Best way to convert HD bitstream audio to PCM?

MKV playback, recompression, remuxing, codec packs, players, howtos, etc.
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amt_austin
Posts: 1
Joined: Sat Dec 04, 2010 7:00 pm

Best way to convert HD bitstream audio to PCM?

Post by amt_austin »

Hello,

I have been very happy with MakeMKV, but there was one thing I wanted to try to do if possible. This really is not MakeMKV dependent, but since this is the file processing section....

I would really like to convert all of my HD audio bitstream tracks to multi-channel PCM. I need to do this because I would like to pass the HDMI signal through a HDMI 1.1 compliant video processor, so I cannot pass the audio like DTS-MA, TrueHD, etc. My media players, SageTV HD 300, cannot decode these codecs like many blu-ray players can (such a shame they don't have this). So... I would like to just avoid all of this and just store the uncompressed audio in my MKV files. What is the best way to achieve this? Are there any gotchas? Any formats which can be decoded, but have problems or glitches?

Edit: forgot to mention that I would really like to do this on Linux or MacOS

Thanks!
Icanseestars
Posts: 70
Joined: Sat Mar 07, 2009 10:12 am

Re: Best way to convert HD bitstream audio to PCM?

Post by Icanseestars »

Can the SageTV 300 decode lossless flac to PCM ?

This is what I do for under Windows no idea about OSX/linux tools I'm afraid
Download Staxrip
* select any preset at startup e.g Divx Plus
* input the video MKV file with True HD or DTS-MA track
* click the blue Divx Plus text and select "Just Mux"
* set MKV as the container (not DivX Plus MKV)
* under filters disable deinterlace and crop borders
* click blue edit button next to AAC

Now you can create a Flac preset
* codec = Flac
* encoder = automatic
* channels = 1 (Mono) - ignore the text label this converts the audio channels as is so True HD 7.1 comes out as Flac 7.1
* Sample rate = original
* Under advanced de-select the downconvert to 16-bit

Click the profiles button and select save to create a new audio preset.
* back on main screen click the blue aac text to change to flac preset
* click next then click okay

This will make Staxrip process the video file leaving the original video in place while converting the audio into lossless Flac. I've done this for all of my Blu-rays as my AMP can handle LPCM 7.1 audio but not TrueHD or DTS-MA unless the player decodes it as LPCM and not all do but lossless flac to LPCM is much better supported in this area.
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