Streaming from the input

[abonam]

Hello Matt,

I would like to try to re-compile ffmpeg/ffplay to exclude the video part, just to see if there are differences on the CPU load of the PI.
Right now with the ffmpeg I got from the distribution package, the CPU load is 30%.

Can you kindly re-post the sequence to compile both?
Thanks!!
Andrea

[flatmax]

I found that avconv has disabled support for avserver completely.

You will want to get the sources and compile ffmpeg to remove all video related stuff. So for example, assuming you want to build only the encoder for ffmpeg and ffserver, with only wav file encoding and muxing, then ...
First get the sources :

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apt-get source ffmpeg

Then configure :

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./configure \
       --disable-filters \
	--disable-postproc \
	--disable-swscale \
	--disable-everything \
	--disable-decoder=pcm_bluray,pcm_dvd \
	--disable-ffplay --disable-ffprobe \
	--disable-demuxers \
	--disable-decoders \
	--disable-avresample \
	--enable-encoder=pcm_* \
	--enable-decoder=pcm_* \
	--enable-libwavpack \
	--enable-encoder=wav \
	--enable-decoder=wav \
	--enable-muxer=wav \
	--enable-demuxer=wav \
	--enable-protocol=file \
	--enable-filter=aresample \
	--enable-indev=alsa \
	--enable-ffserver --enable-ffmpeg \

Then make and install :

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make

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make install

Now if you want to do this and end up with debian packages, then you will need to do the following :
Get the source and edit the file debian/rules. Carefully change the 'CONFIG' variable to keep what is necessary in compile flags and dir detail, but switch out for your required configure flags.
Once that is done, you will want to run this to build the .deb files in the ".." directory :

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dpkg-buildpackage -us -uc -b

Please update this thread once you have success with the steps you took !

Matt

[flatmax]

Oh by the way, if you want most of the audio stuff built in, then here is what you should do ... current problem with this configuration is that it doesn't produce ffplay and ffmpeg only ffprobe and ffserver

Set your configure flags to disable mostly everything :

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	--disable-programs \
	--disable-avfilter \
	--disable-postproc \
	--disable-swresample \
	--disable-swscale \
	--disable-everything \
	--disable-decoder=pcm_bluray,pcm_dvd \

Then enable the following audio decoders, demuxers and parsers :

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	--enable-libspeex --enable-decoder=libspeex \
--enable-ffserver --enable-ffmpeg --enable-ffplay \

Audio decoders :

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	--enable-decoder=aac \
	--enable-decoder=aac_latm \
	--enable-decoder=ac3 \
	--enable-decoder=adpcm_* \
	--enable-decoder=alac \
	--enable-decoder=amrnb \
	--enable-decoder=amrwb \
	--enable-decoder=ape \
	--enable-decoder=atrac3 \
	--enable-decoder=flac \
	--enable-decoder=mp2 \
	--enable-decoder=mp3* \
	--enable-decoder=mpc7 \
	--enable-decoder=mpc8 \
	--enable-decoder=opus \
	--enable-decoder=pcm_* \
	--enable-decoder=vorbis \
	--enable-decoder=wavpack \
	--enable-decoder=wmav1 \
	--enable-decoder=wmav2 \
	--enable-decoder=wmalossless \
	--enable-decoder=wmapro \
	--enable-decoder=zlib \

demuxers :

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	--enable-demuxer=aac \
	--enable-demuxer=ac3 \
	--enable-demuxer=aiff \
	--enable-demuxer=amr \
	--enable-demuxer=ape \
	--enable-demuxer=avi \
	--enable-demuxer=flac \
	--enable-demuxer=ffm \
	--enable-demuxer=matroska \
	--enable-demuxer=mp3 \
	--enable-demuxer=mov \
	--enable-demuxer=mpc \
	--enable-demuxer=mpc8 \
	--enable-demuxer=mpegts \
	--enable-demuxer=ogg \
	--enable-demuxer=rm \
	--enable-demuxer=rtsp \
	--enable-demuxer=rtp \
	--enable-demuxer=sdp \
	--enable-demuxer=wav \
	--enable-demuxer=wv \

audio parsers :

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	--enable-parser=aac \
	--enable-parser=aac_latm \
	--enable-parser=ac3 \
	--enable-parser=flac \
	--enable-parser=mpegaudio \
	--enable-parser=opus \

audio protocols :

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	--enable-protocol=file \
--enable-protocol=http \
--enable-protocol=icecast \
--enable-protocol=rtp \
--enable-protocol=tcp \
--enable-protocol=udp \

[abonam]

Thank you!
Thats exactly what I am trying to do, so far I just run into one issue after the other.
I will follow your steps and post my progress, thanks!

Update:

Step 1: compiling only for wav
I added the

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enable-protocol=http

to the flags.
The ./configure complained about libwavpack.
Installed libwavpack-dev.
./configure ended up with warning
--enable-encoder(decoder)=wav did not match anything

This is not good as we probably will not be able to encode/decode wav.




Step 2 trying to ./configure <flag_list_for_all_the_audio_codecs>

and I get the error

speex not found using pkg-config

which it looks like has to do with the x264 libraries.
More digging to do...

[abonam]

Hello,

I managed to get some configuration working and after trying lot of combinations server-client, I am still not able to stream the audio input with less than 1 second of latency.

I am wondering if the card itself introduces some latency and if this is not the case, what are the parameters to look at in order to minimize the audio latency?
Thanks a lot in advance for your help!

[flatmax]

Hi there,
You should be able to get ultra low latencies with this card. The problem most likely lies in the buffering for the stream.
The RTP will give the lowest latency, but for that I don't think you use the ffserver - perhaps you can ? I would be interested in finding out if you can !

Matt

[abonam]

Thank you !

I will try some combinations ffserver and other things and will let you know my findings.
Cheers,
Andrea

[flatmax]

This initial part of the thread talks a little about rtp :
viewtopic.php?f=5&t=64#p176

But that doesn't implement it using the ffserver.

Matt

[abonam]

Yes, thanks..
Ok, my problem is to stream music wit the lowest latency possible.
ffmpeg is one of the solution, but at this point i don't think it is the only solution.
RTP is needed for low latency.
I managed to measure the card latency with the ecasound command and I noticed a very low latency, about 20 ms.
The latency measured is the chain AD/DA plus the latency introduced by the ecasound command itself.
I want to find the magic combination of commands that let us to stream music almost in real-time

Screen Shot 2017-06-07 at 6.28.49 PM.png (153.01 KiB) Viewed 5654 times

If anyone can chime in, would be really appreciated!!!

The command is:

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ecasound -B:rtlowlatency -b:256 -f:s16_le,2,44100 -i:alsahw,1,0 -o:alsahw,1,0

[Username]

Any updates on this? I'm looking for a sonos play 5 like line-in alternative to stream to multi-room with squeezelite. I haven't found one yet. This post could help me do what I'm looking to do.