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how to enable httpd stream with aac encoding ?

Posted: January 14th, 2019, 7:06 pm
by piogac6088
Hi,

I am successfully (httpd output) streaming using vorbis and lame (mp3) encoder.
I can not find any info how to encode this stream in aac .

So I need some help in this.
Is it possible to do httpd (output) stream using aac encoder ?
If yes - how to do this (compiling mpd ect.) ?

Many thanks in advance,

Peter

Re: how to enable httpd stream with aac encoding ?

Posted: January 15th, 2019, 7:34 am
by max
MPD currently doesn't have an encoder plugin for AAC, so this isn't possible. But since AAC is inferior to Vorbis and Opus, why would anybody want to use AAC?

Re: how to enable httpd stream with aac encoding ?

Posted: January 15th, 2019, 12:04 pm
by piogac6088
max wrote:
January 15th, 2019, 7:34 am
MPD currently doesn't have an encoder plugin for AAC, so this isn't possible. But since AAC is inferior to Vorbis and Opus, why would anybody want to use AAC?
Thank you very much for your answer. It changes my point of view about this issue.
I have always thought that AAC has the best quality/bitrate index among all loseless audio codecs.
Now it is clear ...
All best ...

Re: how to enable httpd stream with aac encoding ?

Posted: January 15th, 2019, 7:06 pm
by tortuga_Bob
AAC is not a lossless codec. You are confusing it with Apple Lossless (ALAC). AAC has a bit rate of 256 kb/s.

Re: how to enable httpd stream with aac encoding ?

Posted: January 15th, 2019, 8:34 pm
by max
Confusingly, both AAC and ALAC use the file name extension ".mp4".

I think neither AAC nor ALAC are worthwile. They are proprietary codecs which are not better than Vorbis/Opus and FLAC. Just stick with those free codecs.

Re: how to enable httpd stream with aac encoding ?

Posted: February 28th, 2019, 11:19 pm
by marmitesandwich
In my experience, aac audio files have an extension of .m4a (mp4 audio?). This is the way iTunes creates aac files, anyway. And it seems to be recognised by mpd.

I also understood that aac encoding gave a more efficient result than .mp3 (quality of result relative to a given bitrate). This is why it is used in Europe for DAB broadcasting (DAB+), and by the BBC for internet streams of BBC radio.That suggests that it is not a proprietary format. And mpd seems to play those streams just fine.

AAC has no fixed bitrate, just like mp3, and other lossy formats.

Maybe I misunderstood?
Marmite.

Re: how to enable httpd stream with aac encoding ?

Posted: March 1st, 2019, 7:42 am
by max
marmitesandwich wrote:
February 28th, 2019, 11:19 pm
That suggests that it is not a proprietary format.
Unlike Vorbis and Opus, it is patent encumbered. See https://en.wikipedia.org/wiki/Advanced_ ... nd_patents

There is no free AAC encoder. There is an AAC encoder in FFmpeg, but its license is incompatible with the GPL, thus its use with MPD is forbidden by copyright law.

Both aspects make AAC "proprietary", by my definition of "proprietary".