libavformat/webmdashenc.c

   1 /*
   2  * WebM DASH Manifest XML muxer
   3  * Copyright (c) 2014 Vignesh Venkatasubramanian
   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 /*
  23  * WebM DASH Specification:
  24  * https://sites.google.com/a/webmproject.org/wiki/adaptive-streaming/webm-dash-specification
  25  * ISO DASH Specification:
  26  * http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip
  27  */
  28
  29 #include <float.h>
  30 #include <stdint.h>
  31 #include <string.h>
  32
  33 #include "avformat.h"
  34 #include "avio_internal.h"
  35 #include "matroska.h"
  36
  37 #include "libavutil/avstring.h"
  38 #include "libavutil/dict.h"
  39 #include "libavutil/opt.h"
  40 #include "libavutil/time_internal.h"
  41
  42 typedef struct AdaptationSet {
  43     char id[10];
  44     int *streams;
  45     int nb_streams;
  46 } AdaptationSet;
  47
  48 typedef struct WebMDashMuxContext {
  49     const AVClass  *class;
  50     char *adaptation_sets;
  51     AdaptationSet *as;
  52     int nb_as;
  53     int representation_id;
  54     int is_live;
  55     int chunk_start_index;
  56     int chunk_duration;
  57     char *utc_timing_url;
  58     double time_shift_buffer_depth;
  59     int minimum_update_period;
  60     int debug_mode;
  61 } WebMDashMuxContext;
  62
  63 static const char *get_codec_name(int codec_id)
  64 {
  65     switch (codec_id) {
  66         case AV_CODEC_ID_VP8:
  67             return "vp8";
  68         case AV_CODEC_ID_VP9:
  69             return "vp9";
  70         case AV_CODEC_ID_VORBIS:
  71             return "vorbis";
  72         case AV_CODEC_ID_OPUS:
  73             return "opus";
  74     }
  75     return NULL;
  76 }
  77
  78 static double get_duration(AVFormatContext *s)
  79 {
  80     int i = 0;
  81     double max = 0.0;
  82     for (i = 0; i < s->nb_streams; i++) {
  83         AVDictionaryEntry *duration = av_dict_get(s->streams[i]->metadata,
  84                                                   DURATION, NULL, 0);
  85         if (!duration || atof(duration->value) < 0) continue;
  86         if (atof(duration->value) > max) max = atof(duration->value);
  87     }
  88     return max / 1000;
  89 }
  90
  91 static int write_header(AVFormatContext *s)
  92 {
  93     WebMDashMuxContext *w = s->priv_data;
  94     double min_buffer_time = 1.0;
  95     avio_printf(s->pb, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
  96     avio_printf(s->pb, "<MPD\n");
  97     avio_printf(s->pb, "  xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"\n");
  98     avio_printf(s->pb, "  xmlns=\"urn:mpeg:DASH:schema:MPD:2011\"\n");
  99     avio_printf(s->pb, "  xsi:schemaLocation=\"urn:mpeg:DASH:schema:MPD:2011\"\n");
 100     avio_printf(s->pb, "  type=\"%s\"\n", w->is_live ? "dynamic" : "static");
 101     if (!w->is_live) {
 102         avio_printf(s->pb, "  mediaPresentationDuration=\"PT%gS\"\n",
 103                     get_duration(s));
 104     }
 105     avio_printf(s->pb, "  minBufferTime=\"PT%gS\"\n", min_buffer_time);
 106     avio_printf(s->pb, "  profiles=\"%s\"%s",
 107                 w->is_live ? "urn:mpeg:dash:profile:isoff-live:2011" : "urn:webm:dash:profile:webm-on-demand:2012",
 108                 w->is_live ? "\n" : ">\n");
 109     if (w->is_live) {
 110         time_t local_time = time(NULL);
 111         struct tm gmt_buffer;
 112         struct tm *gmt = gmtime_r(&local_time, &gmt_buffer);
 113         char gmt_iso[21];
 114         if (!strftime(gmt_iso, 21, "%Y-%m-%dT%H:%M:%SZ", gmt)) {
 115             return AVERROR_UNKNOWN;
 116         }
 117         if (w->debug_mode) {
 118             av_strlcpy(gmt_iso, "", 1);
