OPUS audio woes

Application Development
1

I’m not expecting much help here but I figure I’ll try anyway. I’m trying to end OPUS audio to a Quest 3 headset and I have these 2 pipelines

Sender

pipewiresrc path={path} ! opusenc bitrate=128000 ! opusparse ! rtpopuspay ! udpsink host={ip} port={port} sync=true

Receiver

udpsrc port=%d caps=“application/x-rtp, media=audio, clock-rate=48000, encoding-name=OPUS, payload=96” ! rtpopusdepay ! opusparse ! amcauddec-c2androidopusdecoder ! openslessink

Once the streams initialize and the first packet comes in my app crashes. If I swap the port so packets don’t flow it’s fine and if I swap out the android decoder for

udpsrc port=%d caps=“application/x-rtp, media=audio, clock-rate=48000, encoding-name=OPUS, payload=96” ! rtpopusdepay ! opusparse ! fakesink

It doesn’t crash.

All I get in logcat is a very unhelpful error

04-04 12:06:22.688 26293 26604 I LumaXR : [GStreamer] Waiting for available output buffer
04-04 12:06:22.640 0 0 I : potentially unexpected fatal signal 6.
04-04 12:06:22.640 0 0 I : CPU: 3 PID: 26584 Comm: amcaudiodec-c2a Tainted: G C 5.10.236-gf94cd3dbd5d2 #1
04-04 12:06:22.640 0 0 I Hardware name: Eureka (PVT1.1) (DT)
04-04 12:06:22.640 0 0 I pstate : 00001000 (nzcv daif -PAN -UAO -TCO BTYPE=–)
04-04 12:06:22.640 0 0 I pc : 0000007ed04b2668
04-04 12:06:22.640 0 0 I lr : 0000007ed04b2638
04-04 12:06:22.640 0 0 I sp : 0000007c30118510
04-04 12:06:22.640 0 0 I : x29: 0000007c301185b0 x28: 0000007bde76c80c
04-04 12:06:22.640 0 0 I : x27: 0000007bddbce0ef x26: 0000007c30118d40
04-04 12:06:22.640 0 0 I : x25: 0000007bddc82718 x24: 0000007bddc72a4e
04-04 12:06:22.640 0 0 I : x23: b400007e213d7ba0 x22: 0000007c30118d40
04-04 12:06:22.640 0 0 I : x21: 00000000ffffffff x20: 00000000000067d8
04-04 12:06:22.640 0 0 I : x19: 00000000000066b5 x18: 0000007bd5904000
04-04 12:06:22.640 0 0 I : x17: 0000007ed0506ce0 x16: 0000007ed052c9f8
04-04 12:06:22.640 0 0 I : x15: 0000000017aef525 x14: 0000000044a5a8be
04-04 12:06:22.640 0 0 I : x13: 0000000000000001 x12: 0000000000000003
04-04 12:06:22.640 0 0 I : x11: 0000000000000000 x10: ffffff80fffffbdf
04-04 12:06:22.640 0 0 I : x9 : 00000000000066b5 x8 : 00000000000000f0
04-04 12:06:22.640 0 0 I : x7 : 7f7f7f7f7f7f7f7f x6 : 626c607372662e60
04-04 12:06:22.640 0 0 I : x5 : 626c607372662e60 x4 : 626c607372662e60
04-04 12:06:22.640 0 0 I : x3 : 0000007c30118530 x2 : 0000000000000006
04-04 12:06:22.640 0 0 I : x1 : 00000000000067d8 x0 : 0000000000000000
04-04 12:06:22.695 1468 1607 I DropBoxManagerService: add tag=SYSTEM_TOMBSTONE_PROTO_WITH_HEADERS isTagEnabled=true flags=0x4
04-04 12:06:22.642 0 0 I init : Untracked pid 26597 exited with status 0
04-04 12:06:22.642 0 0 I init : Untracked pid 26597 did not have an associated service entry and will not be reaped
04-04 12:06:22.642 0 0 I init : waitpid(26597) returned 26597
04-04 12:06:22.701 2525 2562 D crash-reporter: Detected a new tombstone file: /data/tombstones/tombstone_01.pb

Which doesn’t mean anything to me. I figure if my caps were wrong the pipeline simply wouldn’t link but maybe I’m missing something obvious here?

2

Probably unrelated to your crash, but opusparse is not needed in these pipelines, you should just remove it (Opus is always parsed/framed in a GStreamer context).

3

Good to know but it doesn’t fix it no. The AAC decoders (amcauddec-c2androidaacdecoder) don’t crash and I’ve been trying to work with them but I’d rather use OPUS.

4

Have you tried opusdec or avdec_opus?

5

Try:

udpsrc port=%d caps=“application/x-rtp,media=audio,clock-rate=48000,encoding-name=OPUS,payload=96,channels=2” !
rtpjitterbuffer latency=50 do-lost=true !
rtpopusdepay ! opusparse ! opusdec !
audioconvert ! audioresample ! openslessink

I think the issue is this that RTP doesn’t carry OpusHead, so opusparse on the receiver synthesizes one with pre_skip=0. The amcauddec plugin derives MediaCodec’s csd-1 (delay in ns) from that pre_skip, so csd-1 comes through as 0.