ffmpeg/libavformat/segment.c

328 lines
9.7 KiB
C

/*
* Generic segmenter
* Copyright (c) 2011, Luca Barbato
*
* 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 <float.h>
#include "avformat.h"
#include "internal.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "libavutil/avstring.h"
#include "libavutil/parseutils.h"
#include "libavutil/mathematics.h"
typedef struct {
const AVClass *class; /**< Class for private options. */
int number;
AVOutputFormat *oformat;
AVFormatContext *avf;
char *format; /**< Set by a private option. */
char *list; /**< Set by a private option. */
float time; /**< Set by a private option. */
int size; /**< Set by a private option. */
int wrap; /**< Set by a private option. */
int individual_header_trailer; /**< Set by a private option. */
int write_header_trailer; /**< Set by a private option. */
int64_t offset_time;
int64_t recording_time;
int has_video;
AVIOContext *pb;
} SegmentContext;
static int segment_mux_init(AVFormatContext *s)
{
SegmentContext *seg = s->priv_data;
AVFormatContext *oc;
int i;
seg->avf = oc = avformat_alloc_context();
if (!oc)
return AVERROR(ENOMEM);
oc->oformat = seg->oformat;
oc->interrupt_callback = s->interrupt_callback;
for (i = 0; i < s->nb_streams; i++) {
AVStream *st;
if (!(st = avformat_new_stream(oc, NULL)))
return AVERROR(ENOMEM);
avcodec_copy_context(st->codec, s->streams[i]->codec);
st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
}
return 0;
}
static int segment_start(AVFormatContext *s, int write_header)
{
SegmentContext *c = s->priv_data;
AVFormatContext *oc = c->avf;
int err = 0;
if (write_header) {
avformat_free_context(oc);
c->avf = NULL;
if ((err = segment_mux_init(s)) < 0)
return err;
oc = c->avf;
}
if (c->wrap)
c->number %= c->wrap;
if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
s->filename, c->number++) < 0)
return AVERROR(EINVAL);
if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
&s->interrupt_callback, NULL)) < 0)
return err;
if (oc->oformat->priv_class && oc->priv_data)
av_opt_set(oc->priv_data, "resend_headers", "1", 0); /* mpegts specific */
if (write_header) {
if ((err = avformat_write_header(oc, NULL)) < 0)
return err;
}
return 0;
}
static int segment_end(AVFormatContext *oc, int write_trailer)
{
int ret = 0;
av_write_frame(oc, NULL); /* Flush any buffered data (fragmented mp4) */
if (write_trailer)
av_write_trailer(oc);
avio_close(oc->pb);
return ret;
}
static int open_null_ctx(AVIOContext **ctx)
{
int buf_size = 32768;
uint8_t *buf = av_malloc(buf_size);
if (!buf)
return AVERROR(ENOMEM);
*ctx = avio_alloc_context(buf, buf_size, AVIO_FLAG_WRITE, NULL, NULL, NULL, NULL);
if (!*ctx) {
av_free(buf);
return AVERROR(ENOMEM);
}
return 0;
}
static void close_null_ctx(AVIOContext *pb)
{
av_free(pb->buffer);
av_free(pb);
}
static int seg_write_header(AVFormatContext *s)
{
SegmentContext *seg = s->priv_data;
AVFormatContext *oc = NULL;
int ret, i;
seg->number = 0;
seg->offset_time = 0;
seg->recording_time = seg->time * 1000000;
if (!seg->write_header_trailer)
seg->individual_header_trailer = 0;
if (seg->list)
if ((ret = avio_open2(&seg->pb, seg->list, AVIO_FLAG_WRITE,
&s->interrupt_callback, NULL)) < 0)
goto fail;
for (i = 0; i < s->nb_streams; i++)
seg->has_video +=
(s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO);
if (seg->has_video > 1)
av_log(s, AV_LOG_WARNING,
"More than a single video stream present, "
"expect issues decoding it.\n");
seg->oformat = av_guess_format(seg->format, s->filename, NULL);
if (!seg->oformat) {
ret = AVERROR_MUXER_NOT_FOUND;
goto fail;
}
if (seg->oformat->flags & AVFMT_NOFILE) {
av_log(s, AV_LOG_ERROR, "format %s not supported.\n",
oc->oformat->name);
ret = AVERROR(EINVAL);
goto fail;
}
if ((ret = segment_mux_init(s)) < 0)
goto fail;
oc = seg->avf;