 119         }
 120         avio_printf(s->pb, "  availabilityStartTime=\"%s\"\n", gmt_iso);
 121         avio_printf(s->pb, "  timeShiftBufferDepth=\"PT%gS\"\n", w->time_shift_buffer_depth);
 122         avio_printf(s->pb, "  minimumUpdatePeriod=\"PT%dS\"", w->minimum_update_period);
 123         avio_printf(s->pb, ">\n");
 124         if (w->utc_timing_url) {
 125             avio_printf(s->pb, "<UTCTiming\n");
 126             avio_printf(s->pb, "  schemeIdUri=\"urn:mpeg:dash:utc:http-iso:2014\"\n");
 127             avio_printf(s->pb, "  value=\"%s\"/>\n", w->utc_timing_url);
 128         }
 129     }
 130     return 0;
 131 }
 132
 133 static void write_footer(AVFormatContext *s)
 134 {
 135     avio_printf(s->pb, "</MPD>\n");
 136 }
 137
 138 static int subsegment_alignment(AVFormatContext *s, AdaptationSet *as) {
 139     int i;
 140     AVDictionaryEntry *gold = av_dict_get(s->streams[as->streams[0]]->metadata,
 141                                           CUE_TIMESTAMPS, NULL, 0);
 142     if (!gold) return 0;
 143     for (i = 1; i < as->nb_streams; i++) {
 144         AVDictionaryEntry *ts = av_dict_get(s->streams[as->streams[i]]->metadata,
 145                                             CUE_TIMESTAMPS, NULL, 0);
 146         if (!ts || strncmp(gold->value, ts->value, strlen(gold->value))) return 0;
 147     }
 148     return 1;
 149 }
 150
 151 static int bitstream_switching(AVFormatContext *s, AdaptationSet *as) {
 152     int i;
 153     AVDictionaryEntry *gold_track_num = av_dict_get(s->streams[as->streams[0]]->metadata,
 154                                                     TRACK_NUMBER, NULL, 0);
 155     AVCodecParameters *gold_par = s->streams[as->streams[0]]->codecpar;
 156     if (!gold_track_num) return 0;
 157     for (i = 1; i < as->nb_streams; i++) {
 158         AVDictionaryEntry *track_num = av_dict_get(s->streams[as->streams[i]]->metadata,
 159                                                    TRACK_NUMBER, NULL, 0);
 160         AVCodecParameters *par = s->streams[as->streams[i]]->codecpar;
 161         if (!track_num ||
 162             strncmp(gold_track_num->value, track_num->value, strlen(gold_track_num->value)) ||
 163             gold_par->codec_id != par->codec_id ||
 164             gold_par->extradata_size != par->extradata_size ||
 165             memcmp(gold_par->extradata, par->extradata, par->extradata_size)) {
 166             return 0;
 167         }
 168     }
 169     return 1;
 170 }
 171
 172 /*
 173  * Writes a Representation within an Adaptation Set. Returns 0 on success and
 174  * < 0 on failure.
 175  */
 176 static int write_representation(AVFormatContext *s, AVStream *stream, char *id,
 177                                 int output_width, int output_height,
 178                                 int output_sample_rate) {
 179     WebMDashMuxContext *w = s->priv_data;
 180     AVDictionaryEntry *irange = av_dict_get(stream->metadata, INITIALIZATION_RANGE, NULL, 0);
 181     AVDictionaryEntry *cues_start = av_dict_get(stream->metadata, CUES_START, NULL, 0);
 182     AVDictionaryEntry *cues_end = av_dict_get(stream->metadata, CUES_END, NULL, 0);
 183     AVDictionaryEntry *filename = av_dict_get(stream->metadata, FILENAME, NULL, 0);
 184     AVDictionaryEntry *bandwidth = av_dict_get(stream->metadata, BANDWIDTH, NULL, 0);
 185     if ((w->is_live && (!filename)) ||
 186         (!w->is_live && (!irange || !cues_start || !cues_end || !filename || !bandwidth))) {
 187         return AVERROR_INVALIDDATA;
 188     }
 189     avio_printf(s->pb, "<Representation id=\"%s\"", id);
 190     // FIXME: For live, This should be obtained from the input file or as an AVOption.
