git.sesse.net Git - ffmpeg/blob - libavformat/dashenc.c

   1 /*
   2  * MPEG-DASH ISO BMFF segmenter
   3  * Copyright (c) 2014 Martin Storsjo
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "config.h"
  23 #if HAVE_UNISTD_H
  24 #include <unistd.h>
  25 #endif
  26
  27 #include "libavutil/avstring.h"
  28 #include "libavutil/intreadwrite.h"
  29 #include "libavutil/mathematics.h"
  30 #include "libavutil/opt.h"
  31 #include "libavutil/time_internal.h"
  32
  33 #include "avc.h"
  34 #include "avformat.h"
  35 #include "avio_internal.h"
  36 #include "internal.h"
  37 #include "isom.h"
  38 #include "os_support.h"
  39 #include "url.h"
  40
  41 typedef struct Segment {
  42     char file[1024];
  43     int64_t start_pos;
  44     int range_length, index_length;
  45     int64_t time;
  46     int duration;
  47     int n;
  48 } Segment;
  49
  50 typedef struct OutputStream {
  51     AVFormatContext *ctx;
  52     int ctx_inited;
  53     uint8_t iobuf[32768];
  54     URLContext *out;
  55     int packets_written;
  56     char initfile[1024];
  57     int64_t init_start_pos;
  58     int init_range_length;
  59     int nb_segments, segments_size, segment_index;
  60     Segment **segments;
  61     int64_t first_dts, start_dts, end_dts;
  62     char bandwidth_str[64];
  63
  64     char codec_str[100];
  65 } OutputStream;
  66
  67 typedef struct DASHContext {
  68     const AVClass *class;  /* Class for private options. */
  69     int window_size;
  70     int extra_window_size;
  71     int min_seg_duration;
  72     int remove_at_exit;
  73     int use_template;
  74     int use_timeline;
  75     int single_file;
  76     OutputStream *streams;
  77     int has_video, has_audio;
  78     int last_duration;
  79     int total_duration;
  80     char availability_start_time[100];
  81     char dirname[1024];
  82 } DASHContext;
  83
  84 static int dash_write(void *opaque, uint8_t *buf, int buf_size)
  85 {
  86     OutputStream *os = opaque;
  87     if (os->out)
  88         ffurl_write(os->out, buf, buf_size);
  89     return buf_size;
  90 }
  91
  92 // RFC 6381
  93 static void set_codec_str(AVFormatContext *s, AVCodecContext *codec,
  94                           char *str, int size)
  95 {
  96     const AVCodecTag *tags[2] = { NULL, NULL };
  97     uint32_t tag;
  98     if (codec->codec_type == AVMEDIA_TYPE_VIDEO)
  99         tags[0] = ff_codec_movvideo_tags;
 100     else if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
 101         tags[0] = ff_codec_movaudio_tags;
 102     else
 103         return;
 104
 105     tag = av_codec_get_tag(tags, codec->codec_id);
 106     if (!tag)
 107         return;
 108     if (size < 5)
 109         return;
 110
 111     AV_WL32(str, tag);
 112     str[4] = '\0';
 113     if (!strcmp(str, "mp4a") || !strcmp(str, "mp4v")) {
 114         uint32_t oti;
 115         tags[0] = ff_mp4_obj_type;
 116         oti = av_codec_get_tag(tags, codec->codec_id);
 117         if (oti)
 118             av_strlcatf(str, size, ".%02x", oti);
 119         else
 120             return;
 121
 122         if (tag == MKTAG('m', 'p', '4', 'a')) {
 123             if (codec->extradata_size >= 2) {
 124                 int aot = codec->extradata[0] >> 3;
 125                 if (aot == 31)
 126                     aot = ((AV_RB16(codec->extradata) >> 5) & 0x3f) + 32;
 127                 av_strlcatf(str, size, ".%d", aot);
 128             }
 129         } else if (tag == MKTAG('m', 'p', '4', 'v')) {
 130             // Unimplemented, should output ProfileLevelIndication as a decimal number
 131             av_log(s, AV_LOG_WARNING, "Incomplete RFC 6381 codec string for mp4v\n");
 132         }
 133     } else if (!strcmp(str, "avc1")) {
 134         uint8_t *tmpbuf = NULL;
 135         uint8_t *extradata = codec->extradata;
 136         int extradata_size = codec->extradata_size;
 137         if (!extradata_size)
 138             return;
 139         if (extradata[0] != 1) {
 140             AVIOContext *pb;
 141             if (avio_open_dyn_buf(&pb) < 0)
 142                 return;
 143             if (ff_isom_write_avcc(pb, extradata, extradata_size) < 0) {
