Here is what I wanted to do …
Some shows that I have recorded with Mythtv I would like to keep – either move to the Videos area or burn to a DVD. In addition I would like to reduce the size of the file by cutting out commercials and cutting the start and end and also compressing using mpeg4 and with a lower quality setting.
I want to do this from the job menu on a recording.
It would also be nice to create a text file so the Video Manager can display something usefull and a thumbnail would be nice too.
First question was to determine the quality that would be good enough while keeping the size small. Others seemed happy with a 1G file for 1 hour.
My system uses a USB digital tuner ie. DVB-T and therefore recordings are mpeg2 with either mp2 or ac3 audio. Sizes are SD (720×576) or HD (1440×1080).
Doing some basic testing on a recorded file. Original recorded file = 3,874,992k – 1h 23m
Testing on the first 1min of this file with ffmpeg – note all videos have no audio.
Original mpeg2 – 1 min – 39,562k
mpeg4 @ 1000kbps 7,633k
mpeg4 @ 2000kbps 14,941k
xvid @ 1000kbps 7,772k
xvid @ 2000kbps 15,210k
xvid @ vbr q=5 16,731
The quality at 1000kbps is quite poor so it is either 2000kbps or vbr – I think it will be vbr q=5
Estimates for sizes for a video of 60min – no audio
Also wanted to ensure that converted file would play on my DVD player so I burnt the file to a DVD and ensured that it played ok.
How to set up a Mythtv job for this
The options are
Use built in Transcode
- Leaves the file in the recordings directory, I want it in videos. Could create a new job running mythtranscoder and use the -o option to put it in the right place.
- Audio processed to mp3. In theory is does not need to be. The stream in the original file could just be copied.
- Built into Mythtv
- Uses the cutlist
nuvexport ( and Mencoder)
nuvexport for xvid resizes and puts audio into mp3
does lossless work for streaming?
– could modify nuvexport
– What is the time impact of mythtranscode
Custom script with mencoder
Using mencoders edl option I could get the cutlist from the database and convert this to a edl file
- mythtranscode is not needed
- It is custom, and I have to write it
- the edl option does not seem to work well. I have had mixed results is testing. This may be because the recording is a ts