[FFmpeg-user] Pipe to ffplay when recording: syntax

[Andy Furniss]

MrNice wrote:
>
>
> On 26/11/15 11:38, MrNice wrote:
>> Hi,
>>
>> When I run the command
>>
>> ./ffmpeg -debug 1 -f pulse -ar 44100 -ac 2 -channel_layout stereo
>> -thread_queue_size 1024 -i alsa_input.pci-0000_00_14.2.analog-stereo -f
>> v4l2 -use_wallclock_as_timestamps 1 -itsoffset 1.70 -channel 1
>> -video_size 720x576 -pix_fmt yuyv422 -thread_queue_size 1024 -i
>> /dev/video0 -c:a pcm_s16le -channel_layout stereo -c:v ffv1 -level 3 -g
>> 1 -aspect 4:3 -pix_fmt yuv422p -top 0 -vsync passthrough
>> /Store3/Test/t_`date +%Y%m%d_%H%M`.mkv
>>
>> I have a perfect output without any error but I don't have preview.
>> When I add
>>
>> -aspect 4:3 -f sdl "Dazzle output"
>> at any position I get the well known RED error message
>>
>> Application provided invalid, non monotonically increasing dts to muxer
>> in stream 0:
>>
>> I know it's very difficult to get ride of this error, so there could be
>> a workaround: pipe the output file to ffplay.
>>
>> Unfortunately I can't find the syntax when the output is a file but only
>> when this is a raw video stream.
>> Could you help me for that?
>>
>> Many thanks
>>
>
> I was thinking the answer easy but maybe not.
>
> I tried all combinations in this page but didn't succeed
> http://superuser.com/questions/322216/how-can-i-pipe-output-of-ffmpeg-to-ffplay
>
> -f rawvideo - | ffplay -f rawvideo -
> pipe:1 | ffplay -i -
> -f matroska - | ffplay -
> pipe:play | ffplay -i pipe:play
> and more
>
> Is it so difficult to get it?

If you use rawvideo you need to say what it is.

Works for me with a quick desktop grab test -

ffmpeg -f x11grab -r 10 -s 128x128  -i :0.0 -f rawvideo - | ffplay -f 
rawvideo -s 128x128 -pix_fmt bgr0 -