See the ffmpeg command?

[Chris230291]

Description

Is there a way to see the ffmpeg command that is being used to play a stream?

streamlink <dash url> best

I am trying to figure out why streamlink has no problems playing back a particular dash stream, but I cant get the same results in ffmpeg. I would like the see the ffmpeg command that streamlink is using.

Thanks,
Chris

[bastimeyer]

--loglevel=debug

Streamlink has its own DASH implementation. Knowing the ffmpeg command won't help you, as it only muxes the video and audio streams that get written to named pipes by Streamlink into a single output.

$ streamlink -l debug 'https://steamcommunity.com/broadcast/watch/76561198948303673' best
[cli][debug] OS:         Linux-6.4.11-1-git-x86_64-with-glibc2.38
[cli][debug] Python:     3.11.3
[cli][debug] OpenSSL:    OpenSSL 3.1.2 1 Aug 2023
[cli][debug] Streamlink: 6.1.0+9.g9d5e2bfc
[cli][debug] Dependencies:
[cli][debug]  certifi: 2023.7.22
[cli][debug]  isodate: 0.6.1
[cli][debug]  lxml: 4.9.3
[cli][debug]  pycountry: 22.3.5
[cli][debug]  pycryptodome: 3.18.0
[cli][debug]  PySocks: 1.7.1
[cli][debug]  requests: 2.31.0
[cli][debug]  trio: 0.22.2
[cli][debug]  trio-websocket: 0.10.3
[cli][debug]  typing-extensions: 4.7.1
[cli][debug]  urllib3: 2.0.4
[cli][debug]  websocket-client: 1.6.1
[cli][debug] Arguments:
[cli][debug]  url=https://steamcommunity.com/broadcast/watch/76561198948303673
[cli][debug]  stream=['best']
[cli][debug]  --loglevel=debug
[cli][debug]  --player=mpv
[plugins.steam][debug] Restored cookies: REDACTED
[cli][info] Found matching plugin steam for URL https://steamcommunity.com/broadcast/watch/76561198948303673
[plugins.steam][debug] Getting broadcast stream: sessionid=REDACTED
[utils.l10n][debug] Language code: en_US
[stream.dash][debug] Available languages for DASH audio streams: und (using: und)
[cli][info] Available streams: 360p (worst), 480p, 720p (best)
[cli][info] Opening stream: 720p (dash)
[cli][info] Starting player: mpv
[stream.dash][debug] Opening DASH reader for: ('1', 'video', '1') - video/mp4
[stream.dash][debug] Opening DASH reader for: ('1', 'audio', '1') - audio/mp4
[stream.dash][debug] video/mp4 segment initialization: downloading (2023-08-21T15:49:46.000000Z / 2023-08-22T20:06:02.597117Z)
[stream.dash_manifest][debug] Generating segment numbers for dynamic playlist: ('1', 'video', '1')
[stream.dash_manifest][debug] Stream start: 2023-08-21 15:49:46+00:00
[stream.dash_manifest][debug] Current time: 2023-08-22 20:06:02.596045+00:00
[stream.dash_manifest][debug] Availability: 2023-08-22 20:05:56+00:00
[stream.dash_manifest][debug] presentationTimeOffset: 0:00:00; suggestedPresentationDelay: 0:00:03; minBufferTime: 0:00:03
[stream.dash_manifest][debug] segmentDuration: 2.0; segmentStart: 1; segmentOffset: 50885 (101770.596045s)
[stream.dash][debug] audio/mp4 segment initialization: downloading (2023-08-21T15:49:46.000000Z / 2023-08-22T20:06:02.598651Z)
[stream.dash_manifest][debug] Generating segment numbers for dynamic playlist: ('1', 'audio', '1')
[stream.dash_manifest][debug] Stream start: 2023-08-21 15:49:46+00:00
[stream.dash_manifest][debug] Current time: 2023-08-22 20:06:02.596045+00:00
[stream.dash_manifest][debug] Availability: 2023-08-22 20:05:56+00:00
[stream.dash_manifest][debug] presentationTimeOffset: 0:00:00; suggestedPresentationDelay: 0:00:03; minBufferTime: 0:00:03
[stream.dash_manifest][debug] segmentDuration: 2.0; segmentStart: 1; segmentOffset: 50885 (101770.596045s)
[stream.ffmpegmux][debug] ffmpeg version n6.0 Copyright (c) 2000-2023 the FFmpeg developers
[stream.ffmpegmux][debug]  built with gcc 13.1.1 (GCC) 20230429
[stream.ffmpegmux][debug]  configuration: --prefix=/usr --disable-debug --disable-static --disable-stripping --enable-amf --enable-avisynth --enable-cuda-llvm --enable-lto --enable-fontconfig --enable-gmp --enable-gnutls --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libdav1d --enable-libdrm --enable-libfreetype --enable-libfribidi --enable-libgsm --enable-libiec61883 --enable-libjack --enable-libjxl --enable-libmfx --enable-libmodplug --enable-libmp3lame --enable-libopencore_amrnb --enable-libopencore_amrwb --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librav1e --enable-librsvg --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-nvdec --enable-nvenc --enable-opencl --enable-opengl --enable-shared --enable-version3 --enable-vulkan
