[FFmpeg-user] Question for using blackdetect video filter

[Paul B Mahol]

On 1/26/13, Wu-bin Zhen <vvubin at gmail.com> wrote:
> On Fri, Jan 25, 2013 at 9:58 PM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
>
>> Wu-bin Zhen <vvubin <at> gmail.com> writes:
>>
>> > Thanks for the quick reply. I am using live http streaming,
>> > so it won't stop transferring data as long as the
>> > connection is alive.
>>
>> The following produces identical output here
>> for the http stream and a local file:
>>
>> $ ffmpeg -loglevel info -i
>> http://samples.ffmpeg.org/V-codecs/SVQ3/Vertical400kbit.sorenson3.mov -vf
>> blackdetect=d=0.1 -f null -t 10 -
>>
>> Please do not top-post here, it is considered rude.
>>
>> Carl Eugen
>>
>> _______________________________________________
>> ffmpeg-user mailing list
>> ffmpeg-user at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>>
>
> Thank you for the reminder. Now I learned this netiquette for English
> speakers and I will keep it in mind here.
>
> So after comparing with your sample, I think the blackdetect filter is not
> working with the non-stop streaming urls. My temporary solution is:
>> ./ffmpeg -i http://<non-stop-streaming-server>/live.flv -vcodec copy -an
> -t 5 ./blackvideo.flv
>> ./ffmpeg -v info -i ./blackvideo.flv -vf blackdetect=d=2 -f null -
>
> This works, but it has two issues: (1) causing more I/O access, (2) time
> delay for the black video detection.
> So I am trying hard to detect the black video without creating small files.
> Any suggestion will be appreciated.

The blackdetect gives output in info only at EOF.
_______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>