diff options
Diffstat (limited to 'webkit/glue/webmediaplayer_impl.cc')
| -rw-r--r-- | webkit/glue/webmediaplayer_impl.cc | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/webkit/glue/webmediaplayer_impl.cc b/webkit/glue/webmediaplayer_impl.cc index 0d96865..04f5dc8 100644 --- a/webkit/glue/webmediaplayer_impl.cc +++ b/webkit/glue/webmediaplayer_impl.cc @@ -27,6 +27,25 @@ namespace { // queue but gives up a pretty good latency on repaint. const int kMaxOutstandingRepaints = 50; +// Limits the range of playback rate. +// +// TODO(kylep): Revisit these. +// +// Vista has substantially lower performance than XP or Windows7. If you speed +// up a video too much, it can't keep up, and rendering stops updating except on +// the time bar. For really high speeds, audio becomes a bottleneck and we just +// use up the data we have, which may not achieve the speed requested, but will +// not crash the tab. +// +// A very slow speed, ie 0.00000001x, causes the machine to lock up. (It seems +// like a busy loop). It gets unresponsive, although its not completely dead. +// +// Also our timers are not very accurate (especially for ogg), which becomes +// evident at low speeds and on Vista. Since other speeds are risky and outside +// the norms, we think 1/16x to 16x is a safe and useful range for now. +const float kMinRate = 0.0625f; +const float kMaxRate = 16.0f; + } // namespace namespace webkit_glue { @@ -248,6 +267,19 @@ void WebMediaPlayerImpl::setEndTime(float seconds) { void WebMediaPlayerImpl::setRate(float rate) { DCHECK(MessageLoop::current() == main_loop_); + // TODO(kylep): Remove when support for negatives is added. Also, modify the + // following checks so rewind uses reasonable values also. + if (rate < 0.0f) + return; + + // Limit rates to reasonable values by clamping. + if (rate != 0.0f) { + if (rate < kMinRate) + rate = kMinRate; + else if (rate > kMaxRate) + rate = kMaxRate; + } + playback_rate_ = rate; if (!paused_) { pipeline_->SetPlaybackRate(rate); |