Some (de)muxers open additional files beyond the main IO context. Currently, they call avio_open() directly, which prevents the caller from using custom IO for such streams. This commit adds callbacks to AVFormatContext that default to avio_open2()/avio_close(), but can be overridden by the caller. All muxers and demuxers using AVIO are switched to using those callbacks instead of calling avio_open()/avio_close() directly. (de)muxers that use the URLProtocol layer directly instead of AVIO remain unconverted for now. This should be fixed in later commits.
		
			
				
	
	
		
			410 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			410 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Generic segmenter
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 * Copyright (c) 2011, Luca Barbato
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 *
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 * This file is part of Libav.
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 *
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 * Libav is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * Libav is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with Libav; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include <float.h>
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#include "avformat.h"
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#include "internal.h"
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#include "libavutil/log.h"
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#include "libavutil/opt.h"
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#include "libavutil/avstring.h"
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#include "libavutil/parseutils.h"
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#include "libavutil/mathematics.h"
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typedef struct SegmentContext {
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    const AVClass *class;  /**< Class for private options. */
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    int number;
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    AVOutputFormat *oformat;
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    AVFormatContext *avf;
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    char *format;          /**< Set by a private option. */
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    char *list;            /**< Set by a private option. */
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    char *entry_prefix;    /**< Set by a private option. */
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    int  list_type;        /**< Set by a private option. */
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    float time;            /**< Set by a private option. */
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    int  size;             /**< Set by a private option. */
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    int  wrap;             /**< Set by a private option. */
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    int  individual_header_trailer; /**< Set by a private option. */
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    int  write_header_trailer; /**< Set by a private option. */
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    int64_t offset_time;
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    int64_t recording_time;
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    int has_video;
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    AVIOContext *pb;
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} SegmentContext;
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enum {
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    LIST_FLAT,
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    LIST_HLS
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};
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static int segment_mux_init(AVFormatContext *s)
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{
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    SegmentContext *seg = s->priv_data;
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    AVFormatContext *oc;
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    int i;
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    seg->avf = oc = avformat_alloc_context();
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    if (!oc)
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        return AVERROR(ENOMEM);
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    oc->oformat            = seg->oformat;
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    oc->interrupt_callback = s->interrupt_callback;
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    oc->opaque             = s->opaque;
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    oc->io_close           = s->io_close;
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    oc->io_open            = s->io_open;
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    for (i = 0; i < s->nb_streams; i++) {
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        AVStream *st;
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        if (!(st = avformat_new_stream(oc, NULL)))
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            return AVERROR(ENOMEM);
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        avcodec_copy_context(st->codec, s->streams[i]->codec);
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        st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
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        st->time_base = s->streams[i]->time_base;
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    }
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    return 0;
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}
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static int segment_hls_window(AVFormatContext *s, int last)
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{
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    SegmentContext *seg = s->priv_data;
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    int i, ret = 0;
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    char buf[1024];
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    if ((ret = s->io_open(s, &seg->pb, seg->list, AVIO_FLAG_WRITE, NULL)) < 0)
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        goto fail;
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    avio_printf(seg->pb, "#EXTM3U\n");
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    avio_printf(seg->pb, "#EXT-X-VERSION:3\n");
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    avio_printf(seg->pb, "#EXT-X-TARGETDURATION:%d\n", (int)seg->time);
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    avio_printf(seg->pb, "#EXT-X-MEDIA-SEQUENCE:%d\n",
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                FFMAX(0, seg->number - seg->size));
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    av_log(s, AV_LOG_VERBOSE, "EXT-X-MEDIA-SEQUENCE:%d\n",
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           FFMAX(0, seg->number - seg->size));
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    for (i = FFMAX(0, seg->number - seg->size);
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         i < seg->number; i++) {
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        avio_printf(seg->pb, "#EXTINF:%d,\n", (int)seg->time);
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        if (seg->entry_prefix) {
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            avio_printf(seg->pb, "%s", seg->entry_prefix);
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        }
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        ret = av_get_frame_filename(buf, sizeof(buf), s->filename, i);
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        if (ret < 0) {
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            ret = AVERROR(EINVAL);
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            goto fail;
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        }
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        avio_printf(seg->pb, "%s\n", buf);
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    }
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    if (last)
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        avio_printf(seg->pb, "#EXT-X-ENDLIST\n");
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fail:
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    ff_format_io_close(s, &seg->pb);
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    return ret;
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}
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static int segment_start(AVFormatContext *s, int write_header)
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{
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    SegmentContext *c = s->priv_data;
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    AVFormatContext *oc = c->avf;
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    int err = 0;
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    if (write_header) {
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        avformat_free_context(oc);
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        c->avf = NULL;
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        if ((err = segment_mux_init(s)) < 0)
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            return err;
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        oc = c->avf;
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    }
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    if (c->wrap)
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        c->number %= c->wrap;
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    if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