 144                 avio_close_dyn_buf(pb, &tmpbuf);
 145                 av_free(tmpbuf);
 146                 return;
 147             }
 148             extradata_size = avio_close_dyn_buf(pb, &extradata);
 149             tmpbuf = extradata;
 150         }
 151
 152         if (extradata_size >= 4)
 153             av_strlcatf(str, size, ".%02x%02x%02x",
 154                         extradata[1], extradata[2], extradata[3]);
 155         av_free(tmpbuf);
 156     }
 157 }
 158
 159 static void dash_free(AVFormatContext *s)
 160 {
 161     DASHContext *c = s->priv_data;
 162     int i, j;
 163     if (!c->streams)
 164         return;
 165     for (i = 0; i < s->nb_streams; i++) {
 166         OutputStream *os = &c->streams[i];
 167         if (os->ctx && os->ctx_inited)
 168             av_write_trailer(os->ctx);
 169         if (os->ctx && os->ctx->pb)
 170             av_free(os->ctx->pb);
 171         ffurl_close(os->out);
 172         os->out =  NULL;
 173         if (os->ctx)
 174             avformat_free_context(os->ctx);
 175         for (j = 0; j < os->nb_segments; j++)
 176             av_free(os->segments[j]);
 177         av_free(os->segments);
 178     }
 179     av_freep(&c->streams);
 180 }
 181
 182 static void output_segment_list(OutputStream *os, AVIOContext *out, DASHContext *c)
 183 {
 184     int i, start_index = 0, start_number = 1;
 185     if (c->window_size) {
 186         start_index  = FFMAX(os->nb_segments   - c->window_size, 0);
 187         start_number = FFMAX(os->segment_index - c->window_size, 1);
 188     }
 189
 190     if (c->use_template) {
 191         int timescale = c->use_timeline ? os->ctx->streams[0]->time_base.den : AV_TIME_BASE;
 192         avio_printf(out, "\t\t\t\t<SegmentTemplate timescale=\"%d\" ", timescale);
 193         if (!c->use_timeline)
 194             avio_printf(out, "duration=\"%d\" ", c->last_duration);
 195         avio_printf(out, "initialization=\"init-stream$RepresentationID$.m4s\" media=\"chunk-stream$RepresentationID$-$Number%%05d$.m4s\" startNumber=\"%d\">\n", c->use_timeline ? start_number : 1);
 196         if (c->use_timeline) {
 197             avio_printf(out, "\t\t\t\t\t<SegmentTimeline>\n");
 198             for (i = start_index; i < os->nb_segments; ) {
 199                 Segment *seg = os->segments[i];
 200                 int repeat = 0;
 201                 avio_printf(out, "\t\t\t\t\t\t<S ");
 202                 if (i == start_index)
 203                     avio_printf(out, "t=\"%"PRId64"\" ", seg->time);
 204                 avio_printf(out, "d=\"%d\" ", seg->duration);
 205                 while (i + repeat + 1 < os->nb_segments && os->segments[i + repeat + 1]->duration == seg->duration)
 206                     repeat++;
 207                 if (repeat > 0)
 208                     avio_printf(out, "r=\"%d\" ", repeat);
 209                 avio_printf(out, "/>\n");
 210                 i += 1 + repeat;
 211             }
 212             avio_printf(out, "\t\t\t\t\t</SegmentTimeline>\n");
 213         }
 214         avio_printf(out, "\t\t\t\t</SegmentTemplate>\n");
 215     } else if (c->single_file) {
 216         avio_printf(out, "\t\t\t\t<BaseURL>%s</BaseURL>\n", os->initfile);
 217         avio_printf(out, "\t\t\t\t<SegmentList timescale=\"%d\" duration=\"%d\" startNumber=\"%d\">\n", AV_TIME_BASE, c->last_duration, start_number);
 218         avio_printf(out, "\t\t\t\t\t<Initialization range=\"%"PRId64"-%"PRId64"\" />\n", os->init_start_pos, os->init_start_pos + os->init_range_length - 1);
 219         for (i = start_index; i < os->nb_segments; i++) {
 220             Segment *seg = os->segments[i];
 221             avio_printf(out, "\t\t\t\t\t<SegmentURL mediaRange=\"%"PRId64"-%"PRId64"\" ", seg->start_pos, seg->start_pos + seg->range_length - 1);
 222             if (seg->index_length)
 223                 avio_printf(out, "indexRange=\"%"PRId64"-%"PRId64"\" ", seg->start_pos, seg->start_pos + seg->index_length - 1);
 224             avio_printf(out, "/>\n");
 225         }
 226         avio_printf(out, "\t\t\t\t</SegmentList>\n");
 227     } else {
