Hello,
I got streaming working using a named pipe on Windows. Great!
The camera (Allied Vision) is streaming 80fps to the pipe.
I'm reading from the pipe like this:
ffmpeg -y -vcodec rawvideo -f rawvideo -hide_banner -s 658x492 -pix_fmt gray
-i \\\\.\\pipe\\Pipe -vsync vfr out.avi
The output video seem to have all the frames and the output looks good.
However, the video plays about 3.5 times slower than the input!?
The output from ffmpeg when running looks like this:
Input #0, rawvideo, from '\\.\pipe\Pipe':
Duration: N/A, start: 0.000000, bitrate: 64747 kb/s
Stream #0:0: Video: rawvideo (Y800 / 0x30303859), gray, 658x492, 64747
kb/s, 25 tbr, 25 tbn, 25 tbc
Stream mapping:
Stream #0:0 -> #0:0 (rawvideo (native) -> mpeg4 (native))
Press [q] to stop, [?] for help
[swscaler @ 0000014f03772000] Warning: data is not aligned! This can lead to a
speed loss
Output #0, avi, to 'out.avi':
Metadata:
ISFT : Lavf58.33.100
Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 658x492, q=2-31,
200 kb/s, 25 fps, 25 tbn, 25 tbc
Metadata:
encoder : Lavc58.59.101 mpeg4
Side data:
cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: N/A
frame= 327 fps= 81 q=5.8 size= 518kB time=00:00:13.08 bitrate=
324.1kbits/s speed=3.22x
and the last 'frame':
frame= 401 fps= 66 q=8.3 Lsize= 704kB time=00:00:16.04 bitrate=
359.6kbits/s speed=2.65x
I also tried -r 80, instead of the -vsync vfr, but the result is the same..
Any helpers appreciated!
-tk
> -----Original Message-----
> From: ffmpeg-user [mailto:[email protected]] On Behalf Of Carl
> Eugen Hoyos
> Sent: Tuesday, October 01, 2019 10:55 AM
> To: FFmpeg user questions <[email protected]>
> Subject: Re: [FFmpeg-user] Piping example?
>
> Am Di., 1. Okt. 2019 um 19:53 Uhr schrieb Totte Karlsson <[email protected]>:
> >
> >
> > > Did you try the following?
> > >
> > > $ ffmpeg -f lavfi -i testsrc -f rawvideo -
> > >
> > > and:
> > >
> > > $ ffmpeg -f rawvideo -s 320x240 -pix_fmt rgb24 -i - out.avi
> > >
> >
> > I did not test that but will test later today. My bitmaps are
> > 658 x 492 and are greyscale 8 bits and are acquired at 100fps.
>
> You asked for an example.
>
> > I assume the line
> > > $ ffmpeg -f lavfi -i testsrc -f rawvideo -
> >
> > means streaming to standard out?
>
> Yes.
>
> Carl Eugen
> _______________________________________________
> ffmpeg-user mailing list
> [email protected]
> https://ffmpeg.org/mailman/listinfo/ffmpeg-user
>
> To unsubscribe, visit link above, or email [email protected] with
> subject "unsubscribe".
_______________________________________________
ffmpeg-user mailing list
[email protected]
https://ffmpeg.org/mailman/listinfo/ffmpeg-user
To unsubscribe, visit link above, or email
[email protected] with subject "unsubscribe".
