libavformat/smoothstreamingenc.c

   1 /*
   2  * Live smooth streaming fragmenter
   3  * Copyright (c) 2012 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 "avformat.h"
  28 #include "internal.h"
  29 #include "mux.h"
  30 #include "os_support.h"
  31 #include "avc.h"
  32 #include "url.h"
  33
  34 #include "libavutil/mem.h"
  35 #include "libavutil/opt.h"
  36 #include "libavutil/avstring.h"
  37 #include "libavutil/mathematics.h"
  38 #include "libavutil/uuid.h"
  39
  40 typedef struct Fragment {
  41     int64_t start_time, duration;
  42     int n;
  43     int64_t start_pos, size;
  44     char file[1024];
  45     char infofile[1024];
  46 } Fragment;
  47
  48 typedef struct OutputStream {
  49     AVFormatContext *ctx;
  50     URLContext *out;  // Current output stream where all output is written
  51     URLContext *out2; // Auxiliary output stream where all output is also written
  52     URLContext *tail_out; // The actual main output stream, if we're currently seeked back to write elsewhere
  53     int64_t tail_pos, cur_pos, cur_start_pos;
  54     int packets_written;
  55     const char *stream_type_tag;
  56     int nb_fragments, fragments_size, fragment_index;
  57     Fragment **fragments;
  58
  59     const char *fourcc;
  60     char *private_str;
  61     int packet_size;
  62     int audio_tag;
  63     char dirname[1024];
  64     uint8_t iobuf[32768];
  65 } OutputStream;
  66
  67 typedef struct SmoothStreamingContext {
  68     const AVClass *class;  /* Class for private options. */
  69     int window_size;
  70     int extra_window_size;
  71     int lookahead_count;
  72     int min_frag_duration;
  73     int remove_at_exit;
  74     OutputStream *streams;
  75     int has_video, has_audio;
  76     int nb_fragments;
  77 } SmoothStreamingContext;
  78
  79 static int ism_write(void *opaque, const uint8_t *buf, int buf_size)
  80 {
  81     OutputStream *os = opaque;
  82     if (os->out)
  83         ffurl_write(os->out, buf, buf_size);
  84     if (os->out2)
  85         ffurl_write(os->out2, buf, buf_size);
  86     os->cur_pos += buf_size;
  87     if (os->cur_pos >= os->tail_pos)
  88         os->tail_pos = os->cur_pos;
  89     return buf_size;
  90 }
  91
  92 static int64_t ism_seek(void *opaque, int64_t offset, int whence)
  93 {
  94     OutputStream *os = opaque;
  95     int i;
  96     if (whence != SEEK_SET)
  97         return AVERROR(ENOSYS);
  98     if (os->tail_out) {
  99         ffurl_closep(&os->out);
 100         ffurl_closep(&os->out2);
 101         os->out = os->tail_out;
 102         os->tail_out = NULL;
 103     }
 104     if (offset >= os->cur_start_pos) {
 105         if (os->out)
 106             ffurl_seek(os->out, offset - os->cur_start_pos, SEEK_SET);
 107         os->cur_pos = offset;
 108         return offset;
 109     }
 110     for (i = os->nb_fragments - 1; i >= 0; i--) {
 111         Fragment *frag = os->fragments[i];
 112         if (offset >= frag->start_pos && offset < frag->start_pos + frag->size) {
 113             int ret;
 114             AVDictionary *opts = NULL;
 115             os->tail_out = os->out;
 116             av_dict_set(&opts, "truncate", "0", 0);
 117             ret = ffurl_open_whitelist(&os->out, frag->file, AVIO_FLAG_WRITE,
 118                                        &os->ctx->interrupt_callback, &opts, os->ctx->protocol_whitelist, os->ctx->protocol_blacklist, NULL);
 119             av_dict_free(&opts);
 120             if (ret < 0) {
 121                 os->out = os->tail_out;
 122                 os->tail_out = NULL;
 123                 return ret;
 124             }
 125             av_dict_set(&opts, "truncate", "0", 0);
 126             ffurl_open_whitelist(&os->out2, frag->infofile, AVIO_FLAG_WRITE,
