[mythtv-users] Mythtranscode TRASHES file to 123KB when re-encoding with cut list

[Jeffrey J. Kosowsky]

Jeffrey J. Kosowsky wrote at about 19:30:38 -0400 on Tuesday, May 24, 2011:
 > Jeffrey J. Kosowsky wrote at about 16:59:09 -0400 on Tuesday, May 24, 2011:
 >  > Jeffrey J. Kosowsky wrote at about 16:13:00 -0400 on Monday, May 23, 2011:
 > Specifically:
 > 1. transcoding with and without cutlists work fine on the original
 >    recording
 > 2. transcoding with cutlists truncates & destroys the recording when
 >    done on an mpeg4 recording (that has already been transcoded from
 >    mpeg2).
 >    However, transcoding without cutlists works fine in mpeg4
 >    recordings.
 > 
 > So, somehow the problem seems to be restricted to (re)transcoding
 > mpeg4 recordings with cutlists!
 > 
 > Note that I never used to have such problems so something has
 > definitely broken in the past 6 months or so...

Some more troubleshooting... the problem is definitely with the
cutlist...

Looking at the code in transcode.cpp and comparing the log output
between the case with and without --honorcutlist, it appears that the
key difference is:

For the --honorcutlist case:
        copyvideo = true;
        VERBOSE(VB_GENERAL, "Reencoding video in 'raw' mode");
Which comes into effect on the initialization line:
	  player->InitForTranscode(copyaudio, copyvideo);

So maybe the problem is 'raw mode' video copying???

Anyway when it comes time to start transcoding, the following are the
key logfile differences between the cutlist and no cutlist cases:

1. In the --honorcutlist case, the program seems to do a few ringbuf reads and
then quits... there is no indication that any transcoding occurs... it
just detects letterbox format and then stops...

RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..123887, normal): ReadDirect checksum 23991
Detect Letterbox: YV12 frame format detected
Detect Letterbox: Strange frame number -1
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..12, normal) @0 -- begin
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..12, normal): ReadDirect checksum 46958
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..768, normal) @0 -- begin
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..768, normal): ReadDirect checksum 15530
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..12, normal) @0 -- begin
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..12, normal): ReadDirect checksum 5546
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..200605, normal) @0 -- begin
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..200605, normal): ReadDirect checksum 40115
Detect Letterbox: The source is already in widescreen (aspect: 1.77778)
MSqlQuery::exec(DBManager0) DELETE FROM recordedseek WHERE chanid = '1021' AND starttime = '2010-11-20T16:30:00' AND type = '7' ;
MSqlQuery::exec(DBManager2) DELETE FROM recordedseek WHERE chanid = '1021' AND starttime = '2010-11-20T16:30:00' AND type = '6' ;
MSqlQuery::exec(DBManager1) DELETE FROM recordedseek WHERE chanid = '1021' AND starttime = '2010-11-20T16:30:00' AND type = '9' ;
Player(0): StopPlaying - begin
Player(0): Decoder thread exiting.
Player(0): Exited decoder loop. ~VideoOutputNull()

----------------------------------------
1. In the no cutlist case, the program does a mysql query to get the
jobqueue (which is missing above) and then continues to read...
We also get the line: "mythtranscode: 0% Completed @ 0 fps" which
presumably indicates the start of actual transcoding which never shows up in the --honorcutlist case

RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..123887, normal): ReadDirect checksum 23991
Detect Letterbox: YV12 frame format detected
Detect Letterbox: Strange frame number -1
MSqlQuery::exec(DBManager0) SELECT cmds FROM jobqueue WHERE id = '-1'; <<<< Returns 0 row(s)
 mythtranscode: 0% Completed @ 0 fps.
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..12, normal) @0 -- begin
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..12, normal): ReadDirect checksum 46958
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..768, normal) @0 -- begin
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..768, normal): ReadDirect checksum 15530
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..12, normal) @0 -- begin
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..12, normal): ReadDirect checksum 5546
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..200605, normal) @0 -- begin
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..200605, normal): ReadDirect checksum 40115
Detect Letterbox: The source is already in widescreen (aspect: 1.77778)
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..12, normal) @0 -- begin
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..12, normal): ReadDirect checksum 14171
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..384, normal) @0 -- begin
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv): ReadPriv(..384, normal): ReadDirect checksum 60887
RingBuf(/mnt/media/mythtv/mythtv-raw/1021_20101120163000.nuv):
ReadPriv(..12, normal) @0 -- begin
....
....
....
continues to transcode...