[mythtv-users] Little gems on MythTV wiki

[Christopher Meredith]

On Mon, Feb 22, 2010 at 7:24 AM, Brent Bolin <brent.bolin at gmail.com> wrote:
> Ran across this info -
>
> Did you know you can merge two MPG files together?
> cat File1 File2 > Merged File-name.
>
> Doesn't appear to work.  I have a couple of DVD's that are on two
> disks.  Currently have them as video.name.disk1.mpg and
> video.name.disk2
>
> So I tested to see what would happen.
>
> Here is a snippet of what I see in  mythfrontend.log
>
> 2010-02-22 07:10:06.282 [h264 @ 0x40646e0]AVC: nal size 1315803467
> 2010-02-22 07:10:06.282 [h264 @ 0x40646e0]no frame!
> 2010-02-22 07:10:06.282 [h264 @ 0x40646e0]AVC: nal size -1686999763
> 2010-02-22 07:10:06.283 [h264 @ 0x40646e0]no frame!
> 2010-02-22 07:10:06.283 [h264 @ 0x40646e0]AVC: nal size -645962405
> 2010-02-22 07:10:06.283 [h264 @ 0x40646e0]no frame!
> 2010-02-22 07:10:06.283 [h264 @ 0x40646e0]AVC: nal size 1296261589
> 2010-02-22 07:10:06.283 [h264 @ 0x40646e0]no frame!
> 2010-02-22 07:10:06.284 [h264 @ 0x40646e0]AVC: nal size -1383481424
> 2010-02-22 07:10:06.284 [h264 @ 0x40646e0]no frame!
> 2010-02-22 07:10:06.333 AFD: Opened codec 0xaed1df70, id(H264) type(Video)
> 2010-02-22 07:10:06.334 AFD: codec AAC has 2 channels
> 2010-02-22 07:10:06.348 AFD: Opened codec 0xac9e8a90, id(AAC) type(Audio)
> 2010-02-22 07:10:06.348 AFD: codec AC3 has 2 channels
> 2010-02-22 07:10:06.350 AFD: Opened codec 0xac9e9010, id(AC3) type(Audio)
> 2010-02-22 07:10:06.350 AFD Error: Could not find decoder for codec
> (Unknown Codec ID), ignoring.
> 2010-02-22 07:10:06.398 AFD: Opened codec 0xacdaad20, id(H264) type(Video)
> 2010-02-22 07:10:06.398 AFD: codec AAC has 2 channels
> 2010-02-22 07:10:06.399 AFD: Opened codec 0xacdab2a0, id(AAC) type(Audio)
> 2010-02-22 07:10:06.399 AFD: codec AC3 has 2 channels
> 2010-02-22 07:10:06.400 AFD: Opened codec 0xacdab820, id(AC3) type(Audio)
> 2010-02-22 07:10:06.400 AFD Error: Could not find decoder for codec
> (Unknown Codec ID), ignoring.
> 2010-02-22 07:10:06.423 Opening audio device 'spdif'. ch 2(2) sr 48000
> 2010-02-22 07:10:06.423 Opening ALSA audio device 'iec958:{ AES0 0x02 }'.
> 2010-02-22 07:10:06.601 Opening audio device 'spdif'. ch 2(2) sr 48000
> 2010-02-22 07:10:06.601 Opening ALSA audio device 'iec958:{ AES0 0x02 }'.
> 2010-02-22 07:10:06.667 VideoOutputXv: XVideo Adaptor Name: 'NV17 Video Texture'
> 2010-02-22 07:10:06.737 OSD Theme Dimensions W: 1280 H: 720
> 2010-02-22 07:10:07.910 TV: StartPlayer(0, Watching Video, main) -- end ok
> 2010-02-22 07:10:07.911 New DB connection, total: 3
> 2010-02-22 07:10:07.912 New DB connection, total: 4
> YadifDeint: In-Pixformat = 1 Out-Pixformat=1
> YadifDeint: size changed from 0 x 0 -> 720 x 432
> YadifDeint: Using existing thread.
> 2010-02-22 07:10:07.920 OpenGLVideoSync()
> 2010-02-22 07:10:07.982 Video timing method: SGI OpenGL
> 2010-02-22 07:10:09.848 NVP(0): Prebuffer wait timed out 10 times.
> 2010-02-22 07:10:11.731 NVP(0): Prebuffer wait timed out 20 times.
>
> The two video files were created using Handbrake with High Profile setting.
>
> filetype shows -
>
>  file ap*
> apocalypse.now.disk1.mpg: setgid ISO Media, MPEG v4 system, version 2
> apocalypse.now.disk2.mpg: setgid ISO Media, MPEG v4 system, version 2
>
> So I guess this doesn't work.

Yeah, you can't do that with H264, only MPEG2. To concatenate those
recordings you have to do:
mencoder -oac copy -ovc copy -forceidx apocalypse.now.disk1.mpg
apocalypse.now.disk2.mpg -o apocalypse.now.mpg

Also, you should use either the mp4 or mkv containers for H264
recordings made with Handbrake. In that case, you could also use
either mkvmerge or MP4Box to easily concatenate files.