Missing audio tracks

[bischelcj]

I uploaded a 5.1 version of an .mp4, but only two audio tracks appeared, 1:1 L and 1:2 R.

Would the .mp4 file collapse the 5.1 into just two outputs?

I'm new to using DCP-o-matic, and I looked for similar posts but couldn't find any. Still, I'm sure I'm missing something.

[carl]

Can you attach or email me the ffprobe.log file from inside the DCP-o-matic project folder?

[bischelcj]

Thanks for responding!

I've attached the file below.

In addition, I received this warning before making the DCP:

Some of your content has audio but you have not set the audio language. It is advisable to set the audio language in the "DCP" tab unless your audio has no spoken parts.
Your DCP has 6 audio channels, rather than 8 or 16. This may cause some distributors to raise QC errors when they check your DCP. To avoid this, set the DCP audio channels to 8 or 16.
Your audio level is very high (on L, R). You should reduce the gain of your audio content.

[carl]

Thanks. The log file shows that the audio is being picked up as

Stream #0:1[0x2](eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)

i.e. AAC 48kHz stereo. If you are 100% sure it's not stereo, something has gone wrong with the way FFmpeg (the decoding library) is reading the file... would it be possible to send me your mp4, or is that not feasible?

Some of your content has audio but you have not set the audio language. It is advisable to set the audio language in the "DCP" tab unless your audio has no spoken parts.
Your DCP has 6 audio channels, rather than 8 or 16. This may cause some distributors to raise QC errors when they check your DCP. To avoid this, set the DCP audio channels to 8 or 16.
Your audio level is very high (on L, R). You should reduce the gain of your audio content.

These are hints of slightly varying importance. The main one you should pay attention to is the audio level - it's likely that unless you fix it your DCP will be very loud in the cinema. It can be adjusted there, but it may surprise people. I would suggest setting the "gain" in the Content Audio tab to -10.

[bischelcj]

I believe what happened is that I exported from Adobe Premiere incorrectly.

Unfortunately, I've been boot-strapping a lot of things because I can't afford professionals.

I will re-export next week when I can go back to the library and make a new DCP again.

Thank you for all of your help, I really do appreciate it!

[bischelcj]

Hi Carl,

I think I've figured this out, but I'd like to double check. I'm uploading the ffprobe.log again. This time, I exported the project from Adobe in multichannel and added each 5.1 track individually. Then, in DCP-o-matic, I lowered the gain by 10 db. How does everything look?

Thank you!

[Carsten]

You should be able to check the number of audio channels contained in the MP4 with Mac OS X Quicktime player, VLC, etc.

I know that setting up proper multichannel timelines and export can be tricky in most editing applications.

[carl]

Looks better!

Stream #0:1[0x2](eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, 5.1, fltp, 317 kb/s (default)