 127                                  &os->ctx->interrupt_callback, &opts, os->ctx->protocol_whitelist, os->ctx->protocol_blacklist, NULL);
 128             av_dict_free(&opts);
 129             ffurl_seek(os->out, offset - frag->start_pos, SEEK_SET);
 130             if (os->out2)
 131                 ffurl_seek(os->out2, offset - frag->start_pos, SEEK_SET);
 132             os->cur_pos = offset;
 133             return offset;
 134         }
 135     }
 136     return AVERROR(EIO);
 137 }
 138
 139 static void get_private_data(OutputStream *os)
 140 {
 141     AVCodecParameters *par = os->ctx->streams[0]->codecpar;
 142     uint8_t *ptr = par->extradata;
 143     int size = par->extradata_size;
 144     int i;
 145     if (par->codec_id == AV_CODEC_ID_H264) {
 146         ff_avc_write_annexb_extradata(ptr, &ptr, &size);
 147         if (!ptr)
 148             ptr = par->extradata;
 149     }
 150     if (!ptr)
 151         return;
 152     os->private_str = av_mallocz(2*size + 1);
 153     if (!os->private_str)
 154         goto fail;
 155     for (i = 0; i < size; i++)
 156         snprintf(&os->private_str[2*i], 3, "%02x", ptr[i]);
 157 fail:
 158     if (ptr != par->extradata)
 159         av_free(ptr);
 160 }
 161
 162 static void ism_free(AVFormatContext *s)
 163 {
 164     SmoothStreamingContext *c = s->priv_data;
 165     int i, j;
 166     if (!c->streams)
 167         return;
 168     for (i = 0; i < s->nb_streams; i++) {
 169         OutputStream *os = &c->streams[i];
 170         ffurl_closep(&os->out);
 171         ffurl_closep(&os->out2);
 172         ffurl_closep(&os->tail_out);
 173         if (os->ctx && os->ctx->pb)
 174             avio_context_free(&os->ctx->pb);
 175         avformat_free_context(os->ctx);
 176         av_freep(&os->private_str);
 177         for (j = 0; j < os->nb_fragments; j++)
 178             av_freep(&os->fragments[j]);
 179         av_freep(&os->fragments);
 180     }
 181     av_freep(&c->streams);
 182 }
 183
 184 static void output_chunk_list(OutputStream *os, AVIOContext *out, int final, int skip, int window_size)
 185 {
 186     int removed = 0, i, start = 0;
 187     if (os->nb_fragments <= 0)
 188         return;
 189     if (os->fragments[0]->n > 0)
 190         removed = 1;
 191     if (final)
 192         skip = 0;
 193     if (window_size)
 194         start = FFMAX(os->nb_fragments - skip - window_size, 0);
 195     for (i = start; i < os->nb_fragments - skip; i++) {
 196         Fragment *frag = os->fragments[i];
 197         if (!final || removed)
 198             avio_printf(out, "<c t=\"%"PRIu64"\" d=\"%"PRIu64"\" />\n", frag->start_time, frag->duration);
 199         else
 200             avio_printf(out, "<c n=\"%d\" d=\"%"PRIu64"\" />\n", frag->n, frag->duration);
 201     }
 202 }
 203
 204 static int write_manifest(AVFormatContext *s, int final)
 205 {
 206     SmoothStreamingContext *c = s->priv_data;
 207     AVIOContext *out;
 208     char filename[1024], temp_filename[1024];
 209     int ret, i, video_chunks = 0, audio_chunks = 0, video_streams = 0, audio_streams = 0;
 210     int64_t duration = 0;
 211
 212     snprintf(filename, sizeof(filename), "%s/Manifest", s->url);
 213     snprintf(temp_filename, sizeof(temp_filename), "%s/Manifest.tmp", s->url);
 214     ret = s->io_open(s, &out, temp_filename, AVIO_FLAG_WRITE, NULL);
 215     if (ret < 0) {
 216         av_log(s, AV_LOG_ERROR, "Unable to open %s for writing\n", temp_filename);
 217         return ret;
 218     }
 219     avio_printf(out, "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n");
 220     for (i = 0; i < s->nb_streams; i++) {
 221         OutputStream *os = &c->streams[i];
 222         if (os->nb_fragments > 0) {
