media/formats/mp4/track_run_iterator.h

   1 // Copyright 2014 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 #ifndef MEDIA_FORMATS_MP4_TRACK_RUN_ITERATOR_H_
   6 #define MEDIA_FORMATS_MP4_TRACK_RUN_ITERATOR_H_
   7
   8 #include <vector>
   9
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/time/time.h"
  12 #include "media/base/media_export.h"
  13 #include "media/base/media_log.h"
  14 #include "media/base/stream_parser_buffer.h"
  15 #include "media/formats/mp4/box_definitions.h"
  16 #include "media/formats/mp4/cenc.h"
  17
  18 namespace media {
  19
  20 class DecryptConfig;
  21
  22 namespace mp4 {
  23
  24 base::TimeDelta MEDIA_EXPORT TimeDeltaFromRational(int64 numer, int64 denom);
  25 DecodeTimestamp MEDIA_EXPORT DecodeTimestampFromRational(int64 numer,
  26                                                          int64 denom);
  27
  28 struct SampleInfo;
  29 struct TrackRunInfo;
  30
  31 class MEDIA_EXPORT TrackRunIterator {
  32  public:
  33   // Create a new TrackRunIterator. A reference to |moov| will be retained for
  34   // the lifetime of this object.
  35   TrackRunIterator(const Movie* moov, const scoped_refptr<MediaLog>& media_log);
  36   ~TrackRunIterator();
  37
  38   // Sets up the iterator to handle all the runs from the current fragment.
  39   bool Init(const MovieFragment& moof);
  40
  41   // Returns true if the properties of the current run or sample are valid.
  42   bool IsRunValid() const;
  43   bool IsSampleValid() const;
  44
  45   // Advance the properties to refer to the next run or sample. Requires that
  46   // the current sample be valid.
  47   void AdvanceRun();
  48   void AdvanceSample();
  49
  50   // Returns true if this track run has auxiliary information and has not yet
  51   // been cached. Only valid if IsRunValid().
  52   bool AuxInfoNeedsToBeCached();
  53
  54   // Caches the CENC data from the given buffer. |buf| must be a buffer starting
  55   // at the offset given by cenc_offset(), with a |size| of at least
  56   // cenc_size(). Returns true on success, false on error.
  57   bool CacheAuxInfo(const uint8* buf, int size);
  58
  59   // Returns the maximum buffer location at which no data earlier in the stream
  60   // will be required in order to read the current or any subsequent sample. You
  61   // may clear all data up to this offset before reading the current sample
  62   // safely. Result is in the same units as offset() (for Media Source this is
  63   // in bytes past the the head of the MOOF box).
  64   int64 GetMaxClearOffset();
  65
  66   // Property of the current run. Only valid if IsRunValid().
  67   uint32 track_id() const;
  68   int64 aux_info_offset() const;
  69   int aux_info_size() const;
  70   bool is_encrypted() const;
  71   bool is_audio() const;
  72   // Only one is valid, based on the value of is_audio().
  73   const AudioSampleEntry& audio_description() const;
  74   const VideoSampleEntry& video_description() const;
  75
  76   // Properties of the current sample. Only valid if IsSampleValid().
  77   int64 sample_offset() const;
  78   int sample_size() const;
  79   DecodeTimestamp dts() const;
  80   base::TimeDelta cts() const;
  81   base::TimeDelta duration() const;
  82   bool is_keyframe() const;
  83   bool is_random_access_point() const;
  84
  85   // Only call when is_encrypted() is true and AuxInfoNeedsToBeCached() is
  86   // false. Result is owned by caller.
  87   scoped_ptr<DecryptConfig> GetDecryptConfig();
  88
  89  private:
  90   void ResetRun();
  91   const TrackEncryption& track_encryption() const;
  92
  93   uint32 GetGroupDescriptionIndex(uint32 sample_index) const;
  94
  95   // Sample encryption information.
  96   bool IsSampleEncrypted(size_t sample_index) const;
  97   uint8 GetIvSize(size_t sample_index) const;
  98   const std::vector<uint8>& GetKeyId(size_t sample_index) const;
  99
 100   const Movie* moov_;
 101   scoped_refptr<MediaLog> media_log_;
 102
 103   std::vector<TrackRunInfo> runs_;
 104   std::vector<TrackRunInfo>::const_iterator run_itr_;
 105   std::vector<SampleInfo>::const_iterator sample_itr_;
 106
 107   std::vector<FrameCENCInfo> cenc_info_;
 108
 109   int64 sample_dts_;
 110   int64 sample_offset_;
 111
 112   DISALLOW_COPY_AND_ASSIGN(TrackRunIterator);
 113 };
 114
 115 }  // namespace mp4
 116 }  // namespace media
 117
 118 #endif  // MEDIA_FORMATS_MP4_TRACK_RUN_ITERATOR_H_