Date: Sat, 15 Apr 2006 21:29:40 -0400 From: Joe Auty <joe@netmusician.org> To: Vayu <vayu@sklinks.com> Cc: freebsd-multimedia@freebsd.org Subject: Re: ffmpeg question Message-ID: <36B5D0D3-2A8C-489B-A190-63084D9EC962@netmusician.org> In-Reply-To: <200604151804.16919.vayu@sklinks.com> References: <FAEBE9DA-2556-4F6E-9A50-3D9A22D42805@netmusician.org> <26EC8B9F-9627-4447-B20F-BF5743CBAEB8@netmusician.org> <87716498-15A6-45D5-8FB2-1D4485C592A1@netmusician.org> <200604151804.16919.vayu@sklinks.com>
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On Apr 15, 2006, at 9:04 PM, Vayu wrote: > On Friday 14 April 2006 23:11, Joe Auty wrote: >> Got it! >> >> This bug is fixed in ffmpeg-devel... >> >> I think I'm good now. >> >> >> I hope my thinking through this problem outloud on the list will be >> of some use to some, and not simply spam. I'll try to be quiet now =) >> > > > Well if you're offering use to others I have two questions. > > What is /dev/cxm0, is it your video camera? No, it's a Hauppauge PVR 250 (video capture card) > What do you mean "fixed in ffmpeg-devel", do you mean you can > compile a newer > version? My particular problem was an issue in the FreeBSD ffmpeg port, but not in the FreeBSD ffmpeg-devel port. > > > >> On Apr 15, 2006, at 1:53 AM, Joe Auty wrote: >> >>> Okay, I think I figured this out.... almost: >>> >>> ffmpeg -i /dev/cxm0 -vcodec copy -acodec copy -t 20 test_ffmpeg.mpg >>> >>> >>> Except doing this completely ignores my -t 20 and keeps on >>> recording after 20 seconds... why is that? >>> >>> >>> On Apr 15, 2006, at 1:14 AM, Joe Auty wrote: >>> >>>> >>>> On Apr 15, 2006, at 1:10 AM, Jacob Meuser wrote: >>>> >>>>> On Fri, Apr 14, 2006 at 11:54:18PM -0400, Joe Auty wrote: >>>>>> Hello, >>>>>> >>>>>> Doing a: >>>>>> >>>>>> cat /dev/cxm0 > myvideo.mpg >>>>>> >>>>>> produces great mpeg2 video... However: >>>>>> >>>>>> ffmpeg -i /dev/cxm0 -t 10 test_ffmpeg.mpg >>>>>> >>>>>> produces 10 seconds of mpeg1 video that doesn't look as good. >>>>>> >>>>>> >>>>>> I've tried adding -f <format> and -vcodec options with -s >>>>>> 640x480, >>>>>> but I just can't seem to find something that will reproduce my >>>>>> raw >>>>>> feed without errors, loss of picture, the size being off, or >>>>>> reverting back to mpeg1. >>>>>> >>>>>> To save me a little further time in just random trial and error, >>>>>> can >>>>>> anybody hook me up with the combination I need? >>>>> >>>>> sorry, but what exactly are you trying to do? what is lacking >>>>> with >>>>> the cat command? >>>>> >>>>> most likely, if you are running a transcoder (like ffmpeg, >>>>> mencoder >>>>> or transcode), it is decoding the input into raw YUV or RGB and >>>>> then >>>>> back to MPEG. this is a lossy and time/cpu consuming process. >>>>> >>>> >>>> The cat command works perfectly, but I'm trying to script it, and >>>> since you can use ffmpeg to specify how many seconds of footage to >>>> capture I'm trying to make this work. >>>> >>>> According to Quicktime's Get Info, the cat files are mpeg2... I'd >>>> like to know the best way to preserve the same quality from the >>>> cat command using ffmpeg. >>>> >>>> Am I starting to make sense now? >>>> >>>> >>>> _______________________________________________ >>>> freebsd-multimedia@freebsd.org mailing list >>>> http://lists.freebsd.org/mailman/listinfo/freebsd-multimedia >>>> To unsubscribe, send any mail to "freebsd-multimedia- >>>> unsubscribe@freebsd.org" >>> >> >> _______________________________________________ >> freebsd-multimedia@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-multimedia >> To unsubscribe, send any mail to > "freebsd-multimedia-unsubscribe@freebsd.org" >>
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