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                              s->filename, c->number++) < 0)
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        return AVERROR(EINVAL);
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    if ((err = s->io_open(s, &oc->pb, oc->filename, AVIO_FLAG_WRITE, NULL)) < 0)
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        return err;
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    if (oc->oformat->priv_class && oc->priv_data)
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        av_opt_set(oc->priv_data, "resend_headers", "1", 0); /* mpegts specific */
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    if (write_header) {
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        if ((err = avformat_write_header(oc, NULL)) < 0)
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            return err;
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    }
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    return 0;
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}
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static int segment_end(AVFormatContext *oc, int write_trailer)
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{
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    int ret = 0;
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    av_write_frame(oc, NULL); /* Flush any buffered data (fragmented mp4) */
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    if (write_trailer)
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        av_write_trailer(oc);
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    ff_format_io_close(oc, &oc->pb);
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    return ret;
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}
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static int open_null_ctx(AVIOContext **ctx)
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{
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    int buf_size = 32768;
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    uint8_t *buf = av_malloc(buf_size);
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    if (!buf)
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        return AVERROR(ENOMEM);
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    *ctx = avio_alloc_context(buf, buf_size, AVIO_FLAG_WRITE, NULL, NULL, NULL, NULL);
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    if (!*ctx) {
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        av_free(buf);
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        return AVERROR(ENOMEM);
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    }
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    return 0;
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}
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static void close_null_ctx(AVIOContext *pb)
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{
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    av_free(pb->buffer);
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    av_free(pb);
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}
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static void seg_free_context(SegmentContext *seg)
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{
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    ff_format_io_close(seg->avf, &seg->pb);
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    avformat_free_context(seg->avf);
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    seg->avf = NULL;
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}
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static int seg_write_header(AVFormatContext *s)
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{
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    SegmentContext *seg = s->priv_data;
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    AVFormatContext *oc = NULL;
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    int ret, i;
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    seg->number = 0;
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    seg->offset_time = 0;
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    seg->recording_time = seg->time * 1000000;
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    if (!seg->write_header_trailer)
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        seg->individual_header_trailer = 0;
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    if (seg->list && seg->list_type != LIST_HLS)
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        if ((ret = s->io_open(s, &seg->pb, seg->list, AVIO_FLAG_WRITE, NULL)) < 0)
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            goto fail;
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    for (i = 0; i < s->nb_streams; i++)
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        seg->has_video +=
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            (s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO);
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    if (seg->has_video > 1)
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        av_log(s, AV_LOG_WARNING,
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               "More than a single video stream present, "
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               "expect issues decoding it.\n");
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    seg->oformat = av_guess_format(seg->format, s->filename, NULL);
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    if (!seg->oformat) {
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        ret = AVERROR_MUXER_NOT_FOUND;
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        goto fail;
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    }
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    if (seg->oformat->flags & AVFMT_NOFILE) {
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        av_log(s, AV_LOG_ERROR, "format %s not supported.\n",
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               seg->oformat->name);
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        ret = AVERROR(EINVAL);
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        goto fail;
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    }
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    if ((ret = segment_mux_init(s)) < 0)
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        goto fail;
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    oc = seg->avf;
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    if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
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                              s->filename, seg->number++) < 0) {
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        ret = AVERROR(EINVAL);
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        goto fail;
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    }
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    if (seg->write_header_trailer) {
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        if ((ret = s->io_open(s, &oc->pb, oc->filename, AVIO_FLAG_WRITE, NULL)) < 0)
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            goto fail;
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    } else {
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        if ((ret = open_null_ctx(&oc->pb)) < 0)
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            goto fail;
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    }
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    if ((ret = avformat_write_header(oc, NULL)) < 0) {
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        ff_format_io_close(oc, &oc->pb);
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        goto fail;
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    }
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    if (!seg->write_header_trailer) {
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        close_null_ctx(oc->pb);
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        if ((ret = s->io_open(s, &oc->pb, oc->filename, AVIO_FLAG_WRITE, NULL)) < 0)
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            goto fail;
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    }
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    if (seg->list) {
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        if (seg->list_type == LIST_HLS) {
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            if ((ret = segment_hls_window(s, 0)) < 0)
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                goto fail;
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        } else {
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            avio_printf(seg->pb, "%s\n", oc->filename);
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            avio_flush(seg->pb);
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        }
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    }
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fail:
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    if (ret < 0)
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        seg_free_context(seg);
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    return ret;
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}
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static int seg_write_packet(AVFormatContext *s, AVPacket *pkt)
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{
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    SegmentContext *seg = s->priv_data;
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    AVFormatContext *oc = seg->avf;
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    AVStream *st = s->streams[pkt->stream_index];
