Demuxed audio filenames

[neuron2]

I'm adding audio demux support to my version of DVD2AVI (now called DGIndex). I'm just now doing MPEG audio demuxing from transport streams. I'm confused about filenames.

There can be either MPEG1 or MPEG2 audio, so I thought to use names like this:

file.m1a (for MPEG1 audio all layers)
file.m2a (for MPEG2 audio all layers)

But media player doesn't play these names. If I demux an MPEG2 layer 2 ES and name it file.mp2, media player plays it.

So my question is whether there is a standard for the filenames. Can I put demuxed MPEG1 into a file called file.mp2? If not, what do I call it so it is playable?

And what do I call demuxed AAC files?

Thank you. If this belongs better in the Audio forum please move it.

[eb]

@ neuron 2,

My proposals: .m2p,.mp2 .mpa, .ac3

It can be seen that today practicly there is tendency for all programs, players that they are in first step analising let say 1MB of the file then use what should be used to play the file, in contrary to the pure Windows players.

eb

[neuron2]

Originally posted by eb
My proposals: .m2p, .mp2, .mpa, .ac3
Thanks, eb.

.ac3 is obvious, but what do the others denote (in terms of MPEG1/MPEG2), and are they playable directly by players or would they need to be renamed?

I'm not so much interested in proposals as I am in the actual naming used by existing applications.

[bb]

- MP2 is MPEG-1 Audio Layer II.
- M2P should be an MPEG-2 program stream, but there was a stupid application which mistakenly understood it as MP2 (I think it was Pinnacle).
- MPA is MPEG Audio in general; can be either MPEG-1 or MPEG-2 audio layers I or II, I believe. MPA can - and often will - contain MP2.
- MP3 is well-known for MPEG-1 Audio Layer III (NOT MPEG-3!)

I have seen m1a and m2a, too, but as far as I know they are rarely used, usually by muxers/demuxers that input or produce pairs like m2v/m2a. I think these are not very common.

Regarding the often used MP2, you have to rename it to MPA for some (e.g. authoring) programs, some insist on MP2...

bb

[neuron2]

Thank you for the information.

So, how about if I just use .mpa for all MPEG audio? Will Media Player recognize that extension?

[eb]

Originally posted by neuron2

So, how about if I just use .mpa for all MPEG audio? Will Media Player recognize that extension?

Yes, it will be universal solution.
In case of multiaudio strems in the .TS files I propose to name them as xx1.mpa, ,,, ,xx16.mpa.
Up to 16 audio PIDs in .TS records will be more and more popular when recording from satelites /Music Choice or Xtra Music channels/

But it will be nice to keep xx?.ac3 for ac3 audios.

eb

PS. neuron 2 if you need such ssmples I can prepare them for you

[SeeMoreDigital]

With regard to de-muxing audio streams. Don't forget to include .AAC audio. It's rare... but it's there!


Cheers

[neuron2]

Yes, AAC is on my work list. Can you please supply a stream with AAC audio? Thank you.

I've done the MPEG audio as .mpa and it works well. I do not have a demux all capability because you can set only one PID at a time. So I don't need xx1.mpa.

[Cyberia]

@neuron2 - I think .mpa will work universally, however please be sure the filename contains the real audio format. MPA will get all the files to be playable, but we may need to know downstream if it's an MPA, MP2 or MP3 file.


eg#1: "VTS01 AC3 T01 2_0ch 192Kbps DELAY 0ms.ac3"
^
|----------Specify the file type like this, as an example.

eg#2: "VTS01 MP3 T01 2_0ch 192Kbps DELAY 0ms.mpa"

[SeeMoreDigital]

Originally posted by neuron2
Yes, AAC is on my work list. Can you please supply a stream with AAC audio? Thank you. Yep sure.

If you PM me with an address I'll mail you the one and only AAC.ts file I've got - the file size is 94.1MB.


Cheers