 228         avio_printf(out, "\t\t\t\t<SegmentList timescale=\"%d\" duration=\"%d\" startNumber=\"%d\">\n", AV_TIME_BASE, c->last_duration, start_number);
 229         avio_printf(out, "\t\t\t\t\t<Initialization sourceURL=\"%s\" />\n", os->initfile);
 230         for (i = start_index; i < os->nb_segments; i++) {
 231             Segment *seg = os->segments[i];
 232             avio_printf(out, "\t\t\t\t\t<SegmentURL media=\"%s\" />\n", seg->file);
 233         }
 234         avio_printf(out, "\t\t\t\t</SegmentList>\n");
 235     }
 236 }
 237
 238 static char *xmlescape(const char *str) {
 239     int outlen = strlen(str)*3/2 + 6;
 240     char *out = av_realloc(NULL, outlen + 1);
 241     int pos = 0;
 242     if (!out)
 243         return NULL;
 244     for (; *str; str++) {
 245         if (pos + 6 > outlen) {
 246             char *tmp;
 247             outlen = 2 * outlen + 6;
 248             tmp = av_realloc(out, outlen + 1);
 249             if (!tmp) {
 250                 av_free(out);
 251                 return NULL;
 252             }
 253             out = tmp;
 254         }
 255         if (*str == '&') {
 256             memcpy(&out[pos], "&amp;", 5);
 257             pos += 5;
 258         } else if (*str == '<') {
 259             memcpy(&out[pos], "&lt;", 4);
 260             pos += 4;
 261         } else if (*str == '>') {
 262             memcpy(&out[pos], "&gt;", 4);
 263             pos += 4;
 264         } else if (*str == '\'') {
 265             memcpy(&out[pos], "&apos;", 6);
 266             pos += 6;
 267         } else if (*str == '\"') {
 268             memcpy(&out[pos], "&quot;", 6);
 269             pos += 6;
 270         } else {
 271             out[pos++] = *str;
 272         }
 273     }
 274     out[pos] = '\0';
 275     return out;
 276 }
 277
 278 static void write_time(AVIOContext *out, int64_t time)
 279 {
 280     int seconds = time / AV_TIME_BASE;
 281     int fractions = time % AV_TIME_BASE;
 282     int minutes = seconds / 60;
 283     int hours = minutes / 60;
 284     seconds %= 60;
 285     minutes %= 60;
 286     avio_printf(out, "PT");
 287     if (hours)
 288         avio_printf(out, "%dH", hours);
 289     if (hours || minutes)
 290         avio_printf(out, "%dM", minutes);
 291     avio_printf(out, "%d.%dS", seconds, fractions / (AV_TIME_BASE / 10));
 292 }
 293
 294 static int write_manifest(AVFormatContext *s, int final)
 295 {
 296     DASHContext *c = s->priv_data;
 297     AVIOContext *out;
 298     char temp_filename[1024];
 299     const char *write_filename;
 300     int ret, i;
 301     AVDictionaryEntry *title = av_dict_get(s->metadata, "title", NULL, 0);
 302
 303     snprintf(temp_filename, sizeof(temp_filename), "%s.tmp", s->filename);
 304     write_filename = USE_RENAME_REPLACE ? temp_filename : s->filename;
 305     ret = avio_open2(&out, write_filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
 306     if (ret < 0) {
 307         av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", write_filename);
 308         return ret;
 309     }
 310     avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
 311     avio_printf(out, "<MPD xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"\n"
 312                 "\txmlns=\"urn:mpeg:dash:schema:mpd:2011\"\n"
 313                 "\txmlns:xlink=\"http://www.w3.org/1999/xlink\"\n"
 314                 "\txsi:schemaLocation=\"urn:mpeg:DASH:schema:MPD:2011 http://standards.iso.org/ittf/PubliclyAvailableStandards/MPEG-DASH_schema_files/DASH-MPD.xsd\"\n"
 315                 "\tprofiles=\"urn:mpeg:dash:profile:isoff-live:2011\"\n"
 316                 "\ttype=\"%s\"\n", final ? "static" : "dynamic");
 317     if (final) {
 318         avio_printf(out, "\tmediaPresentationDuration=\"");
 319         write_time(out, c->total_duration);
 320         avio_printf(out, "\"\n");
 321     } else {
 322         int update_period = c->last_duration / AV_TIME_BASE;
 323         if (c->use_template && !c->use_timeline)
 324             update_period = 500;
 325         avio_printf(out, "\tminimumUpdatePeriod=\"PT%dS\"\n", update_period);