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    int64_t end_pts = seg->recording_time * seg->number;
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    int ret, can_split = 1;
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    if (!oc)
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        return AVERROR(EINVAL);
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    if (seg->has_video) {
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        can_split = st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
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                    pkt->flags & AV_PKT_FLAG_KEY;
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    }
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    if (can_split && av_compare_ts(pkt->pts, st->time_base, end_pts,
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                                   AV_TIME_BASE_Q) >= 0) {
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        av_log(s, AV_LOG_DEBUG, "Next segment starts at %d %"PRId64"\n",
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               pkt->stream_index, pkt->pts);
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        ret = segment_end(oc, seg->individual_header_trailer);
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        if (!ret)
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            ret = segment_start(s, seg->individual_header_trailer);
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        if (ret)
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            goto fail;
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        oc = seg->avf;
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        if (seg->list) {
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            if (seg->list_type == LIST_HLS) {
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                if ((ret = segment_hls_window(s, 0)) < 0)
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                    goto fail;
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            } else {
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                avio_printf(seg->pb, "%s\n", oc->filename);
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                avio_flush(seg->pb);
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                if (seg->size && !(seg->number % seg->size)) {
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                    ff_format_io_close(s, &seg->pb);
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                    if ((ret = s->io_open(s, &seg->pb, seg->list,
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                                          AVIO_FLAG_WRITE, NULL)) < 0)
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                        goto fail;
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                }
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            }
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        }
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    }
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    ret = ff_write_chained(oc, pkt->stream_index, pkt, s);
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fail:
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    if (ret < 0)
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        seg_free_context(seg);
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    return ret;
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}
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static int seg_write_trailer(struct AVFormatContext *s)
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{
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    SegmentContext *seg = s->priv_data;
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    AVFormatContext *oc = seg->avf;
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    int ret = 0;
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    if (!oc)
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        goto fail;
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    if (!seg->write_header_trailer) {
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        if ((ret = segment_end(oc, 0)) < 0)
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            goto fail;
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        if ((ret = open_null_ctx(&oc->pb)) < 0)
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            goto fail;
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        ret = av_write_trailer(oc);
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        close_null_ctx(oc->pb);
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    } else {
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        ret = segment_end(oc, 1);
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    }
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    if (ret < 0)
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        goto fail;
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    if (seg->list && seg->list_type == LIST_HLS) {
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        if ((ret = segment_hls_window(s, 1) < 0))
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            goto fail;
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    }
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fail:
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    ff_format_io_close(s, &seg->pb);
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    avformat_free_context(oc);
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    return ret;
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}
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#define OFFSET(x) offsetof(SegmentContext, x)
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#define E AV_OPT_FLAG_ENCODING_PARAM
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static const AVOption options[] = {
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    { "segment_format",    "container format used for the segments",  OFFSET(format),  AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },
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    { "segment_time",      "segment length in seconds",               OFFSET(time),    AV_OPT_TYPE_FLOAT,  {.dbl = 2},     0, FLT_MAX, E },
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    { "segment_list",      "output the segment list",                 OFFSET(list),    AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },
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    { "segment_list_size", "maximum number of playlist entries",      OFFSET(size),    AV_OPT_TYPE_INT,    {.i64 = 5},     0, INT_MAX, E },
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    { "segment_list_type", "segment list format",                     OFFSET(list_type),    AV_OPT_TYPE_INT,    {.i64 = LIST_FLAT},     0, 2, E, "list_type" },
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    {   "flat",            "plain list (default)",                    0,               AV_OPT_TYPE_CONST,  {.i64 = LIST_FLAT}, 0, 0, E, "list_type" },
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    {   "hls",             "Apple HTTP Live Streaming compatible",    0,               AV_OPT_TYPE_CONST,  {.i64 = LIST_HLS},  0, 0, E, "list_type" },
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    { "segment_wrap",      "number after which the index wraps",      OFFSET(wrap),    AV_OPT_TYPE_INT,    {.i64 = 0},     0, INT_MAX, E },
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    { "segment_list_entry_prefix",  "base url prefix for segments",   OFFSET(entry_prefix), AV_OPT_TYPE_STRING, {.str = NULL},  0, 0,       E },
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    { "individual_header_trailer", "write header/trailer to each segment", OFFSET(individual_header_trailer), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, E },
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    { "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 },
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    { NULL },
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};
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 | 
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static const AVClass seg_class = {
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    .class_name = "segment muxer",
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    .item_name  = av_default_item_name,
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    .option     = options,
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    .version    = LIBAVUTIL_VERSION_INT,
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};
 | 
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 | 
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 | 
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AVOutputFormat ff_segment_muxer = {
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    .name           = "segment",
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    .long_name      = NULL_IF_CONFIG_SMALL("segment"),
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    .priv_data_size = sizeof(SegmentContext),
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						|
    .flags          = AVFMT_NOFILE,
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						|
    .write_header   = seg_write_header,
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						|
    .write_packet   = seg_write_packet,
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    .write_trailer  = seg_write_trailer,
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    .priv_class     = &seg_class,
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};
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