Date: Sat, 15 Apr 2006 01:53:06 -0400 From: Joe Auty <joe@netmusician.org> To: Joe Auty <joe@netmusician.org> Cc: freebsd-multimedia@freebsd.org Subject: Re: ffmpeg question Message-ID: <26EC8B9F-9627-4447-B20F-BF5743CBAEB8@netmusician.org> In-Reply-To: <AEB45AE1-6DDE-4D40-B05B-36CCEB9A7186@netmusician.org> References: <FAEBE9DA-2556-4F6E-9A50-3D9A22D42805@netmusician.org> <20060415051014.GA20238@puff.jakemsr.gom> <AEB45AE1-6DDE-4D40-B05B-36CCEB9A7186@netmusician.org>
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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"
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