 326         avio_printf(out, "\tsuggestedPresentationDelay=\"PT%dS\"\n", c->last_duration / AV_TIME_BASE);
 327         if (!c->availability_start_time[0] && s->nb_streams > 0 && c->streams[0].nb_segments > 0) {
 328             time_t t = time(NULL);
 329             struct tm *ptm, tmbuf;
 330             ptm = gmtime_r(&t, &tmbuf);
 331             if (ptm) {
 332                 if (!strftime(c->availability_start_time, sizeof(c->availability_start_time),
 333                               "%Y-%m-%dT%H:%M:%S", ptm))
 334                     c->availability_start_time[0] = '\0';
 335             }
 336         }
 337         if (c->availability_start_time[0])
 338             avio_printf(out, "\tavailabilityStartTime=\"%s\"\n", c->availability_start_time);
 339         if (c->window_size && c->use_template) {
 340             avio_printf(out, "\ttimeShiftBufferDepth=\"");
 341             write_time(out, c->last_duration * c->window_size);
 342             avio_printf(out, "\"\n");
 343         }
 344     }
 345     avio_printf(out, "\tminBufferTime=\"");
 346     write_time(out, c->last_duration);
 347     avio_printf(out, "\">\n");
 348     avio_printf(out, "\t<ProgramInformation>\n");
 349     if (title) {
 350         char *escaped = xmlescape(title->value);
 351         avio_printf(out, "\t\t<Title>%s</Title>\n", escaped);
 352         av_free(escaped);
 353     }
 354     avio_printf(out, "\t</ProgramInformation>\n");
 355     if (c->window_size && s->nb_streams > 0 && c->streams[0].nb_segments > 0 && !c->use_template) {
 356         OutputStream *os = &c->streams[0];
 357         int start_index = FFMAX(os->nb_segments - c->window_size, 0);
 358         int64_t start_time = av_rescale_q(os->segments[start_index]->time, s->streams[0]->time_base, AV_TIME_BASE_Q);
 359         avio_printf(out, "\t<Period start=\"");
 360         write_time(out, start_time);
 361         avio_printf(out, "\">\n");
 362     } else {
 363         avio_printf(out, "\t<Period start=\"PT0.0S\">\n");
 364     }
 365
 366     if (c->has_video) {
 367         avio_printf(out, "\t\t<AdaptationSet id=\"video\" segmentAlignment=\"true\" bitstreamSwitching=\"true\">\n");
 368         for (i = 0; i < s->nb_streams; i++) {
 369             AVStream *st = s->streams[i];
 370             OutputStream *os = &c->streams[i];
 371             if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_VIDEO)
 372                 continue;
 373             avio_printf(out, "\t\t\t<Representation id=\"%d\" mimeType=\"video/mp4\" codecs=\"%s\"%s width=\"%d\" height=\"%d\">\n", i, os->codec_str, os->bandwidth_str, st->codec->width, st->codec->height);
 374             output_segment_list(&c->streams[i], out, c);
 375             avio_printf(out, "\t\t\t</Representation>\n");
 376         }
 377         avio_printf(out, "\t\t</AdaptationSet>\n");
 378     }
 379     if (c->has_audio) {
 380         avio_printf(out, "\t\t<AdaptationSet id=\"audio\" segmentAlignment=\"true\" bitstreamSwitching=\"true\">\n");
 381         for (i = 0; i < s->nb_streams; i++) {
 382             AVStream *st = s->streams[i];
 383             OutputStream *os = &c->streams[i];
 384             if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO)
 385                 continue;
 386             avio_printf(out, "\t\t\t<Representation id=\"%d\" mimeType=\"audio/mp4\" codecs=\"%s\"%s audioSamplingRate=\"%d\">\n", i, os->codec_str, os->bandwidth_str, st->codec->sample_rate);
 387             avio_printf(out, "\t\t\t\t<AudioChannelConfiguration schemeIdUri=\"urn:mpeg:dash:23003:3:audio_channel_configuration:2011\" value=\"%d\" />\n", st->codec->channels);
 388             output_segment_list(&c->streams[i], out, c);
 389             avio_printf(out, "\t\t\t</Representation>\n");
 390         }
 391         avio_printf(out, "\t\t</AdaptationSet>\n");
 392     }
 393     avio_printf(out, "\t</Period>\n");
 394     avio_printf(out, "</MPD>\n");
 395     avio_flush(out);
 396     avio_close(out);
 397     return USE_RENAME_REPLACE ? ff_rename(temp_filename, s->filename, s) : 0;
 398 }
 399
 400 static int dash_write_header(AVFormatContext *s)
 401 {
 402     DASHContext *c = s->priv_data;
