eac3to - audio conversion tool

[odin24]

Guys, I need some advice. I have a demuxed BD that would be slightly larger than a SL BD-RE, my playback device is my PS3. I could recode the video to fit with the THD track on a BD-RE, which would consume a considerable amount of time, or I could convert the THD track to PCM and play as m2ts from the HDD.

My concern is if I convert the audio, will the PCM file be as close to a replica of the TrueHD track as possible... aside for the CBR and obvioulsy different file type? This would be the first time I convert the audio as I usually process the video with good results. Can anybody vouch for the quality of the audio conversion.

Thanks.

[rica]

odin,
think you unzip a file;
here, zipped file is lossless (THD) and unzipped file is uncompressed (pcm)

[odin24]

Originally Posted by rica

odin,
think you unzip a file;
here, zipped file is lossless (THD) and unzipped file is uncompressed (pcm)

I get that a TrueHD track is a lossless compressed version of the studio track, but I'm not sure how eac3to goes about creating the new PCM file. Does it just "unzip" as you say creating a replicate of the studio track, or does it write a completely new version of the decoded TrueHD track.

Thanks again.

[Snowknight26]

When you go from lossless to lossless, say in this case, the first stream is decoded to RAW audio, then written to a file.

[odin24]

I'm talking about the TrueHD track as the source file, not the BD structure or m2ts.

I just want to know, how true the newly created PCM file by eac3to will be to the BD TrueHD file... or is it worth it to just keep the TrueHD track and recode my video instead.

[rica]

Originally Posted by odin24

I get that a TrueHD track is a lossless compressed version of the studio track, but I'm not sure how eac3to goes about creating the new PCM file. Does it just "unzip" as you say creating a replicate of the studio track, or does it write a completely new version of the decoded TrueHD track.

Thanks again.

OK, i may explain in this way:
think you have a thd decoder as default on your PC; say it is arcsoft audio decoder hd.
If you play an original THD with this decoder it is an unzip processs.
If you decode and re-encode to pcm with your default decoder, the final file can be considered as unzipped .
But in our case libav will be used for decoding in re-encoding process.
So it should be considered a rewrite of the original file.

[odin24]

Originally Posted by rica

OK, i can explain this in this way:
think you have a thd decoder as default on your PC; say it is arcsoft audio decoder hd.
If you play an original THD with this decoder it is an unzip processs.
If you decode and re-encode to pcm with your default decoder to pcm, the final file can be considered as unzipped .
But in our case libav will be used for decoding in re-encoding process.
So it should be considered a rewrite of the original file.

Great, thanks. That's exactly what I needed to know.

Thanks again.

[Steel]

Originally Posted by tebasuna51

Sox -M FL.wav FR.wav FC.wav LF.wav BL.wav BR.wav SL.wav SR.wav multichannel.wav

what app is SOX?

[tebasuna51]

Originally Posted by Steel

what app is SOX?

This is the Sox Homepage

[Thunderbolt8]

got a problem with converting a 2.0 ac3 track to .wavs: both outcoming wav files are slowed massively down, meaning all sounds and voices are played like ultra slowmotion.
can't say though if this is a specific problem of this single file or a general problem of 2.0 ac3 tracks. only had a 5.1 ac3 track to compare and that one played normaly after wave conversion.

edit: just noticed the track is from a mpeg2 cap and according to mpegrepair 5.1, while eac3to only recognizes it as 2.0

20mb sample of the ac3 track: http://www.sendspace.com/file/nbry8n

50mb sample of the .ts: http://www.sendspace.com/file/03nqcj

[dant3s]

Hello Madshi,
There is a little bug when using 2 separated threads of EAC3to, generated logs are the same, even if the source file is different and is located in a different folder.
Log is nicely generated in the prompt window but not in the text log, think my text is clear...
dant3s

[tebasuna51]

Originally Posted by Thunderbolt8

got a problem with converting a 2.0 ac3 track to .wavs: both outcoming wav files are slowed massively down, meaning all sounds and voices are played like ultra slowmotion....

Your answer in DelayCut thread ...

