ACM / PCM encoder

[fred48fm]

Hi,

I try to use the ACM encoder to strea to an Icecast server but it seems that i missed something...
Can you tell me the settings needed ?

With encoder ACM and encoder profile set either to ACM or WAV, nothing works.
After few searches, ACM doesn't seems to be deprecated in windows.

Is there some codec I need to install ?

Best regards

[radio42]

In what format do you want to stream to ICEcast.
The Audio Compression Manager is a legacy option still there for old Win95 compliance. However not really recommended anymore : https://learn.microsoft.com/en-us/windo ... on-manager

But you must configure it first within Windows. I personally have never used it for streaming.
Normally you use a direct codec, like OGG, MP3, FLAC, AAC… for streaming.

[fred48fm]

Thank you for the answer.

Here the point is to stream a raw PCM stream to an Icecast server.
The goal is to use as a source in a IP decoder (Deva RX).

What settings should I use ?
The WAV encoder is not listed in the encoder selection list on the streaming section.

[radio42]

Back from vacation... after some further checking, I don't think Icecast even supports WAV data as a source for streaming. But I'll double check...
Looks like ICEcast is not supporting this format (WAV/PCM data).

So why don't you stream in FLAC format, which is lossless and officially supported?

I enhanced the module, so I could stream in PCM/WAV via ACM to ICEcast without error. ICEcast also receives the data. But I could play such stream, as the header format is unknown by any client ‚listening‘ to such stream. So I could provide such version as an update soon, but I don’t know, if that works with your hardware, as as said, no normal player can playback such stream.

[fred48fm]

Hi

Thank you for your time !
I'll check that.

FLAC is a perfect solution, but it's not supported by our hardware...

Best regards

[radio42]

As said, the new version also supports streaming with ACM and you can set the PCM format withit. But I can not test this with your hardware. Note, that those streams might not directly be playable - but I guess this is not your usecase.

[fred48fm]

I've just tryed.

That work, the stream is received by Icecast.
But the stream is not playable by our hardware.

Thank you for trying

I'll ask the manufacturer for more informations about the way the hardware handle PCM streams.

Best regards

[radio42]

The 'problem' with PCM streams is, that they are plain data streams, but do not carry the meta information. For PCM streams this would be at least the bitrate (e.g. 44100 Hz), the depth (e.g. 16 bit), number of channels (e.g. stereo).

And as this info is missing the client wouldn't know how to decode it.
In your case, the hardway might need to be configured with these exact settings and then it might be used by the hardware. But a client could still not play it.
So I still don't know your use case for the hardware IP decoder (Deva RX)?

Do you want to make a WAV stream available to the public (bt if yes, why the extra hardware and not use FLAC)?
Or transmit lossless data from point A to point B (in that case I would suggest a Virual Audio Cable, i.e. an AoIP solution)?

[fred48fm]

After few more tries, i've gave up on this idea

For full understanding and if that could help someone, our use case is the following :

- For studio to DAB+ broadcast, we use a FLAC stream to avoid multiple signal re-encoding (DAB+ implies to re-encode audio stream to AAC+ at multiplexing stage).
This stream goes from PF internal encoder to an Icecast server.
- For studio to FM broadcast, we currently use AAC encoder from PF. The idea was to level up and use WAV as FLAC was not supported by our hardware. But as you said, it's not well supported. And the hardware manufacturer doesn't seems to plan to support FLAC.
-> So we changed hardware for a FLAC supported device (BARIX M400).

And for public stream we output MP3 from PF to an Azuracast streaming server.

Best regards

[radio42]

Your use case sounds more what I described in my last scenario. You wanted to transit a raw PCM signal from location A to location B.
But you got 'stuck' with your hardware device to do so.
So why don't you directy use an AoIP solution without any hardware at all - the hardware also transmits the signal via internal software to the 2nd location.
I.e. use a virtual audio cable.