ffmpeg/libavformat/mux_utils.c

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/*
* Various muxing utility functions
* Copyright (c) 2000, 2001, 2002 Fabrice Bellard
*
* 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/dict.h"
#include "libavutil/dict_internal.h"
#include "libavutil/internal.h"
#include "libavutil/log.h"
#include "libavutil/mem.h"
#include "libavutil/parseutils.h"
#include "avformat.h"
#include "avio.h"
#include "internal.h"
#include "mux.h"
int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id,
int std_compliance)
{
if (ofmt) {
unsigned int codec_tag;
if (ffofmt(ofmt)->query_codec)
return ffofmt(ofmt)->query_codec(codec_id, std_compliance);
else if (ofmt->codec_tag)
return !!av_codec_get_tag2(ofmt->codec_tag, codec_id, &codec_tag);
else if (codec_id == ofmt->video_codec ||
codec_id == ofmt->audio_codec ||
codec_id == ofmt->subtitle_codec)
return 1;
}
return AVERROR_PATCHWELCOME;
}
int ff_format_shift_data(AVFormatContext *s, int64_t read_start, int shift_size)
{
int ret;
int64_t pos, pos_end;
uint8_t *buf, *read_buf[2];
int read_buf_id = 0;
int read_size[2];
AVIOContext *read_pb;
buf = av_malloc_array(shift_size, 2);
if (!buf)
return AVERROR(ENOMEM);
read_buf[0] = buf;
read_buf[1] = buf + shift_size;
/* Shift the data: the AVIO context of the output can only be used for
* writing, so we re-open the same output, but for reading. It also avoids
* a read/seek/write/seek back and forth. */
avio_flush(s->pb);
ret = s->io_open(s, &read_pb, s->url, AVIO_FLAG_READ, NULL);
if (ret < 0) {
av_log(s, AV_LOG_ERROR, "Unable to re-open %s output file for shifting data\n", s->url);
goto end;
}
/* mark the end of the shift to up to the last data we wrote, and get ready
* for writing */
pos_end = avio_tell(s->pb);
avio_seek(s->pb, read_start + shift_size, SEEK_SET);
avio_seek(read_pb, read_start, SEEK_SET);
pos = avio_tell(read_pb);
#define READ_BLOCK do { \
read_size[read_buf_id] = avio_read(read_pb, read_buf[read_buf_id], shift_size); \
read_buf_id ^= 1; \
} while (0)
/* shift data by chunk of at most shift_size */
READ_BLOCK;
do {
int n;
READ_BLOCK;
n = read_size[read_buf_id];
if (n <= 0)
break;
avio_write(s->pb, read_buf[read_buf_id], n);
pos += n;
} while (pos < pos_end);
ret = ff_format_io_close(s, &read_pb);
end:
av_free(buf);
return ret;
}
int ff_format_output_open(AVFormatContext *s, const char *url, AVDictionary **options)
{
if (!s->oformat)
return AVERROR(EINVAL);
if (!(s->oformat->flags & AVFMT_NOFILE))
return s->io_open(s, &s->pb, url, AVIO_FLAG_WRITE, options);
return 0;
}
int ff_parse_creation_time_metadata(AVFormatContext *s, int64_t *timestamp, int return_seconds)
{
AVDictionaryEntry *entry;
int64_t parsed_timestamp;
int ret;
if ((entry = av_dict_get(s->metadata, "creation_time", NULL, 0))) {
if ((ret = av_parse_time(&parsed_timestamp, entry->value, 0)) >= 0) {
*timestamp = return_seconds ? parsed_timestamp / 1000000 : parsed_timestamp;
return 1;
} else {
av_log(s, AV_LOG_WARNING, "Failed to parse creation_time %s\n", entry->value);
return ret;
}
}
return 0;
}
int ff_standardize_creation_time(AVFormatContext *s)
{
int64_t timestamp;
int ret = ff_parse_creation_time_metadata(s, &timestamp, 0);
if (ret == 1)
return avpriv_dict_set_timestamp(&s->metadata, "creation_time", timestamp);
return ret;
}