 223             Fragment *last = os->fragments[os->nb_fragments - 1];
 224             duration = last->start_time + last->duration;
 225         }
 226         if (s->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
 227             video_chunks = os->nb_fragments;
 228             video_streams++;
 229         } else {
 230             audio_chunks = os->nb_fragments;
 231             audio_streams++;
 232         }
 233     }
 234     if (!final) {
 235         duration = 0;
 236         video_chunks = audio_chunks = 0;
 237     }
 238     if (c->window_size) {
 239         video_chunks = FFMIN(video_chunks, c->window_size);
 240         audio_chunks = FFMIN(audio_chunks, c->window_size);
 241     }
 242     avio_printf(out, "<SmoothStreamingMedia MajorVersion=\"2\" MinorVersion=\"0\" Duration=\"%"PRIu64"\"", duration);
 243     if (!final)
 244         avio_printf(out, " IsLive=\"true\" LookAheadFragmentCount=\"%d\" DVRWindowLength=\"0\"", c->lookahead_count);
 245     avio_printf(out, ">\n");
 246     if (c->has_video) {
 247         int last = -1, index = 0;
 248         avio_printf(out, "<StreamIndex Type=\"video\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(video={start time})\">\n", video_streams, video_chunks);
 249         for (i = 0; i < s->nb_streams; i++) {
 250             OutputStream *os = &c->streams[i];
 251             if (s->streams[i]->codecpar->codec_type != AVMEDIA_TYPE_VIDEO)
 252                 continue;
 253             last = i;
 254             avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%"PRId64"\" FourCC=\"%s\" MaxWidth=\"%d\" MaxHeight=\"%d\" CodecPrivateData=\"%s\" />\n", index, s->streams[i]->codecpar->bit_rate, os->fourcc, s->streams[i]->codecpar->width, s->streams[i]->codecpar->height, os->private_str);
 255             index++;
 256         }
 257         output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
 258         avio_printf(out, "</StreamIndex>\n");
 259     }
 260     if (c->has_audio) {
 261         int last = -1, index = 0;
 262         avio_printf(out, "<StreamIndex Type=\"audio\" QualityLevels=\"%d\" Chunks=\"%d\" Url=\"QualityLevels({bitrate})/Fragments(audio={start time})\">\n", audio_streams, audio_chunks);
 263         for (i = 0; i < s->nb_streams; i++) {
 264             OutputStream *os = &c->streams[i];
 265             if (s->streams[i]->codecpar->codec_type != AVMEDIA_TYPE_AUDIO)
 266                 continue;
 267             last = i;
 268             avio_printf(out, "<QualityLevel Index=\"%d\" Bitrate=\"%"PRId64"\" FourCC=\"%s\" SamplingRate=\"%d\" Channels=\"%d\" BitsPerSample=\"16\" PacketSize=\"%d\" AudioTag=\"%d\" CodecPrivateData=\"%s\" />\n",
 269                         index, s->streams[i]->codecpar->bit_rate, os->fourcc, s->streams[i]->codecpar->sample_rate,
 270                         s->streams[i]->codecpar->ch_layout.nb_channels, os->packet_size, os->audio_tag, os->private_str);
 271             index++;
 272         }
 273         output_chunk_list(&c->streams[last], out, final, c->lookahead_count, c->window_size);
 274         avio_printf(out, "</StreamIndex>\n");
 275     }
 276     avio_printf(out, "</SmoothStreamingMedia>\n");
 277     avio_flush(out);
 278     ff_format_io_close(s, &out);
 279     return ff_rename(temp_filename, filename, s);
 280 }
 281
 282 static int ism_write_header(AVFormatContext *s)
 283 {
 284     SmoothStreamingContext *c = s->priv_data;
 285     int ret = 0, i;
 286     const AVOutputFormat *oformat;
 287
 288     if (mkdir(s->url, 0777) == -1 && errno != EEXIST) {
 289         av_log(s, AV_LOG_ERROR, "mkdir failed\n");
 290         return AVERROR(errno);
 291     }
 292
 293     oformat = av_guess_format("ismv", NULL, NULL);
 294     if (!oformat) {
 295         return AVERROR_MUXER_NOT_FOUND;
