No ID3 metadata in hls output. (2.3.1)

[Piogac]

Hello there,

I am copletely new to liquidsoap (just installed LS 2.3.1 from opam).
I want to transcode 192 kbps aac stream to hls format without re-encoding.
According to this thread (Converting Icecast stream to HLS without re encoding #3256) I copied the script which looks as follows:

---

input = input.http("https://bcast.vigormultimedia.com:48888/sjcompl192aac")
aac_hifi = %ffmpeg(format="mpegts", %audio.copy)

streams = [("aac_hifi", aac_hifi.{ id3 = true, id3_version = 4 })]

def segment_name(~position,~extname,stream_name) =
timestamp = int_of_float(time())
duration = 5
"#{stream_name}#{duration}#{timestamp}_#{position}.#{extname}"
end

output.file.hls(playlist="live.m3u8",
fallible=true,
segment_duration=5.0,
segments=10,
segments_overhead=5,
segment_name=segment_name,
persist_at="station.config",
"/home/piotr/hls/sjcompl",
streams,
input)

---

The above script is working fine except the fact that there are no Tags displyed.
( https://bcast.vigormultimedia.com/sjcompl/live.m3u8 ).
In the source link which is Icecast2 ( https:/bcast.vigormultimedia.com:48888/sjcompl192aac )
the Tags are displayed properly.

What I did to fix that ?

1. According to 2.3.0 documentation I tried to change
   format="mpegts" to format="adts" [ ‘mpegts’ accepts only timed_id3 ].
   But when format="adts" is used, I get the error I have no idea how to fix it.

_At /home/piotr/bin/transcoder_hls_old.liq, line 10, char 24-64:
streams = [("aac_hifi", aac_hifi.{ id3 = true, id3_version = 4 })]
Error 7: Invalid value:
File extension cannot be inferred from codec, please specify it in streams_info.

2. I used the encoder instead %audio.copy but there is no difference.
   (also when mpegts replaced with adts).
   The encoder works fine but there is no Tags displayed.

aac_hifi = %ffmpeg(format="mpegts",
%audio(
codec="aac",
channels=2,
ar=48000,
b="192k"
)).{id3_version = 4}

streams = [("aac_hifi", aac_hifi)]_

Any suggestions kindly welcomed. (I’m copletely new to ls).

Piotr

[gAlleb]

Hi, well, everything should work.

You can check out the metadata here: https://hlsjs.video-dev.org/demo/ at the bottom of the page. You could see segments filled with metadata.

Same with adts. I've checkedd both ways.

Here is my script:

input = input.http("https://bcast.vigormultimedia.com:48888/sjcompl192aac")

aac_hifi = %ffmpeg(format="mpegts", %audio.copy)

#aac_hifi = %ffmpeg(format="adts", %audio.copy)

streams = [("aac_hifi", aac_hifi.{ id3 = true, id3_version = 4 })]

def segment_name(metadata) =
  timestamp = int_of_float(time())
  let {stream_name, duration, position, extname} = metadata
  "#{stream_name}_#{duration}_#{timestamp}_#{position}.#{extname}"
end

output.file.hls(playlist="live.m3u8",
fallible=true,
segment_duration=5.0,
segments=10,
segments_overhead=5,
segment_name=segment_name,
persist_at="station.config",
"./hls/",
streams,

Not all players support timed_id or hls metadta. E.g. mpv supports it. You can try mpv http://your_hls_stream.

[gAlleb]

Your web server should have Allow-Control-Allow-Origin * usually. You can see Radio France conf - https://github.com/radiofrance/rf-liquidsoap/blob/master/example/nginx/hls.conf

So here is the deal. mpv can understand adts metadata, to see timed_id3 - you need to implement it in a player yourself. https://hlsjs.video-dev.org/demo/ can show you timed_id.

Some scrreenshots. First one with mpegts, second with adts. But that's not it. Most players upon receiving metadata from HLS audio stream - won't receive updates especially when it's timed_id3. Hls.js will.

[gAlleb]

Here is a temporary test link https://test.omfm.ru/test.m3u8 relaying your aac stream with LS 2.3.1 . Usually ssl is enough for https://hlsjs.video-dev.org/demo/

VLC shows metadata too

If

def segment_name(~position,~extname,stream_name) =
timestamp = int_of_float(time())
duration = 5
"#{stream_name}#{duration}#{timestamp}_#{position}.#{extname}"
end

works for you, then use it but it's strange. Latest 2.3.1 works with

def segment_name(metadata) =
  timestamp = int_of_float(time())
  let {stream_name, duration, position, extname} = metadata
  "#{stream_name}_#{duration}_#{timestamp}_#{position}.#{extname}"
end

instead. What OS do you use? Sure you're running 2.3.1 version? :)

[Piogac]

Thank you so much Stefan. This weekend Im away from computerr. I will check this on Monday.

[Piogac]

Stefan,
Thank you very much for you help. Now everything works fine.

I made 2 major mistakes:

1. nginx server was not properly configured
2. I was using liguidsoap ver. 2.1.3 instead of 2.3.1 (shame on me - I mis-typed 2.3.1 vs. 2.1.3 while installing).
   I used foobar 2000 which does not show metadata in m3u8 streams (at least my version). VLC shows properly.

BTW. Do you have any expirience with using audio.copy and encoder at the same time ?
I failed ..

input = input.http("https://bcast.vigormultimedia.com:48888/sjcompl192aac")

aac_hifi = %ffmpeg(format="adts", %audio.copy)

aac_midfi = %ffmpeg(
format="adts",
%audio(
codec="aac",
samplerate=44100,
channels=2,
b="96k",
profile="aac_low"
)
).{ id3 = true, id3_version = 4 }

streams = [("aac_midfi", aac_midfi), ("aac_hifi", aac_hifi)]

.....

Thank you once again.

[gAlleb]

BTW. Do you have any expirience with using audio.copy and encoder at the same time ?
I failed ..

If you'd like for example to use aac icecast and hls in one script and not encode two times:

radio = playlist("playlist.m3u")

radio = ffmpeg.encode.audio(%ffmpeg(%audio(codec = "aac",b="192k")), radio)

aac_hifi = %ffmpeg(format="mpegts", %audio.copy)

streams = [("aac_hifi", aac_hifi.{ id3 = true, id3_version = 4 })]

def segment_name(metadata) =
  timestamp = int_of_float(time())
  let {stream_name, duration, position, extname} = metadata
  "#{stream_name}_#{duration}_#{timestamp}_#{position}.#{extname}"
end

output.icecast(%ffmpeg(format = "adts", %audio.copy), ... , radio)

output.file.hls(playlist="live.m3u8",
fallible=true,
segment_duration=5.0,
segments=10,
segments_overhead=5,
segment_name=segment_name,
persist_at="station.config",
"./hls/",
streams,

First you need to encode your source:

radio = ffmpeg.encode.audio(%ffmpeg(%audio(codec = "aac",b="192k")), radio)

Then use %ffmpeg(format = "adts", %audio.copy) for icecast or %ffmpeg(format = "mpegts", %audio.copy) for hls.

---

Update! Ah, I see what you mean. Hm, Don't think that would work.
@vitoyucepi, Hi! Do you know, is it possible to use copied audio and encoded one in adaptive HLS stream?