[BUG] stream_start_offset set incorrectly leading to av sync errors #8779
Description
Describe the bug
Branch from Linux SOF driver bug thesofproject/linux#4781
The FW is not reporting correct start offset, which leads to incorrect delay reporting by the SOF driver to application. This can lead to video playback failures with applications using ALSA delay reporting.
To Reproduce
Play a video with mplayer and native ALSA backend:
- e.g. video from https://www.photojoseph.com/tips/2021/3/29/updated-march-2021-downloadable-audiovideo-sync-tests-2398-24-25-2997-50-5994
- play to system speaker: "mplayer -ao alsa:device=hw=0.2 Audio_Video_Sync_23,98_HEVC_1080p-by_PhotoJoseph.mov"
Reproduction Rate
50%
Expected behavior
Video should play reliably with accurate AV sync with applications using ALSA snd_pcm_delay().
Impact
High
Environment
kernel: thesofproject/linux@66ee247 (sof-dev)
SOF: 6c18829 (SOF main)
platform: MTL
topoplogy: sof-mtl-rt713-l0-rt1316-l12.tplg