 403     int ret = 0, i;
 404     AVOutputFormat *oformat;
 405     char *ptr;
 406     char basename[1024];
 407
 408     if (c->single_file)
 409         c->use_template = 0;
 410
 411     av_strlcpy(c->dirname, s->filename, sizeof(c->dirname));
 412     ptr = strrchr(c->dirname, '/');
 413     if (ptr) {
 414         av_strlcpy(basename, &ptr[1], sizeof(basename));
 415         ptr[1] = '\0';
 416     } else {
 417         c->dirname[0] = '\0';
 418         av_strlcpy(basename, s->filename, sizeof(basename));
 419     }
 420
 421     ptr = strrchr(basename, '.');
 422     if (ptr)
 423         *ptr = '\0';
 424
 425     oformat = av_guess_format("mp4", NULL, NULL);
 426     if (!oformat) {
 427         ret = AVERROR_MUXER_NOT_FOUND;
 428         goto fail;
 429     }
 430
 431     c->streams = av_mallocz(sizeof(*c->streams) * s->nb_streams);
 432     if (!c->streams) {
 433         ret = AVERROR(ENOMEM);
 434         goto fail;
 435     }
 436
 437     for (i = 0; i < s->nb_streams; i++) {
 438         OutputStream *os = &c->streams[i];
 439         AVFormatContext *ctx;
 440         AVStream *st;
 441         AVDictionary *opts = NULL;
 442         char filename[1024];
 443
 444         int bit_rate = s->streams[i]->codec->bit_rate ?
 445                        s->streams[i]->codec->bit_rate :
 446                        s->streams[i]->codec->rc_max_rate;
 447         if (bit_rate) {
 448             snprintf(os->bandwidth_str, sizeof(os->bandwidth_str),
 449                      " bandwidth=\"%d\"", bit_rate);
 450         } else {
 451             int level = s->strict_std_compliance >= FF_COMPLIANCE_STRICT ?
 452                         AV_LOG_ERROR : AV_LOG_WARNING;
 453             av_log(s, level, "No bit rate set for stream %d\n", i);
 454             if (s->strict_std_compliance >= FF_COMPLIANCE_STRICT) {
 455                 ret = AVERROR(EINVAL);
 456                 goto fail;
 457             }
 458         }
 459
 460         ctx = avformat_alloc_context();
 461         if (!ctx) {
 462             ret = AVERROR(ENOMEM);
 463             goto fail;
 464         }
 465         os->ctx = ctx;
 466         ctx->oformat = oformat;
 467         ctx->interrupt_callback = s->interrupt_callback;
 468
 469         if (!(st = avformat_new_stream(ctx, NULL))) {
 470             ret = AVERROR(ENOMEM);
 471             goto fail;
 472         }
 473         avcodec_copy_context(st->codec, s->streams[i]->codec);
 474         st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
 475         st->time_base = s->streams[i]->time_base;
 476         ctx->avoid_negative_ts = s->avoid_negative_ts;
 477
 478         ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), AVIO_FLAG_WRITE, os, NULL, dash_write, NULL);
 479         if (!ctx->pb) {
 480             ret = AVERROR(ENOMEM);
 481             goto fail;
 482         }
 483
 484         if (c->single_file)
 485             snprintf(os->initfile, sizeof(os->initfile), "%s-stream%d.m4s", basename, i);
 486         else
 487             snprintf(os->initfile, sizeof(os->initfile), "init-stream%d.m4s", i);
 488         snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->initfile);
 489         ret = ffurl_open(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
 490         if (ret < 0)
 491             goto fail;
 492         os->init_start_pos = 0;
 493
 494         av_dict_set(&opts, "movflags", "frag_custom+dash", 0);
 495         if ((ret = avformat_write_header(ctx, &opts)) < 0) {
 496              goto fail;
 497         }
 498         os->ctx_inited = 1;
 499         avio_flush(ctx->pb);
 500         av_dict_free(&opts);
 501
 502         if (c->single_file) {
 503             os->init_range_length = avio_tell(ctx->pb);
 504         } else {
 505             ffurl_close(os->out);
 506             os->out = NULL;
 507         }
 508
 509         s->streams[i]->time_base = st->time_base;
 510         // If the muxer wants to shift timestamps, request to have them shifted
 511         // already before being handed to this muxer, so we don't have mismatches
 512         // between the MPD and the actual segments.
