macOS: Cannot play 5.1ch (surround) dsf files

[jonaski]

• I have checked the FAQ for answers.
• I have checked the Changelog that the issue is not already fixed.
• I believe this issue is a bug, and not a general technical issue, question or feature requests that can be discussed on the forum.

Describe the bug
Attempting to play 5.1 channel dsf files results in a playback error:

Internal data stream error.

../ext/libav/gstavdemux.c(1618): gst_ffmpegdemux_loop (): /GstPlayBin3:pipeline-2-pipeline/GstURIDecodeBin3:uridecodebin3/GstURISourceBin:urisourcebin1/GstParseBin:parsebin1/avdemux_dsf:avdemux_dsf3: streaming stopped, reason not-negotiated (-4)

Internal data stream error.

../plugins/elements/gstmultiqueue.c(2778): gst_multi_queue_sink_event (): /GstPlayBin3:pipeline-2-pipeline/GstURIDecodeBin3:uridecodebin3/GstURISourceBin:urisourcebin1/GstMultiQueue:multiqueue5: streaming stopped, reason not-negotiated (-4)

Internal data stream error.

../ext/libav/gstavdemux.c(1618): gst_ffmpegdemux_loop (): /GstPlayBin3:pipeline-2-pipeline/GstURIDecodeBin3:uridecodebin3/GstURISourceBin:urisourcebin1/GstParseBin:parsebin1/avdemux_dsf:avdemux_dsf3: streaming stopped, reason not-negotiated (-4)

Internal data stream error.

../plugins/elements/gstmultiqueue.c(2778): gst_multi_queue_sink_event (): /GstPlayBin3:pipeline-2-pipeline/GstURIDecodeBin3:uridecodebin3/GstURISourceBin:urisourcebin1/GstMultiQueue:multiqueue5: streaming stopped, reason not-negotiated (-4)

Screenshots:

System Information:

• Operating system: macOS Sequoia 15.3.2 (24D81)
• Strawberry Version: 1.2.7 arm64

Additional context

• Same file plays back properly with Strawberry on Linux
• Does not appear to be affected by Backend audio output device selection
  • Same error with "Wrapper audio sink...", "Output to a sound card / MacBook Pro Speakers", "Output to a sound card / SoundBlaster X4 Speakers" (the ones configured with 6ch)

[jonaski]

@coderabbitai
Can you propose a fix for this?
Could a GStreamer plugin be missing? Included plugins are in https://github.com/strawberrymusicplayer/strawberry-coderabbit/blob/master/dist/macos/macgstcopy.sh

[coderabbitai]

Tip

For best results, initiate chat on the files or code changes.

🧩 Analysis chain

🏁 Script executed:

#!/bin/bash
# Read the macgstcopy.sh file to see what GStreamer plugins are included
cat dist/macos/macgstcopy.sh

Length of output: 4334

---

🌐 Web query:

GStreamer not-negotiated error multi-channel surround audio plugins needed

💡 Result:

Cause: "not-negotiated" usually means the pipeline failed caps negotiation — downstream element(s) refuse the audio format (sample format, rate, number of channels, channel positions/mask, or missing parser/codec). Common multi‑channel/surround causes are: the sink/encoder doesn't accept >2 channels, a missing parser/encoder (e.g. ac3/a52/aac elements), or wrong/missing channel-mask/channel-positions in the caps. [1][2][3]

Quick checklist + fixes

• Turn on debug and inspect negotiated caps: GST_DEBUG=GST_CAPS:4 gst-launch-1.0 -v ... — read the caps printed for each pad to see which element rejects what. [1]
• Ensure conversion elements are present before the sink/encoder: audioconvert and audioresample can adapt format and channel counts. Insert them if negotiation fails. Example: ... ! audioconvert ! audioresample ! audio/x-raw,channels=6 ! alsasink. [2]
• Confirm the sink accepts multi-channel: check alsasink/pulsesink caps (many systems advertise only stereo). If the sink only supports 2 channels you must downmix or use a device that supports 5.1/7.1. [3]
• Use the correct parser/codec elements for encoded surround: e.g. avenc_ac3 / ac3parse / rtpac3pay for AC‑3, a52dec/avdec_ac3 for decoding. Missing parser/codec can break negotiation (autoplugging fails). Install gst-plugins-{base,good,bad,ugly} that contain these elements. [4][5]
• If raw multi-channel data has ambiguous channel ordering, set channel-mask or channel-positions in caps (audio/x-raw, channels=6, channel-mask=0x3F or channel-positions=(string)FL,FR,FC,LFE,SL,SR). audioconvert respects channel-mask/positions. [2]
• When using containers/muxers, ensure you insert parser elements (aacparse, ac3parse, mpegaudioparse) between encoder and muxer if needed — muxers often expect exact encoded caps. (Example: lamemp3enc ! mpegaudioparse ! flvmux). [4]

Minimal debugging pipeline examples

• Probe negotiation: gst-launch-1.0 filesrc location=file.mkv ! decodebin ! audioconvert ! audioresample ! audio/x-raw,channels=6 ! fakesink -v
• Encode AC‑3 5.1 and send to RTP: audiotestsrc ! avenc_ac3 ! ac3parse ! rtpac3pay ! udpsink ... [5]

If you paste your gst-launch (or code) pipeline and the -v / GST_DEBUG=GST_CAPS logs showing the caps and the not-negotiated error, I’ll point to the exact missing plugin or caps field to change.

