libavformat/hlsproto.c - manifest_repos/ffmpeg - Git at Google

 /*
  * Apple HTTP Live Streaming Protocol Handler
  * Copyright (c) 2010 Martin Storsjo
  *
  * 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
  */

 /**
  * @file
  * Apple HTTP Live Streaming Protocol Handler
  * http://tools.ietf.org/html/draft-pantos-http-live-streaming
  */

 #include "libavutil/avstring.h"
 #include "libavutil/time.h"
 #include "avformat.h"
 #include "avio_internal.h"
 #include "internal.h"
 #include "url.h"
 #include "version.h"

 /*
  * An apple http stream consists of a playlist with media segment files,
  * played sequentially. There may be several playlists with the same
  * video content, in different bandwidth variants, that are played in
  * parallel (preferably only one bandwidth variant at a time). In this case,
  * the user supplied the url to a main playlist that only lists the variant
  * playlists.
  *
  * If the main playlist doesn't point at any variants, we still create
  * one anonymous toplevel variant for this, to maintain the structure.
  */

 struct segment {
     int64_t duration;
     char url[MAX_URL_SIZE];
 };

 struct variant {
     int bandwidth;
     char url[MAX_URL_SIZE];
 };

 typedef struct HLSContext {
     char playlisturl[MAX_URL_SIZE];
     int64_t target_duration;
     int start_seq_no;
     int finished;
     int n_segments;
     struct segment **segments;
     int n_variants;
     struct variant **variants;
     int cur_seq_no;
     URLContext *seg_hd;
     int64_t last_load_time;
 } HLSContext;

 static void free_segment_list(HLSContext *s)
 {
     int i;
     for (i = 0; i < s->n_segments; i++)
         av_freep(&s->segments[i]);
     av_freep(&s->segments);
     s->n_segments = 0;
 }

 static void free_variant_list(HLSContext *s)
 {
     int i;
     for (i = 0; i < s->n_variants; i++)
         av_freep(&s->variants[i]);
     av_freep(&s->variants);
     s->n_variants = 0;
 }

 struct variant_info {
     char bandwidth[20];
 };

 static void handle_variant_args(struct variant_info *info, const char *key,
                                 int key_len, char **dest, int *dest_len)
 {
     if (!strncmp(key, "BANDWIDTH=", key_len)) {
         *dest     =        info->bandwidth;
         *dest_len = sizeof(info->bandwidth);
     }
 }

 static int parse_playlist(URLContext *h, const char *url)
 {
     HLSContext *s = h->priv_data;
     AVIOContext *in;
     int ret = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
     int64_t duration = 0;
     char line[1024];
     const char *ptr;

     if ((ret = ffio_open_whitelist(&in, url, AVIO_FLAG_READ,
                                    &h->interrupt_callback, NULL,
                                    h->protocol_whitelist, h->protocol_blacklist)) < 0)
         return ret;

     ff_get_chomp_line(in, line, sizeof(line));
     if (strcmp(line, "#EXTM3U")) {
         ret = AVERROR_INVALIDDATA;
         goto fail;
     }

     free_segment_list(s);
     s->finished = 0;
     while (!avio_feof(in)) {
         ff_get_chomp_line(in, line, sizeof(line));
         if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
             struct variant_info info = {{0}};
             is_variant = 1;
             ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
                                &info);
             bandwidth = atoi(info.bandwidth);
         } else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
             s->target_duration = atoi(ptr) * AV_TIME_BASE;
         } else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
             s->start_seq_no = atoi(ptr);
         } else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
             s->finished = 1;
         } else if (av_strstart(line, "#EXTINF:", &ptr)) {
             is_segment = 1;
             duration = atof(ptr) * AV_TIME_BASE;
         } else if (av_strstart(line, "#", NULL)) {
             continue;
         } else if (line[0]) {
             if (is_segment) {
                 struct segment *seg = av_malloc(sizeof(struct segment));
                 if (!seg) {
                     ret = AVERROR(ENOMEM);
                     goto fail;
                 }
                 seg->duration = duration;
                 ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
                 dynarray_add(&s->segments, &s->n_segments, seg);
                 is_segment = 0;
             } else if (is_variant) {
                 struct variant *var = av_malloc(sizeof(struct variant));
                 if (!var) {
                     ret = AVERROR(ENOMEM);
                     goto fail;
                 }
                 var->bandwidth = bandwidth;
                 ff_make_absolute_url(var->url, sizeof(var->url), url, line);
                 dynarray_add(&s->variants, &s->n_variants, var);
                 is_variant = 0;
             }
         }
     }
     s->last_load_time = av_gettime_relative();

