Transcoding AVCHD

Since we're expecting a baby for the end of April, Jimena and I thought it would be really nice to have a video camera to record those precious memories. I thought it was worth it to get an HD camera, even though we don't have any HD devices yet, because we'll be happy to watch our memories in HD in a few years, when we can afford a new TV ;)

So there we went, and got the Panasonic HDC-SD9. It's a great camera, which records directly in HD formats, from 1440x1080 to 1920x1080. The only issue came when I wanted to play these videos on my computer. Our poor dual-core Intel Pentium D with 1.5 GB RAM struggles to play the lowest quality the SD9 can produce. So there was a need to transcode this format into a more readable one, for example avi or mov.

My first approach was to use a simple ffmeg line :

ffmpeg -i somefile.mts -s svga -r 25 somefile.mov


It does convert the file to a .mov successfully, but the result is horrible: the images are almost just as grabbled as reading the mts directly with VLC.


This morning, I found this post, which linked to this forum, which features a great talk on how to efficiently transcode AVCHD to mov or avi. It also linked to Ubuntu forums where a guy proposed to use mencoder for the job with something like

mencoder $f -o `basename $f .mts`.avi -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=10000 -fps 50 -vf scale=720:576


The result, once again, was horrible in my case.

Eventually, I tried the script located at http://marks.org/avchd/hdffxvrt-mov1-8-09, and it worked great! The only problem I had with it was that most of my videos were in 1440, so I had to use "-i 1440x1080" on them. Otherwise, the results are very nice.

This script has preset formats, so you can simply call it this way

./hdffxvrt-mov1-8-09 -p small -i 1440x1080 00000.mts



Nice and efficient, and uses ffmpeg under the hood, only going through a yuv demux before actually transcoding (from the little I understand about video transcoding at least). You only need to be patient.


Update:

I worked a bit on the script and improved it quite a bit. The first improved version can be found on this link and includes the following changes:

• Take -f switch to choose format (mov by default) instead of having two separate scripts ;


• Use mktemp to create the TMPDIR ;


• Add traps to remove temporary files and directories on interrupt, kill and exit ;


• Also remove output file if the file is interrupted ;


• Try to detect resolution if it wasn't specified with the -i switch. This is currently a bit ugly but it works for me so far. Any improvement in this would be welcome.
  

After that, I thought it would be nice to integrate it in Dolphin/Konqueror as a service menu. It gave birth to the script you will find on this link. This is still quite a hack, and I will probably work more on it later on, but you are already welcome to try it and give some feedback.



This KDE version includes the following improvements:

• Register .mts files in the system ;
• Call the script from ServiceMenus (Dolphin/Konqueror) for various preset sizes ;
• Uses kdialog to provide information while encoding ;
  
• Progress bar support interacting with ffmpeg encoding progress ;
  
• Support for the "Cancel" button while encoding.