[flac-dev] using libflac++ on a live internet stream

[Richard Ash]

On Wed, 13 Dec 2017 09:12:43 -0700
Chris Barrett <cbarrett.colo at gmail.com> wrote:

> Thanks Brian.  I converted everything to libFLAC and got the same
> results.
> 
> Here is some debug output
> encoder:
> [34.270050] FLAC encoder set succeeded
> [34.271183] write_callback, frame: 0, samples: 0
> [34.271282] write_callback, frame: 0, samples: 0
> [34.271313] write_callback, frame: 0, samples: 0
> [34.271351] FLAC encoder initialization succeeded
> [34.356251] write_callback, frame: 0, samples: 4096
> [34.441582] write_callback, frame: 1, samples: 4096
> [34.526905] write_callback, frame: 2, samples: 4096
> [34.612213] write_callback, frame: 3, samples: 4096
> [34.697556] write_callback, frame: 4, samples: 4096
> [34.697594] SendChanDataMsg: 146
> [34.782898] write_callback, frame: 5, samples: 4096
> [34.782936] SendChanDataMsg: 12
> [34.868168] write_callback, frame: 6, samples: 4096
> [34.868210] SendChanDataMsg: 12
> 
> The audio is silence, so I believe there is a high compression ratio
> ((4096 x 5) + metadata) -> 146 bytes

I think this is your problem - the encoder is being so effective on
digital silence input, that it isn't filling it's output buffer and so
isn't pushing the packet out. If you send real audio (or even LSB
dither noise) then it will fill the buffer and get going.
I seem to remember a thread on this list complaining about this
behaviour at some point in the past, to which the eventual work-around
was mixing in some dither noise to digital silence stop the frames
getting tiny.

Richard