 fail:
     avio_close(in);
     return ret;
 }

 static int hls_close(URLContext *h)
 {
     HLSContext *s = h->priv_data;

     free_segment_list(s);
     free_variant_list(s);
     ffurl_closep(&s->seg_hd);
     return 0;
 }

 static int hls_open(URLContext *h, const char *uri, int flags)
 {
     HLSContext *s = h->priv_data;
     int ret, i;
     const char *nested_url;

     if (flags & AVIO_FLAG_WRITE)
         return AVERROR(ENOSYS);

     h->is_streamed = 1;

     if (av_strstart(uri, "hls+", &nested_url)) {
         av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl));
     } else if (av_strstart(uri, "hls://", &nested_url)) {
         av_log(h, AV_LOG_ERROR,
                "No nested protocol specified. Specify e.g. hls+http://%s\n",
                nested_url);
         ret = AVERROR(EINVAL);
         goto fail;
     } else {
         av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
         ret = AVERROR(EINVAL);
         goto fail;
     }
     av_log(h, AV_LOG_WARNING,
            "Using the hls protocol is discouraged, please try using the "
            "hls demuxer instead. The hls demuxer should be more complete "
            "and work as well as the protocol implementation. (If not, "
            "please report it.) To use the demuxer, simply use %s as url.\n",
            s->playlisturl);

     if ((ret = parse_playlist(h, s->playlisturl)) < 0)
         goto fail;

     if (s->n_segments == 0 && s->n_variants > 0) {
         int max_bandwidth = 0, maxvar = -1;
         for (i = 0; i < s->n_variants; i++) {
             if (s->variants[i]->bandwidth > max_bandwidth || i == 0) {
                 max_bandwidth = s->variants[i]->bandwidth;
                 maxvar = i;
             }
         }
         av_strlcpy(s->playlisturl, s->variants[maxvar]->url,
                    sizeof(s->playlisturl));
         if ((ret = parse_playlist(h, s->playlisturl)) < 0)
             goto fail;
     }

     if (s->n_segments == 0) {
         av_log(h, AV_LOG_WARNING, "Empty playlist\n");
         ret = AVERROR(EIO);
         goto fail;
     }
     s->cur_seq_no = s->start_seq_no;
     if (!s->finished && s->n_segments >= 3)
         s->cur_seq_no = s->start_seq_no + s->n_segments - 3;

     return 0;

 fail:
     hls_close(h);
     return ret;
 }

 static int hls_read(URLContext *h, uint8_t *buf, int size)
 {
     HLSContext *s = h->priv_data;
     const char *url;
     int ret;
     int64_t reload_interval;

