Mastering MythTV MPEG2 files to DVD
MythTV is a wonderful project, which I’ve been running for nearly 12 months. In the AFL season 2007, I was downloading the Geelong games from the internet. Unfortunately, you’re at the mercy of whomever was encoding the game, in terms of quality. By Geelong winning the premiership last season, most of the games were broadcasted on free-to-air TV and I was recoding them all using MythTV, with the intention of putting them on DVD later.
I tried using MythArchive, but it was clumsy and didn’t give me enough control of the DVD creation process. I wanted the video to fit exactly on a single sided DVD, with minimal loss of quality, so I had to the process manually.
The problem I found trying to encode MythTV’s mpeg2 files was that you would always get the the video and audio out of sync. The length of the broadcast was around 3 hours long, so by the end, the sound could be more than a second behind the video. I think this is due to missing little pieces of the data from the broadcast.
To fix the broadcasting issues, use ProjectX to split the video and audio
java -jar /usr/share/java/ProjectX.jar -demux -out <your tmp directory> -name <your output filename prefix> <input mythtv recording file>
You’ll see some output like this:
demuxing DVB MPEG-TS file 1010_20080802192500.mpg
!> PID 0x0 (PAT) (0 #1) -> ignored
!> PID 0x100 (PMT) (188 #2) -> ignored
ok> PID 0x200 has PES-ID 0xEA (MPEG Video) (376 #3)
ok> PID 0x240 has PES-ID 0xBD (private stream 1) (TTX) (5264 #29)
ok> PID 0x28B has PES-ID 0xBD (private stream 1) (20680 #111)
ok> PID 0x28A has PES-ID 0xC0 (MPEG Audio) (84412 #450)
-> video basics: 720*576 @ 25fps @ 0.7031 (16:9) @ 9000000bps, vbvBuffer 95
-> starting export of video data @ GOP# 0
!> dropping useless B-Frames @ GOP# 0 / new Timecode 00:00:00.000
6 %!> PID 0x200 -> packet 2687051 @ pos. 505165400 out of sequence (15/11) (shifting..) (~00:12:34.480)
!> PID 0x200 -> packet 2687616 @ pos. 505271620 out of sequence (1/14) (shifting..) (~00:12:34.960)
12 %!> PID 0x200 -> packet 5943135 @ pos. 1117309192 out of sequence (12/6) (shifting..) (~00:27:44.080)
16 %!> PID 0x200 -> packet 7860852 @ pos. 1477839988 out of sequence (8/14) (shifting..) (~00:36:38.320)
17 %!> PID 0x200 -> packet 8427938 @ pos. 1584452156 out of sequence (6/10) (shifting..) (~00:39:16.720)
Once this is done, multiplex the Video and Audio files back together again
mplex -f 9 -o <your output filename> <video file>.m2v <audio file>.mp2
This should give us a nice clean MPEG2 file, which we can then cut all the ads out of. Rather than using something like nuvexport and making the ads in MythTV itself, I found it much easier to use Avidemux.
Load the video into Avidemux, then
- Use the arrow keys and mousewheel to find cutting spots.
- Use the A_> and <_B buttons to mark the start and finish of ads
- Hit the delete key to cut the ads
Once you’re done, I always save a project file, in case Avidemux crashes.
You can then load the ‘DVD’ profile from the Auto -> DVD menu. Leave the ratios at 1:1.
Hit the calculator button, select Format: MPEG and Medium: DVD5. Hit apply, and then close.
Hit the configure button underneath the video part on the left. Configure the video output to Interlaced (I used TFF, but prob doesn’t matter) and 16:9 Aspect ratio.
Then, just save the new encoded video. On my AMD 3200+ machine, it takes somewhere around 5-6 hours to encode about 2.5 hours of video.
For me, I found that the Avidemux encoding sometimes failed in the 2nd pass at one of my defined cutpoints. To combat this, I opened the output video to the end of the file to find out which cutpoint the video failed encoding at. With this, I would open up my project file in Avidemux again, and remove a few extra frames either side of my original cut. This was usually enough to get it over the line.
Once this is done, use DeVeDe to create the DVD ISO file.
When adding the newly encoded MPEG PS file, make sure you open the properties of the file click ‘Advanced Options’, and in the Misc tab, select the checkbox ‘This file is already a DVD/xCD-suitable MPEG-PS file’. Don’t worry if DeVeDe tells you the file is 106%, it will fit on a 4.7 DVD.
Once this is done, you should have a nice ISO image which you can burn straight to disc.
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hehe
