I’m playing around with membrane, trying to stream an MP4(h264/aac) file through HLS to my phone, I think the first thing is to demux the file into video and audio streams. The code look like this
use Membrane.Pipeline
def handle_init(path_to_file) do
children = %{
source_file: %Membrane.File.Source{location: path_to_file},
demuxer: Membrane.MPEG.TS.Demuxer,
video_parser: %Membrane.H264.FFmpeg.Parser{framerate: {24, 1}},
video_decoder: Membrane.H264.FFmpeg.Decoder,
audio_decoder: Membrane.AAC.FDK.Decoder,
audio_converter: %FFmpeg.SWResample.Converter{
output_caps: %Membrane.Caps.Audio.Raw{channels: 2, format: :s16le, sample_rate: 48_000}
},
sink: %Membrane.File.Sink{location: "video_output"},
portaudio: PortAudio.Sink
}
links = [
link(:source_file) |> to(:demuxer),
link(:demuxer) |> via_out(Pad.ref(:output, 256)) |> to(:video_parser),
link(:demuxer) |> via_out(Pad.ref(:output, 257)) |> to(:audio_decoder),
link(:video_parser) |> to(:video_decoder),
link(:video_decoder) |> to(:sink),
link(:audio_decoder) |> to(:audio_converter),
link(:audio_converter) |> to(:portaudio)
]
spec = %ParentSpec{
children: children,
links: links
}
{{:ok, spec: spec}, %{}}
end
However, when I run it, there’s no sound, and also video_output is zero bytes.
iex(3)> Pipeline.play(pid)
:ok
iex(4)>
21:01:41.415 [debug] [pipeline@<0.295.0>] Changing playback state from stopped to prepared
21:01:41.441 [debug] [pipeline@<0.295.0>] Playback state changed from stopped to prepared
21:01:41.441 [debug] [pipeline@<0.295.0>] Changing playback state from prepared to playing
21:01:41.441 [debug] [:video_decoder] Evaluating playback buffer
21:01:41.441 [debug] [:source_file] Evaluating playback buffer
21:01:41.441 [debug] [:video_parser] Evaluating playback buffer
21:01:41.441 [debug] [:audio_converter] Evaluating playback buffer
21:01:41.441 [debug] [:audio_decoder] Evaluating playback buffer
21:01:41.441 [debug] [:sink] Evaluating playback buffer
21:01:41.441 [debug] [:demuxer] Evaluating playback buffer
21:01:41.488 [debug] [:portaudio] Evaluating playback buffer
21:01:41.488 [debug] [pipeline@<0.295.0>] Playback state changed from prepared to playing
21:01:41.499 [debug] [:video_parser] Ignoring event %Membrane.Core.Events.EndOfStream{}
21:01:41.499 [debug] [:audio_decoder] Ignoring event %Membrane.Core.Events.EndOfStream{}
I need a bit help here, am I doing this correctly?
