[FFmpeg-user] difference between filter_complex and vf

[Atli Thorbjornsson]

On 3 June 2012 07:34, Nicolas George <nicolas.george at normalesup.org> wrote:

> amerge is used to merge several audio channels together, and you are
> plugging it to the output of the overlay filter, i.e. video. That does not
> make sense. Try '[0:1][1:1] amerge'.
>

Thanks for you help NIcolas, so I tried the following

ffmpeg -i test1.flv  -i test2.flv -filter_complex
'[0:0]scale=iw/2:ih/2,pad=2*iw:ih[left];[1:0]scale=iw/2:ih/2[right];[left][right]overlay=main_w/2:0;[0:1][1:1]
amerge' out.flv

It returns

[buffersink @ 0xa1255c0] No opaque field provided
[abuffersink @ 0xa066920] No opaque field provided, an AVABufferSinkParams
struct is required

Thanks for your help, I'm really groping in the dark here.

Atli.