Sources

• Caps negotiation docs (how negotiation and caps fields like channels/channel-mask work). [1]
• audioconvert element docs (supported channel handling and channel-mask/positions). [2]
• Example showing alsasink caps & how sinks advertise channel limits (discussion). [3]
• GStreamer plugins list / common parsers & encoders (ac3parse, a52dec, aacparse, mpegaudioparse). [4]
• rtpac3pay / AC‑3 pipeline example. [5]

References
[1] https://gstreamer.freedesktop.org/documentation/plugin-development/advanced/negotiation.html
[2] https://gstreamer.freedesktop.org/documentation/audioconvert/index.html
[3] https://discourse.gstreamer.org/t/webrtcsrc-gst-parse-no-more-pads/305/4
[4] https://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer-plugins/html/gstreamer-plugins-leakstracer.html
[5] https://gstreamer.freedesktop.org/documentation/rsrtp/rtpac3pay2.html

---

🌐 Web query:

GStreamer DSF DSD multi-channel 5.1 dsddec audioconvert plugin

💡 Result:

Short answer: GStreamer can play/convert DSF (DSD) multichannel (5.1) files by using the libav DSF demuxer/decoders (avdemux_dsf / avdec_dsd_*), the DSD helpers (dsdconvert) and audioconvert for channel/format mapping. Example pipeline and notes below.

Example pipeline (play/pass-through to 6-channel PCM then to ALSA):
gst-launch-1.0 filesrc location=album_track.dsf ! avdemux_dsf ! avdec_dsd_msbf_planar ! audioconvert ! audioresample ! "audio/x-raw,format=F32LE,channels=6" ! alsasink device=hw:0,0

Notes

• avdemux_dsf is the libav-based DSF demuxer. Use it to feed a DSD decoder. [1]
• libav provides DSD decoders (avdec_dsd_msbf, avdec_dsd_msbf_planar, etc.) that output audio/x-raw (usually F32LE) which can be consumed by audioconvert. Use the planar or interleaved variant that matches the demuxer output. [2][3]
• dsdconvert (GStreamer element) can be used for converting between DSD grouping/layout formats if needed prior to decoding/processing. [4]
• audioconvert supports channel transformations (upmix/downmix and remapping) and format conversion; set the caps (audio/x-raw, channels=6, layout/interleaved as needed) or use a mix matrix property to map channels into a 5.1 layout. [3]
• If you need bit-perfect DSD passthrough to a DSD-capable device (not decoded to PCM), that’s a different path (dsd passthrough via appropriate sink/driver) and may require special support in ALSA/driver/hardware; the pipeline above decodes to PCM.

References
[1] avdemux_dsf (GStreamer/libav docs).
[2] avdec_dsd_msbf / avdec_dsd_msbf_planar (GStreamer/libav docs).
[3] audioconvert (GStreamer documentation — channel/format conversion, mix matrix).
[4] GStreamer plugin list / dsdconvert element (dsd grouping converter).

---

@jonaski

Looking at the error and the included GStreamer plugins in macgstcopy.sh, I believe the issue is related to multi-channel audio negotiation on macOS. The "not-negotiated" error indicates that pipeline elements can't agree on the audio format for 5.1 channels.

Missing Plugins

The script is missing some plugins that are important for multi-channel audio handling:

libgstinterleave
libgstdeinterleave
libgstaudiomixer

These plugins help with channel layout conversion and interleaving, which is crucial for multi-channel (5.1) audio.

Proposed Fix

Add these plugins to the gst_plugins list in dist/macos/macgstcopy.sh:

gst_plugins="
libgstadaptivedemux2
libgstaes
libgstaiff
libgstapetag
libgstapp
libgstasf
libgstasfmux
libgstaudioconvert
libgstaudiofx
libgstaudiomixer
libgstaudioparsers
libgstaudioresample
libgstautodetect
libgstbs2b
libgstcdio
libgstcoreelements
libgstdash
libgstdeinterleave
libgstdsd
libgstequalizer
libgstfaac
libgstfaad
libgstfdkaac
libgstflac
libgstgio
libgsthls
libgsticydemux
libgstid3demux
libgstid3tag
libgstinterleave
libgstisomp4
libgstlame
libgstmpegpsdemux
libgstmpegpsmux
libgstmpegtsdemux
libgstmpegtsmux
libgstlibav
libgstmpg123
libgstmusepack
libgstogg
libgstopenmpt
libgstopus
libgstopusparse
libgstosxaudio
libgstpbtypes
libgstplayback
libgstreplaygain
libgstrtp
libgstrtsp
libgstsoup
libgstspectrum
libgstspeex
libgstspotify
libgsttaglib
libgsttcp
libgsttwolame
libgsttypefindfunctions
libgstudp
libgstvolume
libgstvorbis
libgstwavenc
libgstwavpack
libgstwavparse
libgstxingmux
"

Additional Considerations

The osxaudio sink might also have limitations with advertising or handling 5.1 channel configurations properly. The fact that it works on Linux (which typically uses PulseAudio or ALSA sinks) suggests the macOS audio sink might need special handling for multi-channel audio.

You could also consider:

1. Testing whether downmixing to stereo works as a workaround
2. Checking if the selected output device properly advertises 5.1 support
3. Enabling GStreamer debug output to see exact caps negotiation failure: GST_DEBUG=GST_CAPS:4

Let me know if you'd like me to investigate further or if adding these plugins resolves the issue!