media/filters/ffmpeg_demuxer.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/filters/ffmpeg_demuxer.h"
   6
   7 #include <algorithm>
   8 #include <string>
   9
  10 #include "base/base64.h"
  11 #include "base/bind.h"
  12 #include "base/callback.h"
  13 #include "base/callback_helpers.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/message_loop/message_loop_proxy.h"
  16 #include "base/metrics/sparse_histogram.h"
  17 #include "base/strings/string_util.h"
  18 #include "base/strings/stringprintf.h"
  19 #include "base/sys_byteorder.h"
  20 #include "base/task_runner_util.h"
  21 #include "base/time/time.h"
  22 #include "media/base/audio_decoder_config.h"
  23 #include "media/base/bind_to_current_loop.h"
  24 #include "media/base/decoder_buffer.h"
  25 #include "media/base/decrypt_config.h"
  26 #include "media/base/limits.h"
  27 #include "media/base/media_log.h"
  28 #include "media/base/video_decoder_config.h"
  29 #include "media/ffmpeg/ffmpeg_common.h"
  30 #include "media/filters/ffmpeg_glue.h"
  31 #include "media/filters/ffmpeg_h264_to_annex_b_bitstream_converter.h"
  32 #include "media/filters/webvtt_util.h"
  33 #include "media/formats/webm/webm_crypto_helpers.h"
  34
  35 namespace media {
  36
  37 //
  38 // FFmpegDemuxerStream
  39 //
  40 FFmpegDemuxerStream::FFmpegDemuxerStream(
  41     FFmpegDemuxer* demuxer,
  42     AVStream* stream)
  43     : demuxer_(demuxer),
  44       task_runner_(base::MessageLoopProxy::current()),
  45       stream_(stream),
  46       type_(UNKNOWN),
  47       end_of_stream_(false),
  48       last_packet_timestamp_(kNoTimestamp()),
  49       bitstream_converter_enabled_(false) {
  50   DCHECK(demuxer_);
  51
  52   bool is_encrypted = false;
  53
  54   // Determine our media format.
  55   switch (stream->codec->codec_type) {
  56     case AVMEDIA_TYPE_AUDIO:
  57       type_ = AUDIO;
  58       AVStreamToAudioDecoderConfig(stream, &audio_config_, true);
  59       is_encrypted = audio_config_.is_encrypted();
  60       break;
  61     case AVMEDIA_TYPE_VIDEO:
  62       type_ = VIDEO;
  63       AVStreamToVideoDecoderConfig(stream, &video_config_, true);
  64       is_encrypted = video_config_.is_encrypted();
  65       break;
  66     case AVMEDIA_TYPE_SUBTITLE:
  67       type_ = TEXT;
  68       break;
  69     default:
  70       NOTREACHED();
  71       break;
  72   }
  73
  74   // Calculate the duration.
  75   duration_ = ConvertStreamTimestamp(stream->time_base, stream->duration);
  76
  77   if (stream_->codec->codec_id == AV_CODEC_ID_H264) {
  78     bitstream_converter_.reset(
  79         new FFmpegH264ToAnnexBBitstreamConverter(stream_->codec));
  80   }
  81
  82   if (is_encrypted) {
  83     AVDictionaryEntry* key = av_dict_get(stream->metadata, "enc_key_id", NULL,
  84                                          0);
  85     DCHECK(key);
  86     DCHECK(key->value);
  87     if (!key || !key->value)
  88       return;
  89     base::StringPiece base64_key_id(key->value);
  90     std::string enc_key_id;
  91     base::Base64Decode(base64_key_id, &enc_key_id);
  92     DCHECK(!enc_key_id.empty());
  93     if (enc_key_id.empty())
  94       return;
  95
  96     encryption_key_id_.assign(enc_key_id);
  97     demuxer_->FireNeedKey(kWebMEncryptInitDataType, enc_key_id);
  98   }
  99 }
 100
 101 void FFmpegDemuxerStream::EnqueuePacket(ScopedAVPacket packet) {
 102   DCHECK(task_runner_->BelongsToCurrentThread());
 103
 104   if (!demuxer_ || end_of_stream_) {
 105     NOTREACHED() << "Attempted to enqueue packet on a stopped stream";
 106     return;
 107   }
 108
 109   // Convert the packet if there is a bitstream filter.
 110   if (packet->data && bitstream_converter_enabled_ &&
 111       !bitstream_converter_->ConvertPacket(packet.get())) {
 112     LOG(ERROR) << "Format conversion failed.";
 113   }
 114
 115   // Get side data if any. For now, the only type of side_data is VP8 Alpha. We
 116   // keep this generic so that other side_data types in the future can be
 117   // handled the same way as well.
