On 14/09/05, Michael T. Dean <[EMAIL PROTECTED]> wrote: > Brian McEntire wrote: > > > I'm recording OTA HDTV with a PC HD-3000 card. > > > > The video quality looks perfect, rarely pixelates, but the audio is > > very bad: it sounds choppy, echos frequently, and has a pulsing > > quality to it. > > > > I'm recording on a P3 1.6 with 768 MB RAM. From what I understand, > > recording OTA HDTV doesn't take a lot of resources because the card is > > just capturing the (already encoded) MPEG2 stream from within the ATSC > > broadcast. > > > > I think the problem does lay in the capture side though because even > > if I transcode a captured show to xvid using nuvexport, the audio > > still sounds the same on playback and I think those transcoded formats > > wouldn't tax the CPU enough to cause audio problems. > > Actually, MPEG-4 (DivX, XviD, etc.) requires more resources to decode > than MPEG-2. Basically, the higher the compression, the harder your CPU > has to work (for both compression and decompression). H.264 gives even > more compression than MPEG-4, but will put the the best-on-the-market > general-purpose CPU's to the test for decoding a 1920x1080 stream. > > So, how about fessing up--what kind of system are you using to play back > the video? Have you tried playing it back in other players (i.e. > MPlayer or xine)? Have you tested it on a Windows machine? It sounds > to me like a playback problem since--as you correctly observed--HDTV > capture is just writing the already-encoded MPEG-2 stream to disk.
I'd second a playback or transcoding issue rather than a capturing problem. DVB here in the UK (like HDTV in the US) is 'recorded' by 'dumping' the broadcast streams to disk 'as they are' - so no additional manipulation of the streams is carried out. I'd check your audio config (are you using OSS or ALSA) and connections (how are you listening to the audio? SPDIF or analog connection?) I'd also check the specs of your transcoding output - try using 720x480 with stereo audio and see if anything improves. Nick _______________________________________________ mythtv-users mailing list mythtv-users@mythtv.org http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
