L3D DASH - Seek and playback start optimizations #4877
Description
Description
The current L3D implementation in dash.js checks for AdaptationSets/Representations that contain an IDR at the beginning of each partial segment. However, the start time or the time after a seek does not necessarily correspond to a partial segment that starts with an IDR.
dash.js always downloads the partial segment that corresponds to the target time. In the worst case, we download multiple partial segments for the target time that do not contain an IDR. Therefore, playback will only start after we downloaded a partial segment with an IDR which might belong only to the next segment.
For these scenarios, we need to force dash.js to download partial segments that are before the target time (after seek or at playback start) to always have an IDR to decode at the target time.
