Automated Cutting and Transcoding Guide Using Mencoder

[5%NationofCasiotone]

Ok. I'll just hope it was a fluke. Luckily I didn't miss anything too important (just trashy MTV programming). I'll see if I run into problems again when I tape tonight.

Hmm, well I restarted my computer, it worked again, now it stopped working again. I can't have this working only occasionally.

[-stattik-]

Hmm, well I restarted my computer, it worked again, now it stopped working again. I can't have this working only occasionally.

What stopped working? The script? Comskip? Are the files getting deleted again?

[5%NationofCasiotone]

What stopped working? The script? Comskip? Are the files getting deleted again?

Well, I think they are never getting recorded in the first place. A file is created when a show is taped, but it is just a 0 kb file.

[wintermute]

stattik, Can you help?

On and HDTV recording (recorded straight to an mpg file) that was 6.4GB for a one hour show I attempted to run mencoder. It kept flashing through it, exiting and creating a 0KB mpg file.
I ran the option manually (see below) and it was erroring out (see at the bottom of the results). What is causing that and can I correct it for the HDTV recordings that create a larger file? It appears that the mpeg2video cannot handle the higher fps. Can this be adjusted/fixed?
Thanks

G:\Support\UPDATES\HDTV EPG\mplayer>G:\Support\UPDATES\HDTVEP~1\mplayer\me ncoder
.exe "G:\My Videos\Star Trek\Star Trek- Enterprise.mpg" -edl "G:\My Videos\Star
Trek\Star Trek- Enterprise.edl" -oac copy -ovc lavc -of mpeg -mpegopts format=dv
d -vf filmdint,softskip,harddup -lavcopts vcodec=mpeg2video:vrc_buf_size=1835:vr
c_maxrate=9800:vbitrate=4000:keyint=18 -o "G:\My Videos\Star Trek\Star Trek-Ente
rprise new.mpg"
MEncoder dev-CVS-060323-00:54-4.0.2 © 2000-2006 MPlayer Team
CPU: Advanced Micro Devices Sempron/Athlon MP/XP Thoroughbred; Duron Applebred (
Family: 6, Stepping: 1)
CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 0 SSE2: 0
Compiled for x86 CPU with extensions: MMX MMX2 3DNow 3DNowEx SSE

91 audio & 206 video codecs
success: format: 0 data: 0x0 - 0x8b4f5f33
MPEG-PS file format detected.
VIDEO: MPEG2 1280x720 (aspect 3) 59.940 fps 15000.0 kbps (1875.0 kbyte/s)
[V] filefmt:2 fourcc:0x10000002 size:1280x720 fps:59.94 ftime:=0.0167
================================================== ========================
Opening audio decoder: [liba52] AC3 decoding with liba52
Using 3DNowEx optimized IMDCT transform
AC3: 2.0 (stereo) 48000 Hz 192.0 kbit/s
Using MMX optimized resampler
AUDIO: 48000 Hz, 2 ch, s16le, 192.0 kbit/12.50% (ratio: 24000->192000)
Selected audio codec: [a52] afm: liba52 (AC3-liba52)
================================================== ========================
PACKET SIZE: 2048 bytes
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
Opening video filter: [harddup]
Opening video filter: [softskip]
Opening video filter: [filmdint]
================================================== ========================
Opening video decoder: [mpegpes] MPEG 1/2 Video passthrough
VDec: vo config request - 1280 x 720 (preferred colorspace: Mpeg PES)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
Try adding the scale filter, e.g. -vf spp,scale instead of -vf spp.
VDecoder init failed
Opening video decoder: [libmpeg2] MPEG 1/2 Video decoder libmpeg2-v0.4.0b
Selected video codec: [mpeg12] vfm: libmpeg2 (MPEG-1 or 2 (libmpeg2))
================================================== ========================
audiocodec: framecopy (format=2000 chans=2 rate=48000 bits=16 B/s=24000 sample-1
)
Limiting audio preload to 0.4s
Increasing audio density to 4
Read 7 EDL actions.
VDec: vo config request - 1280 x 720 (preferred colorspace: Planar YV12)
VDec: using Planar YV12 as output csp (no 0)
Movie-Aspect is 1.78:1 - prescaling to correct movie aspect.
videocodec: libavcodec (1280x720 fourcc=3267706d [mpg2])
[mpeg2video @ 00A72E48]MPEG1/2 does not support 19001/317 fps
Could not open codec.
FATAL: Cannot initialize video driver.

Exiting...

[FitzGerald]

I'll provide some feedback on this script.