 191     avio_printf(s->pb, " bandwidth=\"%s\"",
 192                 w->is_live ? (stream->codecpar->codec_type == AVMEDIA_TYPE_AUDIO ? "128000" : "1000000") : bandwidth->value);
 193     if (stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && output_width)
 194         avio_printf(s->pb, " width=\"%d\"", stream->codecpar->width);
 195     if (stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO && output_height)
 196         avio_printf(s->pb, " height=\"%d\"", stream->codecpar->height);
 197     if (stream->codecpar->codec_type == AVMEDIA_TYPE_AUDIO && output_sample_rate)
 198         avio_printf(s->pb, " audioSamplingRate=\"%d\"", stream->codecpar->sample_rate);
 199     if (w->is_live) {
 200         // For live streams, Codec and Mime Type always go in the Representation tag.
 201         avio_printf(s->pb, " codecs=\"%s\"", get_codec_name(stream->codecpar->codec_id));
 202         avio_printf(s->pb, " mimeType=\"%s/webm\"",
 203                     stream->codecpar->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio");
 204         // For live streams, subsegments always start with key frames. So this
 205         // is always 1.
 206         avio_printf(s->pb, " startsWithSAP=\"1\"");
 207         avio_printf(s->pb, ">");
 208     } else {
 209         avio_printf(s->pb, ">\n");
 210         avio_printf(s->pb, "<BaseURL>%s</BaseURL>\n", filename->value);
 211         avio_printf(s->pb, "<SegmentBase\n");
 212         avio_printf(s->pb, "  indexRange=\"%s-%s\">\n", cues_start->value, cues_end->value);
 213         avio_printf(s->pb, "<Initialization\n");
 214         avio_printf(s->pb, "  range=\"0-%s\" />\n", irange->value);
 215         avio_printf(s->pb, "</SegmentBase>\n");
 216     }
 217     avio_printf(s->pb, "</Representation>\n");
 218     return 0;
 219 }
 220
 221 /*
 222  * Checks if width of all streams are the same. Returns 1 if true, 0 otherwise.
 223  */
 224 static int check_matching_width(AVFormatContext *s, AdaptationSet *as) {
 225     int first_width, i;
 226     if (as->nb_streams < 2) return 1;
 227     first_width = s->streams[as->streams[0]]->codecpar->width;
 228     for (i = 1; i < as->nb_streams; i++)
 229         if (first_width != s->streams[as->streams[i]]->codecpar->width)
 230           return 0;
 231     return 1;
 232 }
 233
 234 /*
 235  * Checks if height of all streams are the same. Returns 1 if true, 0 otherwise.
 236  */
 237 static int check_matching_height(AVFormatContext *s, AdaptationSet *as) {
 238     int first_height, i;
 239     if (as->nb_streams < 2) return 1;
 240     first_height = s->streams[as->streams[0]]->codecpar->height;
 241     for (i = 1; i < as->nb_streams; i++)
 242         if (first_height != s->streams[as->streams[i]]->codecpar->height)
 243           return 0;
 244     return 1;
 245 }
 246
 247 /*
 248  * Checks if sample rate of all streams are the same. Returns 1 if true, 0 otherwise.
