video slows down on full CPU utilization, but audio does not

Started by zhangweiwu, August 23, 2014, 01:33:38 PM

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zhangweiwu

When CPU is full, video slows down on playback, but on my avidemux3_qt 2.6.8 audio does not slow down (Pulse audio of OpenSUSE 13.1). For a 8.7s clip, audio finishes at around 6.9, followed by two seconds of silent video.

The intuitive behaviour is either audio slows down too, making women's sound like men, or extend the audio in some means, e.g. repeat the last 1ms for every 10ms of audio. Right?

Anyway, the current behaviour is confusing and editing is impossible. Is there a workaround? Thanks. (One workaround is to activate hardware decoding, which I did unsuccessfully, see my other post).

Jan Gruuthuse

see your other post, tried to give you some answers.
To give you impression of video decoding en slider action: download this video Avidemux263EditCutTrim.mp4 34.8 MB https://www.dropbox.com/s/3idao0bju5j5mbm/Avidemux263EditCutTrim.mp4?dl=1

zhangweiwu

I think these are two seperate problems: one being that audio and video are out of sync during playback when CPU can't catch-up (they should remain synced even if CPU can't catch up), the other being video decoding HW acceleration for freeing CPU seems not working. My follow up will try to maintain the topics seperated by threads. This one is about the first problem.

Quote from: Jan Gruuthuse on August 23, 2014, 03:07:08 PM
"audio finishes 25% ahead of video when I play the source media before attempting to edit at all".
Do check in Avidemux preferences on Audio TAB: Local playback downmixing: Stereo or any other setting here and see what works best for you.

I tried all of these options: none/Stereo/Pro Logic/Pro Logic II. They all results my audio finishing 25% ahead of the 1080p video.

The video I am working on is here (one of them):
ftp://realss.6600.org/Downloads/fetch/IMG_0409.MOV

Quote
Check if this 720p4audioTracks3sat video is playing without audio delay correct audio. 69 MB: https://www.dropbox.com/s/a8scxh0m134zxh0/720p4audioTracks3sat.ts?dl=1
Video is multi track if audio delay, switch to track 1, track 0 is AC3

This clip I can playback without video delay, that is, audio does not finish before video, they end at the same full stop.

Jan Gruuthuse

Quote from: zhangweiwu on August 23, 2014, 05:21:37 PM
The video I am working on is here (one of them):
ftp://realss.6600.org/Downloads/fetch/IMG_0409.MOV
This clip I can playback without video delay, that is, audio does not finish before video, they end at the same full stop.
The connection has timed out

The server at realss.6600.org is taking too long to respond.

Tried several times today: can't get access to your clip.
As the multiple audio track clip plays fine audio wise. Probably cause: kind of video clip used in relation with hardware and setup of avidemux 2.8.6.

Follow developer mean's advice given in your other thread. Could be afterall these are related issues.