Transcode: Difference between revisions
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== Recording from v4l == |
== Recording from v4l == |
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This example works on saa7134 cards, using the [[saa7134-alsa]] DMA module: |
This example works on saa7134 cards, using the [[saa7134-alsa]] DMA module under OSS emulation: |
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transcode -x v4l2,v4l2 -M 2 |
transcode -x v4l2=resync_margin=1:resync_interval=250,v4l2 -M 2 \ |
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-i /dev/video$DEV -p /dev/dsp$DEV -y ffmpeg -F h264 -c 00:$TIM \ |
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-g 640x480 -f 29.970,4 -u 1024,2 -w 800 -b 128 -Q 5 -e 32000,16,2 \ |
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-o $DIR/$FIL.avi |
--lame_preset medium -o $DIR/$FIL.avi |
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The trick here is to set the audio import to 32000,16,2 -- the parameters used by the DMA audio channel on the card, and thus by the 7134-alsa module. |
The trick here is to set the audio import to 32000,16,2 -- the parameters used by the DMA audio channel on the card, and thus by the 7134-alsa module. The resync parameters are borrowed from Francesco Romani's recent addition to the [http://www.transcoding.org/cgi-bin/transcode?Video4linux_Examples transcode wiki]; I've not yet had a chance to test them, but sync is a known problem without these parameters. |
Revision as of 21:45, 30 March 2006
Introduction
The transcode program provides an integrated framework for encoding and transcoding, bringing together a large number of multimedia projects under one umbrella.
Recording from v4l
This example works on saa7134 cards, using the saa7134-alsa DMA module under OSS emulation:
transcode -x v4l2=resync_margin=1:resync_interval=250,v4l2 -M 2 \ -i /dev/video$DEV -p /dev/dsp$DEV -y ffmpeg -F h264 -c 00:$TIM \ -g 640x480 -f 29.970,4 -u 1024,2 -w 800 -b 128 -Q 5 -e 32000,16,2 \ --lame_preset medium -o $DIR/$FIL.avi
The trick here is to set the audio import to 32000,16,2 -- the parameters used by the DMA audio channel on the card, and thus by the 7134-alsa module. The resync parameters are borrowed from Francesco Romani's recent addition to the transcode wiki; I've not yet had a chance to test them, but sync is a known problem without these parameters.