Impossible to get metadata from FLAC stream

[jduffas]

Describe the bug
Impossible to get metadata from FLAC source with Liquidsoap 2.x

To Reproduce

I use B.U.T.T. to stream a FLAC stream, and get it with input.harbor or input.http on icecast2 server.
I got no metadata,

my code :
`source_Flac = input.http("http://localhost:8000/source_TEST")

source = mksafe(source_Flac)

output.icecast(%fdkaac(aot="mpeg4_aac_lc", bitrate=128), host = "localhost", port = 8000, password = "xxx", mount = "singsingaac128TEST", name="Radio Sing Sing aac 128 Kb/s", description="Un nouveau souffle pour vos oreilles", url="http://sing-sing-bis.org", genre="eclectic", source)`

source can also be
source_Flac = input.harbor("Source_TEST",port=8080,password="xxx")

no matter what the output format is (I tried aac, mp3, etc.)

Expected behavior
A clear and concise description of what you expected to happen.

Version details

• Ubuntu Focal
• Version 2.1.4 or even Dev version of liquidsoap
• icecast2 server version 1.4.4 or 2.4.99.3 (2.5 beta 3)

In the contrary, if I use Liquidsoap version 1.4.3 I got metadata with no problem.

Install method
I installed the Ubuntu : liquidsoap_2.1.4-ubuntu-focal-1_amd64.deb
idem with the 2.2.0+git@2a3bf62 version.
the icecast is the 2.5 Beta 3 (I got the same result with 2.4.4 version)

Common issues
Only FLAC source with 2.x version doesn't get metadata.

[toots]

From the corresponding discussion:

I see thanks for reporting. This looks like a bug with the ffmpeg code that is specific to ogg/flac. ogg/vorbis and ogg/opus seem to work just fine.

If I understand well your solution, you are probably using input.harbor with it. This settings probably simply disable the ffmpeg stream decoder, which has the highest priority and, so, I imagine your stream is being decoded by the native ogg decoder.

With input.http, we are limited to the ffmpeg decoder only, so the bug remains. I'll see if I can isolate it and either report or send a patch upstream.

Keeping this open to follow-up if/when needed.

[toots]

Patch submitted to ffmpeg: http://ffmpeg.org/pipermail/ffmpeg-devel/2023-April/308780.html