[IDEA] codec selector (switcher)

[kitamura_design]

I saw different strange lines in the log when I played my test m4a files that MPD determined needed the ffmpeg aac decoder.

Convert the files to FLAC and all will be good :-)

I know all will be good with converting to FLAC :-)

But I want higher sound quality on playing Web-radio casted by AAC as much as I could.

FDK-AAC codec will be the best solution for AAC playback on MPD, I think.
But I've heard before that FDK-AAC is not allowed to be distributed as binary due to its license or something like that.

[Tim Curtis]

Ok now I understand.

AAC encoded web radio is decoded by faad according to MPD log

Code:

Oct 18 20:41 : playlist: play 4:"http://aac-64.streamthejazzgroove.com:80/stream"
Oct 18 20:41 : curl: icy-metaint=16000
Oct 18 20:41 : decoder_thread: probing plugin faad
Oct 18 20:41 : decoder: audio_format=44100:16:2, seekable=false
Oct 18 20:41 : alsa_output: opened hw:0,0 type=HW
Oct 18 20:41 : alsa_output: buffer: size=128..131072 time=2902..2972155
Oct 18 20:41 : alsa_output: period: size=64..65536 time=1451..1486078
Oct 18 20:41 : alsa_output: default period_time = buffer_time/4 = 500000/4 = 125000
Oct 18 20:41 : alsa_output: format=S16_LE (Signed 16 bit Little Endian)
Oct 18 20:41 : alsa_output: buffer_size=22050 period_size=4410
Oct 18 20:41 : output: opened plugin=alsa name="ALSA default" audio_format=44100:16:2

To use fdk-aac for AAC encoded web radio you would need to have the code block in mpd.conf with enable="no" for faad decoder and due to the restrictive license, you would need to custom compile ffmpeg (libav) with the fdk-aac codec and install it on Moode OS. The license prohibits me from doing this and redistributing it.
https://trac.ffmpeg.org/wiki/Encode/AAC#fdk_aac
https://wiki.libav.org/Encoding/aac

-Tim

[kitamura_design]

Ok now I understand.

AAC encoded web radio is decoded by faad according to MPD log

Code:

Oct 18 20:41 : playlist: play 4:"http://aac-64.streamthejazzgroove.com:80/stream"
Oct 18 20:41 : curl: icy-metaint=16000
Oct 18 20:41 : decoder_thread: probing plugin faad
Oct 18 20:41 : decoder: audio_format=44100:16:2, seekable=false
Oct 18 20:41 : alsa_output: opened hw:0,0 type=HW
Oct 18 20:41 : alsa_output: buffer: size=128..131072 time=2902..2972155
Oct 18 20:41 : alsa_output: period: size=64..65536 time=1451..1486078
Oct 18 20:41 : alsa_output: default period_time = buffer_time/4 = 500000/4 = 125000
Oct 18 20:41 : alsa_output: format=S16_LE (Signed 16 bit Little Endian)
Oct 18 20:41 : alsa_output: buffer_size=22050 period_size=4410
Oct 18 20:41 : output: opened plugin=alsa name="ALSA default" audio_format=44100:16:2

To use fdk-aac for AAC encoded web radio you would need to have the code block in mpd.conf with enable="no" for faad decoder and due to the restrictive license, you would need to custom compile ffmpeg (libav) with the fdk-aac codec and install it on Moode OS. The license prohibits me from doing this and redistributing it.
https://trac.ffmpeg.org/wiki/Encode/AAC#fdk_aac
https://wiki.libav.org/Encoding/aac

-Tim

Thanks for your understanding

Installing fdk-aac codec is not the best solution for everyone, its so difficult for Linux beginners like me.
But at least, we could expect to improve the sound quality of AAC only by making disable faad codec.
Because faad decodes at 16bit, but ffmpeg/aac can decode at 24bit.

So, if you can accept to build the next moOde without faad, everyone would be little happier at AAC - radio - listening, I think.
(But need to fix the strange "Clipping Noise" message bug on ffmpeg/aac first, you know)

kitamura_design

[Tim Curtis]

Bit depth does not exist in lossy audio encoding formats like AAC or MP3 so even if the decoder output was 24 bit it has no way of knowing what the source bit depth was. 

-Tim

[kitamura_design]

Bit depth does not exist in lossy audio encoding formats like AAC or MP3 so even if the decoder output was 24 bit it has no way of knowing what the source bit depth was. 

-Tim

Hmm...
But seems sound become better with ffmpeg/aac. Did you try it?