = s->priv_data;
int ret = 0;
st = avformat_new_stream(s, NULL);
if (!st) {
ret = AVERROR(ENOMEM);
goto fail;
}
sti = ffstream(st);
st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
st->codecpar->codec_id = AV_CODEC_ID_EVC;
// This causes sending to the parser full frames, not chunks of data
// The flag PARSER_FLAG_COMPLETE_FRAMES will be set in demux.c (demux.c: 1316)
sti->need_parsing = AVSTREAM_PARSE_HEADERS;
st->avg_frame_rate = c->framerate;
// taken from rawvideo demuxers
avpriv_set_pts_info(st, 64, 1, 1200000);
ret = av_bsf_alloc(filter, &c->bsf);
if (ret < 0)
return ret;
ret = avcodec_parameters_copy(c->bsf->par_in, st->codecpar);
if (ret < 0)
return ret;
ret = av_bsf_init(c->bsf);
if (ret < 0)
return ret;
fail:
return ret;
}
static int evc_read_packet(AVFormatContext *s, AVPacket *pkt)
{
int ret;
uint32_t nalu_size;
int au_end_found = 0;
EVCDemuxContext *const c = s->priv_data;
while(!au_end_found) {
uint8_t buf[EVC_NALU_LENGTH_PREFIX_SIZE];
if (avio_feof(s->pb))
goto end;
ret = ffio_ensure_seekback(s->pb, EVC_NALU_LENGTH_PREFIX_SIZE);
if (ret < 0)
return ret;
ret = avio_read(s->pb, buf, EVC_NALU_LENGTH_PREFIX_SIZE);
if (ret < 0)
return ret;
if (ret != EVC_NALU_LENGTH_PREFIX_SIZE)
return AVERROR_INVALIDDATA;
nalu_size = evc_read_nal_unit_length(buf, EVC_NALU_LENGTH_PREFIX_SIZE);
if (!nalu_size || nalu_size > INT_MAX)
return AVERROR_INVALIDDATA;
avio_seek(s->pb, -EVC_NALU_LENGTH_PREFIX_SIZE, SEEK_CUR);
ret = av_get_packet(s->pb, pkt, nalu_size + EVC_NALU_LENGTH_PREFIX_SIZE);
if (ret < 0)
return ret;
if (ret != (nalu_size + EVC_NALU_LENGTH_PREFIX_SIZE))
return AVERROR_INVALIDDATA;
end:
ret = av_bsf_send_packet(c->bsf, pkt);
if (ret < 0) {
av_log(s, AV_LOG_ERROR, "Failed to send packet to "
"evc_frame_merge filter\n");
return ret;
}
ret = av_bsf_receive_packet(c->bsf, pkt);
if (ret < 0 && ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)
av_log(s, AV_LOG_ERROR, "evc_frame_merge filter failed to "
"send output packet\n");
if (ret != AVERROR(EAGAIN))
au_end_found = 1;
}
return ret;
}
static int evc_read_close(AVFormatContext *s)
{
EVCDemuxContext *const c = s->priv_data;
av_bsf_free(&c->bsf);
return 0;
}
const AVInputFormat ff_evc_demuxer = {
.name = "evc",
.long_name = NULL_IF_CONFIG_SMALL("EVC Annex B"),
.read_probe = annexb_probe,
.read_header = evc_read_header, // annexb_read_header
.read_packet = evc_read_packet, // annexb_read_packet
.read_close = evc_read_close,
.extensions = "evc",
.flags = AVFMT_GENERIC_INDEX | AVFMT_NOTIMESTAMPS,
.flags_internal = FF_FMT_INIT_CLEANUP,
.raw_codec_id = AV_CODEC_ID_EVC,
.priv_data_size = sizeof(EVCDemuxContext),
.priv_class = &evc_demuxer_class,
};
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