 start:
     if (s->seg_hd) {
         ret = ffurl_read(s->seg_hd, buf, size);
         if (ret > 0)
             return ret;
     }
     if (s->seg_hd) {
         ffurl_closep(&s->seg_hd);
         s->cur_seq_no++;
     }
     reload_interval = s->n_segments > 0 ?
                       s->segments[s->n_segments - 1]->duration :
                       s->target_duration;
 retry:
     if (!s->finished) {
         int64_t now = av_gettime_relative();
         if (now - s->last_load_time >= reload_interval) {
             if ((ret = parse_playlist(h, s->playlisturl)) < 0)
                 return ret;
             /* If we need to reload the playlist again below (if
              * there's still no more segments), switch to a reload
              * interval of half the target duration. */
             reload_interval = s->target_duration / 2;
         }
     }
     if (s->cur_seq_no < s->start_seq_no) {
         av_log(h, AV_LOG_WARNING,
                "skipping %d segments ahead, expired from playlist\n",
                s->start_seq_no - s->cur_seq_no);
         s->cur_seq_no = s->start_seq_no;
     }
     if (s->cur_seq_no - s->start_seq_no >= s->n_segments) {
         if (s->finished)
             return AVERROR_EOF;
         while (av_gettime_relative() - s->last_load_time < reload_interval) {
             if (ff_check_interrupt(&h->interrupt_callback))
                 return AVERROR_EXIT;
             av_usleep(100*1000);
         }
         goto retry;
     }
     url = s->segments[s->cur_seq_no - s->start_seq_no]->url;
     av_log(h, AV_LOG_DEBUG, "opening %s\n", url);
     ret = ffurl_open_whitelist(&s->seg_hd, url, AVIO_FLAG_READ,
                                &h->interrupt_callback, NULL,
                                h->protocol_whitelist, h->protocol_blacklist, h);
     if (ret < 0) {
         if (ff_check_interrupt(&h->interrupt_callback))
             return AVERROR_EXIT;
         av_log(h, AV_LOG_WARNING, "Unable to open %s\n", url);
         s->cur_seq_no++;
         goto retry;
     }
     goto start;
 }

 const URLProtocol ff_hls_protocol = {
     .name           = "hls",
     .url_open       = hls_open,
     .url_read       = hls_read,
     .url_close      = hls_close,
     .flags          = URL_PROTOCOL_FLAG_NESTED_SCHEME,
     .priv_data_size = sizeof(HLSContext),
 };
	/*
	* Apple HTTP Live Streaming Protocol Handler
	* Copyright (c) 2010 Martin Storsjo
	*
	* 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
	*/

	/**
	* @file
	* Apple HTTP Live Streaming Protocol Handler
	* http://tools.ietf.org/html/draft-pantos-http-live-streaming
	*/

	#include "libavutil/avstring.h"
	#include "libavutil/time.h"
	#include "avformat.h"
	#include "avio_internal.h"
	#include "internal.h"
	#include "url.h"
	#include "version.h"

	/*
	* An apple http stream consists of a playlist with media segment files,
	* played sequentially. There may be several playlists with the same
	* video content, in different bandwidth variants, that are played in
	* parallel (preferably only one bandwidth variant at a time). In this case,
	* the user supplied the url to a main playlist that only lists the variant
	* playlists.
	*
	* If the main playlist doesn't point at any variants, we still create
	* one anonymous toplevel variant for this, to maintain the structure.
	*/

	struct segment {
	int64_t duration;
	char url[MAX_URL_SIZE];
	};

	struct variant {
	int bandwidth;
	char url[MAX_URL_SIZE];
	};

	typedef struct HLSContext {
	char playlisturl[MAX_URL_SIZE];
	int64_t target_duration;
	int start_seq_no;
	int finished;
	int n_segments;
	struct segment **segments;
	int n_variants;
	struct variant **variants;
	int cur_seq_no;
	URLContext *seg_hd;
	int64_t last_load_time;
	} HLSContext;

	static void free_segment_list(HLSContext *s)
	{
	int i;
	for (i = 0; i < s->n_segments; i++)
	av_freep(&s->segments[i]);
	av_freep(&s->segments);
	s->n_segments = 0;
	}

	static void free_variant_list(HLSContext *s)
	{
	int i;
	for (i = 0; i < s->n_variants; i++)
	av_freep(&s->variants[i]);
	av_freep(&s->variants);
	s->n_variants = 0;
	}

	struct variant_info {
	char bandwidth[20];
	};

	static void handle_variant_args(struct variant_info info, const char key,
	int key_len, char *dest, int dest_len)
	{
	if (!strncmp(key, "BANDWIDTH=", key_len)) {
	*dest = info->bandwidth;
	*dest_len = sizeof(info->bandwidth);
	}
	}

