[mythtv] Re:Transcoding pvr-250 files
vintonc at redzone.com
Sat Aug 30 13:48:41 EDT 2003
So I updated mythtv CVS (Aug 30 @ 1:00 a.m. EDT) with the -C option to
overwrite the changes I had made and pick up the commits Isaac had
made. Here's the latest results.
None of the settings have changed for capture or transcoding (see my
first post for the exact settings).
I edited the cutlist (some channels seem to lend themselves to
automatic commercial detection better than others). It was Boston
Public (1 hour show).
The good: The audio seems to match the original. The changes I tried
earlier seemed to cause the audio pitch to be lower. The commercials
have be cut out. The video seems really good too. None of the odd lip
movements described above.
The odd: The transcoded file isn't significantly different in size.
Saving only 14.35 MB after cut out all of the commercials! The files
were captured at 4/8 Mbps bitrate/peak bitrate 720 x 480 and transcoded
to 4 Mbps mpeg-4 (see first post for all settings) at 640 x 480.
Shouldn't it save 25% - 30% by removing 15 - 20 minutes of a 60 minute
for the 1 hour show.
# ls -la |grep '20030829210000_20030829220000'
-rw-r--r-- 1 mythtv mythtv 2094915330 Aug 30 11:45
-rw-r--r-- 1 mythtv mythtv 2109267904 Aug 29 22:00
-rw-rw-r-- 1 mythtv mythtv 32495 Aug 30 01:31
similar results for 30 minute show. More precise timing.
Original length 29:56
edited length 21:33 (timed while watching original w/cutlist)
displayed total elapse time 10:44
ls -la |grep '1024_20030829220000_20030829223000'
-rw-r--r-- 1 mythtv mythtv 980055361 Aug 30 12:13
-rw-r--r-- 1 mythtv mythtv 1052573632 Aug 29 22:30
-rw-rw-r-- 1 mythtv mythtv 33286 Aug 30 01:31
The same: Elapse time still not right. Skipping forward one 30 second
increment yields about a 62-63 second skip real time but is indicated
as a 30 increment in the timer. I would expect this since the total
elapse time is 23:02 instead of ~47:00.
Let me know if you need more info or want something tested.
More information about the mythtv-dev