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Merge pull request #810 from OpenShot/make-cache-less-aggressive

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Make Cache Less Aggressive
This commit is contained in:
Jonathan Thomas
2022-02-25 15:09:38 -06:00
committed by GitHub
parent f2b89e3254 64815d6bae
commit d8cb71c544
1 changed files with 3 additions and 31 deletions
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34
src/Qt/VideoCacheThread.cpp
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@@ -27,7 +27,7 @@ namespace openshot
VideoCacheThread::VideoCacheThread()
: Thread("video-cache"), speed(0), last_speed(1), is_playing(false),
reader(NULL), current_display_frame(1), cached_frame_count(0),
min_frames_ahead(24), max_frames_ahead(OPEN_MP_NUM_PROCESSORS * 6)
min_frames_ahead(4), max_frames_ahead(8)
{
}
@@ -80,40 +80,12 @@ namespace openshot
const auto frame_duration = double_micro_sec(1000000.0 / reader->info.fps.ToDouble());
int current_speed = speed;
// Calculate bytes per frame. If we have a reference openshot::Frame, use that instead (the preview
// window can be smaller, can thus reduce the bytes per frame)
int64_t bytes_per_frame = (reader->info.height * reader->info.width * 4) +
(reader->info.sample_rate * reader->info.channels * 4);
if (last_cached_frame && last_cached_frame->has_image_data && last_cached_frame->has_audio_data) {
bytes_per_frame = last_cached_frame->GetBytes();
}
// Calculate # of frames on Timeline cache (when paused)
if (reader->GetCache() && reader->GetCache()->GetMaxBytes() > 0) {
if (speed == 0) {
// When paused, use 1/2 the cache size (so our cache will be 50% before the play-head, and 50% after it)
max_frames_ahead = (reader->GetCache()->GetMaxBytes() / bytes_per_frame) / 2;
if (max_frames_ahead > 300) {
// Ignore values that are too large, and default to a safer value
max_frames_ahead = 300;
}
} else {
// When playing back video (speed == 1), keep cache # small
max_frames_ahead = min_frames_ahead;
}
}
// Calculate increment (based on speed)
// Support caching in both directions
int16_t increment = speed;
if (speed == 0) {
// When paused, we still want to increment our cache position
// to fully cache frames while paused
if (last_speed > 0) {
increment = 1;
} else {
increment = -1;
}
std::this_thread::sleep_for(frame_duration / 4);
continue;
}
// Always cache frames from the current display position to our maximum (based on the cache size).