So my problem is that when I play certain media files, I get incredibly quiet audio. I’ve done some investigation myself, and it seems the culprit is passthrough. Certain media files are played without passthrough (as far as I can tell from the log files), and then the audio is super super quiet. I set my AVR to max volume and I can just barely hear it – and the quality is poor probably due to the limit of my AVR. The vast majority of my media plays with passthrough and there is no volume issue whatsoever. To be clear, I want to reiterate this point, almost all of my media plays just fine at normal volume. 90% of the issues arise from a small subset of certain TV shows, usually news shows and documentary type shows, sometimes 30 minute comedies suffer from the problem too. Rarely does this affect any movies or more cinematic/drama type TV shows. It’s an odd correlation to be sure, and I could provide more examples of what works and what doesn’t if it helps.
Also, if I disable passthrough entirely in the Kodi settings, then all media suffers this same problem, which makes sense if passthrough is the problem.
So either a) I need to figure out how to force passthrough on all media or b) I need to fix the volume problem when passthrough is not active.
Running the latest LibreElec 8.0.1/Kodi 17.1 on a Asus Chromebox-M004U with Denon AVR-X4100W AVR
Using Plex backend media server and Official Plex player plugin (version 0.101)
LibreELEC:~/.kodi/temp # uname -a
Linux LibreELEC 4.9.13 #1 SMP Wed Mar 22 17:35:19 GMT 2017 x86_64 GNU/LinuxLog snipped showing the 3 pieces of media played:
1) TV show with 2 channel audio – DOESNT WORK (extremely low volume)
2) Movie with multi channel audio – DOESNT WORK (extremely low volume)
3) Movie with multi channel audio – WORKS (normal volume)
LibreELEC:~/.kodi/temp # grep "audio stream" kodi.log
08:19:43.977 T:140139832170240 DEBUG: CDVDAudio::Pause - pausing audio stream
08:19:43.977 T:140139832170240 NOTICE: Creating audio stream (codec id: 86018, channels: 2, sample rate: 48000, no pass-through)
08:19:44.666 T:140139832170240 DEBUG: CDVDAudio::Pause - pausing audio stream
08:19:44.700 T:140139832170240 DEBUG: CDVDAudio::Resume - resume audio stream
08:19:44.700 T:140141306631936 DEBUG: ActiveAE - start sync of audio stream
08:19:52.567 T:140139890919168 DEBUG: CDVDAudio::Flush - flush audio stream
08:19:52.567 T:140141306631936 DEBUG: CActiveAE::DiscardStream - audio stream deleted
08:20:12.593 T:140139815384832 DEBUG: CDVDAudio::Pause - pausing audio stream
08:20:12.594 T:140139815384832 NOTICE: Creating audio stream (codec id: 86028, channels: 6, sample rate: 48000, no pass-through)
08:20:13.075 T:140139815384832 DEBUG: CDVDAudio::Flush - flush audio stream
08:20:13.075 T:140139815384832 DEBUG: CDVDAudio::Pause - pausing audio stream
08:20:13.085 T:140139815384832 DEBUG: CDVDAudio::Pause - pausing audio stream
08:20:13.996 T:140139815384832 DEBUG: CDVDAudio::Resume - resume audio stream
08:20:13.996 T:140141306631936 DEBUG: ActiveAE - start sync of audio stream
08:20:56.290 T:140139752523520 DEBUG: CDVDAudio::Flush - flush audio stream
08:20:56.290 T:140141306631936 DEBUG: CActiveAE::DiscardStream - audio stream deleted
08:21:07.922 T:140139890919168 DEBUG: CDVDAudio::Pause - pausing audio stream
08:21:07.922 T:140139890919168 NOTICE: Creating audio stream (codec id: 86020, channels: 8, sample rate: 48000, pass-through)
08:21:08.701 T:140139890919168 DEBUG: CDVDAudio::Pause - pausing audio stream
08:21:08.786 T:140139890919168 DEBUG: CDVDAudio::Flush - flush audio stream
08:21:08.786 T:140139890919168 DEBUG: CDVDAudio::Pause - pausing audio stream
08:21:08.925 T:140139890919168 DEBUG: CDVDAudio::Pause - pausing audio stream
08:21:08.961 T:140139890919168 DEBUG: CDVDAudio::Resume - resume audio stream
08:21:08.961 T:140141306631936 DEBUG: ActiveAE - start sync of audio stream
08:21:16.787 T:140139826534144 DEBUG: CDVDAudio::Flush - flush audio stream
08:21:16.787 T:140141306631936 DEBUG: CActiveAE::DiscardStream - audio stream deletedFull Debug Log – only containing the above 3 plays after a fresh reboot
