Avisynth Error: flv cannot be opened in VirtualDub / YV12 frame not mod2

[KyaniteD]

I downloaded some flv videos to get a closer frame-by-frame look at them in VirtualDub.

When I open them in flv-player, they all show up as 320x240 and play just fine. They are all from the same site, supposedly encoded in the same format/bitrate/dimension...

When I use an avisynth script to open them in VirtualDub, some open and some don't. Those that don't cause the error message:

Avisynth read error: Attempted to request an YV12 frame that wasn't mod2 in width and height.

As I learned from a brief google search, dimensions must be dividable by 4, and indeed: For the flv files that don't open/show in V-Dub, V-Dub reports a height of 239 instead of 240.

I don't want to convert the files, for fear of losing even more quality/resolution.

Is there anything I can do to fix the height or open them in VirtualDub, anyway? (They don't open in V-DubMod, either.)


PS: The avisynth scrypt:

#ASYNTHER FLV 29.76fps
DirectShowSource("<filepath>", fps=29.76, convertfps=true)

FFDshow is set to use libavcodec for FLV1.
Installed Codec Pack: CCCP
Additional Codecs: Divx, CoreAVC h.264, Xvid

[Soopafresh]

You can open them up directly in Vdubmod. Demux

http://www.moitah.net/download/latest/FLV_Extract.zip


Make sure you have ffdshow installed and you have FLV1 decoding by Libavcodec in the settings.

Your other option is to batch resize and convert to uncompressed video via ffmpeg. Pretty easy - Download this version of ffmpeg http://www.paehl.com/open_source/?download=ffmpeg.zip

Save the following as Convert.cmd

convert.cmd

It is just one line which resizes and converts the flv files into uncompressed AVIs.
for %%a in (*.flv) do ffmpeg -i "%%a" -vcodec rawvideo -s 320x240 -acodec copy -b 600 "%%~na.avi"

Note - The uncompressed file can be 100x the size of the source!

You can convert instead to high bitrate Xvid instead, ala

for %%a in (*.flv) do ffmpeg -i "%%a" -vcodec xvid -qscale 1 -s 320x240 -acodec copy "%%~na.avi"

[KyaniteD]

Nifty! Many thanks!

[jagabo]

Try

#ASYNTHER FLV 29.76fps 
DirectShowSource("<filepath>", fps=29.76, convertfps=true)
#if frame height an odd value add a line to make it even:
Addborders(0, 0, 0, 1)

Although I'm not sure AVISynth will let you do that with a YV12 source. You might try converting to YUY2 first:

#ASYNTHER FLV 29.76fps 
DirectShowSource("<filepath>", fps=29.76, convertfps=true)
#if frame height an odd value add a line to make it even:
ConvertToYUY2()
Addborders(0, 0, 0, 1)

[Soopafresh]

No prob - Had to modify the xvid parameters. They're correct now. Resulting Xvid files are 8X the size of the flvs

[theewizard]

I might catch some 'flame' for this suggestion

but try super, I have used it to convert flv to mp4 or 3g2 keeping the resolution or changing the size ( smaller not bigger )

the results have been satisfactory , even your 239 error producing flv will convert in super

[KyaniteD]

Thanks for the help guys, you're zee awesomest. XD

@Jagabo - both didn't work. Just adding the border got me the same error message, and including the conversion got me the error message that conversion isn't possible if the height value is an odd number. It suggested to crop first and then convert... (Just for future reference.)

@Soopafresh - As so often the first thought is the best - flv-extract is the perfect solution for my problem and what I want to do.

@threewizard - Yeah, I have Super, and I would have used it had there not been any other solution. I wouldn't know why it should get you flamed... it's just a GUI combining several decoders and encoders...


Again, many thanks! *bows and ducks out*