koying / SPMC

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SPMC 16.7-17.x: E-AC3 frequent high pitched glitch, identified and fixed in ffmpeg #1173

Open neelrock opened 6 years ago

neelrock commented 6 years ago

Hello Koying,

I'm using a wetek play 2 with lastest ricardo's ATV rom and tvheadend to drive the integrated dvb-t tuner.

There is a very frequent high pitched audio glitch happening with french dvb-t channels using e-ac3 audio. This glitch is present in many apps like SPMC 16.7 and 17.x but also in kodi, in google live channels app, or also on PC when using ffdshow as audio decoder.

I have made researches to try to narrow down the source of this issue and it seems very likely to be libavcodec.

The described issue was reported some time ago in ffmpeg bugtracker and is now fixed:

I have done my own testing with the sample provided in the ffmpeg bug report (here is a mkv version to help testing small-audio_ac3_glitch.zip to verify libavcodec was the culprit and earlier versions fixed the issue:

The glitch occurs 2 times in this sample, at 00:20 and 00:41

On Win10 with potplayer:

On the wetek play 2:

Link to my extended reports for this E-AC3 issue in ricardo's ATV rom thread on the wetek forum, 1st post on January 25 (username: neel)

Do you think you could patch SPMC 16.7.2 to fix that issue ? (SPMC 16.7.2 was the only app with excellent video smoothness for dvb-t channels on the wetek play 2 with ricardo's ATV rom).

Thank you for all the work you are doing :)

Neel