View Full Version : Idiot transcode question

January 2nd, 2011, 12:09 PM
On a new 10.10 install, transcode autodetect (btw all transcode jobs were failing until I went in and saved all the settings, no changes just had to save them???), transcode is INCREASING disk usage not decreasing it - 4.9GB becomes 7.2G???
ATM MP4 is setup as per default but doesn't this strike as being rather odd re disk usage?

ian dobson
January 2nd, 2011, 12:52 PM

Could it be that the transcoder isn't deleting the old files?

Ian Dobson

January 2nd, 2011, 07:12 PM
Not sure, would mythweb report file size of 7G if that was the case?

January 2nd, 2011, 07:15 PM
Not sure, would mythweb report file size of 7G if that was the case?

ian dobson
January 2nd, 2011, 08:14 PM

If mythweb is showing a larger size, then transcoding is actually increasing the file size.

Do you see anything interesting in your log files (/var/log/mythtv/)?

Ian Dobson

January 3rd, 2011, 04:14 PM
Hmm, something very odd, tried a transcode on another file to get a log to check and this time it's transcoded down fine. All I could see really in the log re te other file was some errors re audio and missed frames.

January 5th, 2011, 05:58 PM
Nope, it's definitely still doing it. file size increases every time:
Backend log


ian dobson
January 5th, 2011, 07:22 PM

OK, your transcoding to NUV format, NUV was the format that MythTV used to save videos in if the tuner card didn't support hardware encoding. NUV requires almost no CPU for playback (It's just jpeg compressed pictures) but the compression ratio for video is not that good.

Maybe try transcoding to x264 or mpeg4 format, that should reduce the file size alot, but it's really slow.

woops, it looks as if mythtranscode doesn't support many formats:-

/usr/bin/mythtranscode <--chanid <channelid>>
<--starttime <starttime>> <--profile <profile>>

--mpeg2 or -m: Perform MPEG2 to MPEG2 transcode.
--ostream <type> or -e: Output stream type. Options: dvd, ps.
--chanid or -c: Takes a channel id. REQUIRED
--starttime or -s: Takes a starttime for the
recording. REQUIRED
--infile or -i: Input file (Alternative to -c and -s)
--outfile or -o: Output file
--profile or -p: Takes a profile number or 'autodetect'
recording profile. REQUIRED
--honorcutlist or -l: Specifies whether to use the cutlist.
Optionally takes a cutlist as an argument
when used with --infile.
--inversecut : Specifies a list of frames to keep
while cutting everything else out.
Only works with --infile.
--allkeys or -k: Specifies that the output file
should be made entirely of keyframes.
--fifodir or -f: Directory to write fifos to
If --fifodir is specified, 'audout' and 'vidout'
will be created in the specified directory
--fifosync : Enforce fifo sync
--buildindex or -b: Build a new keyframe index
(use only if audio and video fifos are read independantly)
--video : Specifies that this is not a mythtv recording
(must be used with --infile)
--showprogress : Display status info to the stdout
--recorderOptions <OPTIONS>
or -ro: Pass a comma-separated list of
recordingprofile options to override
values in the database.
--verbose level or -v: Use '-v help' for level info
--help or -h: Prints this help statement.

Maybe try playing with the transcoder profiles.

Ian Dobson

January 6th, 2011, 12:04 AM
Hmm. OK I'll check it out. It's supposed to be set for mpeg4 though afaik , just the defaults from the install. Nothing has been changed apart from it wouldn't tx at all for a start until I went into them all and clicked through till finish.