Russell Treleaven wrote: > >> -----Original Message----- >> From: [EMAIL PROTECTED] >> [mailto:[EMAIL PROTECTED] On Behalf Of >> Darren Wilkinson >> Sent: Tuesday, April 15, 2008 4:47 PM >> To: User discussion about IVTV >> Subject: [ivtv-users] Converting FROM mpeg2 using 350's >> onboard decoding >> >> >> I'm considering buying the Hauppauge 350 to use as not only >> as a capture >> card but mainly to use the onboard mpeg2 decoder to speed up >> transcoding >> 720x576 "pal" recorded dvb and dvd streams to xvid. >> >> I'm using a low speed cpu due to wanting a silent setup. It is often >> clocked as less than 1Ghz so I can turn the fan speeds down. >> I want to >> know if there is some app (preferrably for linux but not necessarily) >> that can take the decoded stream and won't rely on being able to >> re-encode in realtime to avoid dropped frames. >> >> Can anyone help? >> > > I am curious how the mpeg2 decoder could be used to speed up the > tranformation to xvid. I guess that transcoders work something like > this. > > Decode the input stream to some intermediate representation. > Encode the intermediate representation to the output stream.
Yes but in this case the hardware would be doing the decoding rather than the cpu. > > The transcoder could go directly from one format to another but a ton > more code would need to be written to support the same number of > formats. > Standard definition DVB and DVD in the U.K are both 720x576*25i mpeg2 streams which the hardware decoder already supports. > <snip> > Also there are issues of audio video synchronization,decrypting the dvd > and possibly > Selecting the audio channels. > > Sounds like a fair bit of work even if the hardware supports it. Audio can be decoded seperately and easily and won't need resyncing if the first frame of the mpeg2 stream matches the first frame of the xvid stream. DVD decrypting is largely a "click here to decrypt" issue nowadays and stripping one audio and video stream from a vob is likewise. _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
