[MPlayer-users] MOV Dimensions Not Set Error

[Larry Reznick]

RC wrote:
> On Wed, 13 Jun 2007 09:27:53 -0700
> Larry Reznick <lreznick at idistream.com> wrote:
>
>   
>> 1. Why is it skipping frames or calling out duplicate frames, which it
>> does from frame 125 on for nearly all the frames following?
>>     
>
> You didn't use -mc 0 and -noskip.  Tends to be a problem when copying
> video, or using an external audio file, and you're doing both.  I
> believe this is in the FAQ and HTML docs.
>   

You're right. When I rechecked (20/20 hindsight), there it was in the 
sync section. I've been so focused on the video issues that when I got 
the sync errors, I didn't check further on that in particular. Thanks!


>> 2. When playing the muxed result, the frame rate is correct until the 
>> next VUI comes along. Then, the frame rate goes back to the ~15 fps 
>> (15000:1001) instead of staying with the ~30 fps (30000:1001)
>> requested  during the encoding. Shouldn't mencoder's -ofps override
>> whatever the  VUI says?
>>     
>
> You're copying the video, unmodified, not reencoding, so no, probably
> not.
>
> Also, I'm not sure using a colon ':' is valid for ofps.
>   

I think my own misunderstanding was that the -ofps would affect the 
facts written into the container's headers. From what you're saying, it 
applies only to the encoding stage. Because I'm not encoding, it's 
irrelevant, so I'll cut out the -ofps.

BTW, without looking at the code for the use of the colon, because I 
know that the -fps uses the colon, it just seems to me that both methods 
would use the same parser and colon works for -fps. However, it's moot 
because I'm going to cut out use of -ofps.

I ran the command like this:

~/download/mplayer/mencoder -fps 30000:1001 gow_2000.264 -ovc copy 
-audiofile gearsofwar_g264_2000.wav -mc 0 -noskip -o gow_2000.mov -of 
lavf -lavfopts i_certify_that_my_video_stream_does_not_use_b_frames -oac 
mp3lame -lameopts abr:br=64

and it worked without complaint. Playing it back shows perfect sync and 
no picture deterioration during the 1st VUI or any of them for that 
matter. Also, the container's 30000:1001 frame rate overrode the VUIs' 
(mistaken) half rate settings during play back.

BTW, I ran the same command line to produce an AVI file format except 
that I cut out the -of and -lavfopts settings and that worked correctly, 
too, except for a complaint about the aspect information. I tried adding 
a -aspect option, but that didn't make a difference. Still the result 
played correctly. I'll try both output containers on a Windows player 
and see how they look.

Thanks, RC.

BTW, I just did an svn update and got 23557. The libmpdemux/video.c 
didn't update, so nobody yet incorporated my changes for the missing 
disp_w & disp_h settings I mentioned before. Was I correct to make that 
change in that module or should that go somewhere else?

--Larry