 118   av_packet_split_side_data(packet.get());
 119
 120   scoped_refptr<DecoderBuffer> buffer;
 121
 122   if (type() == DemuxerStream::TEXT) {
 123     int id_size = 0;
 124     uint8* id_data = av_packet_get_side_data(
 125         packet.get(),
 126         AV_PKT_DATA_WEBVTT_IDENTIFIER,
 127         &id_size);
 128
 129     int settings_size = 0;
 130     uint8* settings_data = av_packet_get_side_data(
 131         packet.get(),
 132         AV_PKT_DATA_WEBVTT_SETTINGS,
 133         &settings_size);
 134
 135     std::vector<uint8> side_data;
 136     MakeSideData(id_data, id_data + id_size,
 137                  settings_data, settings_data + settings_size,
 138                  &side_data);
 139
 140     buffer = DecoderBuffer::CopyFrom(packet.get()->data, packet.get()->size,
 141                                      side_data.data(), side_data.size());
 142   } else {
 143     int side_data_size = 0;
 144     uint8* side_data = av_packet_get_side_data(
 145         packet.get(),
 146         AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
 147         &side_data_size);
 148
 149     scoped_ptr<DecryptConfig> decrypt_config;
 150     int data_offset = 0;
 151     if ((type() == DemuxerStream::AUDIO && audio_config_.is_encrypted()) ||
 152         (type() == DemuxerStream::VIDEO && video_config_.is_encrypted())) {
 153       if (!WebMCreateDecryptConfig(
 154           packet->data, packet->size,
 155           reinterpret_cast<const uint8*>(encryption_key_id_.data()),
 156           encryption_key_id_.size(),
 157           &decrypt_config,
 158           &data_offset)) {
 159         LOG(ERROR) << "Creation of DecryptConfig failed.";
 160       }
 161     }
 162
 163     // If a packet is returned by FFmpeg's av_parser_parse2() the packet will
 164     // reference inner memory of FFmpeg.  As such we should transfer the packet
 165     // into memory we control.
 166     if (side_data_size > 0) {
 167       buffer = DecoderBuffer::CopyFrom(packet.get()->data + data_offset,
 168                                        packet.get()->size - data_offset,
 169                                        side_data, side_data_size);
 170     } else {
 171       buffer = DecoderBuffer::CopyFrom(packet.get()->data + data_offset,
 172                                        packet.get()->size - data_offset);
 173     }
 174
 175     int skip_samples_size = 0;
 176     uint8* skip_samples = av_packet_get_side_data(packet.get(),
 177                                                   AV_PKT_DATA_SKIP_SAMPLES,
 178                                                   &skip_samples_size);
 179     const int kSkipSamplesValidSize = 10;
 180     const int kSkipSamplesOffset = 4;
 181     if (skip_samples_size >= kSkipSamplesValidSize) {
 182       int discard_padding_samples = base::ByteSwapToLE32(
 183           *(reinterpret_cast<const uint32*>(skip_samples +
 184                                             kSkipSamplesOffset)));
 185       // TODO(vigneshv): Change decoder buffer to use number of samples so that
 186       // this conversion can be avoided.
 187       buffer->set_discard_padding(base::TimeDelta::FromMicroseconds(
 188           discard_padding_samples * 1000000.0 /
 189           audio_decoder_config().samples_per_second()));
 190     }
 191
 192     if (decrypt_config)
 193       buffer->set_decrypt_config(decrypt_config.Pass());
 194   }
 195
 196   buffer->set_timestamp(ConvertStreamTimestamp(
 197       stream_->time_base, packet->pts));
 198   buffer->set_duration(ConvertStreamTimestamp(
 199       stream_->time_base, packet->duration));
 200   if (buffer->timestamp() != kNoTimestamp() &&
 201       last_packet_timestamp_ != kNoTimestamp() &&
 202       last_packet_timestamp_ < buffer->timestamp()) {
 203     buffered_ranges_.Add(last_packet_timestamp_, buffer->timestamp());
 204     demuxer_->NotifyBufferingChanged();
 205   }
 206   last_packet_timestamp_ = buffer->timestamp();
 207
 208   buffer_queue_.Push(buffer);
 209   SatisfyPendingRead();
 210 }
 211
 212 void FFmpegDemuxerStream::SetEndOfStream() {
 213   DCHECK(task_runner_->BelongsToCurrentThread());
 214   end_of_stream_ = true;
 215   SatisfyPendingRead();
 216 }
 217
 218 void FFmpegDemuxerStream::FlushBuffers() {
 219   DCHECK(task_runner_->BelongsToCurrentThread());
 220   DCHECK(read_cb_.is_null()) << "There should be no pending read";
 221   buffer_queue_.Clear();
 222   end_of_stream_ = false;
 223   last_packet_timestamp_ = kNoTimestamp();
 224 }
 225
 226 void FFmpegDemuxerStream::Stop() {
 227   DCHECK(task_runner_->BelongsToCurrentThread());
 228   buffer_queue_.Clear();
 229   if (!read_cb_.is_null()) {
 230     base::ResetAndReturn(&read_cb_).Run(
 231         DemuxerStream::kOk, DecoderBuffer::CreateEOSBuffer());
 232   }
 233   demuxer_ = NULL;
 234   stream_ = NULL;
 235   end_of_stream_ = true;
 236 }
 237
 238 base::TimeDelta FFmpegDemuxerStream::duration() {
 239   return duration_;
 240 }
 241
 242 DemuxerStream::Type FFmpegDemuxerStream::type() {
 243   DCHECK(task_runner_->BelongsToCurrentThread());
 244   return type_;
 245 }
 246
 247 void FFmpegDemuxerStream::Read(const ReadCB& read_cb) {
 248   DCHECK(task_runner_->BelongsToCurrentThread());
 249   CHECK(read_cb_.is_null()) << "Overlapping reads are not supported";
 250   read_cb_ = BindToCurrentLoop(read_cb);
 251
 252   // Don't accept any additional reads if we've been told to stop.
