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Old 27th January 2019, 13:56   #1  |  Link
vanden
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Join Date: Sep 2007
Posts: 104
.thd to .thd+ac3 bit depth

Hello,

I have a problem with a TrueHD Atmos 7.1 track from a MKV.
I want to remux it to ISO bluray with TSMuxer ... but we have to add the AC3 track for TSMuxer accept muxing.
So I create a TrueHD+ac3 track with eac3to :
Code:
eac3to v3.34
command line: "C:\Users\Administrateur\Desktop\eac3to334-UsEac3to129\eac3to.exe"  "G:\Ready Player One Dolby TrueHD French.thd" "G:\Ready Player One Dolby TrueHD French.thd_.thd+ac3" -640 -progressnumbers -log="G:\Ready Player One Dolby TrueHD French.thd_Job_2.log"
------------------------------------------------------------------------------
TrueHD (Atmos), 7.1 channels, 48kHz
AC3 encoding doesn't support back channels. Will mix them into the surround.
Decoding with libav/ffmpeg...
Mixing surround channels...
Remapping channels...
Encoding AC3 <640kbps> with libAften...
Creating file "G:\Ready Player One Dolby TrueHD French.thd_.thd+ac3"...
Original audio track, L+R+C+BL+BR+SL+SR: max 24 bits, average 17 bits.
Original audio track, LFE: constant bit depth of 16 bits.
Processed audio track, L+R+C+SL+SR: max 24 bits, average 18 bits.
Processed audio track, LFE: constant bit depth of 16 bits.
eac3to processing took 28 minutes, 16 seconds.
Done.
The track seems in 24bit according to eac3to log ... but when I look with MediaInfo or BDinfo I am told that it is 16 bit :
Code:
BDinfo AUDIO :

Codec                           Language        Bitrate         Description     
-----                           --------        -------         -----------     
Dolby TrueHD/Atmos Audio        French          3748 kbps       7.1 / 48 kHz /  3108 kbps / 16-bit (AC3 Embedded: 5.1 / 48 kHz /   640 kbps / DN -31dB)


MediaInfo Audio :
Format                                   : AC-3 MLP FBA 16-ch
Format/Info                              : Audio Coding 3 + Meridian Lossless Packing FBA with 16-channel presentation
Nom commercial                           : Dolby TrueHD with Dolby Atmos
Durée                                    : 13 h 39 min
Type de débit                            : Variable
Débit                                    : 640 kb/s
Débit maximum                            : 4 917 kb/s
Canaux                                   : 8 canaux
Channel layout                           : L R C LFE Ls Rs Lb Rb
Echantillonnage                          : 48,0 kHz
Images par seconde                       : 31,250 Im/s (1536 SPF)
Profondeur des couleurs                  : 16 bits
Mode de compression                      : Avec perte
Taille du flux                           : 3,66 Gio (100%)
ServiceKind/String                       : Complete Main
Number of dynamic objects                : 11
Bed channel count                        : 1 canal
Bed channel configuration                : LFE
On the other hand when I encode the track TrueHD+ac3 in Wav it is well of 24 bit (MediaInfo & Foobar2000) :
Code:
eac3to :
eac3to v3.34
command line: "C:\Users\Administrateur\Desktop\eac3to334-UsEac3to129\eac3to.exe"  "G:\Ready Player One Dolby TrueHD French.thd+ac3" "G:\Ready Player One Dolby TrueHD French.thd+ac3_.wav" -progressnumbers -log="G:\Ready Player One Dolby TrueHD French.thd+ac3_Job_4.log"
------------------------------------------------------------------------------
TrueHD/AC3 (Atmos), 7.1 channels, 48kHz
(embedded: AC3, 5.1 channels, 640kbps, 48kHz)
Extracting TrueHD stream...
Decoding with libav/ffmpeg...
Writing WAV...
Creating file "G:\Ready Player One Dolby TrueHD French.thd+ac3_.wav"...
Original audio track, L+R+C+BL+BR+SL+SR: max 24 bits, average 17 bits.
Original audio track, LFE: constant bit depth of 16 bits.
Caution: The WAV file is bigger than 4GB.  <WARNING>
Some WAV readers might not be able to handle this file correctly.  <WARNING>
eac3to processing took 9 minutes, 59 seconds.
Done.


MediaInfo :
Général
Nom complet                              : G:\Ready Player One Dolby TrueHD French.thd+ac3_.wav
Format                                   : Wave
Taille du fichier                        : 9,01 Gio
Durée                                    : 2 h 19 min
Type de débit global                     : Constant
Débit global moyen                       : 9 216 kb/s

Audio
Format                                   : PCM
Paramètres du format                     : Little / Signed
Identifiant du codec                     : 00000001-0000-0010-8000-00AA00389B71
Durée                                    : 2 h 19 min
Type de débit                            : Constant
Débit                                    : 9 216 kb/s
Canaux                                   : 8 canaux
Channel layout                           : L R C LFE Lb Lr Ls Rs
Echantillonnage                          : 48,0 kHz
Profondeur des couleurs                  : 24 bits
Taille du flux                           : 9,01 Gio (100%)
So it's 16bit or the 24bit ... I'm lost !

Last edited by vanden; 27th January 2019 at 14:38.
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