FFmpeg: libavformat/hlsenc.c Source File

00001 /*
00002  * Apple HTTP Live Streaming segmenter
00003  * Copyright (c) 2012, Luca Barbato
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include <float.h>
00023 
00024 #include "libavutil/mathematics.h"
00025 #include "libavutil/parseutils.h"
00026 #include "libavutil/avstring.h"
00027 #include "libavutil/opt.h"
00028 #include "libavutil/log.h"
00029 
00030 #include "avformat.h"
00031 #include "internal.h"
00032 
00033 typedef struct ListEntry {
00034     char  name[1024];
00035     int   duration;
00036     struct ListEntry *next;
00037 } ListEntry;
00038 
00039 typedef struct HLSContext {
00040     const AVClass *class;  // Class for private options.
00041     int number;
00042     AVOutputFormat *oformat;
00043     AVFormatContext *avf;
00044     float time;            // Set by a private option.
00045     int  size;             // Set by a private option.
00046     int  wrap;             // Set by a private option.
00047     int64_t recording_time;
00048     int has_video;
00049     int64_t start_pts;
00050     int64_t end_pts;
00051     ListEntry *list;
00052     ListEntry *end_list;
00053     char *basename;
00054     AVIOContext *pb;
00055 } HLSContext;
00056 
00057 static int hls_mux_init(AVFormatContext *s)
00058 {
00059     HLSContext *hls = s->priv_data;
00060     AVFormatContext *oc;
00061     int i;
00062 
00063     hls->avf = oc = avformat_alloc_context();
00064     if (!oc)
00065         return AVERROR(ENOMEM);
00066 
00067     oc->oformat            = hls->oformat;
00068     oc->interrupt_callback = s->interrupt_callback;
00069 
00070     for (i = 0; i < s->nb_streams; i++) {
00071         AVStream *st;
00072         if (!(st = avformat_new_stream(oc, NULL)))
00073             return AVERROR(ENOMEM);
00074         avcodec_copy_context(st->codec, s->streams[i]->codec);
00075         st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
00076     }
00077 
00078     return 0;
00079 }
00080 
00081 static int append_entry(HLSContext *hls, uint64_t duration)
00082 {
00083     ListEntry *en = av_malloc(sizeof(*en));
00084 
00085     if (!en)
00086         return AVERROR(ENOMEM);
00087 
00088     av_get_frame_filename(en->name, sizeof(en->name), hls->basename,
00089                           hls->number -1);
00090 
00091     en->duration = duration;
00092     en->next     = NULL;
00093 
00094     if (!hls->list)
00095         hls->list = en;
00096     else
00097         hls->end_list->next = en;
00098 
00099     hls->end_list = en;
00100 
00101     if (hls->number >= hls->size) {
00102         en = hls->list;
00103         hls->list = en->next;
00104         av_free(en);
00105     }
00106 
00107     return 0;
00108 }
00109 
00110 static void free_entries(HLSContext *hls)
00111 {
00112     ListEntry *p = hls->list, *en;
00113 
00114     while(p) {
00115         en = p;
00116         p = p->next;
00117         av_free(en);
00118     }
00119 }
00120 
00121 static int hls_window(AVFormatContext *s, int last)
00122 {
00123     HLSContext *hls = s->priv_data;
00124     ListEntry *en;
00125     int ret = 0;
00126 
00127     if ((ret = avio_open2(&hls->pb, s->filename, AVIO_FLAG_WRITE,
00128                           &s->interrupt_callback, NULL)) < 0)
00129         goto fail;
00130 
00131     avio_printf(hls->pb, "#EXTM3U\n");
00132     avio_printf(hls->pb, "#EXT-X-VERSION:3\n");
00133     avio_printf(hls->pb, "#EXT-X-TARGETDURATION:%d\n", (int)hls->time);
00134     avio_printf(hls->pb, "#EXT-X-MEDIA-SEQUENCE:%d\n",
00135                 FFMAX(0, hls->number - hls->size));
00136 
00137     for (en = hls->list; en; en = en->next) {
00138         avio_printf(hls->pb, "#EXTINF:%d,\n", en->duration);
00139         avio_printf(hls->pb, "%s\n", en->name);
00140     }
00141 
00142     if (last)
00143         avio_printf(hls->pb, "#EXT-X-ENDLIST\n");
00144 
00145 fail:
00146     avio_closep(&hls->pb);
00147     return ret;
00148 }
00149 
00150 static int hls_start(AVFormatContext *s)
00151 {
00152     HLSContext *c = s->priv_data;
00153     AVFormatContext *oc = c->avf;
00154     int err = 0;
00155 
00156     if (c->wrap)
00157         c->number %= c->wrap;
00158 
00159     if (av_get_frame_filename(oc->filename, sizeof(oc->filename),
00160                               c->basename, c->number++) < 0)
00161         return AVERROR(EINVAL);
00162 
00163     if ((err = avio_open2(&oc->pb, oc->filename, AVIO_FLAG_WRITE,
00164                           &s->interrupt_callback, NULL)) < 0)
00165         return err;
00166 
00167     if (oc->oformat->priv_class && oc->priv_data)
00168         av_opt_set(oc->priv_data, "mpegts_flags", "resend_headers", 0);
00169 
00170     return 0;
00171 }
00172 
00173 static int hls_write_header(AVFormatContext *s)
00174 {
00175     HLSContext *hls = s->priv_data;
00176     int ret, i;
00177     char *p;
00178     const char *pattern = "%d.ts";
00179     int basename_size = strlen(s->filename) + strlen(pattern);