 249  */
 250 static int check_matching_sample_rate(AVFormatContext *s, AdaptationSet *as) {
 251     int first_sample_rate, i;
 252     if (as->nb_streams < 2) return 1;
 253     first_sample_rate = s->streams[as->streams[0]]->codecpar->sample_rate;
 254     for (i = 1; i < as->nb_streams; i++)
 255         if (first_sample_rate != s->streams[as->streams[i]]->codecpar->sample_rate)
 256           return 0;
 257     return 1;
 258 }
 259
 260 static void free_adaptation_sets(AVFormatContext *s) {
 261     WebMDashMuxContext *w = s->priv_data;
 262     int i;
 263     for (i = 0; i < w->nb_as; i++) {
 264         av_freep(&w->as[i].streams);
 265     }
 266     av_freep(&w->as);
 267     w->nb_as = 0;
 268 }
 269
 270 /*
 271  * Parses a live header filename and computes the representation id,
 272  * initialization pattern and the media pattern. Pass NULL if you don't want to
 273  * compute any of those 3. Returns 0 on success and non-zero on failure.
 274  *
 275  * Name of the header file should conform to the following pattern:
 276  * <file_description>_<representation_id>.hdr where <file_description> can be
 277  * anything. The chunks should be named according to the following pattern:
 278  * <file_description>_<representation_id>_<chunk_number>.chk
 279  */
 280 static int parse_filename(char *filename, char **representation_id,
 281                           char **initialization_pattern, char **media_pattern) {
 282     char *underscore_pos = NULL;
 283     char *period_pos = NULL;
 284     char *temp_pos = NULL;
 285     char *filename_str = av_strdup(filename);
 286     if (!filename_str) return AVERROR(ENOMEM);
 287     temp_pos = av_stristr(filename_str, "_");
 288     while (temp_pos) {
 289         underscore_pos = temp_pos + 1;
 290         temp_pos = av_stristr(temp_pos + 1, "_");
 291     }
 292     if (!underscore_pos) return AVERROR_INVALIDDATA;
 293     period_pos = av_stristr(underscore_pos, ".");
 294     if (!period_pos) return AVERROR_INVALIDDATA;
 295     *(underscore_pos - 1) = 0;
 296     if (representation_id) {
 297         *representation_id = av_malloc(period_pos - underscore_pos + 1);
 298         if (!(*representation_id)) return AVERROR(ENOMEM);
 299         av_strlcpy(*representation_id, underscore_pos, period_pos - underscore_pos + 1);
 300     }
 301     if (initialization_pattern) {
 302         *initialization_pattern = av_asprintf("%s_$RepresentationID$.hdr",
 303                                               filename_str);
 304         if (!(*initialization_pattern)) return AVERROR(ENOMEM);
 305     }
 306     if (media_pattern) {
 307         *media_pattern = av_asprintf("%s_$RepresentationID$_$Number$.chk",
 308                                      filename_str);
 309         if (!(*media_pattern)) return AVERROR(ENOMEM);
 310     }
 311     av_free(filename_str);
 312     return 0;
 313 }
 314
 315 /*
 316  * Writes an Adaptation Set. Returns 0 on success and < 0 on failure.
 317  */
 318 static int write_adaptation_set(AVFormatContext *s, int as_index)
 319 {
 320     WebMDashMuxContext *w = s->priv_data;
 321     AdaptationSet *as = &w->as[as_index];
 322     AVCodecParameters *par = s->streams[as->streams[0]]->codecpar;
 323     AVDictionaryEntry *lang;
 324     int i;
 325     static const char boolean[2][6] = { "false", "true" };
 326     int subsegmentStartsWithSAP = 1;
 327
 328     // Width, Height and Sample Rate will go in the AdaptationSet tag if they
 329     // are the same for all contained Representations. otherwise, they will go
 330     // on their respective Representation tag. For live streams, they always go
 331     // in the Representation tag.
