Hardware vs software encoders: Difference between revisions

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==Can you get raw video from hardware encoder cards?==
==Can you get raw video from hardware encoder cards?==


* For card combos where the decoder is on the PCI bus (Conexant Blackbird, Philips Empress, ATI Theatre, etc.), you can grab either the raw video or the compressed video. These cards register two devices, one for raw video (/dev/video0) and one for compressed (/dev/video1).
* For card combos where the decoder is on the PCI bus (Conexant Blackbird, Philips Empress, ATI Theatre, etc.), you can grab either the raw video or the compressed (MPEG2) video. These cards register two devices, one for raw video (/dev/video0) and one for compressed (/dev/video1).


* Cards with the encoder on the PCI bus ([[ivtv_devices |PVR-350/250]], DVB, etc.) only provide compressed streams. This is because the decoder is not accessable on the PCI bus, so you can't grab the raw stream from it.
* Cards with the encoder on the PCI bus ([[ivtv_devices |PVR-350/250]], DVB, etc.) only provide compressed streams. This is because the decoder is not accessable on the PCI bus, so you can't grab the raw stream from it.

Revision as of 06:16, 2 March 2006

Can you get raw video from hardware encoder cards?

  • For card combos where the decoder is on the PCI bus (Conexant Blackbird, Philips Empress, ATI Theatre, etc.), you can grab either the raw video or the compressed (MPEG2) video. These cards register two devices, one for raw video (/dev/video0) and one for compressed (/dev/video1).
  • Cards with the encoder on the PCI bus (PVR-350/250, DVB, etc.) only provide compressed streams. This is because the decoder is not accessable on the PCI bus, so you can't grab the raw stream from it.
  • Some cards have MPEG2 in their name, but have no hardware encoder. The card vendor bundles a software decoder (Windows only) with these.