	static int parse_playlist(URLContext h, const char url)
	{
	HLSContext *s = h->priv_data;
	AVIOContext *in;
	int ret = 0, is_segment = 0, is_variant = 0, bandwidth = 0;
	int64_t duration = 0;
	char line[1024];
	const char *ptr;

	if ((ret = ffio_open_whitelist(&in, url, AVIO_FLAG_READ,
	&h->interrupt_callback, NULL,
	h->protocol_whitelist, h->protocol_blacklist)) < 0)
	return ret;

	ff_get_chomp_line(in, line, sizeof(line));
	if (strcmp(line, "#EXTM3U")) {
	ret = AVERROR_INVALIDDATA;
	goto fail;
	}

	free_segment_list(s);
	s->finished = 0;
	while (!avio_feof(in)) {
	ff_get_chomp_line(in, line, sizeof(line));
	if (av_strstart(line, "#EXT-X-STREAM-INF:", &ptr)) {
	struct variant_info info = {{0}};
	is_variant = 1;
	ff_parse_key_value(ptr, (ff_parse_key_val_cb) handle_variant_args,
	&info);
	bandwidth = atoi(info.bandwidth);
	} else if (av_strstart(line, "#EXT-X-TARGETDURATION:", &ptr)) {
	s->target_duration = atoi(ptr) * AV_TIME_BASE;
	} else if (av_strstart(line, "#EXT-X-MEDIA-SEQUENCE:", &ptr)) {
	s->start_seq_no = atoi(ptr);
	} else if (av_strstart(line, "#EXT-X-ENDLIST", &ptr)) {
	s->finished = 1;
	} else if (av_strstart(line, "#EXTINF:", &ptr)) {
	is_segment = 1;
	duration = atof(ptr) * AV_TIME_BASE;
	} else if (av_strstart(line, "#", NULL)) {
	continue;
	} else if (line[0]) {
	if (is_segment) {
	struct segment *seg = av_malloc(sizeof(struct segment));
	if (!seg) {
	ret = AVERROR(ENOMEM);
	goto fail;
	}
	seg->duration = duration;
	ff_make_absolute_url(seg->url, sizeof(seg->url), url, line);
	dynarray_add(&s->segments, &s->n_segments, seg);
	is_segment = 0;
	} else if (is_variant) {
	struct variant *var = av_malloc(sizeof(struct variant));
	if (!var) {
	ret = AVERROR(ENOMEM);
	goto fail;
	}
	var->bandwidth = bandwidth;
	ff_make_absolute_url(var->url, sizeof(var->url), url, line);
	dynarray_add(&s->variants, &s->n_variants, var);
	is_variant = 0;
	}
	}
	}
	s->last_load_time = av_gettime_relative();

	fail:
	avio_close(in);
	return ret;
	}

	static int hls_close(URLContext *h)
	{
	HLSContext *s = h->priv_data;

	free_segment_list(s);
	free_variant_list(s);
	ffurl_closep(&s->seg_hd);
	return 0;
	}

	static int hls_open(URLContext h, const char uri, int flags)
	{
	HLSContext *s = h->priv_data;
	int ret, i;
	const char *nested_url;

	if (flags & AVIO_FLAG_WRITE)
	return AVERROR(ENOSYS);

	h->is_streamed = 1;

	if (av_strstart(uri, "hls+", &nested_url)) {
	av_strlcpy(s->playlisturl, nested_url, sizeof(s->playlisturl));
	} else if (av_strstart(uri, "hls://", &nested_url)) {
	av_log(h, AV_LOG_ERROR,
	"No nested protocol specified. Specify e.g. hls+http://%s\n",
	nested_url);
	ret = AVERROR(EINVAL);
	goto fail;
	} else {
	av_log(h, AV_LOG_ERROR, "Unsupported url %s\n", uri);
	ret = AVERROR(EINVAL);
	goto fail;
	}
	av_log(h, AV_LOG_WARNING,
	"Using the hls protocol is discouraged, please try using the "
	"hls demuxer instead. The hls demuxer should be more complete "
	"and work as well as the protocol implementation. (If not, "
	"please report it.) To use the demuxer, simply use %s as url.\n",
	s->playlisturl);

