Transcode Recordings

[Bussiebaer]

This thread has been pulled from the archives, some editing has been done to reflect the new name. -Mod

I'd like to know if/what someone use to transcode recordings to a more compact filesize, without manual interaction. I record with MP into the .ts-format. Recordings of about an hour already uses about 2 GBs or more, that is to much for the recorded quality.

I have seen MCE-Buddy, but didn't try it out yet (have to re-install my system first) . Have someone experience with it? Are there alternatives?

As OS I use Vista Ultimate 32bit.

[johandm_be]

Hi Bussiebaer,

I do have experience with transcoding.
I am using ffmpeg which is a free, open source, transcoding tool.
Several builds exist, and they don't all come with the same codecs linked in. So, depending what format you are targeting, you may need to search a little before you find a build that has the correct codec.

The way I use this is: I have ARGUS TV setup that some of my recordings have a "transcode" processing command associated with them. These recordings can then be transferred to my iPOD Touch for offline viewing.

Since the transcoding command I made takes 100% CPU, I have set it up that rule only starts at a fixed time (2:00 AM) after the recording was finished.

The day after recording, these recordings that were queued for transcoding now have the original .TS file and also an .MP4 file in the same dir. I can just drag and drop that .MP4 into iTunes and I am done!

Hope this helps.

Thanks,
Johan.

[Bussiebaer]

Thanks, will have a look at it

[binary64]

hi Johan - what does your transcoding batch file look like please? I'm trying similar but I am getting audio/video sync error of about 0.5secs with mencoder

thanks

[johandm_be]

hi Johan - what does your transcoding batch file look like please? I'm trying similar but I am getting audio/video sync error of about 0.5secs with mencoder

thanks

Hi binary64,

I remember having that too in the beginning. I was able to fix it by experimenting with the -async switch.

I have quite a few batch files that I use, I will paste some below:

This one is 2 pass, it uses all CPU cores available:

ffmpeg.exe -y -i %1 -pass 1 -passlogfile %1 -threads auto -s 480x320 -aspect 480:320 -b 768k -minrate 0k -maxrate 3072k -bufsize 10M -vcodec libx264 -level 13 -async 50 -acodec libfaac -ar 48000 -ac 2 -ab 128k -f mp4 NUL
ffmpeg.exe -y -i %1 -pass 2 -passlogfile %1 -threads auto -s 480x320 -aspect 480:320 -b 768k -minrate 0k -maxrate 3072k -bufsize 10M -vcodec libx264 -level 13 -async 50 -acodec libfaac -ar 48000 -ac 2 -ab 128k -f mp4 %1.mp4
del %1-0.log
del *.log*

This one is 2 pass, it limits to one CPU core: (can be usefull if you have dual/quad core and you don't want to max out your cpu usage while transcoding)

ffmpeg.exe -y -i %1 -pass 1 -passlogfile %1 -s 480x320 -aspect 480:320 -b 768k -minrate 0k -maxrate 3072k -bufsize 10M -vcodec libx264 -level 13 -async 50 -acodec libfaac -ar 48000 -ac 2 -ab 128k -f mp4 NUL
ffmpeg.exe -y -i %1 -pass 2 -passlogfile %1 -s 480x320 -aspect 480:320 -b 768k -minrate 0k -maxrate 3072k -bufsize 10M -vcodec libx264 -level 13 -async 50 -acodec libfaac -ar 48000 -ac 2 -ab 128k -f mp4 %1.mp4
del %1-0.log
del *.log*

This one is single pass, max CPU:

ffmpeg.exe -y -i %1 -threads auto -s 480x320 -aspect 480:320 -b 1300k -bt 108k -vcodec libx264 -level 13 -async 50 -acodec libfaac -ar 48000 -ac 2 -ab 128k %1.mp4
del *.log*

etc.

The dual pass typically takes twice as long to run (makes sense ) but it does create slightly better PQ. When you compare side by side, you can see the difference if you look close enough to the details.

Thanks,
Johan.

[binary64]

Wow, it works! Thank you very much.

Do you know how to control deinterlacing? And the various algorithms..? I want to pre-deinterlace the mp4.

I'm also trying to tweak your batch file so it supports any input file - interlaced or not, ntsc or pal.

Then to work out how to make it read comskip edl files without an intermediate step to cut the ts.

[johandm_be]

Hi Binary64,

sorry for the delayed reply, I was on vacation last 10 days.

No, I have not experimented with pre-deinterlacing yet. (and nor with the other options/algorithms you mentioned).
But I am curious about your experiences

Thanks,
Johan.