 296     }
 297
 298     c->streams = av_calloc(s->nb_streams, sizeof(*c->streams));
 299     if (!c->streams) {
 300         return AVERROR(ENOMEM);
 301     }
 302
 303     for (i = 0; i < s->nb_streams; i++) {
 304         OutputStream *os = &c->streams[i];
 305         AVFormatContext *ctx;
 306         AVStream *st;
 307         AVDictionary *opts = NULL;
 308
 309         if (!s->streams[i]->codecpar->bit_rate) {
 310             av_log(s, AV_LOG_WARNING, "No bit rate set for stream %d\n", i);
 311             // create a tmp name for the directory of fragments
 312             snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(Tmp_%d)", s->url, i);
 313         } else {
 314             snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%"PRId64")", s->url, s->streams[i]->codecpar->bit_rate);
 315         }
 316
 317         if (mkdir(os->dirname, 0777) == -1 && errno != EEXIST) {
 318             av_log(s, AV_LOG_ERROR, "mkdir failed\n");
 319             return AVERROR(errno);
 320         }
 321
 322         os->ctx = ctx = avformat_alloc_context();
 323         if (!ctx) {
 324             return AVERROR(ENOMEM);
 325         }
 326         if ((ret = ff_copy_whiteblacklists(ctx, s)) < 0)
 327             return ret;
 328         ctx->oformat = oformat;
 329         ctx->interrupt_callback = s->interrupt_callback;
 330
 331         if (!(st = avformat_new_stream(ctx, NULL))) {
 332             return AVERROR(ENOMEM);
 333         }
 334         if ((ret = avcodec_parameters_copy(st->codecpar, s->streams[i]->codecpar)) < 0) {
 335             return ret;
 336         }
 337         st->sample_aspect_ratio = s->streams[i]->sample_aspect_ratio;
 338         st->time_base = s->streams[i]->time_base;
 339
 340         ctx->pb = avio_alloc_context(os->iobuf, sizeof(os->iobuf), 1, os, NULL, ism_write, ism_seek);
 341         if (!ctx->pb) {
 342             return AVERROR(ENOMEM);
 343         }
 344
 345         av_dict_set_int(&opts, "ism_lookahead", c->lookahead_count, 0);
 346         av_dict_set(&opts, "movflags", "+frag_custom", 0);
 347         ret = avformat_write_header(ctx, &opts);
 348         av_dict_free(&opts);
 349         if (ret < 0) {
 350              return ret;
 351         }
 352         avio_flush(ctx->pb);
 353         s->streams[i]->time_base = st->time_base;
 354         if (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) {
 355             c->has_video = 1;
 356             os->stream_type_tag = "video";
 357             if (st->codecpar->codec_id == AV_CODEC_ID_H264) {
 358                 os->fourcc = "H264";
 359             } else if (st->codecpar->codec_id == AV_CODEC_ID_VC1) {
 360                 os->fourcc = "WVC1";
 361             } else {
 362                 av_log(s, AV_LOG_ERROR, "Unsupported video codec\n");
 363                 return AVERROR(EINVAL);
 364             }
 365         } else {
 366             c->has_audio = 1;
 367             os->stream_type_tag = "audio";
 368             if (st->codecpar->codec_id == AV_CODEC_ID_AAC) {
 369                 os->fourcc = "AACL";
 370                 os->audio_tag = 0xff;
 371             } else if (st->codecpar->codec_id == AV_CODEC_ID_WMAPRO) {
 372                 os->fourcc = "WMAP";
 373                 os->audio_tag = 0x0162;
 374             } else {
 375                 av_log(s, AV_LOG_ERROR, "Unsupported audio codec\n");
 376                 return AVERROR(EINVAL);
 377             }
 378             os->packet_size = st->codecpar->block_align ? st->codecpar->block_align : 4;
 379         }
 380         get_private_data(os);
 381     }
 382
 383     if (!c->has_video && c->min_frag_duration <= 0) {
 384         av_log(s, AV_LOG_WARNING, "no video stream and no min frag duration set\n");
