[MEncoder-users] Problem with DV AVIs decoded with dshow

[David Toole]

Hi everyone,

 

Long time reader, first time poster. Jon Drukman usually passes on anything he or I discover about some things. :-)

 

Anyhow, this is a problem I had long ago with mencoder on Win32 but we ran into the issue this week with mencoder on Linux.

 

The problem: When a DV AVI is decoded w/ dshow (the default decoder) the final file only has half of its screen showing. The right side is simply black. :-) Is this a known issue? I can replicate it on both Win32 and Linux, so wanted to point this out.

 

To resolve it for the time being, I have the system forcing mencoder to use the ffmpeg DV decoder and everything comes out fine.

 

Although, the overall encoding time is about 20% slower when using ffmpeg, but it could also be because using dshow it's only having to encode ½ the screen since the rest is just black.

 

Also, the instructions the mencoder docs have for making a QuickTime compatible H.264 using purely mencoder and mp4creator don't work so well when WMVHD is the source file (glad there are docs, though...I had to figure out a method a long time ago and think I found the original method using mencoder, ffmpeg (for audio), and mp4creator (since mp4box muxed files didn't work in QT half the time). Anyhow, the reason why is a bit weird and it honestly doesn't make sense to me but I do have a fix for it that I can post if anyone cares. Just let me know!

 

Dave