aos-AVP: Audio Pass-trough Mode 2 causes erratic playback speed in some videos
I was trying to find the source of this issue for a long time and finally tested it out until I found the culprit: When using audio Pass-trough Mode 2 the playback speed of some videos is very fast (and there is no sound. But even if it was it wouldn’t be watchable, because the playback is seriously fast).
The file I played was an MKV with the following properties:
Video: MPEG4 Video (H264) 1280x528 23.976fps [V: h264 high L4.1, yuv420p, 1280x528 [default]]
Audio: DTS 48000Hz 6ch 1536kbps [A: English [eng] (dts, 48000 Hz, 5.1, 1536 kb/s) [default]]
Subtitle: UTF-8 [S: English [eng] (subrip) [default]]
Subtitle: UTF-8 [S: Romanian [rum] (subrip)]
Subtitle: UTF-8 [S: No subtitles]
By switching to Audio passtrough mode to 1 or disabled the issue is resolved. The downsides are, that mode 1 doesn’t work for many files/formats (results in high-pitched and distorted sound) and disabled of course disables the pass-trough completely.
This was tested/reproduced on an Nvidia Shield running on the Shield Software level 7.2.1 (Based on Android 8.0). This happened while using the latest version of the Nova Player.
Needless to say, I’d be very happy to use Mode 2 without this issue. I’d be happy to provide any information/details necessary to get this fix.
About this issue
- Original URL
- State: open
- Created 5 years ago
- Comments: 18 (9 by maintainers)
I do have the same behavior with DTS audio and passthrough on my Android TV box connected directly to my AV. According to the UI, it is using hardware decoding.
Disabling passthrough is not an option as it results in Stereo only output encapsulated in Dolby Digital Plus (EAC3). This is because my device like many others can’t output multi-channel PCM but only stereo PCM, AC3, EAC3, DTS and DTS-HD.
It would be great if this bug could be fixed. Playing the same in VLC results in the right playback speed but a significant Audio/video sync issue.
Thx for the detailed feedback. What I do not understand is that if DTS is processed via passthrough this is your external AV device that handles decoding and volume (not NVP). The only explanation I would have is that somehow we revert to SWdec on DTS in your particular case but I guess that you would have noticed. Strange
I have detailed a bit passthrough here: https://www.reddit.com/r/NovaVideoPlayer/comments/aif64n/audio_passthrough_mode_1_and_2_what_is_the/
Are you using ARC? What kind of connectivity and 5.1 equipment is used?
If you could share privately your or part of your sample, I could try to reproduce.
Hi @courville - I just managed to update the app to beta (Version is 1.0-20190130.1101) but I’ve confirmed the issue persists. 😦 Any other ideas? How could I help troubleshoot/investigate?