 332     int width_in_as = 1, height_in_as = 1, sample_rate_in_as = 1;
 333     if (par->codec_type == AVMEDIA_TYPE_VIDEO) {
 334       width_in_as = !w->is_live && check_matching_width(s, as);
 335       height_in_as = !w->is_live && check_matching_height(s, as);
 336     } else {
 337       sample_rate_in_as = !w->is_live && check_matching_sample_rate(s, as);
 338     }
 339
 340     avio_printf(s->pb, "<AdaptationSet id=\"%s\"", as->id);
 341     avio_printf(s->pb, " mimeType=\"%s/webm\"",
 342                 par->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio");
 343     avio_printf(s->pb, " codecs=\"%s\"", get_codec_name(par->codec_id));
 344
 345     lang = av_dict_get(s->streams[as->streams[0]]->metadata, "language", NULL, 0);
 346     if (lang) avio_printf(s->pb, " lang=\"%s\"", lang->value);
 347
 348     if (par->codec_type == AVMEDIA_TYPE_VIDEO && width_in_as)
 349         avio_printf(s->pb, " width=\"%d\"", par->width);
 350     if (par->codec_type == AVMEDIA_TYPE_VIDEO && height_in_as)
 351         avio_printf(s->pb, " height=\"%d\"", par->height);
 352     if (par->codec_type == AVMEDIA_TYPE_AUDIO && sample_rate_in_as)
 353         avio_printf(s->pb, " audioSamplingRate=\"%d\"", par->sample_rate);
 354
 355     avio_printf(s->pb, " bitstreamSwitching=\"%s\"",
 356                 boolean[bitstream_switching(s, as)]);
 357     avio_printf(s->pb, " subsegmentAlignment=\"%s\"",
 358                 boolean[w->is_live || subsegment_alignment(s, as)]);
 359
 360     for (i = 0; i < as->nb_streams; i++) {
 361         AVDictionaryEntry *kf = av_dict_get(s->streams[as->streams[i]]->metadata,
 362                                             CLUSTER_KEYFRAME, NULL, 0);
 363         if (!w->is_live && (!kf || !strncmp(kf->value, "0", 1))) subsegmentStartsWithSAP = 0;
 364     }
 365     avio_printf(s->pb, " subsegmentStartsWithSAP=\"%d\"", subsegmentStartsWithSAP);
 366     avio_printf(s->pb, ">\n");
 367
 368     if (w->is_live) {
 369         AVDictionaryEntry *filename =
 370             av_dict_get(s->streams[as->streams[0]]->metadata, FILENAME, NULL, 0);
 371         char *initialization_pattern = NULL;
 372         char *media_pattern = NULL;
 373         int ret = parse_filename(filename->value, NULL, &initialization_pattern,
 374                                  &media_pattern);
 375         if (ret) return ret;
 376         avio_printf(s->pb, "<ContentComponent id=\"1\" type=\"%s\"/>\n",
 377                     par->codec_type == AVMEDIA_TYPE_VIDEO ? "video" : "audio");
 378         avio_printf(s->pb, "<SegmentTemplate");
 379         avio_printf(s->pb, " timescale=\"1000\"");
 380         avio_printf(s->pb, " duration=\"%d\"", w->chunk_duration);
 381         avio_printf(s->pb, " media=\"%s\"", media_pattern);
 382         avio_printf(s->pb, " startNumber=\"%d\"", w->chunk_start_index);
 383         avio_printf(s->pb, " initialization=\"%s\"", initialization_pattern);
 384         avio_printf(s->pb, "/>\n");
 385         av_free(initialization_pattern);
 386         av_free(media_pattern);
 387     }
 388
 389     for (i = 0; i < as->nb_streams; i++) {
 390         char *representation_id = NULL;
 391         int ret;
 392         if (w->is_live) {
 393             AVDictionaryEntry *filename =
 394                 av_dict_get(s->streams[as->streams[i]]->metadata, FILENAME, NULL, 0);
 395             if (!filename)
 396                 return AVERROR(EINVAL);
 397             if (ret = parse_filename(filename->value, &representation_id, NULL, NULL))
 398                 return ret;
 399         } else {
 400             representation_id = av_asprintf("%d", w->representation_id++);
 401             if (!representation_id) return AVERROR(ENOMEM);
