Edit the frame rate of an avi file

Question

Is it possible to change the frame rate of an avi file using the Video for windows library? I tried the following steps but did not succeed. 1) AviFileInit 2) AviFileOpen(OF_READWRITE) 3) pavi1 = AviFileGetStream 4) avi_info = AviStreamInfo 5) avi_info.dwrate = 15 6) EditStreamSetInfo(dwrate) returns -2147467262.

Answer 1

I don't know anything about VfW, but you could always try hex-editing the file. The framerate is probably a field somewhere in the header of the AVI file.

Otherwise, you can script some tool like mencoder[1] to copy the stream to a new file under a different framerate.

[1] http://www.mplayerhq.hu/

Answer 2

HRESULT: 0x80004002 (2147500034)
Name: E_NOINTERFACE
Description: The requested COM interface is not available
Severity code: Failed
Facility Code: FACILITY_NULL (0)
Error Code: 0x4002 (16386)

Does it work if you DON'T call EditStreamSetInfo?

Can you post up the code you use to set the stream info?

Answer 3

I'm pretty sure the AVIFile* APIs don't support this. (Disclaimer: I was the one who defined those APIs, but it was over 15 years ago...)

You can't just call EditStreamSetInfo on an plain AVIStream, only one returned from CreateEditableStream.

You could use AVISave, then, but that would obviously re-copy the whole file.

So, yes, you would probably want to do this by parsing the AVI file header enough to find the one DWORD you want to change. There are lots of documents on the RIFF and AVI file formats out there, such as http://www.opennet.ru/docs/formats/avi.txt.