 385         return AVERROR(EINVAL);
 386     }
 387     ret = write_manifest(s, 0);
 388     if (ret < 0)
 389         return ret;
 390
 391     return 0;
 392 }
 393
 394 static int parse_fragment(AVFormatContext *s, const char *filename, int64_t *start_ts, int64_t *duration, int64_t *moof_size, int64_t size)
 395 {
 396     AVIOContext *in;
 397     int ret;
 398     uint32_t len;
 399     if ((ret = s->io_open(s, &in, filename, AVIO_FLAG_READ, NULL)) < 0)
 400         return ret;
 401     ret = AVERROR(EIO);
 402     *moof_size = avio_rb32(in);
 403     if (*moof_size < 8 || *moof_size > size)
 404         goto fail;
 405     if (avio_rl32(in) != MKTAG('m','o','o','f'))
 406         goto fail;
 407     len = avio_rb32(in);
 408     if (len > *moof_size)
 409         goto fail;
 410     if (avio_rl32(in) != MKTAG('m','f','h','d'))
 411         goto fail;
 412     avio_seek(in, len - 8, SEEK_CUR);
 413     avio_rb32(in); /* traf size */
 414     if (avio_rl32(in) != MKTAG('t','r','a','f'))
 415         goto fail;
 416     while (avio_tell(in) < *moof_size) {
 417         uint32_t len = avio_rb32(in);
 418         uint32_t tag = avio_rl32(in);
 419         int64_t end = avio_tell(in) + len - 8;
 420         if (len < 8 || len >= *moof_size)
 421             goto fail;
 422         if (tag == MKTAG('u','u','i','d')) {
 423             static const AVUUID tfxd = {
 424                 0x6d, 0x1d, 0x9b, 0x05, 0x42, 0xd5, 0x44, 0xe6,
 425                 0x80, 0xe2, 0x14, 0x1d, 0xaf, 0xf7, 0x57, 0xb2
 426             };
 427             AVUUID uuid;
 428             avio_read(in, uuid, 16);
 429             if (av_uuid_equal(uuid, tfxd) && len >= 8 + 16 + 4 + 16) {
 430                 avio_seek(in, 4, SEEK_CUR);
 431                 *start_ts = avio_rb64(in);
 432                 *duration = avio_rb64(in);
 433                 ret = 0;
 434                 break;
 435             }
 436         }
 437         avio_seek(in, end, SEEK_SET);
 438     }
 439 fail:
 440     ff_format_io_close(s, &in);
 441     return ret;
 442 }
 443
 444 static int add_fragment(OutputStream *os, const char *file, const char *infofile, int64_t start_time, int64_t duration, int64_t start_pos, int64_t size)
 445 {
 446     int err;
 447     Fragment *frag;
 448     if (os->nb_fragments >= os->fragments_size) {
 449         os->fragments_size = (os->fragments_size + 1) * 2;
 450         if ((err = av_reallocp_array(&os->fragments, sizeof(*os->fragments),
 451                                os->fragments_size)) < 0) {
 452             os->fragments_size = 0;
 453             os->nb_fragments = 0;
 454             return err;
 455         }
 456     }
 457     frag = av_mallocz(sizeof(*frag));
 458     if (!frag)
 459         return AVERROR(ENOMEM);
 460     av_strlcpy(frag->file, file, sizeof(frag->file));
 461     av_strlcpy(frag->infofile, infofile, sizeof(frag->infofile));
 462     frag->start_time = start_time;
 463     frag->duration = duration;
 464     frag->start_pos = start_pos;
 465     frag->size = size;
 466     frag->n = os->fragment_index;
 467     os->fragments[os->nb_fragments++] = frag;
 468     os->fragment_index++;
 469     return 0;
 470 }
 471
 472 static int copy_moof(AVFormatContext *s, const char* infile, const char *outfile, int64_t size)
 473 {
 474     AVIOContext *in, *out;
 475     int ret = 0;
 476     if ((ret = s->io_open(s, &in, infile, AVIO_FLAG_READ, NULL)) < 0)
 477         return ret;
 478     if ((ret = s->io_open(s, &out, outfile, AVIO_FLAG_WRITE, NULL)) < 0) {
 479         ff_format_io_close(s, &in);
 480         return ret;
 481     }
 482     while (size > 0) {
 483         uint8_t buf[8192];
 484         int n = FFMIN(size, sizeof(buf));