 402         }
 403         ret = write_representation(s, s->streams[as->streams[i]],
 404                                    representation_id, !width_in_as,
 405                                    !height_in_as, !sample_rate_in_as);
 406         av_free(representation_id);
 407         if (ret) return ret;
 408     }
 409     avio_printf(s->pb, "</AdaptationSet>\n");
 410     return 0;
 411 }
 412
 413 static int to_integer(char *p, int len)
 414 {
 415     int ret;
 416     char *q = av_malloc(sizeof(char) * len);
 417     if (!q)
 418         return AVERROR(ENOMEM);
 419     av_strlcpy(q, p, len);
 420     ret = atoi(q);
 421     av_free(q);
 422     return ret;
 423 }
 424
 425 static int parse_adaptation_sets(AVFormatContext *s)
 426 {
 427     WebMDashMuxContext *w = s->priv_data;
 428     char *p = w->adaptation_sets;
 429     char *q;
 430     enum { new_set, parsed_id, parsing_streams } state;
 431     if (!w->adaptation_sets) {
 432         av_log(s, AV_LOG_ERROR, "The 'adaptation_sets' option must be set.\n");
 433         return AVERROR(EINVAL);
 434     }
 435     // syntax id=0,streams=0,1,2 id=1,streams=3,4 and so on
 436     state = new_set;
 437     while (p < w->adaptation_sets + strlen(w->adaptation_sets)) {
 438         if (*p == ' ')
 439             continue;
 440         else if (state == new_set && !strncmp(p, "id=", 3)) {
 441             void *mem = av_realloc(w->as, sizeof(*w->as) * (w->nb_as + 1));
 442             const char *comma;
 443             if (mem == NULL)
 444                 return AVERROR(ENOMEM);
 445             w->as = mem;
 446             ++w->nb_as;
 447             w->as[w->nb_as - 1].nb_streams = 0;
 448             w->as[w->nb_as - 1].streams = NULL;
 449             p += 3; // consume "id="
 450             q = w->as[w->nb_as - 1].id;
 451             comma = strchr(p, ',');
 452             if (!comma || comma - p >= sizeof(w->as[w->nb_as - 1].id)) {
 453                 av_log(s, AV_LOG_ERROR, "'id' in 'adaptation_sets' is malformed.\n");
 454                 return AVERROR(EINVAL);
 455             }
 456             while (*p != ',') *q++ = *p++;
 457             *q = 0;
 458             p++;
 459             state = parsed_id;
 460         } else if (state == parsed_id && !strncmp(p, "streams=", 8)) {
 461             p += 8; // consume "streams="
 462             state = parsing_streams;
 463         } else if (state == parsing_streams) {
 464             struct AdaptationSet *as = &w->as[w->nb_as - 1];
 465             int ret = av_reallocp_array(&as->streams, ++as->nb_streams,
 466                                         sizeof(*as->streams));
 467             if (ret < 0)
 468                 return ret;
 469             q = p;
 470             while (*q != '\0' && *q != ',' && *q != ' ') q++;
 471             as->streams[as->nb_streams - 1] = to_integer(p, q - p + 1);
 472             if (as->streams[as->nb_streams - 1] < 0 ||
 473                 as->streams[as->nb_streams - 1] >= s->nb_streams) {
 474                 av_log(s, AV_LOG_ERROR, "Invalid value for 'streams' in adapation_sets.\n");
 475                 return AVERROR(EINVAL);
 476             }
 477             if (*q == '\0') break;
 478             if (*q == ' ') state = new_set;
 479             p = ++q;
 480         } else {
 481             return -1;
 482         }
 483     }
 484     return 0;
 485 }
 486
 487 static int webm_dash_manifest_write_header(AVFormatContext *s)
 488 {
 489     int i;
 490     double start = 0.0;
 491     int ret;
 492     WebMDashMuxContext *w = s->priv_data;
 493
 494     for (unsigned i = 0; i < s->nb_streams; i++) {
 495         enum AVCodecID codec_id = s->streams[i]->codecpar->codec_id;
