GNOME Bugzilla – Bug 748947
playout: New example for seamless audio/video playback
Last modified: 2015-06-12 19:50:12 UTC
Created attachment 302922 [details] [review] playout: New example for seamless audio/video playback An example app that takes video URIs as command line arguments and switches between them seamlessly one after the other using compositor and audiomixer. Both audio-video and video-only media files are valid inputs, but mixing files of both types in a single invocation is cumbersome to support, and hence does not work. The example attempts to keep the audio stream moving along perfectly, and duplicates video frames where necessary to cover gaps in the video timestamps using the 'aggregate-eos' videoaggregator pad property. Ensuring seamless (and mostly-glitch-free) switching is harder than it sounds, and hence the example contains plenty of pad probes and running time calculations to make things work. The GPtrArray play_queue contains items that are being played back, have been prepared for playback, and will be played back in the future. The queue itself is mutable besides the first two items (playing and prepared). The item that has been prepared should not be edited or removed since it has been prepared in advance to be activated immediately on the current item's EOS. The example also has support for switching to the next item in the queue prematurely; see the --switch-after/-s flag to the application. Note: the output video is hard-coded at 1280x720, and input video is scaled as needed to fit this size. Set OUTPUT_VIDEO_WIDTH/HEIGHT to change this.
Created attachment 302925 [details] [review] playout: New example for seamless audio/video playback Fix copyright notice (wrong year)
Created attachment 303081 [details] [review] playout: New example for seamless audio/video playback "aggregate-eos" was renamed to "ignore-eos"
Created attachment 303098 [details] [review] playout: New example for seamless audio/video playback Add a check to fail while activating an item if there's no available pads on it.
Created attachment 303103 [details] [review] playout: New example for seamless audio/video playback Fix incorrect last item freeing when the last pad in that item is an audio pad. The last pad is usually the video pad due to buffering in the audio sink. Also rename a function, remove redundant parameters in other, similar functions, etc.
Cool, pushed: commit 5da10b4f57f5f1a9490873f4f13302c03ece3e09 Author: Nirbheek Chauhan <nirbheek@centricular.com> Date: Thu Jan 29 00:56:26 2015 +0000 playout: New example for seamless audio/video playback An example app that takes video URIs as command line arguments and switches between them seamlessly one after the other using compositor and audiomixer. Both audio-video and video-only media files are valid inputs, but mixing files of both types in a single invocation is cumbersome to support, and hence does not work. The example attempts to keep the audio stream moving along perfectly, and duplicates video frames where necessary to cover gaps in the video timestamps using the 'ignore-eos' videoaggregator pad property. Ensuring seamless (and mostly-glitch-free) switching is harder than it sounds, and hence the example contains plenty of pad probes and running time calculations to make things work. The GPtrArray play_queue contains items that are being played back, have been prepared for playback, and will be played back in the future. The queue itself is mutable besides the first two items (playing and prepared). The item that has been prepared should not be edited or removed since it has been prepared in advance to be activated immediately on the current item's EOS. The example also has support for switching to the next item in the queue prematurely; see the --switch-after/-s flag to the application. Note: the output video is hard-coded at 1280x720, and input video is scaled as needed to fit this size. Set OUTPUT_VIDEO_WIDTH/HEIGHT to change this. https://bugzilla.gnome.org/show_bug.cgi?id=748947