[mythtv-users] Re: Bit Rates. [Was Commercial Flagging vs. Transcoding]

[Jeff]

At 05:04 PM 2/18/2004 -0500, you wrote:
>John DeLuca wrote:
>
>>I currently transcode all recordings (set to kick off immediately 
>>following completion of recording).  I don't intend to save the files...I 
>>merely transcode to have the commercials flagged so when I watch them 
>>later, I can skip past them (assuming it's done a good job of properly 
>>detecting commercials).
>>
>>In reading another post, I am wondering if I really need transcoding?
>>I have a PVR-x50 and the recording profiles are set up for MPEG2- at 2200 
>>bits for 720x480.  That's also the setting of transcoding.  My questions are:
>
>Bit rates are bit rates.  To benefit from transcoding you want to lower 
>the bit rate.  MPEG4 can produce better looking images at lower 
>bitrates.  2200 is REALLY low for the resolution you're capturing your 
>MPEG2 stream at.  Try 440x480 at that bitrate and you'll notice a nice 
>improvement in image quality for "free" (assuming you're capturing NTSC)

I've seen various posts from different people about resolution v. bitrate and
MPEG2 v. MPEG4. I've done a lot of playing around with this and I have settings
that work well but is there some rule of thumb people have for choosing values
for these settings?