if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
s->filename, seg->number++) < 0) {
ret = AVERROR(EINVAL);
goto fail;
}
if (seg->write_header_trailer) {
if ((ret = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
&s->interrupt_callback, NULL)) < 0)
goto fail;
} else {
if ((ret = open_null_ctx(&oc->pb)) < 0)
goto fail;
}
if ((ret = avformat_write_header(oc, NULL)) < 0) {
avio_close(oc->pb);
goto fail;
}
if (!seg->write_header_trailer) {
close_null_ctx(oc->pb);
if ((ret = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
&s->interrupt_callback, NULL)) < 0)
goto fail;
}
if (seg->list) {
avio_printf(seg->pb, "%s\n", oc->filename);
avio_flush(seg->pb);
}
fail:
if (ret) {
if (seg->list)
avio_close(seg->pb);
if (seg->avf)
avformat_free_context(seg->avf);
}
return ret;
}
static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
{
SegmentContext *seg = s->priv_data;
AVFormatContext *oc = seg->avf;
AVStream *st = s->streams[pkt->stream_index];
int64_t end_pts = seg->recording_time * seg->number;
int ret;
if ((seg->has_video && st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
av_compare_ts(pkt->pts, st->time_base,
end_pts, AV_TIME_BASE_Q) >= 0 &&
pkt->flags & AV_PKT_FLAG_KEY) {
av_log(s, AV_LOG_DEBUG, "Next segment starts at %d %"PRId64"\n",
pkt->stream_index, pkt->pts);
ret = segment_end(oc, seg->individual_header_trailer);
if (!ret)
ret = segment_start(s, seg->individual_header_trailer);
if (ret)
goto fail;
oc = seg->avf;
if (seg->list) {
avio_printf(seg->pb, "%s\n", oc->filename);
avio_flush(seg->pb);
if (seg->size && !(seg->number % seg->size)) {
avio_close(seg->pb);
if ((ret = avio_open2(&seg->pb, seg->list, AVIO_FLAG_WRITE,
&s->interrupt_callback, NULL)) < 0)
goto fail;
}
}
}
ret = ff_write_chained(oc, pkt->stream_index, pkt, s);
fail:
if (ret < 0) {
if (seg->list)
avio_close(seg->pb);
avformat_free_context(oc);
}
return ret;
}
static int seg_write_trailer(struct AVFormatContext *s)
{
SegmentContext *seg = s->priv_data;
AVFormatContext *oc = seg->avf;
int ret;
if (!seg->write_header_trailer) {
ret = segment_end(oc, 0);
open_null_ctx(&oc->pb);
av_write_trailer(oc);
close_null_ctx(oc->pb);
} else {
ret = segment_end(oc, 1);
}
if (seg->list)
avio_close(seg->pb);
avformat_free_context(oc);
return ret;
}
#define OFFSET(x) offsetof(SegmentContext, x)
#define E AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
{ "segment_format", "container format used for the segments", OFFSET(format), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
{ "segment_time", "segment length in seconds", OFFSET(time), AV_OPT_TYPE_FLOAT, {.dbl = 2}, 0, FLT_MAX, E },
{ "segment_list", "output the segment list", OFFSET(list), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, E },
{ "segment_list_size", "maximum number of playlist entries", OFFSET(size), AV_OPT_TYPE_INT, {.i64 = 5}, 0, INT_MAX, E },
{ "segment_wrap", "number after which the index wraps", OFFSET(wrap), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, E },
{ "individual_header_trailer", "write header/trailer to each segment", OFFSET(individual_header_trailer), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, E },
{ "write_header_trailer", "write a header to the first segment and a trailer to the last one", OFFSET(write_header_trailer), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, E },
{ NULL },
};
static const AVClass seg_class = {
.class_name = "segment muxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVOutputFormat ff_segment_muxer = {
.name = "segment",
.long_name = NULL_IF_CONFIG_SMALL("segment"),
.priv_data_size = sizeof(SegmentContext),
.flags = AVFMT_NOFILE,
.write_header = seg_write_header,
.write_packet = seg_write_packet,
.write_trailer = seg_write_trailer,
.priv_class = &seg_class,
};