 253   // The |demuxer_| may have been destroyed in the pipeline thread.
 254   //
 255   // TODO(scherkus): it would be cleaner to reply with an error message.
 256   if (!demuxer_) {
 257     base::ResetAndReturn(&read_cb_).Run(
 258         DemuxerStream::kOk, DecoderBuffer::CreateEOSBuffer());
 259     return;
 260   }
 261
 262   SatisfyPendingRead();
 263 }
 264
 265 void FFmpegDemuxerStream::EnableBitstreamConverter() {
 266   DCHECK(task_runner_->BelongsToCurrentThread());
 267   CHECK(bitstream_converter_.get());
 268   bitstream_converter_enabled_ = true;
 269 }
 270
 271 AudioDecoderConfig FFmpegDemuxerStream::audio_decoder_config() {
 272   DCHECK(task_runner_->BelongsToCurrentThread());
 273   CHECK_EQ(type_, AUDIO);
 274   return audio_config_;
 275 }
 276
 277 VideoDecoderConfig FFmpegDemuxerStream::video_decoder_config() {
 278   DCHECK(task_runner_->BelongsToCurrentThread());
 279   CHECK_EQ(type_, VIDEO);
 280   return video_config_;
 281 }
 282
 283 FFmpegDemuxerStream::~FFmpegDemuxerStream() {
 284   DCHECK(!demuxer_);
 285   DCHECK(read_cb_.is_null());
 286   DCHECK(buffer_queue_.IsEmpty());
 287 }
 288
 289 base::TimeDelta FFmpegDemuxerStream::GetElapsedTime() const {
 290   return ConvertStreamTimestamp(stream_->time_base, stream_->cur_dts);
 291 }
 292
 293 Ranges<base::TimeDelta> FFmpegDemuxerStream::GetBufferedRanges() const {
 294   return buffered_ranges_;
 295 }
 296
 297 void FFmpegDemuxerStream::SatisfyPendingRead() {
 298   DCHECK(task_runner_->BelongsToCurrentThread());
 299   if (!read_cb_.is_null()) {
 300     if (!buffer_queue_.IsEmpty()) {
 301       base::ResetAndReturn(&read_cb_).Run(
 302           DemuxerStream::kOk, buffer_queue_.Pop());
 303     } else if (end_of_stream_) {
 304       base::ResetAndReturn(&read_cb_).Run(
 305           DemuxerStream::kOk, DecoderBuffer::CreateEOSBuffer());
 306     }
 307   }
 308
 309   // Have capacity? Ask for more!
 310   if (HasAvailableCapacity() && !end_of_stream_) {
 311     demuxer_->NotifyCapacityAvailable();
 312   }
 313 }
 314
 315 bool FFmpegDemuxerStream::HasAvailableCapacity() {
 316   // TODO(scherkus): Remove early return and reenable time-based capacity
 317   // after our data sources support canceling/concurrent reads, see
 318   // http://crbug.com/165762 for details.
 319   return !read_cb_.is_null();
 320
 321   // Try to have one second's worth of encoded data per stream.
 322   const base::TimeDelta kCapacity = base::TimeDelta::FromSeconds(1);
 323   return buffer_queue_.IsEmpty() || buffer_queue_.Duration() < kCapacity;
 324 }
 325
 326 TextKind FFmpegDemuxerStream::GetTextKind() const {
 327   DCHECK_EQ(type_, DemuxerStream::TEXT);
 328
 329   if (stream_->disposition & AV_DISPOSITION_CAPTIONS)
 330     return kTextCaptions;
 331
 332   if (stream_->disposition & AV_DISPOSITION_DESCRIPTIONS)
 333     return kTextDescriptions;
 334
 335   if (stream_->disposition & AV_DISPOSITION_METADATA)
 336     return kTextMetadata;
 337
 338   return kTextSubtitles;
 339 }
 340
 341 std::string FFmpegDemuxerStream::GetMetadata(const char* key) const {
 342   const AVDictionaryEntry* entry =
 343       av_dict_get(stream_->metadata, key, NULL, 0);
 344   return (entry == NULL || entry->value == NULL) ? "" : entry->value;
 345 }
 346
 347 // static
 348 base::TimeDelta FFmpegDemuxerStream::ConvertStreamTimestamp(
 349     const AVRational& time_base, int64 timestamp) {
 350   if (timestamp == static_cast<int64>(AV_NOPTS_VALUE))
 351     return kNoTimestamp();
 352
 353   return ConvertFromTimeBase(time_base, timestamp);
 354 }
 355
 356 //
 357 // FFmpegDemuxer
 358 //
 359 FFmpegDemuxer::FFmpegDemuxer(
 360     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
 361     DataSource* data_source,
 362     const NeedKeyCB& need_key_cb,
 363     const scoped_refptr<MediaLog>& media_log)
 364     : host_(NULL),
 365       task_runner_(task_runner),
 366       weak_factory_(this),
 367       blocking_thread_("FFmpegDemuxer"),
 368       pending_read_(false),
 369       pending_seek_(false),
 370       data_source_(data_source),
 371       media_log_(media_log),
 372       bitrate_(0),
 373       start_time_(kNoTimestamp()),
 374       audio_disabled_(false),
 375       text_enabled_(false),
 376       duration_known_(false),
 377       need_key_cb_(need_key_cb) {
 378   DCHECK(task_runner_.get());
 379   DCHECK(data_source_);
 380 }
 381
 382 FFmpegDemuxer::~FFmpegDemuxer() {}
 383
 384 void FFmpegDemuxer::Stop(const base::Closure& callback) {
 385   DCHECK(task_runner_->BelongsToCurrentThread());
 386   url_protocol_->Abort();
 387   data_source_->Stop(BindToCurrentLoop(base::Bind(
 388       &FFmpegDemuxer::OnDataSourceStopped, weak_this_,
 389       BindToCurrentLoop(callback))));
 390   data_source_ = NULL;
 391 }
 392
 393 void FFmpegDemuxer::Seek(base::TimeDelta time, const PipelineStatusCB& cb) {
 394   DCHECK(task_runner_->BelongsToCurrentThread());
 395   CHECK(!pending_seek_);
 396
 397   // TODO(scherkus): Inspect |pending_read_| and cancel IO via |blocking_url_|,
 398   // otherwise we can end up waiting for a pre-seek read to complete even though
 399   // we know we're going to drop it on the floor.
