[FFmpeg-user] converting a video without sound : Error while opening encoder for output stream #0.1

[dE .]

On 02/15/12 16:40, Access-Dev wrote:
> Hello,
>
> I m using FFMPEG to convert some videos that comes from a Wowza 
> streaming server.
>
> For some reasons, some videos dont have sound and ffmpeg dont want to 
> convert them
>
> Video with sound:
>
>  /usr/bin/ffmpeg -loglevel 0 -i 
> /usr/local/WowzaMediaServer-3.0.4/content/167.flv.flv -ar 44100 -b 
> 700k -sameq -f avi -r 24 -ab 160k 167.avi
>
>
> Result :   OK
>
> Stream mapping:
>   Stream #0.0 -> #0.0
>   Stream #0.1 -> #0.1
>
> Press [q] to stop encoding
> frame=  141 fps=  0 q=0.0 Lsize=    1480kB time=10.97 
> bitrate=1104.8kbits/s dup=0 drop=8
> video:1239kB audio:214kB global headers:0kB muxing overhead 1.800813%
>
> Videos infos:
>
>  Duration: 00:00:11.33, start: 0.000000, bitrate: N/A
>     Stream #0.0: Video: flv, yuv420p, 320x200, 1k tbr, 1k tbn, 1k tbc
>     Stream #0.1: Audio: nellymoser, 44100 Hz, mono, s16
>
>
> Video without sound:
>
> /usr/bin/ffmpeg -loglevel 0 -i 
> /usr/local/WowzaMediaServer-3.0.4/content/169.flv.flv -ar 44100 -b 
> 700k -sameq -f avi -r 24 -ab 160k 169.avi
>
> Stream mapping:
>   Stream #0.0 -> #0.0
>   Stream #0.1 -> #0.1
> Error while opening encoder for output stream #0.1 - maybe incorrect 
> parameters such as bit_rate, rate, width or height
>
> Videos infos:
>
>  Duration: 00:00:11.24, start: 0.000000, bitrate: N/A
>     Stream #0.0: Video: flv, yuv420p, 320x200, 1k tbr, 1k tbn, 1k tbc
>     Stream #0.1: Audio: [0][0][0][0] / 0x0000, 0 channels
>
>
> How can I tell ffmpeg to create an empty audio track if the source 
> video dont have sound ?

-an, but this should not happen. What's the output of ffprobe on the 
file, and can you play it using ffplay.