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mirror of https://git.videolan.org/git/ffmpeg.git synced 2024-09-10 17:41:09 +02:00
ffmpeg/libavformat/assenc.c
Clément Bœsch 7308439158 lavf: Don't explicitly flush after each written packet in muxers
Since 596e5d4783, this is not necessary anymore. It also allows to
actually disable the flushing, improving write performance (but
possibly giving worse latency in real-time streaming).

Signed-off-by: Martin Storsjö <martin@martin.st>
2013-09-16 22:17:33 +03:00

87 lines
2.5 KiB
C

/*
* SSA/ASS muxer
* Copyright (c) 2008 Michael Niedermayer
*
* 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 "avformat.h"
typedef struct ASSContext{
unsigned int extra_index;
}ASSContext;
static int write_header(AVFormatContext *s)
{
ASSContext *ass = s->priv_data;
AVCodecContext *avctx= s->streams[0]->codec;
uint8_t *last= NULL;
if(s->nb_streams != 1 || avctx->codec_id != AV_CODEC_ID_SSA){
av_log(s, AV_LOG_ERROR, "Exactly one ASS/SSA stream is needed.\n");
return -1;
}
while(ass->extra_index < avctx->extradata_size){
uint8_t *p = avctx->extradata + ass->extra_index;
uint8_t *end= strchr(p, '\n');
if(!end) end= avctx->extradata + avctx->extradata_size;
else end++;
avio_write(s->pb, p, end-p);
ass->extra_index += end-p;
if(last && !memcmp(last, "[Events]", 8))
break;
last=p;
}
avio_flush(s->pb);
return 0;
}
static int write_packet(AVFormatContext *s, AVPacket *pkt)
{
avio_write(s->pb, pkt->data, pkt->size);
return 0;
}
static int write_trailer(AVFormatContext *s)
{
ASSContext *ass = s->priv_data;
AVCodecContext *avctx= s->streams[0]->codec;
avio_write(s->pb, avctx->extradata + ass->extra_index,
avctx->extradata_size - ass->extra_index);
return 0;
}
AVOutputFormat ff_ass_muxer = {
.name = "ass",
.long_name = NULL_IF_CONFIG_SMALL("SSA (SubStation Alpha) subtitle"),
.mime_type = "text/x-ssa",
.extensions = "ass,ssa",
.priv_data_size = sizeof(ASSContext),
.subtitle_codec = AV_CODEC_ID_SSA,
.write_header = write_header,
.write_packet = write_packet,
.write_trailer = write_trailer,
.flags = AVFMT_GLOBALHEADER | AVFMT_NOTIMESTAMPS,
};