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jameschyn

Member

Registered: 2011-10-20

Posts: 41

ffmpeg transcode from trueHD to flac (multichannel) ?

Hey, guys, I have tested using ffmpeg to transcode from trueHD(6.1ch) to flac(6.1ch):
$ ffmpeg -i INPUT.mka OUTPUT.flac
(INPUT.mka is separated from a MKV movie with trueHD 6.1ch using mkvtoolnix)
And I repeat the test with libav (a branch orgnization of ffmpeg), both produced the same amount OUTPUT.flac.

And here comes the question:
1. Since the INPUT.mka, aka trueHD is lossless audio, is the OUTPUT.flac also a lossless audio by this transcoding means ?
2. Can I set a level for OUTPUT.flac when transcoding, not the bitrate ? Since I find during the transcoding process, there is a "default" beside the OUTPUT.flac.

Anybody knows this ?

DrZaius

Member

Registered: 2008-01-02

Posts: 193

Re: ffmpeg transcode from trueHD to flac (multichannel) ?

Hey, guys, I have tested using ffmpeg to transcode from trueHD(6.1ch) to flac(6.1ch):
$ ffmpeg -i INPUT.mka OUTPUT.flac

Please use the code tag for commands and console outputs.

And I repeat the test with libav (a branch orgnization of ffmpeg), both produced the same amount OUTPUT.flac.

Probably no need to ever use this.

1. Since the INPUT.mka, aka trueHD is lossless audio, is the OUTPUT.flac also a lossless audio by this transcoding means ?

Try the MD5 muxer:

$ ffmpeg -i truehd.mka -map 0:a -f md5 - 2>/dev/null
MD5=bcad648bc1adb3b427927271e5425b37

$ ffmpeg -i audio.flac -map 0:a -f md5 - 2>/dev/null
MD5=bcad648bc1adb3b427927271e5425b37

2. Can I set a level for OUTPUT.flac when transcoding, not the bitrate ? Since I find during the transcoding process, there is a "default" beside the OUTPUT.flac.

You can see the available flac encoder "private" options:

$ ffmpeg -h encoder=flac

One of the resulting options may provide what you need, but I'm not very familiar with this encoder.

Last edited by DrZaius (2013-07-06 19:38:57)