The VideoLAN Forums

Posted: **29 Dec 2020 03:16**

Hi,

VLC is throwing this error on an mp4 that contains a Dolby TrueHD track along a video stream:
main error: Codec `mlpa' (No description for this codec) is not supported.

Audio stream was extracted with ffmpeg v4.3.1 and remuxed with video using mp4box (which also throws a warning). Link to VLC debug file as well here's a link to the mp4. According to http://mp4ra.org/#/codecs , mlpa is Dolby MLP. Not sure if this is an VLC issue or ffmpeg ... thanks.

Mediainfo output: (audio section)

Code: Select all

Audio
ID                                       : 2
Format                                   : MLP FBA 16-ch
Format/Info                              : Meridian Lossless Packing FBA with 16-channel presentation
Commercial name                          : Dolby TrueHD with Dolby Atmos
Codec ID                                 : mlpa
Duration                                 : 22 s 998 ms
Source duration                          : 22 s 931 ms
Bit rate mode                            : Variable
Maximum bit rate                         : 7 134 kb/s
Channel(s)                               : 8 channels
Channel layout                           : L R C LFE Ls Rs Lb Rb
Sampling rate                            : 48.0 kHz
Frame rate                               : 1 200.000 FPS (40 SPF)
Compression mode                         : Lossless
Source stream size                       : 11.0 MiB (8%)
Default                                  : Yes
Alternate group                          : 1
Tagged date                              : UTC 2020-12-28 13:29:50
Number of dynamic objects                : 13
Bed channel count                        : 1 channel
Bed channel configuration                : LFE

Posted: **29 Dec 2020 11:09**

check Nightly Build of VLC from tomorrow

unsure for 3.x

Posted: **29 Dec 2020 11:50**

check Nightly Build of VLC from tomorrow

unsure for 3.x

Thx for the reply. Tomorrow as in Dec 29 or Dec 30 ? Does this imply that potentially some support or code change is added in VLC 4.x for codec ‘mlpa’ ? Oh someone already made a change

Posted: **30 Dec 2020 17:56**

Ok I tried this nightly version: https://artifacts.videolan.org/vlc/nigh ... 1230-0432/ I don't get the error, the video and audio plays but within 10-30sec, VLC controls/video freezes. I can't take any logs and this happens every time I play the linked media in first post, the main player goes over the messages window and then freezes, but audio continues to play. thx.

I started vlc own CLI with -vv. when it freezes it keeps spitting these out:

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[00007f97138af400] main input debug: EOF reached
[00007f97138af400] main input debug: waiting decoder fifos to empty
[00007f97138af400] main input debug: waiting decoder fifos to empty
...

Posted: **31 Dec 2020 11:59**

Try these builds instead:
http://nightlies.videolan.org

The VideoLAN Forums

Codec `mlpa' is not supported

Codec `mlpa' is not supported

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