 400
 401   // Always seek to a timestamp less than or equal to the desired timestamp.
 402   int flags = AVSEEK_FLAG_BACKWARD;
 403
 404   // Passing -1 as our stream index lets FFmpeg pick a default stream.  FFmpeg
 405   // will attempt to use the lowest-index video stream, if present, followed by
 406   // the lowest-index audio stream.
 407   pending_seek_ = true;
 408   base::PostTaskAndReplyWithResult(
 409       blocking_thread_.message_loop_proxy().get(),
 410       FROM_HERE,
 411       base::Bind(&av_seek_frame,
 412                  glue_->format_context(),
 413                  -1,
 414                  time.InMicroseconds(),
 415                  flags),
 416       base::Bind(&FFmpegDemuxer::OnSeekFrameDone, weak_this_, cb));
 417 }
 418
 419 void FFmpegDemuxer::OnAudioRendererDisabled() {
 420   DCHECK(task_runner_->BelongsToCurrentThread());
 421   audio_disabled_ = true;
 422   StreamVector::iterator iter;
 423   for (iter = streams_.begin(); iter != streams_.end(); ++iter) {
 424     if (*iter && (*iter)->type() == DemuxerStream::AUDIO) {
 425       (*iter)->Stop();
 426     }
 427   }
 428 }
 429
 430 void FFmpegDemuxer::Initialize(DemuxerHost* host,
 431                                const PipelineStatusCB& status_cb,
 432                                bool enable_text_tracks) {
 433   DCHECK(task_runner_->BelongsToCurrentThread());
 434   host_ = host;
 435   weak_this_ = weak_factory_.GetWeakPtr();
 436   text_enabled_ = enable_text_tracks;
 437
 438   // TODO(scherkus): DataSource should have a host by this point,
 439   // see http://crbug.com/122071
 440   data_source_->set_host(host);
 441
 442   url_protocol_.reset(new BlockingUrlProtocol(data_source_, BindToCurrentLoop(
 443       base::Bind(&FFmpegDemuxer::OnDataSourceError, base::Unretained(this)))));
 444   glue_.reset(new FFmpegGlue(url_protocol_.get()));
 445   AVFormatContext* format_context = glue_->format_context();
 446
 447   // Disable ID3v1 tag reading to avoid costly seeks to end of file for data we
 448   // don't use.  FFmpeg will only read ID3v1 tags if no other metadata is
 449   // available, so add a metadata entry to ensure some is always present.
 450   av_dict_set(&format_context->metadata, "skip_id3v1_tags", "", 0);
 451
 452   // Open the AVFormatContext using our glue layer.
 453   CHECK(blocking_thread_.Start());
 454   base::PostTaskAndReplyWithResult(
 455       blocking_thread_.message_loop_proxy().get(),
 456       FROM_HERE,
 457       base::Bind(&FFmpegGlue::OpenContext, base::Unretained(glue_.get())),
 458       base::Bind(&FFmpegDemuxer::OnOpenContextDone, weak_this_, status_cb));
 459 }
 460
 461 DemuxerStream* FFmpegDemuxer::GetStream(DemuxerStream::Type type) {
 462   DCHECK(task_runner_->BelongsToCurrentThread());
 463   return GetFFmpegStream(type);
 464 }
 465
 466 FFmpegDemuxerStream* FFmpegDemuxer::GetFFmpegStream(
 467     DemuxerStream::Type type) const {
 468   StreamVector::const_iterator iter;
 469   for (iter = streams_.begin(); iter != streams_.end(); ++iter) {
 470     if (*iter && (*iter)->type() == type) {
 471       return *iter;
 472     }
 473   }
 474   return NULL;
 475 }
 476
 477 base::TimeDelta FFmpegDemuxer::GetStartTime() const {
 478   DCHECK(task_runner_->BelongsToCurrentThread());
 479   return start_time_;
 480 }
 481
 482 void FFmpegDemuxer::AddTextStreams() {
 483   DCHECK(task_runner_->BelongsToCurrentThread());
 484
 485   for (StreamVector::size_type idx = 0; idx < streams_.size(); ++idx) {
 486     FFmpegDemuxerStream* stream = streams_[idx];
 487     if (stream == NULL || stream->type() != DemuxerStream::TEXT)
 488       continue;
 489
 490     TextKind kind = stream->GetTextKind();
 491     std::string title = stream->GetMetadata("title");
 492     std::string language = stream->GetMetadata("language");
 493
 494     // TODO: Implement "id" metadata in FFMPEG.
