Dolby MLP (mlpa): Codec not supported


InfusePro (ATV4K) is silently discarding the audio stream in an mp4 that contains a Dolby TrueHD track along a video stream.

Audio stream was extracted with ffmpeg v4.3.1 and remuxed with video using mp4box (which also throws a warning). Here’s a link to the mp4. According to The 'MP4' Registration Authority , mlpa is Dolby MLP. Not sure if this is an InfusePro issue or ffmpeg … thanks.

Mediainfo output: (audio section)

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

Videolan VLC devs replied and provided an update to their nightly 4.0 which indicates some issue with media players not handling properly Dolby TrueHD codec support in ISO BMFF such as mp4.

In a nutshell, does InfusePro support Dolby TrueHD (MLP) in an mp4 container?

Would you be able to upload a sample video we could review here?

Samples up to 20GB in size can be submitted here.

Hi, is the link in the first post not ok or do I need to instead upload to dropbox ? thanks. (its uploaded to DB)

Ah missed that.

We’ll take a look. Thanks.

@james I was just about to open a new topic about this :slight_smile:
Did you guys already look into this and can share status / details ?

Note that converting the Dolby TrueHD to lpcm (pcm_s24be) and then muxing it into the mp4, works well in infuse. Showing as PCM 7.1 .

yes doing the conversion to lpcm works. if you have a small segment of an mp4 with mlpa to share, please do and provide a link or upload to Infuse DB, the more the better to help Infuse. I’ve shared a link to one in my OP.