Video encoding / muxing for TF & TV

[Guest MaxiP]

Hi all - read all the relevant posts but haven't quite answered my question yet.

I'll (hopefully) be getting one in the near future so want to prepare my movie collection for tablet viewing - currently have an Advent Vega that is off for repair (design flaw with early screen and is not likely to be fixed so replace / refund). At the minute, all my movies are MKV with aspect ratio of 1280*544 and with mainly AC3 audio. So, I know that I have to do something to allow my movies to play on TF but I want to try and retain quality so the same movies can be viewed on HDMI TV (via HTPC). I've been playing with HandBrake and have used the profiles hosted elsewhere (TF101 720p Base & TF101 720p High Profile) to see how things work out.

I know that any re-encode with give me a 1280*544 image but as the default resolution of the TF is 1280*800, this will mean letterbox effect unless I pan / scan or choose a different ratio.

So, any suggestions on what I could try to re-encode to (I have to re-encode to swap audio from AC3 to AAC). I was thinking about something like 1360*700 which would be scaled on both TF & TV to give 'acceptable' results but I'd rather hear what anyone else has done and what was successful / unsuccessful.

Thanks

[Guest SilentMobius]

Hi all - read all the relevant posts but haven't quite answered my question yet.

I'll (hopefully) be getting one in the near future so want to prepare my movie collection for tablet viewing - currently have an Advent Vega that is off for repair (design flaw with early screen and is not likely to be fixed so replace / refund). At the minute, all my movies are MKV with aspect ratio of 1280*544 and with mainly AC3 audio. So, I know that I have to do something to allow my movies to play on TF but I want to try and retain quality so the same movies can be viewed on HDMI TV (via HTPC). I've been playing with HandBrake and have used the profiles hosted elsewhere (TF101 720p Base & TF101 720p High Profile) to see how things work out.

I know that any re-encode with give me a 1280*544 image but as the default resolution of the TF is 1280*800, this will mean letterbox effect unless I pan / scan or choose a different ratio.

So, any suggestions on what I could try to re-encode to (I have to re-encode to swap audio from AC3 to AAC). I was thinking about something like 1360*700 which would be scaled on both TF & TV to give 'acceptable' results but I'd rather hear what anyone else has done and what was successful / unsuccessful.

Thanks

I would never re-encode with the resolution higher than the source, you are just wasting bandwidth/quality. 1280*544 is "720p" for the cinemascope aspect ratio (2.35:1) I'd leave it alone.

Your best option all depends on the profile/level/codec/bitrate of your existing collection. I suggest getting hold of the command-line utility "mediainfo" and posting the output from one of your movies. If you're lucky and you currently have h.264/baseline profile or h.264/high profile/level3.1 then you may only need to re-encode the audio and remux. That way the video will suffer no degradation at all.

As of 3.1 the transformer can play high profile h.264 using mkv containers with a little fiddling.

[Guest MaxiP]

Thanks - I've started to re-encode audio from AC3 to AAC using Freemake Video Converter (also reduces file size) or Avidemux (only changes audio stream). Freemake give me a MP4 output whilst Avidemux retains the MKV container and just changes the audio stream.

[Guest SilentMobius]

Thanks - I've started to re-encode audio from AC3 to AAC using Freemake Video Converter (also reduces file size) or Avidemux (only changes audio stream). Freemake give me a MP4 output whilst Avidemux retains the MKV container and just changes the audio stream.

I always use ffmpeg command line, makes it nice an easy and much easier to do as a batch

ffmpeg -i INFILE.mkv -vcodec copy -acodec libfaac OUTFILE.mp4

And add any specific tweaks you want to the aac encoding

[Guest MaxiP]

I always use ffmpeg command line, makes it nice an easy and much easier to do as a batch

ffmpeg -i INFILE.mkv -vcodec copy -acodec libfaac OUTFILE.mp4

And add any specific tweaks you want to the aac encoding

I have scripted a command line for AVIDEMux that will scan all folders from a top level then re-mux any that meet the criteria (re-encode audio only, leave video as MKV). In the example below, the top level folder is called "H:\AVIDMUX Test" and I want to scan for all files with MKV extension. This creates a muxed file in the same folder with the extension ???.MKVAAC - now I just need a script to scan folders and delete MKV then rename MKVAAC, but I haven't got that part working yet :)

set moviefolder="H:\AVIDEMUX Test"

set avidemux="C:\Program Files\Avidemux 2.5\avidemux2.exe"

set audiocodec=AAC

set outputfolder=h:\output


for /r %moviefolder% %%f in (*.mkv) do (

%avidemux% --output-format MATROSKA --audio-codec %audiocodec% --force-alt-h264 --load "%%f" --save "%%faac" --quit

)

I can run the script through and have all the output going to my 'output' folder by changing the code to "%avidemux% --output-format MATROSKA --audio-codec %audiocodec% --force-alt-h264 --load "%%f" --save "%outputfolder%\%%f" --quit" but then I would have to move all the new files back into the correct folders. As I have 250 movies and 300-400 TV episodes, don't fancy that !

I know that there are freeware apps that can do the scan / delete / move but I'd prefer to keep everything within a CMD file as it makes it completely portable - any suggestions welcome.

Edited June 24, 2011 by MaxiP