[mythtv-users] WatchingLiveTV mode depends on encoders?
Joseph A. Caputo
jcaputo1 at comcast.net
Tue Mar 22 18:02:20 UTC 2005
On Sunday 20 March 2005 17:25, Justin Gombos wrote:
> Does it make sense to you folks that watching live tv would require
> encoders to be running?
Yes. Perhaps you've been under a misleading impression all this time.
When you tested your card with xawtv, all you did was verify that the
card works. Myth is much more complex than xawtv. Xawtv simply takes
the raw incoming signal and overlays it onto your video ouput (screen).
Myth, in order to support time-shifting (pause, rewind) of LiveTV,
takes the incoming signal, encodes it as either MPEG-4 or RTjpeg, and
writes it to a ringbuffer on the disk. Then the frontend (playback)
reads the ringbuffer, decodes the stream from disk and plays back the
decoded video & audio.
> I'm not sure what the backend is instructing me when it says:
> Please go into the TV Settings, Recording Profiles and setup the
> four 'Software Encoders' profiles.
> I went there, and there already was a profile group for "Software
> Encoders (v4l based)" and "Transcoders". I created a new group
> anyway, and it didn't change anything. Now I'd like to erase what I
> just created, but there seems to be no option for that.
It's not enough that the group just exist. You need to go through the
"Software Encoders" group and configure the individual settings
(especially for "LiveTV", since that's what you're testing). At
minimum, you should configure the settings for:
Software Encoders (v4l based)
For each profile, you need to specify the video capture resolution,
video codec (MPEG-4 or RTjpeg), video bitrate/quality, audio codec (raw
or mp3), and audio bitrate/quality. For you system (rather
underpowered, IIRC), I'd suggest using RTjpeg, as it takes less
horsepower to encode.
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