diff options
Diffstat (limited to 'pica-client/audiodevice.h')
| -rw-r--r-- | pica-client/audiodevice.h | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/pica-client/audiodevice.h b/pica-client/audiodevice.h index 988438c..ef7e5b3 100644 --- a/pica-client/audiodevice.h +++ b/pica-client/audiodevice.h @@ -188,13 +188,28 @@ private: void waitForPreroll(); bool nextPacket(QByteArray *out); - static const int kMaxQueueDepth = 8; + // Ceiling on the queue, in packets of 20ms each - one second. This is a + // runaway guard, not a latency control: Play() pops as fast as it can and + // the standing latency ends up in the sound card's buffer, not here, so + // the queue only grows when the peer sends a burst or our playback thread + // is not being scheduled. It has to be well clear of kPrerollDepth, + // because overflow is handled by dropping the OLDEST packet + // (enqueuePacket()) - that is, by throwing away audio that was about to + // be played. At the previous value of 8 that was only 160ms, close enough + // to the preroll that ordinary reordering over the direct UDP transport + // could reach it and punch holes in the speech. + static const int kMaxQueueDepth = 50; // Number of packets Play() waits to have buffered before writing the // first one, to build up a cushion against arrival jitter (packets // this call apart arrive roughly every 20ms - see // AudioVideoCallController::startAudioPipeline()). - static const int kPrerollDepth = 3; + // + // This is standing latency: whatever is prerolled here is audio the + // listener hears that much later, for the whole call. 100ms buys a + // useful margin over the 60ms this used to be while staying inside the + // range where a conversation still feels immediate. + static const int kPrerollDepth = 5; }; #endif // AUDIODEVICE_H |