I'm barely running GB-PVR on a P3 866 Mhz with 512 MB RAM, using a PVR-150 (on my 1 recording I have the timestamp bug). I have a capture from GB-PVR of an hourlong SportsCenter. I originally thought I could transcode VirtualDubMod, but that program doesn't support MPEG-2 audio conversion (unless there is a conflict with the timestamp bug).

I am transcoding the file right now. By my estimation it will take ~ 6 hours to do the transcoding (and I'll probably get skippy video/audio due to my web-surfing). Currently I'm 75% done... unless this is only part I of a more than I part process, in which case I'll be done by Christmas.

Is anyone else having success on such an underpowered machine? If I cut the commercials out manually (with some type of MPEG2 editor?) would it save me a bunch of time over running comskip? comskip didn't run fast with what I've got at all. I know the ultimate solution is to get a new CPU... but I think there are some optimizations I could do to make transcoding faster. I just downloaded a P3 version of Mencoder which will probably help some.

[wtg]

FitzGerald,

The mencoder batch file in this thread does an excellent job transcoding, but isn't ideal for simply correcting a timeshift error from a PVR-150. Mencoder has a nice option for doing that. Try this command:

mencoder -oac copy -ovc copy <input_file> -f mpeg -o <output_file>

(I think that's the entire command - doing this from memory)

The -ovc copy options tells mencoder not to re-encode the video in the file and makes it blazing fast, even on a slow CPU. I think on my old 1.1 GHz celeron it could fix a 1 hr program in about 10 minutes.

However, in my experience this can't really be combined with mencoder's -edl option for cutting out commercials. If you do that I've found my timelines get even more screwed up, the programs showing a duration of 0:00 in both Windows Media player and Real player. (When they're like this you can watch them but you can't skip or FF.) Nero's player actually shows the duration correctly and works with them fine. If you want to cut commercials using mencoder, you have to let it re-encode.

Some mpeg editors will work on frame boundaries in a video, allowing you to cut without re-encoding, like the Nanopeg editor that comes on Hauppauge's CD. Since it works on frame boundaries it only has about 1/2 second granularity for positioning your cuts, and it's got a lousy interface but it does cut quickly. There are other editors that work this way too.

[cakes]

Hi,

I tried this script and got it working in no time ! Great work!

But when I play the resulting .avi via MVP, the video & audio are out of sync. It looks like the video is progressing way too fast. Also via the Hauppauge MVP soft the .avi doesn't play correctly.

In WMP and also in GBPVR on the PC the .avi play just fine (although in GBPVR I had to use VRM9 instead of VRM7).

Does anyone else have this problem? What could be wrong?

[-stattik-]

I am transcoding the file right now. By my estimation it will take ~ 6 hours to do the transcoding (and I'll probably get skippy video/audio due to my web-surfing). Currently I'm 75% done... unless this is only part I of a more than I part process, in which case I'll be done by Christmas.

The video shouldn't be skippy because of web surfing. Mencoder takes whatever CPU cycles it can get. 6 hours is long but I just leave my PC on all the time. There's not much that can be done with the script to speed things up unless you want a noticible loss in quality. Cutting out commercials will help because you'll only have to transcode 42 min instead of 60. An automated process like comskip or showanalyzer would be better in the long run because you'd need to manually create the EDL files for mencoder to use.

Tell me how the trancode works out.

[-stattik-]

Hi,

I tried this script and got it working in no time ! Great work!

But when I play the resulting .avi via MVP, the video & audio are out of sync. It looks like the video is progressing way too fast. Also via the Hauppauge MVP soft the .avi doesn't play correctly.

In WMP and also in GBPVR on the PC the .avi play just fine (although in GBPVR I had to use VRM9 instead of VRM7).

Does anyone else have this problem? What could be wrong?

I don't have a MVP so I can't test. I know King Mob had posted in this thread saying that MVP playback worked well:

http://forums.gbpvr.com/showpost.php?p=8...stcount=80


Perhaps you two can compare notes(firmware, software level, MVP transcoder software,etc.)

[FitzGerald]

The video shouldn't be skippy because of web surfing. Mencoder takes whatever CPU cycles it can get. 6 hours is long but I just leave my PC on all the time. There's not much that can be done with the script to speed things up unless you want a noticible loss in quality. Cutting out commercials will help because you'll only have to transcode 42 min instead of 60. An automated process like comskip or showanalyzer would be better in the long run because you'd need to manually create the EDL files for mencoder to use.

Tell me how the trancode works out.

Just watched it. Video and audio synch up great. I've got a bit of a dot crawl issue... I need some type of Sports setting. I think I'm going to post-process with comskip at some point over the next few days.