 495     // See: http://crbug.com/323183
 496     host_->AddTextStream(stream, TextTrackConfig(kind, title, language,
 497         std::string()));
 498   }
 499 }
 500
 501 // Helper for calculating the bitrate of the media based on information stored
 502 // in |format_context| or failing that the size and duration of the media.
 503 //
 504 // Returns 0 if a bitrate could not be determined.
 505 static int CalculateBitrate(
 506     AVFormatContext* format_context,
 507     const base::TimeDelta& duration,
 508     int64 filesize_in_bytes) {
 509   // If there is a bitrate set on the container, use it.
 510   if (format_context->bit_rate > 0)
 511     return format_context->bit_rate;
 512
 513   // Then try to sum the bitrates individually per stream.
 514   int bitrate = 0;
 515   for (size_t i = 0; i < format_context->nb_streams; ++i) {
 516     AVCodecContext* codec_context = format_context->streams[i]->codec;
 517     bitrate += codec_context->bit_rate;
 518   }
 519   if (bitrate > 0)
 520     return bitrate;
 521
 522   // See if we can approximate the bitrate as long as we have a filesize and
 523   // valid duration.
 524   if (duration.InMicroseconds() <= 0 ||
 525       duration == kInfiniteDuration() ||
 526       filesize_in_bytes == 0) {
 527     return 0;
 528   }
 529
 530   // Do math in floating point as we'd overflow an int64 if the filesize was
 531   // larger than ~1073GB.
 532   double bytes = filesize_in_bytes;
 533   double duration_us = duration.InMicroseconds();
 534   return bytes * 8000000.0 / duration_us;
 535 }
 536
 537 void FFmpegDemuxer::OnOpenContextDone(const PipelineStatusCB& status_cb,
 538                                       bool result) {
 539   DCHECK(task_runner_->BelongsToCurrentThread());
 540   if (!blocking_thread_.IsRunning()) {
 541     status_cb.Run(PIPELINE_ERROR_ABORT);
 542     return;
 543   }
 544
 545   if (!result) {
 546     status_cb.Run(DEMUXER_ERROR_COULD_NOT_OPEN);
 547     return;
 548   }
 549
 550   // Fully initialize AVFormatContext by parsing the stream a little.
 551   base::PostTaskAndReplyWithResult(
 552       blocking_thread_.message_loop_proxy().get(),
 553       FROM_HERE,
 554       base::Bind(&avformat_find_stream_info,
 555                  glue_->format_context(),
 556                  static_cast<AVDictionary**>(NULL)),
 557       base::Bind(&FFmpegDemuxer::OnFindStreamInfoDone, weak_this_, status_cb));
 558 }
 559
 560 void FFmpegDemuxer::OnFindStreamInfoDone(const PipelineStatusCB& status_cb,
 561                                          int result) {
 562   DCHECK(task_runner_->BelongsToCurrentThread());
 563   if (!blocking_thread_.IsRunning() || !data_source_) {
 564     status_cb.Run(PIPELINE_ERROR_ABORT);
 565     return;
 566   }
 567
 568   if (result < 0) {
 569     status_cb.Run(DEMUXER_ERROR_COULD_NOT_PARSE);
 570     return;
 571   }
 572
 573   // Create demuxer stream entries for each possible AVStream. Each stream
 574   // is examined to determine if it is supported or not (is the codec enabled
 575   // for it in this release?). Unsupported streams are skipped, allowing for
 576   // partial playback. At least one audio or video stream must be playable.
 577   AVFormatContext* format_context = glue_->format_context();
 578   streams_.resize(format_context->nb_streams);
 579
 580   AVStream* audio_stream = NULL;
 581   AudioDecoderConfig audio_config;
 582
 583   AVStream* video_stream = NULL;
 584   VideoDecoderConfig video_config;
 585
 586   base::TimeDelta max_duration;
 587   for (size_t i = 0; i < format_context->nb_streams; ++i) {
 588     AVStream* stream = format_context->streams[i];
 589     AVCodecContext* codec_context = stream->codec;
 590     AVMediaType codec_type = codec_context->codec_type;
 591
 592     if (codec_type == AVMEDIA_TYPE_AUDIO) {
 593       if (audio_stream)
 594         continue;
 595
 596       // Log the codec detected, whether it is supported or not.