 485         n = avio_read(in, buf, n);
 486         if (n <= 0) {
 487             ret = AVERROR(EIO);
 488             break;
 489         }
 490         avio_write(out, buf, n);
 491         size -= n;
 492     }
 493     avio_flush(out);
 494     ff_format_io_close(s, &out);
 495     ff_format_io_close(s, &in);
 496     return ret;
 497 }
 498
 499 static int ism_flush(AVFormatContext *s, int final)
 500 {
 501     SmoothStreamingContext *c = s->priv_data;
 502     int i, ret = 0;
 503
 504     for (i = 0; i < s->nb_streams; i++) {
 505         OutputStream *os = &c->streams[i];
 506         char filename[1024], target_filename[1024], header_filename[1024], curr_dirname[1024];
 507         int64_t size;
 508         int64_t start_ts, duration, moof_size;
 509         if (!os->packets_written)
 510             continue;
 511
 512         snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
 513         ret = ffurl_open_whitelist(&os->out, filename, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL, s->protocol_whitelist, s->protocol_blacklist, NULL);
 514         if (ret < 0)
 515             break;
 516         os->cur_start_pos = os->tail_pos;
 517         av_write_frame(os->ctx, NULL);
 518         avio_flush(os->ctx->pb);
 519         os->packets_written = 0;
 520         if (!os->out || os->tail_out)
 521             return AVERROR(EIO);
 522
 523         ffurl_closep(&os->out);
 524         size = os->tail_pos - os->cur_start_pos;
 525         if ((ret = parse_fragment(s, filename, &start_ts, &duration, &moof_size, size)) < 0)
 526             break;
 527
 528         if (!s->streams[i]->codecpar->bit_rate) {
 529             int64_t bitrate = (int64_t) size * 8 * AV_TIME_BASE / av_rescale_q(duration, s->streams[i]->time_base, AV_TIME_BASE_Q);
 530             if (!bitrate) {
 531                 av_log(s, AV_LOG_ERROR, "calculating bitrate got zero.\n");
 532                 ret = AVERROR(EINVAL);
 533                 return ret;
 534             }
 535
 536             av_log(s, AV_LOG_DEBUG, "calculated bitrate: %"PRId64"\n", bitrate);
 537             s->streams[i]->codecpar->bit_rate = bitrate;
 538             memcpy(curr_dirname, os->dirname, sizeof(os->dirname));
 539             snprintf(os->dirname, sizeof(os->dirname), "%s/QualityLevels(%"PRId64")", s->url, s->streams[i]->codecpar->bit_rate);
 540             snprintf(filename, sizeof(filename), "%s/temp", os->dirname);
 541
 542             // rename the tmp folder back to the correct name since we now have the bitrate
 543             if ((ret = ff_rename((const char*)curr_dirname,  os->dirname, s)) < 0)
 544                 return ret;
 545         }
 546
 547         snprintf(header_filename, sizeof(header_filename), "%s/FragmentInfo(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
 548         snprintf(target_filename, sizeof(target_filename), "%s/Fragments(%s=%"PRIu64")", os->dirname, os->stream_type_tag, start_ts);
 549         copy_moof(s, filename, header_filename, moof_size);
 550         ret = ff_rename(filename, target_filename, s);
 551         if (ret < 0)
 552             break;
 553         add_fragment(os, target_filename, header_filename, start_ts, duration,
 554                      os->cur_start_pos, size);
 555     }
 556
 557     if (c->window_size || (final && c->remove_at_exit)) {
 558         for (i = 0; i < s->nb_streams; i++) {
 559             OutputStream *os = &c->streams[i];
 560             int j;
 561             int remove = os->nb_fragments - c->window_size - c->extra_window_size - c->lookahead_count;
 562             if (final && c->remove_at_exit)
 563                 remove = os->nb_fragments;
 564             if (remove > 0) {
 565                 for (j = 0; j < remove; j++) {
