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View Full Version : Missing ~4 sec audio when using yadif


ryujin
3rd September 2009, 03:10
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The original file is a Canopus avi file:
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Input #0, avi, from '3109000451.avi':
Duration: 00:57:08.02, start: 0.000000, bitrate: 147477 kb/s
Stream #0.0: Video: CUVC / 0x43565543, 1920x1080, 29.97 tbr, 29.97 tbn, 29.97 tbc
Stream #0.1: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s

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My avisynth script:
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LoadPlugin("DirectShowSource.dll")
DirectShowSource("3109000451.avi")
ConvertToYV12
Trim(0, -0)
LoadCplugin("yadif.dll")
pointresize(width,height+(4), 0,-2, width,height+(4))
Yadif(mode=1, order=0)
Crop(0,2,-0,-2)
Crop(0, 0, -0, -0)
AddBorders(0, 0, 0, 0, $000000)


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The encoding command
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ffmpeg -i "3109000451.avi.avs" -threads 0 -vcodec libx264 -vpre default -r 29.97 -pix_fmt yuv420p -padtop 0 -padbottom 0 -padleft 0 -padright 0 -croptop 0 -cropbottom 0 -cropleft 0 -cropright 0 -sws_flags lanczos -s 1280x720 -b 2000000 -bt 2000000 -pass 2 -acodec aac -f mp4 "3109000451.mp4" -map 0:0 -map 0:1


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The problem
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When the original file is larger than 30 minutes the resulting mp4 has a hard silence at the last four seconds of the clip.

I tried a lot of diferent combinations and when removing the yadif the problem disappears.

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The question
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Has anyone experienced this? is this a bug of yadif, avisynth or ffmpeg? I tried with three different versions of ffmpeg including latest svn as today and the result is the same. I bet for yadif but I do not want to remove it as I get the best deinterlaced picture with it.


regards....

shoopdabloop
3rd September 2009, 03:14
First off, perhaps you should try a better alternative to DirectShowSource? I would like to help more than that, but I only work with avis and virtualdubmod.

burfadel
3rd September 2009, 08:41
When encoding AVI's I noticed ages ago that the audio may by cut off at the end of some files, and it happens quite frequently. Actually that is over more than one system, different installations and different OS's! but nobody seemed to corroborate my claim :) (I'm sure you could find it if you searched).

Some files are fine, but the length cut off of those that aren't are never the same, it could be a few seconds to 5 mins or more. The extracted audio from the avi file is the problem, I thought it was probably an issue with virtualdubmod and possible with vbr mp3 files?

Gavino
3rd September 2009, 11:46
What happens if you simply play the script (from beginning to end) in a player?
If the audio is intact in that case, it would show the problem is downstream of Avisynth.

ryujin
17th September 2009, 09:08
First off, perhaps you should try a better alternative to DirectShowSource? I would like to help more than that, but I only work with avis and virtualdubmod.


Can you specify a better source?? I use DirectSource because with it I can decode almost anything as long as I have the VistaCodec Pack installed. Also it can decode the Canopus AVI files that I require.


regards