[stream.ffmpegmux][debug]  libavutil      58.  2.100 / 58.  2.100
[stream.ffmpegmux][debug]  libavcodec     60.  3.100 / 60.  3.100
[stream.ffmpegmux][debug]  libavformat    60.  3.100 / 60.  3.100
[stream.ffmpegmux][debug]  libavdevice    60.  1.100 / 60.  1.100
[stream.ffmpegmux][debug]  libavfilter     9.  3.100 /  9.  3.100
[stream.ffmpegmux][debug]  libswscale      7.  1.100 /  7.  1.100
[stream.ffmpegmux][debug]  libswresample   4. 10.100 /  4. 10.100
[stream.ffmpegmux][debug]  libpostproc    57.  1.100 / 57.  1.100
[utils.named_pipe][info] Creating pipe streamlinkpipe-34962-1-2569
[utils.named_pipe][info] Creating pipe streamlinkpipe-34962-2-8028
[stream.ffmpegmux][debug] ffmpeg command: /usr/bin/ffmpeg -nostats -y -i /tmp/streamlinkpipe-34962-1-2569 -i /tmp/streamlinkpipe-34962-2-8028 -c:v copy -c:a copy -copyts -f matroska pipe:1
[stream.ffmpegmux][debug] Starting copy to pipe: /tmp/streamlinkpipe-34962-1-2569
[stream.ffmpegmux][debug] Starting copy to pipe: /tmp/streamlinkpipe-34962-2-8028
[cli][debug] Pre-buffering 8192 bytes
[stream.dash][debug] video/mp4 segment 50886: downloading (2023-08-22T20:05:56.000000Z / 2023-08-22T20:06:02.663213Z)
[stream.dash][debug] video/mp4 segment initialization: completed
[stream.dash][debug] audio/mp4 segment 50886: downloading (2023-08-22T20:05:56.000000Z / 2023-08-22T20:06:02.692869Z)
[stream.dash][debug] audio/mp4 segment initialization: completed
[stream.dash][debug] audio/mp4 segment 50887: downloading (2023-08-22T20:05:58.000000Z / 2023-08-22T20:06:02.734117Z)
[stream.dash][debug] audio/mp4 segment 50886: completed
[stream.dash][debug] audio/mp4 segment 50888: downloading (2023-08-22T20:06:00.000000Z / 2023-08-22T20:06:02.763006Z)
[stream.dash][debug] audio/mp4 segment 50887: completed
[stream.dash][debug] audio/mp4 segment 50889: downloading (2023-08-22T20:06:02.000000Z / 2023-08-22T20:06:02.806097Z)
[stream.dash][debug] audio/mp4 segment 50888: completed
[stream.dash][debug] audio/mp4 segment 50890: waiting 1.1s (2023-08-22T20:06:04.000000Z / 2023-08-22T20:06:02.885307Z)
[stream.dash][debug] audio/mp4 segment 50889: completed
[stream.dash][debug] video/mp4 segment 50887: downloading (2023-08-22T20:05:58.000000Z / 2023-08-22T20:06:02.888473Z)
[stream.dash][debug] video/mp4 segment 50886: completed
[cli.output][debug] Opening subprocess: ['/home/basti/.local/bin/mpv', '--force-media-title=https://steamcommunity.com/broadcast/watch/76561198948303673', '-']
[stream.dash][debug] video/mp4 segment 50888: downloading (2023-08-22T20:06:00.000000Z / 2023-08-22T20:06:03.174457Z)
[stream.dash][debug] video/mp4 segment 50887: completed
[stream.dash][debug] video/mp4 segment 50889: downloading (2023-08-22T20:06:02.000000Z / 2023-08-22T20:06:03.396459Z)
[stream.dash][debug] video/mp4 segment 50888: completed
[cli][debug] Writing stream to output
[stream.dash][debug] video/mp4 segment 50890: waiting 0.4s (2023-08-22T20:06:04.000000Z / 2023-08-22T20:06:03.557069Z)
[stream.dash][debug] video/mp4 segment 50889: completed
[stream.dash][debug] audio/mp4 segment 50890: downloading (2023-08-22T20:06:04.000000Z / 2023-08-22T20:06:04.000369Z)
[stream.dash][debug] video/mp4 segment 50890: downloading (2023-08-22T20:06:04.000000Z / 2023-08-22T20:06:04.000575Z)
[stream.dash][debug] audio/mp4 segment 50891: waiting 2.0s (2023-08-22T20:06:06.000000Z / 2023-08-22T20:06:04.035885Z)
[stream.dash][debug] audio/mp4 segment 50890: completed
[stream.dash][debug] video/mp4 segment 50891: waiting 1.8s (2023-08-22T20:06:06.000000Z / 2023-08-22T20:06:04.171861Z)
[stream.dash][debug] video/mp4 segment 50890: completed
[cli][info] Player closed
[stream.ffmpegmux][debug] Closing ffmpeg thread
[stream.ffmpegmux][error] Error while writing to pipe /tmp/streamlinkpipe-34962-1-2569: [Errno 32] Broken pipe
[stream.segmented][debug] Closing worker thread
[stream.segmented][debug] Closing writer thread
[stream.segmented][debug] Closing worker thread
[stream.segmented][debug] Closing writer thread
[stream.ffmpegmux][debug] Pipe copy complete: /tmp/streamlinkpipe-34962-2-8028
[stream.dash][debug] audio/mp4 segment 50891: cancelled
[stream.dash][debug] video/mp4 segment 50891: cancelled
[stream.ffmpegmux][debug] Closed all the substreams
[cli][info] Stream ended
[cli][info] Closing currently open stream...