 566                     unlink(os->fragments[j]->file);
 567                     unlink(os->fragments[j]->infofile);
 568                     av_freep(&os->fragments[j]);
 569                 }
 570                 os->nb_fragments -= remove;
 571                 memmove(os->fragments, os->fragments + remove, os->nb_fragments * sizeof(*os->fragments));
 572             }
 573             if (final && c->remove_at_exit)
 574                 rmdir(os->dirname);
 575         }
 576     }
 577
 578     if (ret >= 0)
 579         ret = write_manifest(s, final);
 580     return ret;
 581 }
 582
 583 static int ism_write_packet(AVFormatContext *s, AVPacket *pkt)
 584 {
 585     SmoothStreamingContext *c = s->priv_data;
 586     AVStream *st = s->streams[pkt->stream_index];
 587     FFStream *const sti = ffstream(st);
 588     OutputStream *os = &c->streams[pkt->stream_index];
 589     int64_t end_dts = (c->nb_fragments + 1) * (int64_t) c->min_frag_duration;
 590     int ret;
 591
 592     if (sti->first_dts == AV_NOPTS_VALUE)
 593         sti->first_dts = pkt->dts;
 594
 595     if ((!c->has_video || st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO) &&
 596         av_compare_ts(pkt->dts - sti->first_dts, st->time_base,
 597                       end_dts, AV_TIME_BASE_Q) >= 0 &&
 598         pkt->flags & AV_PKT_FLAG_KEY && os->packets_written) {
 599
 600         if ((ret = ism_flush(s, 0)) < 0)
 601             return ret;
 602         c->nb_fragments++;
 603     }
 604
 605     os->packets_written++;
 606     return ff_write_chained(os->ctx, 0, pkt, s, 0);
 607 }
 608
 609 static int ism_write_trailer(AVFormatContext *s)
 610 {
 611     SmoothStreamingContext *c = s->priv_data;
 612     ism_flush(s, 1);
 613
 614     if (c->remove_at_exit) {
 615         char filename[1024];
 616         snprintf(filename, sizeof(filename), "%s/Manifest", s->url);
 617         unlink(filename);
 618         rmdir(s->url);
 619     }
 620
 621     return 0;
 622 }
 623
 624 #define OFFSET(x) offsetof(SmoothStreamingContext, x)
 625 #define E AV_OPT_FLAG_ENCODING_PARAM
 626 static const AVOption options[] = {
 627     { "window_size", "number of fragments kept in the manifest", OFFSET(window_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, E },
 628     { "extra_window_size", "number of fragments kept outside of the manifest before removing from disk", OFFSET(extra_window_size), AV_OPT_TYPE_INT, { .i64 = 5 }, 0, INT_MAX, E },
 629     { "lookahead_count", "number of lookahead fragments", OFFSET(lookahead_count), AV_OPT_TYPE_INT, { .i64 = 2 }, 0, INT_MAX, E },
 630     { "min_frag_duration", "minimum fragment duration (in microseconds)", OFFSET(min_frag_duration), AV_OPT_TYPE_INT64, { .i64 = 5000000 }, 0, INT_MAX, E },
 631     { "remove_at_exit", "remove all fragments when finished", OFFSET(remove_at_exit), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, E },
 632     { NULL },
 633 };
 634
 635 static const AVClass ism_class = {
 636     .class_name = "smooth streaming muxer",
 637     .item_name  = av_default_item_name,
 638     .option     = options,
 639     .version    = LIBAVUTIL_VERSION_INT,
 640 };
 641
 642
 643 const FFOutputFormat ff_smoothstreaming_muxer = {
 644     .p.name         = "smoothstreaming",
 645     .p.long_name    = NULL_IF_CONFIG_SMALL("Smooth Streaming Muxer"),
 646     .p.audio_codec  = AV_CODEC_ID_AAC,
 647     .p.video_codec  = AV_CODEC_ID_H264,
 648     .p.flags        = AVFMT_GLOBALHEADER | AVFMT_NOFILE,
 649     .p.priv_class   = &ism_class,
 650     .priv_data_size = sizeof(SmoothStreamingContext),
 651     .write_header   = ism_write_header,
 652     .write_packet   = ism_write_packet,
 653     .write_trailer  = ism_write_trailer,
 654     .deinit         = ism_free,
 655 };