[FFmpeg-user] Could not write header for output file #0 (incorrect codec parameters ?)

Carl Eugen Hoyos cehoyos at ag.or.at
Mon Jul 20 17:02:28 CEST 2015

MrNice <wxcvbn2006 <at> iol.ie> writes:

> [video4linux2,v4l2  <at>  0x1d33fa0] Thread 
> message queue blocking; consider raising the 
> thread_queue_size option (current value: 8)

> Thread message queue blocking;
> What does this warning mean? 

> How to remove it?

Are you sure that you read the message?

> The objective is to get lossless audio and video 

Just to make sure: Do you mean video and 
lossless audio?

> from what the Dazzle DVC100 provide.

> AFAIK, yuyv422 is better than yuv420p. I tried to 
> use yuyv422 but I have the error:
> Incompatible pixel format 'yuyv422' for codec 
> 'mpeg4', auto-selecting format 'yuv420p'
> What is the codec I could use the get 422?

-vcodec mpeg2video supports 4:2:2 subsampling.

> Is my ffmpeg command good to get the best quality?

No, it is missing -qscale 2 -mbd 2
(if you don't want to use libx264).

Carl Eugen

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