	if ((ret = parse_playlist(h, s->playlisturl)) < 0)
	goto fail;

	if (s->n_segments == 0 && s->n_variants > 0) {
	int max_bandwidth = 0, maxvar = -1;
	for (i = 0; i < s->n_variants; i++) {
	if (s->variants[i]->bandwidth > max_bandwidth \|\| i == 0) {
	max_bandwidth = s->variants[i]->bandwidth;
	maxvar = i;
	}
	}
	av_strlcpy(s->playlisturl, s->variants[maxvar]->url,
	sizeof(s->playlisturl));
	if ((ret = parse_playlist(h, s->playlisturl)) < 0)
	goto fail;
	}

	if (s->n_segments == 0) {
	av_log(h, AV_LOG_WARNING, "Empty playlist\n");
	ret = AVERROR(EIO);
	goto fail;
	}
	s->cur_seq_no = s->start_seq_no;
	if (!s->finished && s->n_segments >= 3)
	s->cur_seq_no = s->start_seq_no + s->n_segments - 3;

	return 0;

	fail:
	hls_close(h);
	return ret;
	}

	static int hls_read(URLContext h, uint8_t buf, int size)
	{
	HLSContext *s = h->priv_data;
	const char *url;
	int ret;
	int64_t reload_interval;

	start:
	if (s->seg_hd) {
	ret = ffurl_read(s->seg_hd, buf, size);
	if (ret > 0)
	return ret;
	}
	if (s->seg_hd) {
	ffurl_closep(&s->seg_hd);
	s->cur_seq_no++;
	}
	reload_interval = s->n_segments > 0 ?
	s->segments[s->n_segments - 1]->duration :
	s->target_duration;
	retry:
	if (!s->finished) {
	int64_t now = av_gettime_relative();
	if (now - s->last_load_time >= reload_interval) {
	if ((ret = parse_playlist(h, s->playlisturl)) < 0)
	return ret;
	/* If we need to reload the playlist again below (if
	* there's still no more segments), switch to a reload
	* interval of half the target duration. */
	reload_interval = s->target_duration / 2;
	}
	}
	if (s->cur_seq_no < s->start_seq_no) {
	av_log(h, AV_LOG_WARNING,
	"skipping %d segments ahead, expired from playlist\n",
	s->start_seq_no - s->cur_seq_no);
	s->cur_seq_no = s->start_seq_no;
	}
	if (s->cur_seq_no - s->start_seq_no >= s->n_segments) {
	if (s->finished)
	return AVERROR_EOF;
	while (av_gettime_relative() - s->last_load_time < reload_interval) {
	if (ff_check_interrupt(&h->interrupt_callback))
	return AVERROR_EXIT;
	av_usleep(100*1000);
	}
	goto retry;
	}
	url = s->segments[s->cur_seq_no - s->start_seq_no]->url;
	av_log(h, AV_LOG_DEBUG, "opening %s\n", url);
	ret = ffurl_open_whitelist(&s->seg_hd, url, AVIO_FLAG_READ,
	&h->interrupt_callback, NULL,
	h->protocol_whitelist, h->protocol_blacklist, h);
	if (ret < 0) {
	if (ff_check_interrupt(&h->interrupt_callback))
	return AVERROR_EXIT;
	av_log(h, AV_LOG_WARNING, "Unable to open %s\n", url);
	s->cur_seq_no++;
	goto retry;
	}
	goto start;
	}

	const URLProtocol ff_hls_protocol = {
	.name = "hls",
	.url_open = hls_open,
	.url_read = hls_read,
	.url_close = hls_close,
	.flags = URL_PROTOCOL_FLAG_NESTED_SCHEME,
	.priv_data_size = sizeof(HLSContext),
	};