 597       UMA_HISTOGRAM_SPARSE_SLOWLY("Media.DetectedAudioCodec",
 598                                   codec_context->codec_id);
 599       // Ensure the codec is supported. IsValidConfig() also checks that the
 600       // channel layout and sample format are valid.
 601       AVStreamToAudioDecoderConfig(stream, &audio_config, false);
 602       if (!audio_config.IsValidConfig())
 603         continue;
 604       audio_stream = stream;
 605     } else if (codec_type == AVMEDIA_TYPE_VIDEO) {
 606       if (video_stream)
 607         continue;
 608
 609       // Log the codec detected, whether it is supported or not.
 610       UMA_HISTOGRAM_SPARSE_SLOWLY("Media.DetectedVideoCodec",
 611                                   codec_context->codec_id);
 612       // Ensure the codec is supported. IsValidConfig() also checks that the
 613       // frame size and visible size are valid.
 614       AVStreamToVideoDecoderConfig(stream, &video_config, false);
 615
 616       if (!video_config.IsValidConfig())
 617         continue;
 618       video_stream = stream;
 619     } else if (codec_type == AVMEDIA_TYPE_SUBTITLE) {
 620       if (codec_context->codec_id != AV_CODEC_ID_WEBVTT || !text_enabled_) {
 621         continue;
 622       }
 623     } else {
 624       continue;
 625     }
 626
 627     streams_[i] = new FFmpegDemuxerStream(this, stream);
 628     max_duration = std::max(max_duration, streams_[i]->duration());
 629
 630     if (stream->first_dts != static_cast<int64_t>(AV_NOPTS_VALUE)) {
 631       const base::TimeDelta first_dts = ConvertFromTimeBase(
 632           stream->time_base, stream->first_dts);
 633       if (start_time_ == kNoTimestamp() || first_dts < start_time_)
 634         start_time_ = first_dts;
 635     }
 636   }
 637
 638   if (!audio_stream && !video_stream) {
 639     status_cb.Run(DEMUXER_ERROR_NO_SUPPORTED_STREAMS);
 640     return;
 641   }
 642
 643   if (text_enabled_)
 644     AddTextStreams();
 645
 646   if (format_context->duration != static_cast<int64_t>(AV_NOPTS_VALUE)) {
 647     // If there is a duration value in the container use that to find the
 648     // maximum between it and the duration from A/V streams.
 649     const AVRational av_time_base = {1, AV_TIME_BASE};
 650     max_duration =
 651         std::max(max_duration,
 652                  ConvertFromTimeBase(av_time_base, format_context->duration));
 653   } else {
 654     // The duration is unknown, in which case this is likely a live stream.
 655     max_duration = kInfiniteDuration();
 656   }
 657
 658   // Some demuxers, like WAV, do not put timestamps on their frames. We
 659   // assume the the start time is 0.
 660   if (start_time_ == kNoTimestamp())
 661     start_time_ = base::TimeDelta();
 662
 663   // MPEG-4 B-frames cause grief for a simple container like AVI. Enable PTS
 664   // generation so we always get timestamps, see http://crbug.com/169570
 665   if (strcmp(format_context->iformat->name, "avi") == 0)
 666     format_context->flags |= AVFMT_FLAG_GENPTS;
 667
 668   // Good to go: set the duration and bitrate and notify we're done
 669   // initializing.
 670   host_->SetDuration(max_duration);
 671   duration_known_ = (max_duration != kInfiniteDuration());
 672
 673   int64 filesize_in_bytes = 0;
 674   url_protocol_->GetSize(&filesize_in_bytes);
 675   bitrate_ = CalculateBitrate(format_context, max_duration, filesize_in_bytes);
 676   if (bitrate_ > 0)
 677     data_source_->SetBitrate(bitrate_);
 678
 679   // Audio logging
 680   if (audio_stream) {
 681     AVCodecContext* audio_codec = audio_stream->codec;
 682     media_log_->SetBooleanProperty("found_audio_stream", true);
 683
 684     SampleFormat sample_format = audio_config.sample_format();
 685     std::string sample_name = SampleFormatToString(sample_format);
 686
 687     media_log_->SetStringProperty("audio_sample_format", sample_name);
 688
 689     AVCodec* codec = avcodec_find_decoder(audio_codec->codec_id);
 690     if (codec) {
 691       media_log_->SetStringProperty("audio_codec_name", codec->name);
 692     }
 693
 694     media_log_->SetIntegerProperty("audio_channels_count",
 695                                    audio_codec->channels);
 696     media_log_->SetIntegerProperty("audio_samples_per_second",
 697                                    audio_config.samples_per_second());
 698   } else {
 699     media_log_->SetBooleanProperty("found_audio_stream", false);
 700   }
 701
 702   // Video logging
 703   if (video_stream) {
 704     AVCodecContext* video_codec = video_stream->codec;
 705     media_log_->SetBooleanProperty("found_video_stream", true);
 706
 707     AVCodec* codec = avcodec_find_decoder(video_codec->codec_id);
 708     if (codec) {