[itsancho]

hi all!
madshi, thank you for the great work!
well, is this a bug or it's nothing serious?

eac3to v2.77
command line: z\eac3to "E:\Music and Lyrics (2007) Blu-ray VC-1 DD" 1) 1: f:\Chapters.txt 2: f:\Music.mkv 3: a:\Music.ac3 9: a:\Music.sup 10: a:\Music1.sup
------------------------------------------------------------------------------
M2TS, 1 video track, 6 audio tracks, 14 subtitle tracks, 1:44:07
1: Chapters, 25 chapters
2: VC-1, 1080p24 /1.001 (16:9)
3: AC3, English, 5.1 channels, 640kbps, 48khz, dialnorm: -27dB
...
9: Subtitle (PGS), English
10: Subtitle (PGS), English
...
22: Subtitle (PGS), Swedish
Creating file "f:\Chapters.txt"...
[v02] Extracting video track number 2...
[s09] Extracting subtitle track number 9...
[a03] Extracting audio track number 3...
[s10] Extracting subtitle track number 10...
[a03] Removing AC3 dialog normalization...
[v02] Muxing video to Matroska...
[a03] Creating file "a:\Music.ac3"...
[s10] Creating file "a:\Music1.sup"...
[s09] Creating file "a:\Music.sup"...
24000/1001
Adding fps value to MKV header failed.
Video track 2 contains 149775 frames.
eac3to processing took 11 minutes, 25 seconds.
Done.

with 2.76 is the same, but with 2.75...

eac3to v2.75
command line: zzz\eac3to "E:\Music and Lyrics (2007) Blu-ray VC-1 DD" 1) 2: f:\Music.mkv
------------------------------------------------------------------------------
M2TS, 1 video track, 6 audio tracks, 14 subtitle tracks, 1:44:07
1: Chapters, 25 chapters
2: VC-1, 1080p24 /1.001 (16:9)
3: AC3, English, 5.1 channels, 640kbps, 48khz, dialnorm: -27dB
...
9: Subtitle (PGS), English
10: Subtitle (PGS), English
...
22: Subtitle (PGS), Swedish
[v02] Extracting video track number 2...
[v02] Muxing video to Matroska...
Added fps value to MKV header.
Video track 2 contains 149775 frames.
eac3to processing took 9 minutes, 23 seconds.
Done.

[Daodan]

I noticed latest version makes monowavs from 5.1 to BL and BR instead of old style SL and SR.
Now my question is, in case of 7.1 track, which are the extra 2 (compared to 5.1), SB,SL or BR,BL?
Thank you.

[tebasuna51]

Originally Posted by Daodan

Now my question is, in case of 7.1 track, which are the extra 2 (compared to 5.1), SB,SL or BR,BL?

Your question have not sense, the surround channels in 5.1 aren't the Side or Back channels in 7.1, maybe a mix.

[Thunderbolt8]

Originally Posted by tebasuna51

Your answer in DelayCut thread ...

thanks

[Daodan]

Originally Posted by tebasuna51

Your question have not sense, the surround channels in 5.1 aren't the Side or Back channels in 7.1, maybe a mix.

I don't see what doesn't make sense. It's the way they are labeled by eac3to and I want to now what is what. Following channels were created: L,R,C,LFE,SL,SR,BL,BR

[Snowknight26]

Any chances of speed increases for demuxing? Just demuxed the PCM track and an AC3->WAV track from A Few Good Men Blu-ray on a RAID array that can sustain 700MB/s, yet eac3to purportedly took 20 minutes.

[Chumbo]

Originally Posted by Daodan

I don't see what doesn't make sense. It's the way they are labeled by eac3to and I want to now what is what. Following channels were created: L,R,C,LFE,SL,SR,BL,BR

Your question doesn't make sense. It's like asking which one of the stereo channels is used for the mono track, Left or Right? It's how it's mixed. A mono recording would still contain all the info, but in one channel.

It doesn't matter what they're labeled. You only have 2 rear channels in 5.1 which will include the entire surround mix.

[Daodan]

But those channels are from somewhere, they didn't drop from the sky. They are from a 7.1 track and I want to know what label correspons to what channel. Just like you know the LFE or C mean, I want to know what's the difference between SR and BR.