 496         if (codec_id != AV_CODEC_ID_VP8    && codec_id != AV_CODEC_ID_VP9 &&
 497             codec_id != AV_CODEC_ID_VORBIS && codec_id != AV_CODEC_ID_OPUS)
 498             return AVERROR(EINVAL);
 499     }
 500
 501     ret = parse_adaptation_sets(s);
 502     if (ret < 0) {
 503         goto fail;
 504     }
 505     ret = write_header(s);
 506     if (ret < 0) {
 507         goto fail;
 508     }
 509     avio_printf(s->pb, "<Period id=\"0\"");
 510     avio_printf(s->pb, " start=\"PT%gS\"", start);
 511     if (!w->is_live) {
 512         avio_printf(s->pb, " duration=\"PT%gS\"", get_duration(s));
 513     }
 514     avio_printf(s->pb, " >\n");
 515
 516     for (i = 0; i < w->nb_as; i++) {
 517         ret = write_adaptation_set(s, i);
 518         if (ret < 0) {
 519             goto fail;
 520         }
 521     }
 522
 523     avio_printf(s->pb, "</Period>\n");
 524     write_footer(s);
 525 fail:
 526     free_adaptation_sets(s);
 527     return ret < 0 ? ret : 0;
 528 }
 529
 530 static int webm_dash_manifest_write_packet(AVFormatContext *s, AVPacket *pkt)
 531 {
 532     return AVERROR_EOF;
 533 }
 534
 535 static int webm_dash_manifest_write_trailer(AVFormatContext *s)
 536 {
 537     free_adaptation_sets(s);
 538     return 0;
 539 }
 540
 541 #define OFFSET(x) offsetof(WebMDashMuxContext, x)
 542 static const AVOption options[] = {
 543     { "adaptation_sets", "Adaptation sets. Syntax: id=0,streams=0,1,2 id=1,streams=3,4 and so on", OFFSET(adaptation_sets), AV_OPT_TYPE_STRING, { 0 }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
 544     { "debug_mode", "[private option - users should never set this]. Create deterministic output", OFFSET(debug_mode), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
 545     { "live", "create a live stream manifest", OFFSET(is_live), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM },
 546     { "chunk_start_index",  "start index of the chunk", OFFSET(chunk_start_index), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
 547     { "chunk_duration_ms", "duration of each chunk (in milliseconds)", OFFSET(chunk_duration), AV_OPT_TYPE_INT, {.i64 = 1000}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
 548     { "utc_timing_url", "URL of the page that will return the UTC timestamp in ISO format", OFFSET(utc_timing_url), AV_OPT_TYPE_STRING, { 0 }, 0, 0, AV_OPT_FLAG_ENCODING_PARAM },
 549     { "time_shift_buffer_depth", "Smallest time (in seconds) shifting buffer for which any Representation is guaranteed to be available.", OFFSET(time_shift_buffer_depth), AV_OPT_TYPE_DOUBLE, { .dbl = 60.0 }, 1.0, DBL_MAX, AV_OPT_FLAG_ENCODING_PARAM },
 550     { "minimum_update_period", "Minimum Update Period (in seconds) of the manifest.", OFFSET(minimum_update_period), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
 551     { NULL },
 552 };
 553
 554 #if CONFIG_WEBM_DASH_MANIFEST_MUXER
 555 static const AVClass webm_dash_class = {
 556     .class_name = "WebM DASH Manifest muxer",
 557     .item_name  = av_default_item_name,
 558     .option     = options,
 559     .version    = LIBAVUTIL_VERSION_INT,
 560 };
 561
 562 AVOutputFormat ff_webm_dash_manifest_muxer = {
 563     .name              = "webm_dash_manifest",
 564     .long_name         = NULL_IF_CONFIG_SMALL("WebM DASH Manifest"),
 565     .mime_type         = "application/xml",
 566     .extensions        = "xml",
 567     .priv_data_size    = sizeof(WebMDashMuxContext),
 568     .write_header      = webm_dash_manifest_write_header,
 569     .write_packet      = webm_dash_manifest_write_packet,
 570     .write_trailer     = webm_dash_manifest_write_trailer,
 571     .priv_class        = &webm_dash_class,
 572 };
 573 #endif