 709       media_log_->SetStringProperty("video_codec_name", codec->name);
 710     }
 711
 712     media_log_->SetIntegerProperty("width", video_codec->width);
 713     media_log_->SetIntegerProperty("height", video_codec->height);
 714     media_log_->SetIntegerProperty("coded_width",
 715                                    video_codec->coded_width);
 716     media_log_->SetIntegerProperty("coded_height",
 717                                    video_codec->coded_height);
 718     media_log_->SetStringProperty(
 719         "time_base",
 720         base::StringPrintf("%d/%d",
 721                            video_codec->time_base.num,
 722                            video_codec->time_base.den));
 723     media_log_->SetStringProperty(
 724         "video_format", VideoFrame::FormatToString(video_config.format()));
 725     media_log_->SetBooleanProperty("video_is_encrypted",
 726                                    video_config.is_encrypted());
 727   } else {
 728     media_log_->SetBooleanProperty("found_video_stream", false);
 729   }
 730
 731
 732   media_log_->SetDoubleProperty("max_duration", max_duration.InSecondsF());
 733   media_log_->SetDoubleProperty("start_time", start_time_.InSecondsF());
 734   media_log_->SetIntegerProperty("bitrate", bitrate_);
 735
 736   status_cb.Run(PIPELINE_OK);
 737 }
 738
 739 void FFmpegDemuxer::OnSeekFrameDone(const PipelineStatusCB& cb, int result) {
 740   DCHECK(task_runner_->BelongsToCurrentThread());
 741   CHECK(pending_seek_);
 742   pending_seek_ = false;
 743
 744   if (!blocking_thread_.IsRunning()) {
 745     cb.Run(PIPELINE_ERROR_ABORT);
 746     return;
 747   }
 748
 749   if (result < 0) {
 750     // Use VLOG(1) instead of NOTIMPLEMENTED() to prevent the message being
 751     // captured from stdout and contaminates testing.
 752     // TODO(scherkus): Implement this properly and signal error (BUG=23447).
 753     VLOG(1) << "Not implemented";
 754   }
 755
 756   // Tell streams to flush buffers due to seeking.
 757   StreamVector::iterator iter;
 758   for (iter = streams_.begin(); iter != streams_.end(); ++iter) {
 759     if (*iter)
 760       (*iter)->FlushBuffers();
 761   }
 762
 763   // Resume reading until capacity.
 764   ReadFrameIfNeeded();
 765
 766   // Notify we're finished seeking.
 767   cb.Run(PIPELINE_OK);
 768 }
 769
 770 void FFmpegDemuxer::ReadFrameIfNeeded() {
 771   DCHECK(task_runner_->BelongsToCurrentThread());
 772
 773   // Make sure we have work to do before reading.
 774   if (!blocking_thread_.IsRunning() || !StreamsHaveAvailableCapacity() ||
 775       pending_read_ || pending_seek_) {
 776     return;
 777   }
 778
 779   // Allocate and read an AVPacket from the media. Save |packet_ptr| since
 780   // evaluation order of packet.get() and base::Passed(&packet) is
 781   // undefined.
 782   ScopedAVPacket packet(new AVPacket());
 783   AVPacket* packet_ptr = packet.get();
 784
 785   pending_read_ = true;
 786   base::PostTaskAndReplyWithResult(
 787       blocking_thread_.message_loop_proxy().get(),
 788       FROM_HERE,
 789       base::Bind(&av_read_frame, glue_->format_context(), packet_ptr),
 790       base::Bind(
 791           &FFmpegDemuxer::OnReadFrameDone, weak_this_, base::Passed(&packet)));
 792 }
 793
 794 void FFmpegDemuxer::OnReadFrameDone(ScopedAVPacket packet, int result) {
 795   DCHECK(task_runner_->BelongsToCurrentThread());
 796   DCHECK(pending_read_);
 797   pending_read_ = false;
 798
 799   if (!blocking_thread_.IsRunning() || pending_seek_) {
 800     return;
 801   }
 802
 803   if (result < 0) {
 804     // Update the duration based on the highest elapsed time across all streams
 805     // if it was previously unknown.
 806     if (!duration_known_) {
 807       base::TimeDelta max_duration;
 808
 809       for (StreamVector::iterator iter = streams_.begin();
 810            iter != streams_.end();
 811            ++iter) {
 812         if (!*iter)
 813           continue;
 814
 815         base::TimeDelta duration = (*iter)->GetElapsedTime();
 816         if (duration != kNoTimestamp() && duration > max_duration)
 817           max_duration = duration;
 818       }
 819
 820       if (max_duration > base::TimeDelta()) {
 821         host_->SetDuration(max_duration);
 822         duration_known_ = true;
 823       }
 824     }
 825     // If we have reached the end of stream, tell the downstream filters about
 826     // the event.
 827     StreamHasEnded();
 828     return;
 829   }
 830
 831   // Queue the packet with the appropriate stream.
 832   DCHECK_GE(packet->stream_index, 0);
 833   DCHECK_LT(packet->stream_index, static_cast<int>(streams_.size()));
 834
 835   // Defend against ffmpeg giving us a bad stream index.