[stream.ffmpegmux][debug] ffmpeg command: /usr/bin/ffmpeg -nostats -y -i /tmp/streamlinkpipe-34962-1-2569 -i /tmp/streamlinkpipe-34962-2-8028 -c:v copy -c:a copy -copyts -f matroska pipe:1

I am trying to figure out why streamlink has no problems playing back a particular dash stream

Check your system clock and whether it's properly synced to UTC.

[Chris230291]

OK I didn't realise that ffmpeg is only used to mux the streams.
Its funny you mention the system clock. The streams that wont play in ffmpeg are not meant for my region.
Assuming its time zone related, do you have any advice on how I can fix/avoid whatever is happening?

[bastimeyer]

I don't use ffmpeg to watch DASH streams. If it's indeed caused by an invalid system clock and/or FFmpeg doesn't respecy the timezones correctly, then have a look at libfaketime.

[Chris230291]

OK thanks.
Is there a way to tell streamlink to mux all audio tracks?
The only reason I am not using streamlink is because I cant figure out how to keep all tracks.
Honestly id prefer to use streamlink because "tuning" seems much faster.

[bastimeyer]

I've already answered your question here:
#5426

That doesn't mean that it's impossible to achieve, but you'd need to rewrite DASHStream.parse_manifest() and DASHStream.open(). No support from my side on that. Good luck...

[bastimeyer]

Btw, very much related: #4902