 513         s->avoid_negative_ts = ctx->avoid_negative_ts;
 514         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO)
 515             c->has_video = 1;
 516         else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO)
 517             c->has_audio = 1;
 518
 519         set_codec_str(s, os->ctx->streams[0]->codec, os->codec_str, sizeof(os->codec_str));
 520         os->first_dts = AV_NOPTS_VALUE;
 521         os->segment_index = 1;
 522     }
 523
 524     if (!c->has_video && c->min_seg_duration <= 0) {
 525         av_log(s, AV_LOG_WARNING, "no video stream and no min seg duration set\n");
 526         ret = AVERROR(EINVAL);
 527     }
 528     ret = write_manifest(s, 0);
 529
 530 fail:
 531     if (ret)
 532         dash_free(s);
 533     return ret;
 534 }
 535
 536 static int add_segment(OutputStream *os, const char *file,
 537                        int64_t time, int duration,
 538                        int64_t start_pos, int64_t range_length,
 539                        int64_t index_length)
 540 {
 541     int err;
 542     Segment *seg;
 543     if (os->nb_segments >= os->segments_size) {
 544         os->segments_size = (os->segments_size + 1) * 2;
 545         if ((err = av_reallocp(&os->segments, sizeof(*os->segments) *
 546                                os->segments_size)) < 0) {
 547             os->segments_size = 0;
 548             os->nb_segments = 0;
 549             return err;
 550         }
 551     }
 552     seg = av_mallocz(sizeof(*seg));
 553     if (!seg)
 554         return AVERROR(ENOMEM);
 555     av_strlcpy(seg->file, file, sizeof(seg->file));
 556     seg->time = time;
 557     seg->duration = duration;
 558     seg->start_pos = start_pos;
 559     seg->range_length = range_length;
 560     seg->index_length = index_length;
 561     os->segments[os->nb_segments++] = seg;
 562     os->segment_index++;
 563     return 0;
 564 }
 565
 566 static void write_styp(AVIOContext *pb)
 567 {
 568     avio_wb32(pb, 24);
 569     ffio_wfourcc(pb, "styp");
 570     ffio_wfourcc(pb, "msdh");
 571     avio_wb32(pb, 0); /* minor */
 572     ffio_wfourcc(pb, "msdh");
 573     ffio_wfourcc(pb, "msix");
 574 }
 575
 576 static void find_index_range(AVFormatContext *s, const char *dirname,
 577                              const char *filename, int64_t pos,
 578                              int *index_length)
 579 {
 580     char full_path[1024];
 581     uint8_t buf[8];
 582     URLContext *fd;
 583     int ret;
 584
 585     snprintf(full_path, sizeof(full_path), "%s%s", dirname, filename);
 586     ret = ffurl_open(&fd, full_path, AVIO_FLAG_READ, &s->interrupt_callback, NULL);
 587     if (ret < 0)
 588         return;
 589     if (ffurl_seek(fd, pos, SEEK_SET) != pos) {
 590         ffurl_close(fd);
 591         return;
 592     }
 593     ret = ffurl_read(fd, buf, 8);
 594     ffurl_close(fd);
 595     if (ret < 8)
 596         return;
 597     if (AV_RL32(&buf[4]) != MKTAG('s', 'i', 'd', 'x'))
 598         return;
 599     *index_length = AV_RB32(&buf[0]);
 600 }
 601
 602 static int dash_flush(AVFormatContext *s, int final, int stream)
 603 {
 604     DASHContext *c = s->priv_data;
 605     int i, ret = 0;
 606     int cur_flush_segment_index = 0;
 607     if (stream >= 0)
 608         cur_flush_segment_index = c->streams[stream].segment_index;
 609
 610     for (i = 0; i < s->nb_streams; i++) {
 611         OutputStream *os = &c->streams[i];
 612         char filename[1024] = "", full_path[1024], temp_path[1024];
 613         const char *write_path;
 614         int64_t start_pos = avio_tell(os->ctx->pb);
 615         int range_length, index_length = 0;
 616
 617         if (!os->packets_written)
 618             continue;
 619
 620         // Flush the single stream that got a keyframe right now.
