Streaming - Works from CMD but not from Python

[MisfitGeek]

Hello All,

Hoping someone can help me solve this puzzle.

I'm trying to stream from a Python script on Windows.

It works using this command line:

"C:\Program Files\VideoLAN\VLC\vlc.exe" sample-mp4-file.mp4 --sout="#transcode{vcodec=h264,acodec=mpga,ab=128,channels=2,samplerate=44100,scodec=none}:duplicate{dst=http{mux=ffmpeg{mux=flv},dst=:8080/}", :no-sout-all :sout-keep

However, this code using the same sout doesn't seem to work.

import vlc
inst = vlc.Instance("""--sout="#transcode{vcodec=h264,acodec=mpga,ab=128,channels=2,samplerate=44100,scodec=none}:duplicate{dst=http{mux=ffmpeg{mux=flv},dst=:8080/}", :no-sout-all :sout-keep""")
med = inst.media_new("sample-mp4-file.mp4")
p = med.player_new_from_media()
p.play()

while True:
pass

Does anyone have any suggestions

TIA

[MisfitGeek]

This code works - don't ask me why

import vlc

inst = vlc.Instance()
param=[
"sample-mp4-file.mp4"
,"sout=#transcode{vcodec=h264,acodec=mpga,ab=128,channels=2,samplerate=44100,scodec=none}:duplicate{dst=http{mux=ffmpeg{mux=flv},dst=:8080/}"
]
Media = inst.media_new(*param)
player = Media.player_new_from_media()
player.play()

while True:
pass

[unidan]

Hi, in the first code, because of the """ string marker, you gave only one big option which was

Code: Select all

--sout="#transcode{vcodec=h264,acodec=mpga,ab=128,channels=2,samplerate=44100,scodec=none}:duplicate{dst=http{mux=ffmpeg{mux=flv},dst=:8080/}", :no-sout-all :sout-keep

Python libvlc will split it at spaces, but then the first argument will become

Code: Select all

--sout="#transcode{vcodec=h264,acodec=mpga,ab=128,channels=2,samplerate=44100,scodec=none}:duplicate{dst=http{mux=ffmpeg{mux=flv},dst=:8080/}",

Which might have raised an error at the sout creation.

Using media_new is correct here and you can keep that!

[peppy.player]

Hi,

I've prepared the following code using the example from this thread:

Code: Select all

import vlc import time inst = vlc.Instance() url = "https://rockthecradle.stream.publicradio.org/rockthecradle-tunein.mp3" param=[url, "--sout=#transcode{acodec=flac}:std{access=http,mux=flac,dst=10.0.0.6:8080}"] m = inst.media_new(*param) player = m.player_new_from_media() player.play() while True: time.sleep(0.2)

When I run it I can hear the stream played locally but I cannot connect any client to that stream (e.g. Firefox browser): http://10.0.0.6:8080

If I do the same from command line:

Code: Select all

vlc --sout=#transcode{acodec=flac}:std{access=http,mux=flac,dst=10.0.0.6:8080} "https://rockthecradle.stream.publicradio.org/rockthecradle-tunein.mp3"

I can connect clients (Firefox) to that stream.
I'm just wondering how my example is different from the suggested solution?
Thanks!

[Rémi Denis-Courmont]

The LibVLC media player API does not support the streaming output (except through the renderer selection).

[peppy.player]

OK, how does the player stream without selecting renderer when I start it from command line?

Code: Select all

vlc --sout=#transcode{acodec=flac}:std{access=http,mux=flac,dst=10.0.0.6:8080} "https://rockthecradle.stream.publicradio.org/rockthecradle-tunein.mp3"

Does it use some default renderer?
Thanks!

[Rémi Denis-Courmont]

VLC does not use the LibVLC media player API.

[peppy.player]

Hmm, the second post in this thread is saying that it works. Though my example which follows that code doesn't actually work. Then it looks like the Python binding for libVLC doesn't support streaming output. Though I was able to use it about 4-5 years ago:
https://github.com/oaubert/python-vlc/issues/105
So more likely something was changed in the code and the only way to make streaming working now is to start 'vlc' as external process. That makes it more difficult to control the player in this case and defeats the purpose of using Python binding at all.

Thank you anyway.

[Rémi Denis-Courmont]

The first post uses instance options while the second post uses media/item options.

Either way, there is explicitly no compatibility promise when using options, precisely because they are not compatible across versions.

[unidan]

Hmm, the second post in this thread is saying that it works

Actually Rémi's right, --sout won't work on any recent libvlc version (sort of since renderer API in libvlc).

A media option will work though, by passing the option to `media_new`, because it's no different than what VLC does, but as always it's not "public supported API" and might break some time. But you can still pass :sout-keep (or :no-sout-keep to destroy the sout) and still pass sout option in a more flexible way than when passing the option to the instance.

[peppy.player]

Actually Rémi's right, --sout won't work on any recent libvlc version (sort of since renderer API in libvlc).
A media option will work though, by passing the option to `media_new`, because it's no different than what VLC does, but as always it's not "public supported API" and might break some time. But you can still pass :sout-keep (or :no-sout-keep to destroy the sout) and still pass sout option in a more flexible way than when passing the option to the instance.

OK, I understand that --sout options will not work in Instance class but should work in Media class. I'm just wondering why my example which is using Media doesn't work? Is it just because now is exactly that time which you mentioned - "and might break some time"?
Thanks!

[peppy.player]

Never mind, I found the problem - it should be 'sout' not '--sout'. So, this code works:

Code: Select all

import vlc import time inst = vlc.Instance() url = "https://rockthecradle.stream.publicradio.org/rockthecradle-tunein.mp3" param=[url, "sout=#transcode{acodec=flac}:std{access=http,mux=flac,dst=:8080}"] m = inst.media_new(*param) player = m.player_new_from_media() player.play() while True: time.sleep(0.2)

I can connect to the stream from browser.
Thanks!

[unidan]

What makes it working is that you're using `media_new` to pass the option instead of `vlc.Instance`