MediaInfo for the 3 pieces of media above in the logs:
1) TV Show 1 - Doesnt work
General
Format : Matroska
Format version : Version 4 / Version 2
File size : 1.80 GiB
Duration : 57 min 5 s
Overall bit rate : 4 505 kb/s
Encoded date : UTC 2017-04-22 03:01:50
Writing application : mkvmerge v9.6.0 ('Slave To Your Mind') 64bit
Writing library : libebml v1.3.4 + libmatroska v1.4.5
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : [email protected]
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 57 min 5 s
Bit rate mode : Constant
Nominal bit rate : 4 372 kb/s
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 59.940 (60000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.079
Default : Yes
Forced : No
Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : A_AAC
Duration : 57 min 5 s
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 kHz
Frame rate : 46.875 FPS (1024 spf)
Compression mode : Lossy
Default : Yes
Forced : No
2) Movie 1 - Doesnt work
General
Format : Matroska
Format version : Version 4 / Version 2
File size : 15.3 GiB
Duration : 2 h 39 min
Overall bit rate mode : Variable
Overall bit rate : 13.8 Mb/s
Encoded date : UTC 2016-09-14 13:12:51
Writing application : mkvmerge v9.4.0 ('Knurl') 64bit
Writing library : libebml v1.3.4 + libmatroska v1.4.5
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : [email protected]
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : V_MPEG4/ISO/AVC
Duration : 2 h 39 min
Bit rate : 12.6 Mb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.253
Stream size : 14.0 GiB (91%)
Writing library : x264 core 148 r2705 3f5ed56
Encoding settings : cabac=1 / ref=4 / deblock=1:-3:-3 / analyse=0x3:0x133 / me=umh / subme=9 / psy=1 / psy_rd=1.00:0.25 / mixed_ref=1 / me_range=24 / chroma_me=1 / trellis=2 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-4 / threads=24 / lookahead_threads=2 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=2 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=240 / keyint_min=24 / scenecut=40 / intra_refresh=0 / rc_lookahead=60 / rc=2pass / mbtree=1 / bitrate=12575 / ratetol=1.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / cplxblur=20.0 / qblur=0.5 / ip_ratio=1.40 / aq=1:0.50
Default : Yes
Forced : No
Audio
ID : 2
Format : FLAC
Format/Info : Free Lossless Audio Codec
Codec ID : A_FLAC
Duration : 2 h 39 min
Bit rate mode : Variable
Bit rate : 1 199 kb/s
Channel(s) : 6 channels
Channel positions : Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Frame rate : 11.719 FPS (4096 spf)
Bit depth : 16 bits
Stream size : 1.33 GiB (9%)
Writing library : libFLAC 1.2.1 (UTC 2007-09-17)
Language : English
Default : Yes
Forced : No
3) Movie 2 - works
General
Format : Matroska
Format version : Version 4 / Version 2
File size : 25.7 GiB
Duration : 1 h 56 min
Overall bit rate mode : Variable
Overall bit rate : 31.6 Mb/s
Encoded date : UTC 2017-02-04 06:09:06
Writing application : mkvmerge v9.8.0 ('Kuglblids') 64bit
Writing library : libebml v1.3.4 + libmatroska v1.4.5
Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : [email protected]
Format settings, CABAC : Yes
Format settings, ReFrames : 2 frames
Format settings, GOP : M=1, N=10
Codec ID : V_MPEG4/ISO/AVC
Duration : 1 h 56 min
Bit rate mode : Variable
Bit rate : 27.3 Mb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 23.976 (24000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.550
Stream size : 22.2 GiB (87%)
Title : MPEG-4 AVC Video / 27340 kbps / 1080p / 23.976 fps / 16:9 / High Profile 4.1
Default : Yes
Forced : No
Audio
ID : 2
Format : DTS
Format/Info : Digital Theater Systems
Format profile : MA / Core
Mode : 16
Format settings, Endianness : Big
Codec ID : A_DTS
Duration : 1 h 56 min
Bit rate mode : Variable / Constant
Bit rate : 4 207 kb/s / 1 509 kb/s
Channel(s) : 8 channels / 6 channels
Channel positions : Front: L C R, Side: L R, Back: L R, LFE / Front: L C R, Side: L R, LFE
Sampling rate : 48.0 kHz
Frame rate : 93.750 FPS (512 spf)
Bit depth : 24 bits
Compression mode : Lossless / Lossy
Stream size : 3.42 GiB (13%)
Title : DTS-HD Master Audio / 7.1 / 48 kHz / 4207 kbps / 24-bit
Language : English
Default : Yes
Forced : No