00180 
00181     hls->number      = 0;
00182 
00183     hls->recording_time = hls->time * 1000000;
00184     hls->start_pts      = AV_NOPTS_VALUE;
00185 
00186     for (i = 0; i < s->nb_streams; i++)
00187         hls->has_video +=
00188             s->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO;
00189 
00190     if (hls->has_video > 1)
00191         av_log(s, AV_LOG_WARNING,
00192                "More than a single video stream present, "
00193                "expect issues decoding it.\n");
00194 
00195     hls->oformat = av_guess_format("mpegts", NULL, NULL);
00196 
00197     if (!hls->oformat) {
00198         ret = AVERROR_MUXER_NOT_FOUND;
00199         goto fail;
00200     }
00201 
00202     hls->basename = av_malloc(basename_size);
00203 
00204     if (!hls->basename) {
00205         ret = AVERROR(ENOMEM);
00206         goto fail;
00207     }
00208 
00209     strcpy(hls->basename, s->filename);
00210 
00211     p = strrchr(hls->basename, '.');
00212 
00213     if (p)
00214         *p = '\0';
00215 
00216     av_strlcat(hls->basename, "%d.ts", basename_size);
00217 
00218     if ((ret = hls_mux_init(s)) < 0)
00219         goto fail;
00220 
00221     if ((ret = hls_start(s)) < 0)
00222         goto fail;
00223 
00224     if ((ret = avformat_write_header(hls->avf, NULL)) < 0)
00225         return ret;
00226 
00227 
00228 fail:
00229     if (ret) {
00230         av_free(hls->basename);
00231         if (hls->avf)
00232             avformat_free_context(hls->avf);
00233     }
00234     return ret;
00235 }
00236 
00237 static int hls_write_packet(AVFormatContext *s, AVPacket *pkt)
00238 {
00239     HLSContext *hls = s->priv_data;
00240     AVFormatContext *oc = hls->avf;
00241     AVStream *st = s->streams[pkt->stream_index];
00242     int64_t end_pts = hls->recording_time * hls->number;
00243     int ret;
00244 
00245     if (hls->start_pts == AV_NOPTS_VALUE) {
00246         hls->start_pts = pkt->pts;
00247         hls->end_pts   = pkt->pts;
00248     }
00249     end_pts += hls->start_pts;
00250 
00251     if ((hls->has_video && st->codec->codec_type == AVMEDIA_TYPE_VIDEO)      &&
00252         av_compare_ts(pkt->pts, st->time_base, end_pts, AV_TIME_BASE_Q) >= 0 &&
00253         pkt->flags & AV_PKT_FLAG_KEY) {
00254 
00255         append_entry(hls, av_rescale(pkt->pts - hls->end_pts,
00256                                      st->time_base.num,
00257                                      st->time_base.den));
00258         hls->end_pts = pkt->pts;
00259 
00260         av_write_frame(oc, NULL); /* Flush any buffered data */
00261         avio_close(oc->pb);
00262 
00263         ret = hls_start(s);
00264 
00265         if (ret)
00266             return ret;
00267 
00268         oc = hls->avf;
00269 
00270         if ((ret = hls_window(s, 0)) < 0)
00271             return ret;
00272     }
00273 
00274     ret = ff_write_chained(oc, pkt->stream_index, pkt, s);
00275 
00276     return ret;
00277 }
00278 
00279 static int hls_write_trailer(struct AVFormatContext *s)
00280 {
00281     HLSContext *hls = s->priv_data;
00282     AVFormatContext *oc = hls->avf;
00283 
00284     av_write_trailer(oc);
00285     avio_closep(&oc->pb);
00286     avformat_free_context(oc);
00287     av_free(hls->basename);
00288     hls_window(s, 1);
00289 
00290     free_entries(hls);
00291     avio_close(hls->pb);
00292     return 0;
00293 }
00294 
00295 #define OFFSET(x) offsetof(HLSContext, x)
00296 #define E AV_OPT_FLAG_ENCODING_PARAM
00297 static const AVOption options[] = {
00298     { "start_number", "first number in the sequence",            OFFSET(number),  AV_OPT_TYPE_INT,    {.i64 = 0},     0, INT_MAX, E},
00299     {"hls_time",      "segment length in seconds",               OFFSET(time),    AV_OPT_TYPE_FLOAT,  {.dbl = 2},     0, FLT_MAX, E},
00300     {"hls_list_size", "maximum number of playlist entries",      OFFSET(size),    AV_OPT_TYPE_INT,    {.i64 = 5},     0, INT_MAX, E},
00301     {"hls_wrap",      "number after which the index wraps",      OFFSET(wrap),    AV_OPT_TYPE_INT,    {.i64 = 0},     0, INT_MAX, E},
00302     { NULL },
00303 };
00304 
00305 static const AVClass hls_class = {
00306     .class_name = "hls muxer",
00307     .item_name  = av_default_item_name,
00308     .option     = options,
00309     .version    = LIBAVUTIL_VERSION_INT,
00310 };
00311 
00312 
00313 AVOutputFormat ff_hls_muxer = {
00314     .name           = "hls",
00315     .long_name      = NULL_IF_CONFIG_SMALL("Apple HTTP Live Streaming"),
00316     .extensions     = "m3u8",
00317     .priv_data_size = sizeof(HLSContext),
00318     .audio_codec    = AV_CODEC_ID_MP2,
00319     .video_codec    = AV_CODEC_ID_MPEG2VIDEO,
00320     .flags          = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH,
00321     .write_header   = hls_write_header,
00322     .write_packet   = hls_write_packet,
00323     .write_trailer  = hls_write_trailer,
00324     .priv_class     = &hls_class,
00325 };