 621         // Flush all audio streams as well, in sync with video keyframes,
 622         // but not the other video streams.
 623         if (stream >= 0 && i != stream) {
 624             if (s->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO)
 625                 continue;
 626             // Make sure we don't flush audio streams multiple times, when
 627             // all video streams are flushed one at a time.
 628             if (c->has_video && os->segment_index > cur_flush_segment_index)
 629                 continue;
 630         }
 631
 632         if (!c->single_file) {
 633             snprintf(filename, sizeof(filename), "chunk-stream%d-%05d.m4s", i, os->segment_index);
 634             snprintf(full_path, sizeof(full_path), "%s%s", c->dirname, filename);
 635             snprintf(temp_path, sizeof(temp_path), "%s.tmp", full_path);
 636             write_path = USE_RENAME_REPLACE ? temp_path : full_path;
 637             ret = ffurl_open(&os->out, write_path, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
 638             if (ret < 0)
 639                 break;
 640             write_styp(os->ctx->pb);
 641         }
 642         av_write_frame(os->ctx, NULL);
 643         avio_flush(os->ctx->pb);
 644         os->packets_written = 0;
 645
 646         range_length = avio_tell(os->ctx->pb) - start_pos;
 647         if (c->single_file) {
 648             find_index_range(s, c->dirname, os->initfile, start_pos, &index_length);
 649         } else {
 650             ffurl_close(os->out);
 651             os->out = NULL;
 652             ret = USE_RENAME_REPLACE ? ff_rename(temp_path, full_path, s) : 0;
 653             if (ret < 0)
 654                 break;
 655         }
 656         add_segment(os, filename, os->start_dts, os->end_dts - os->start_dts, start_pos, range_length, index_length);
 657     }
 658
 659     if (c->window_size || (final && c->remove_at_exit)) {
 660         for (i = 0; i < s->nb_streams; i++) {
 661             OutputStream *os = &c->streams[i];
 662             int j;
 663             int remove = os->nb_segments - c->window_size - c->extra_window_size;
 664             if (final && c->remove_at_exit)
 665                 remove = os->nb_segments;
 666             if (remove > 0) {
 667                 for (j = 0; j < remove; j++) {
 668                     char filename[1024];
 669                     snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->segments[j]->file);
 670                     unlink(filename);
 671                     av_free(os->segments[j]);
 672                 }
 673                 os->nb_segments -= remove;
 674                 memmove(os->segments, os->segments + remove, os->nb_segments * sizeof(*os->segments));
 675             }
 676         }
 677     }
 678
 679     if (ret >= 0)
 680         ret = write_manifest(s, final);
 681     return ret;
 682 }
 683
 684 static int dash_write_packet(AVFormatContext *s, AVPacket *pkt)
 685 {
 686     DASHContext *c = s->priv_data;
 687     AVStream *st = s->streams[pkt->stream_index];
 688     OutputStream *os = &c->streams[pkt->stream_index];
 689     int64_t seg_end_duration = (os->segment_index) * (int64_t) c->min_seg_duration;
 690     int ret;
 691
 692     // If forcing the stream to start at 0, the mp4 muxer will set the start
 693     // timestamps to 0. Do the same here, to avoid mismatches in duration/timestamps.
