LPCM channel mapping

[Tripplesixty]

I am currently trying to rip a few of my Blurays to my HTPC. I have been very successful thus far however I am running into problems with the current Bluray, Deja Vu.

I am trying to capture the 5.1 LPCM audio from the source however when I demux the source m2ts using eac3to HD stream extractor GUI, I get a .wav file that I believe has the channels mapped improperly.

I tested it by muxing the .wav and the h264 stream into an mkv container and playing it back with VLC on a 2 channel system. The FL speaker seems to play fine however the audio coming from the FR speaker sounds as if it was a rear channel (little or no vocals, mainly back ground noise).

My Question is, what program can I use to (1) Inspect the 5.1 channel .wav file (2) remap the channels (3) what is the proper channel ordering for 5.1 channel LPCM?

[tebasuna51]

Put the eac3to log.

1) Audacity or other multichannel audio editor (SoundForge, Audition, ...)

2) The same audio editor.

3) You don't need know the internal LPCM channel order because you can't edit it.
eac3to work fine remapping the LPCM 5.1 channels. Maybe you have corrupt data.

[Tripplesixty]

Here is the eac3to log

eac3to v3.24
command line: "C:\Program Files (x86)\eac3to\eac3to.exe" "E:\" 2) 2:"G:\Videos\Deja Vu\2_2_video.mkv" 3:"G:\Videos\Deja Vu\2_3_audio.wav" 4:"G:\Videos\Deja Vu\2_4_audio.ac3" 8:"G:\Videos\Deja Vu\2_8_subtitle.sup" -progressnumbers
------------------------------------------------------------------------------
M2TS, 1 video track, 5 audio tracks, 6 subtitle tracks, 2:06:26, 24p /1.001
1: Chapters, 16 chapters
2: VC-1, 1080p24 /1.001 (16:9)
3: RAW/PCM, English, 5.1 channels, 16 bits, 48kHz
4: AC3, English, 5.1 channels, 640kbps, 48kHz, dialnorm: -27dB
5: AC3, French, 5.1 channels, 640kbps, 48kHz, dialnorm: -27dB
6: AC3, Spanish, 5.1 channels, 640kbps, 48kHz, dialnorm: -27dB
7: AC3, English, 2.0 channels, 192kbps, 48kHz, dialnorm: -27dB
8: Subtitle (PGS), English
9: Subtitle (PGS), French
10: Subtitle (PGS), Spanish
11: Subtitle (PGS), French
12: Subtitle (PGS), Spanish
13: Subtitle (PGS), English
[v02] Extracting video track number 2...
[a04] Extracting audio track number 4...
[a04] Removing AC3 dialog normalization...
[a03] Extracting audio track number 3...
[a03] Reading RAW/PCM...
[a03] Swapping endian...
[a03] Remapping channels...
[a03] Writing WAV...
[s08] Extracting subtitle track number 8...
[v02] Muxing video to Matroska...
[a03] Creating file "G:\Videos\Deja Vu\2_3_audio.wav"...
[a04] Creating file "G:\Videos\Deja Vu\2_4_audio.ac3"...
[s08] Creating file "G:\Videos\Deja Vu\2_8_subtitle.sup"...
[a03] The original audio track has a constant bit depth of 16 bits.
[a03] Caution: The WAV file is bigger than 4GB. <WARNING>
[a03] Some WAV readers might not be able to handle this file correctly. <WARNING>
[a03] Audio overlaps for 8ms at playtime 0:31:16. <WARNING>
[a03] Audio overlaps for 6ms at playtime 1:07:09. <WARNING>
[a03] Audio overlaps for 6ms at playtime 1:49:07. <WARNING>
[a04] Audio overlaps for 10ms at playtime 0:05:04. <WARNING>
[a04] Audio overlaps for 31ms at playtime 0:11:25. <WARNING>
[a04] Audio overlaps for 10ms at playtime 0:17:04. <WARNING>
[a04] Audio overlaps for 21ms at playtime 0:31:16. <WARNING>
[a04] Audio overlaps for 12ms at playtime 0:38:37. <WARNING>
[a04] Audio overlaps for 31ms at playtime 0:44:38. <WARNING>
[a04] Audio overlaps for 24ms at playtime 1:07:09. <WARNING>
[a04] Audio overlaps for 27ms at playtime 1:09:41. <WARNING>
[a04] Audio overlaps for 23ms at playtime 1:16:11. <WARNING>
[a04] Audio overlaps for 11ms at playtime 1:30:43. <WARNING>
[a04] Audio overlaps for 25ms at playtime 1:49:07. <WARNING>
[a03] Starting 2nd pass...
[a03] Reading WAV...
[a03] Realizing RAW/PCM gaps...
[a03] Writing WAV...
[a03] Creating file "G:\Videos\Deja Vu\2_3_audio.wav"...
[a03] The processed audio track has a constant bit depth of 16 bits.
[a03] Caution: The WAV file is bigger than 4GB. <WARNING>
[a03] Some WAV readers might not be able to handle this file correctly. <WARNING>
[a04] Starting 2nd pass...
[a04] Realizing (E-)AC3 gaps...
[a04] Creating file "G:\Videos\Deja Vu\2_4_audio.ac3"...
Added fps value (24 /1.001) to MKV header.
Video track 2 contains 181905 frames.
Subtitle track 8 contains 1595 captions.
eac3to processing took 34 minutes, 2 seconds.
Done.

[tebasuna51]

[a03] Audio overlaps for 8ms at playtime 0:31:16. <WARNING>
[a03] Audio overlaps for 6ms at playtime 1:07:09. <WARNING>
[a03] Audio overlaps for 6ms at playtime 1:49:07. <WARNING>

I read about some problems with Deja Vu and overlaps between .m2ts (I don't remember where), check if the problem appears after the cut points.
Maybe a option is join before all .m2ts, from the playlist, with tsMuxeR.

[Tripplesixty]

I used tsMuxeR to join the .m2ts files from the play list, however the audio track still seems to be messed up (same issue as before) when playing the combined .m2ts file in VLC.

[tebasuna51]

If you play the wav, channel by channel, in Audacity you listen the same problem?

[Tripplesixty]

I opened up the .wav file in audacity and all the channels were there in what appears to be correct order. FL FR C... and so on. Obviously all of the voice comes through on the center channel. R and L audio only provide environmental sounds, music and other loud stuff.

I figured out there were a number of problems that led to my my audio being off. I currently have a receiver and speakers in 2.0 configuration, the hardware is set to downmix everything to 2.0 which is great when I bit stream DTS-MA and TrueHD signals. However the problem with LPCM when played in VLC is the separate channels were getting downmixed in software (because VLC knows or previously asked me for my speaker configuration) and VLC was set to some generic audio output module so it was not delivering the raw LPCM channels through S/PDIF over HDMI.

I still cannot get VLC to stream 5.1 LPCM through S/PDIF but thats a separate issue I'm not too worried about as I don't use VLC for watching movies. But I am able to get the signal properly downmixed and playing in 2.0 using a different speaker config settings and the correct audio output module for my ATI HDMI audio.

Soon enough Ill have a 5.1 setup and will be able to listen to most tracks in their entirety :).