- From: Tomer Lahav via GitHub <sysbot+gh@w3.org>
- Date: Mon, 09 Nov 2015 18:58:55 +0000
- To: public-html-media@w3.org
Melatonin64 has just created a new issue for https://github.com/w3c/media-source: == Support sample accurate audio splicing using timestampOffset/appendWindowStart/appendWindowEnd == One of the use cases for sample-accurate-audio-splicing is gapless audio playback (by removing the excess front/back padding added by most audio codecs). Step 9 of the for loop in the **Coded Frame Processing** algorithm states: `If frame end timestamp is greater than appendWindowEnd, then set the need random access point flag to true, drop the coded frame, and jump to the top of the loop to start processing the next coded frame.` For audio, this means that we'll be dropping a complete coded frame (i.e. for AAC - 1024 audio samples) even if some of the audio samples would have fallen within the append window. This granularity (coded frames) is not sufficient in order to achieve gapless audio playback. It would be great if instead, we could keep the frame, and mark a range of samples to be discarded from frame, so that once the frame is decoded only the samples that fall within the append window will be used. It's possible that this change alone is not sufficient to support sample-accurate-audio-splicing... A test webpage can be found [here](http://melatonin64.github.io/gapless-mse-audio/), (based on Dale Curtis' [article](https://developers.google.com/web/updates/2015/06/Media-Source-Extensions-for-Audio?hl=en)). Further discussion can be found [here](https://bugzilla.mozilla.org/show_bug.cgi?id=1222851) See https://github.com/w3c/media-source/issues/37
Received on Monday, 9 November 2015 18:58:57 UTC