content/renderer/media/websourcebuffer_impl.cc

   1 // Copyright 2013 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 "content/renderer/media/websourcebuffer_impl.h"
   6
   7 #include <limits>
   8
   9 #include "base/float_util.h"
  10 #include "media/filters/chunk_demuxer.h"
  11
  12 namespace content {
  13
  14 static base::TimeDelta DoubleToTimeDelta(double time) {
  15   DCHECK(!base::IsNaN(time));
  16   DCHECK_NE(time, -std::numeric_limits<double>::infinity());
  17
  18   if (time == std::numeric_limits<double>::infinity())
  19     return media::kInfiniteDuration();
  20
  21   // Don't use base::TimeDelta::Max() here, as we want the largest finite time
  22   // delta.
  23   base::TimeDelta max_time = base::TimeDelta::FromInternalValue(kint64max - 1);
  24   double max_time_in_seconds = max_time.InSecondsF();
  25
  26   if (time >= max_time_in_seconds)
  27     return max_time;
  28
  29   return base::TimeDelta::FromMicroseconds(
  30       time * base::Time::kMicrosecondsPerSecond);
  31 }
  32
  33 WebSourceBufferImpl::WebSourceBufferImpl(
  34     const std::string& id, media::ChunkDemuxer* demuxer)
  35     : id_(id),
  36       demuxer_(demuxer),
  37       append_window_end_(media::kInfiniteDuration()) {
  38   DCHECK(demuxer_);
  39 }
  40
  41 WebSourceBufferImpl::~WebSourceBufferImpl() {
  42   DCHECK(!demuxer_) << "Object destroyed w/o removedFromMediaSource() call";
  43 }
  44
  45 bool WebSourceBufferImpl::setMode(WebSourceBuffer::AppendMode mode) {
  46   if (demuxer_->IsParsingMediaSegment(id_))
  47     return false;
  48
  49   switch (mode) {
  50     case WebSourceBuffer::AppendModeSegments:
  51       demuxer_->SetSequenceMode(id_, false);
  52       return true;
  53     case WebSourceBuffer::AppendModeSequence:
  54       demuxer_->SetSequenceMode(id_, true);
  55       return true;
  56   }
  57
  58   NOTREACHED();
  59   return false;
  60 }
  61
  62 blink::WebTimeRanges WebSourceBufferImpl::buffered() {
  63   media::Ranges<base::TimeDelta> ranges = demuxer_->GetBufferedRanges(id_);
  64   blink::WebTimeRanges result(ranges.size());
  65   for (size_t i = 0; i < ranges.size(); i++) {
  66     result[i].start = ranges.start(i).InSecondsF();
  67     result[i].end = ranges.end(i).InSecondsF();
  68   }
  69   return result;
  70 }
  71
  72 void WebSourceBufferImpl::append(
  73     const unsigned char* data,
  74     unsigned length,
  75     double* timestamp_offset) {
  76   base::TimeDelta old_offset = timestamp_offset_;
  77   demuxer_->AppendData(id_, data, length,
  78                        append_window_start_, append_window_end_,
  79                        &timestamp_offset_);
  80
  81   // Coded frame processing may update the timestamp offset. If the caller
  82   // provides a non-NULL |timestamp_offset| and frame processing changes the
  83   // timestamp offset, report the new offset to the caller. Do not update the
  84   // caller's offset otherwise, to preserve any pre-existing value that may have
  85   // more than microsecond precision.
  86   if (timestamp_offset && old_offset != timestamp_offset_)
  87     *timestamp_offset = timestamp_offset_.InSecondsF();
  88 }
  89
  90 void WebSourceBufferImpl::abort() {
  91   demuxer_->Abort(id_,
  92                   append_window_start_, append_window_end_,
  93                   &timestamp_offset_);
  94
  95   // TODO(wolenetz): abort should be able to modify the caller timestamp offset
  96   // (just like WebSourceBufferImpl::append).
  97   // See http://crbug.com/370229 for further details.
  98 }
  99
 100 void WebSourceBufferImpl::remove(double start, double end) {
 101   DCHECK_GE(start, 0);
 102   DCHECK_GE(end, 0);
 103   demuxer_->Remove(id_, DoubleToTimeDelta(start), DoubleToTimeDelta(end));
 104 }
 105
 106 bool WebSourceBufferImpl::setTimestampOffset(double offset) {
 107   if (demuxer_->IsParsingMediaSegment(id_))
 108     return false;
 109
 110   timestamp_offset_ = DoubleToTimeDelta(offset);
 111
 112   // http://www.w3.org/TR/media-source/#widl-SourceBuffer-timestampOffset
 113   // Step 6: If the mode attribute equals "sequence", then set the group start
 114   // timestamp to new timestamp offset.
 115   demuxer_->SetGroupStartTimestampIfInSequenceMode(id_, timestamp_offset_);
 116   return true;
 117 }
 118
 119 void WebSourceBufferImpl::setAppendWindowStart(double start) {
 120   DCHECK_GE(start, 0);
 121   append_window_start_ = DoubleToTimeDelta(start);
 122 }
 123
 124 void WebSourceBufferImpl::setAppendWindowEnd(double end) {
 125   DCHECK_GE(end, 0);
 126   append_window_end_ = DoubleToTimeDelta(end);
 127 }
 128
 129 void WebSourceBufferImpl::removedFromMediaSource() {
 130   demuxer_->RemoveId(id_);
 131   demuxer_ = NULL;
 132 }
 133
 134 }  // namespace content