 694     if (os->first_dts == AV_NOPTS_VALUE &&
 695         s->avoid_negative_ts == AVFMT_AVOID_NEG_TS_MAKE_ZERO) {
 696         pkt->pts -= pkt->dts;
 697         pkt->dts  = 0;
 698     }
 699
 700     if (os->first_dts == AV_NOPTS_VALUE)
 701         os->first_dts = pkt->dts;
 702
 703     if ((!c->has_video || st->codec->codec_type == AVMEDIA_TYPE_VIDEO) &&
 704         pkt->flags & AV_PKT_FLAG_KEY && os->packets_written &&
 705         av_compare_ts(pkt->dts - os->first_dts, st->time_base,
 706                       seg_end_duration, AV_TIME_BASE_Q) >= 0) {
 707         int64_t prev_duration = c->last_duration;
 708
 709         c->last_duration = av_rescale_q(pkt->dts - os->start_dts,
 710                                         st->time_base,
 711                                         AV_TIME_BASE_Q);
 712         c->total_duration = av_rescale_q(pkt->dts - os->first_dts,
 713                                          st->time_base,
 714                                          AV_TIME_BASE_Q);
 715
 716         if ((!c->use_timeline || !c->use_template) && prev_duration) {
 717             if (c->last_duration < prev_duration*9/10 ||
 718                 c->last_duration > prev_duration*11/10) {
 719                 av_log(s, AV_LOG_WARNING,
 720                        "Segment durations differ too much, enable use_timeline "
 721                        "and use_template, or keep a stricter keyframe interval\n");
 722             }
 723         }
 724
 725         if ((ret = dash_flush(s, 0, pkt->stream_index)) < 0)
 726             return ret;
 727     }
 728
 729     if (!os->packets_written)
 730         os->start_dts = pkt->dts;
 731     os->end_dts = pkt->dts + pkt->duration;
 732     os->packets_written++;
 733     return ff_write_chained(os->ctx, 0, pkt, s, 0);
 734 }
 735
 736 static int dash_write_trailer(AVFormatContext *s)
 737 {
 738     DASHContext *c = s->priv_data;
 739
 740     if (s->nb_streams > 0) {
 741         OutputStream *os = &c->streams[0];
 742         // If no segments have been written so far, try to do a crude
 743         // guess of the segment duration
 744         if (!c->last_duration)
 745             c->last_duration = av_rescale_q(os->end_dts - os->start_dts,
 746                                             s->streams[0]->time_base,
 747                                             AV_TIME_BASE_Q);
 748         c->total_duration = av_rescale_q(os->end_dts - os->first_dts,
 749                                          s->streams[0]->time_base,
 750                                          AV_TIME_BASE_Q);
 751     }
 752     dash_flush(s, 1, -1);
 753
 754     if (c->remove_at_exit) {
 755         char filename[1024];
 756         int i;
 757         for (i = 0; i < s->nb_streams; i++) {
 758             OutputStream *os = &c->streams[i];
 759             snprintf(filename, sizeof(filename), "%s%s", c->dirname, os->initfile);
 760             unlink(filename);
 761         }
 762         unlink(s->filename);
 763     }
 764
 765     dash_free(s);
 766     return 0;
 767 }
 768
 769 #define OFFSET(x) offsetof(DASHContext, x)
 770 #define E AV_OPT_FLAG_ENCODING_PARAM
 771 static const AVOption options[] = {
 772     { "window_size", "number of segments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
 773     { "extra_window_size", "number of segments kept outside of the manifest before removing from disk", OFFSET(extra_window_size), AV_OPT_TYPE_INT, { .i64 = 5 }, 0, INT_MAX, E },
 774     { "min_seg_duration", "minimum segment duration (in microseconds)", OFFSET(min_seg_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E },
 775     { "remove_at_exit", "remove all segments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, E },
 776     { "use_template", "Use SegmentTemplate instead of SegmentList", OFFSET(use_template), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E },
 777     { "use_timeline", "Use SegmentTimeline in SegmentTemplate", OFFSET(use_timeline), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 1, E },
 778     { "single_file", "Store all segments in one file, accessed using byte ranges", OFFSET(single_file), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, E },
 779     { NULL },
 780 };
 781
 782 static const AVClass dash_class = {
 783     .class_name = "dash muxer",
 784     .item_name  = av_default_item_name,
 785     .option     = options,
 786     .version    = LIBAVUTIL_VERSION_INT,
 787 };
 788
 789 AVOutputFormat ff_dash_muxer = {
 790     .name           = "dash",
 791     .long_name      = NULL_IF_CONFIG_SMALL("DASH Muxer"),
 792     .priv_data_size = sizeof(DASHContext),
 793     .audio_codec    = AV_CODEC_ID_AAC,
 794     .video_codec    = AV_CODEC_ID_H264,
 795     .flags          = AVFMT_GLOBALHEADER | AVFMT_NOFILE | AVFMT_TS_NEGATIVE,
 796     .write_header   = dash_write_header,
 797     .write_packet   = dash_write_packet,
 798     .write_trailer  = dash_write_trailer,
 799     .codec_tag      = (const AVCodecTag* const []){ ff_mp4_obj_type, 0 },
 800     .priv_class     = &dash_class,
 801 };