Doom9's Forum - View Single Post - Encoding damaged video with ffmpeg : audio desynchronisation

Kivenkantaja · 14th July 2014, 18:05

Hello,

a few years ago, I've captured (with Huffyuv codec) movies from an old camera (analog source). Then, I converted them to DV format (audio in FLAC), which I call "masters".

However, some of the sources where damaged...

Now, I want to convert my masters (DV) to accessible standards (x264) to share with family.

I use AviSynth for several treatment (Trim, TomsMoComp, Crop, LanczosResize, ConvertToYV12, Convolution3D, Blur) and encode them with ffmpeg.

It's working well with non-damaged sources.

But, with the damaged sources, the audio is coming much later than the video.

I guess that the damaged framed are "dropped" or something like that...

I could use some Delay() function on my avs Script but that's not a relevant option...

I tried some -vsync, -async, -r 25 option, without result (anyway, I'm not sure is I'm using them well)

As a test, I converted directly the DV sources to x264 : I don't have any desynchronisation. So there is something with the avs Script and the ffmpeg command I guess.

My ffmpeg command line is the following :
ffmpeg -i !SRC! -map 0 -c copy -c:v libx264 -preset faster -crf 20 -profile:v high -level:v 4.1 -c:a:0 libfdk_aac -b:a 128k !DST!

Actually, I don't where to start... Any clue is welcome !

Thanks in advance !

14th July 2014, 18:05	#1 \| Link
Kivenkantaja Registered User Join Date: Feb 2009 Posts: 14	Encoding damaged video with ffmpeg : audio desynchronisation Hello, a few years ago, I've captured (with Huffyuv codec) movies from an old camera (analog source). Then, I converted them to DV format (audio in FLAC), which I call "masters". However, some of the sources where damaged... Now, I want to convert my masters (DV) to accessible standards (x264) to share with family. I use AviSynth for several treatment (Trim, TomsMoComp, Crop, LanczosResize, ConvertToYV12, Convolution3D, Blur) and encode them with ffmpeg. It's working well with non-damaged sources. But, with the damaged sources, the audio is coming much later than the video. I guess that the damaged framed are "dropped" or something like that... I could use some Delay() function on my avs Script but that's not a relevant option... I tried some -vsync, -async, -r 25 option, without result (anyway, I'm not sure is I'm using them well) As a test, I converted directly the DV sources to x264 : I don't have any desynchronisation. So there is something with the avs Script and the ffmpeg command I guess. My ffmpeg command line is the following : ffmpeg -i !SRC! -map 0 -c copy -c:v libx264 -preset faster -crf 20 -profile:v high -level:v 4.1 -c:a:0 libfdk_aac -b:a 128k !DST! Actually, I don't where to start... Any clue is welcome ! Thanks in advance !