 836   if (packet->stream_index >= 0 &&
 837       packet->stream_index < static_cast<int>(streams_.size()) &&
 838       streams_[packet->stream_index] &&
 839       (!audio_disabled_ ||
 840        streams_[packet->stream_index]->type() != DemuxerStream::AUDIO)) {
 841
 842     // TODO(scherkus): Fix demuxing upstream to never return packets w/o data
 843     // when av_read_frame() returns success code. See bug comment for ideas:
 844     //
 845     // https://code.google.com/p/chromium/issues/detail?id=169133#c10
 846     if (!packet->data) {
 847       ScopedAVPacket new_packet(new AVPacket());
 848       av_new_packet(new_packet.get(), 0);
 849
 850       new_packet->pts = packet->pts;
 851       new_packet->dts = packet->dts;
 852       new_packet->pos = packet->pos;
 853       new_packet->duration = packet->duration;
 854       new_packet->convergence_duration = packet->convergence_duration;
 855       new_packet->flags = packet->flags;
 856       new_packet->stream_index = packet->stream_index;
 857
 858       packet.swap(new_packet);
 859     }
 860
 861     // Special case for opus in ogg.  FFmpeg is pre-trimming the codec delay
 862     // from the packet timestamp.  Chrome expects to handle this itself inside
 863     // the decoder, so shift timestamps by the delay in this case.
 864     // TODO(dalecurtis): Try to get fixed upstream.  See http://crbug.com/328207
 865     if (strcmp(glue_->format_context()->iformat->name, "ogg") == 0) {
 866       const AVCodecContext* codec_context =
 867           glue_->format_context()->streams[packet->stream_index]->codec;
 868       if (codec_context->codec_id == AV_CODEC_ID_OPUS &&
 869           codec_context->delay > 0) {
 870         packet->pts += codec_context->delay;
 871       }
 872     }
 873
 874     FFmpegDemuxerStream* demuxer_stream = streams_[packet->stream_index];
 875     demuxer_stream->EnqueuePacket(packet.Pass());
 876   }
 877
 878   // Keep reading until we've reached capacity.
 879   ReadFrameIfNeeded();
 880 }
 881
 882 void FFmpegDemuxer::OnDataSourceStopped(const base::Closure& callback) {
 883   // This will block until all tasks complete. Note that after this returns it's
 884   // possible for reply tasks (e.g., OnReadFrameDone()) to be queued on this
 885   // thread. Each of the reply task methods must check whether we've stopped the
 886   // thread and drop their results on the floor.
 887   DCHECK(task_runner_->BelongsToCurrentThread());
 888   blocking_thread_.Stop();
 889
 890   StreamVector::iterator iter;
 891   for (iter = streams_.begin(); iter != streams_.end(); ++iter) {
 892     if (*iter)
 893       (*iter)->Stop();
 894   }
 895
 896   callback.Run();
 897 }
 898
 899 bool FFmpegDemuxer::StreamsHaveAvailableCapacity() {
 900   DCHECK(task_runner_->BelongsToCurrentThread());
 901   StreamVector::iterator iter;
 902   for (iter = streams_.begin(); iter != streams_.end(); ++iter) {
 903     if (*iter && (*iter)->HasAvailableCapacity()) {
 904       return true;
 905     }
 906   }
 907   return false;
 908 }
 909
 910 void FFmpegDemuxer::StreamHasEnded() {
 911   DCHECK(task_runner_->BelongsToCurrentThread());
 912   StreamVector::iterator iter;
 913   for (iter = streams_.begin(); iter != streams_.end(); ++iter) {
 914     if (!*iter ||
 915         (audio_disabled_ && (*iter)->type() == DemuxerStream::AUDIO)) {
 916       continue;
 917     }
 918     (*iter)->SetEndOfStream();
 919   }
 920 }
 921
 922 void FFmpegDemuxer::FireNeedKey(const std::string& init_data_type,
 923                                 const std::string& encryption_key_id) {
 924   std::vector<uint8> key_id_local(encryption_key_id.begin(),
 925                                   encryption_key_id.end());
 926   need_key_cb_.Run(init_data_type, key_id_local);
 927 }
 928
 929 void FFmpegDemuxer::NotifyCapacityAvailable() {
 930   DCHECK(task_runner_->BelongsToCurrentThread());
 931   ReadFrameIfNeeded();
 932 }
 933
 934 void FFmpegDemuxer::NotifyBufferingChanged() {
 935   DCHECK(task_runner_->BelongsToCurrentThread());
 936   Ranges<base::TimeDelta> buffered;
 937   FFmpegDemuxerStream* audio =
 938       audio_disabled_ ? NULL : GetFFmpegStream(DemuxerStream::AUDIO);
 939   FFmpegDemuxerStream* video = GetFFmpegStream(DemuxerStream::VIDEO);
 940   if (audio && video) {
 941     buffered = audio->GetBufferedRanges().IntersectionWith(
 942         video->GetBufferedRanges());
 943   } else if (audio) {
 944     buffered = audio->GetBufferedRanges();
 945   } else if (video) {
 946     buffered = video->GetBufferedRanges();
 947   }
 948   for (size_t i = 0; i < buffered.size(); ++i)
 949     host_->AddBufferedTimeRange(buffered.start(i), buffered.end(i));
 950 }
 951
 952 void FFmpegDemuxer::OnDataSourceError() {
 953   host_->OnDemuxerError(PIPELINE_ERROR_READ);
 954 }
 955
 956 }  // namespace media