Implement ISO BMFF support in Media Source.

media/mp4/track_run_iterator.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef MEDIA_MP4_TRACK_RUN_ITERATOR_H_
+#define MEDIA_MP4_TRACK_RUN_ITERATOR_H_
+
+#include "base/time.h"
+#include "media/mp4/box_definitions.h"
+#include "media/mp4/cenc.h"
+
+namespace media {
+namespace mp4 {
+
+using base::TimeDelta;
+
+base::TimeDelta TimeDeltaFromFrac(int64 numer, uint64 denom);
+
+struct SampleInfo {
+  size_t size;
+  TimeDelta duration;
+  TimeDelta cts_offset;
+  bool is_keyframe;
+};
+
+struct TrackRunInfo {
+  uint32 track_id;
+  std::vector<SampleInfo> samples;
+  TimeDelta start_dts;
+  size_t sample_start_offset;
+
+  bool is_encrypted;
+  size_t cenc_start_offset;
+  size_t cenc_total_size;
+  uint8 default_cenc_size;
+  // Only valid if default_cenc_size == 0. (In this case, infer the sample count
+  // from the 'samples' parameter; they shall be the same.)
+  std::vector<uint8> cenc_sizes;
+
+  TrackRunInfo();
+  ~TrackRunInfo();
+};
+
+class TrackRunIterator {
+ public:
+  TrackRunIterator();
+  ~TrackRunIterator();
+
+  void Reset();
+
+  // Sets up the iterator to handle all the runs from the current fragment.
+  bool Init(const Movie& moov, const MovieFragment& moof);
+
+  // Returns true if the properties of the current run or sample are valid.
+  bool RunValid();
+  bool SampleValid();
+
+  // Advance the properties to refer to the next run or sample. Requires that
+  // the current sample be valid.
+  void AdvanceRun();
+  void AdvanceSample();
+
+  // Returns true iff the track is encrypted and the common encryption sample
+  // auxiliary information has not yet been cached for the current track.
+  bool NeedsCENC();
+
+  // Cache the CENC data from the given buffer.
+  bool CacheCENC(const uint8* buf, size_t size);
+
+  // Returns the maximum buffer location at which no data earlier in the stream
+  // will be required in order to read the current or any subsequent sample. You
+  // may clear all data up to this offset before reading the current sample
+  // safely. Result is in the same units as offset() (for Media Source this is
+  // in bytes past the the head of the MOOF box).
+  size_t GetMaxClearOffset();
+
+  // Property of the current run. Reqiures RunValid().
+  uint32 track_id() const     { return run_itr_->track_id; }

[acolwell GONE FROM CHROMIUM, 2012/06/06 17:32:39]

Move all these impls into cc file and add DCHECKS for RunValid(), SampleValid(),
or is_encrypted() as appropriate.

[strobe_, 2012/06/07 16:33:54]

Done.

+  bool is_encrypted() const   { return run_itr_->is_encrypted; }
+  // Only valid if is_encrypted() is true.
+  size_t cenc_offset() const  { return run_itr_->cenc_start_offset; }
+  size_t cenc_size() const    { return run_itr_->cenc_total_size; }
+
+  // Properties of the current sample. Requires SampleValid().
+  size_t offset() const       { return sample_offset_; }
+  size_t size() const         { return sample_itr_->size; }
+  TimeDelta dts() const       { return sample_dts_; }
+  TimeDelta cts() const       { return sample_dts_ + sample_itr_->cts_offset; }
+  TimeDelta duration() const  { return sample_itr_->duration; }
+  bool is_keyframe() const    { return sample_itr_->is_keyframe; }
+  // Only valid if is_encrypted() is true and NeedsCENC() is false.
+  const FrameCENCInfo& frame_cenc_info();
+
+ private:
+  void ResetRun();
+  std::vector<TrackRunInfo> runs_;
+  std::vector<TrackRunInfo>::const_iterator run_itr_;
+
+  std::vector<SampleInfo>::const_iterator sample_itr_;
+  std::vector<uint8> cenc_cache_;
+
+  std::vector<size_t> min_clear_offsets_;
+  std::vector<size_t>::const_iterator min_clear_offset_itr_;
+
+  TimeDelta sample_dts_;
+  size_t sample_offset_;
+  FrameCENCInfo frame_cenc_info_;
+};
+
+}  // namespace mp4
+}  // namespace media
+
+#endif  // MEDIA_MP4_TRACK_RUN_ITERATOR_H_