From 15f76339c831589a441ec970fa41f69c66b409da Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Wed, 19 Jan 2022 10:29:49 +1100
Subject: [PATCH] [client] audio: move the memory copy into the pull function

---
 client/audiodevs/PipeWire/pipewire.c     |  5 +----
 client/audiodevs/PulseAudio/pulseaudio.c |  5 ++---
 client/include/interface/audiodev.h      |  4 ++--
 client/src/audio.c                       | 15 +++++++++++++--
 4 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/client/audiodevs/PipeWire/pipewire.c b/client/audiodevs/PipeWire/pipewire.c
index 40ec88fe..738edc4b 100644
--- a/client/audiodevs/PipeWire/pipewire.c
+++ b/client/audiodevs/PipeWire/pipewire.c
@@ -106,8 +106,7 @@ static void pipewire_onPlaybackProcess(void * userdata)
   if (pw.playback.rateMatch && pw.playback.rateMatch->size > 0)
     frames = min(frames, pw.playback.rateMatch->size);
 
-  uint8_t * data;
-  frames = pw.playback.pullFn(&data, frames);
+  frames = pw.playback.pullFn(dst, frames);
   if (!frames)
   {
     if (pw.playback.state == STREAM_STATE_FLUSHING)
@@ -123,8 +122,6 @@ static void pipewire_onPlaybackProcess(void * userdata)
     return;
   }
 
-  memcpy(dst, data, frames * pw.playback.stride);
-
   sbuf->datas[0].chunk->offset = 0;
   sbuf->datas[0].chunk->stride = pw.playback.stride;
   sbuf->datas[0].chunk->size   = frames * pw.playback.stride;
diff --git a/client/audiodevs/PulseAudio/pulseaudio.c b/client/audiodevs/PulseAudio/pulseaudio.c
index d435cb2c..c313ba46 100644
--- a/client/audiodevs/PulseAudio/pulseaudio.c
+++ b/client/audiodevs/PulseAudio/pulseaudio.c
@@ -220,14 +220,13 @@ static void pulseaudio_free(void)
 
 static void pulseaudio_write_cb(pa_stream * p, size_t nbytes, void * userdata)
 {
-  uint8_t * dst, * src;
+  uint8_t * dst;
 
   pa_stream_begin_write(p, (void **)&dst, &nbytes);
 
   int frames = nbytes / pa.sinkStride;
-  frames = pa.sinkPullFn(&src, frames);
+  frames = pa.sinkPullFn(dst, frames);
 
-  memcpy(dst, src, frames * pa.sinkStride);
   pa_stream_write(p, dst, frames * pa.sinkStride, NULL, 0, PA_SEEK_RELATIVE);
 }
 
diff --git a/client/include/interface/audiodev.h b/client/include/interface/audiodev.h
index 5acc7796..92952f77 100644
--- a/client/include/interface/audiodev.h
+++ b/client/include/interface/audiodev.h
@@ -25,8 +25,8 @@
 #include <stdint.h>
 #include <stddef.h>
 
-typedef int  (*LG_AudioPullFn)(uint8_t ** data, int frames);
-typedef void (*LG_AudioPushFn)(uint8_t *  data, int frames);
+typedef int  (*LG_AudioPullFn)(uint8_t * dst, int frames);
+typedef void (*LG_AudioPushFn)(uint8_t * src, int frames);
 
 struct LG_AudioDevOps
 {
diff --git a/client/src/audio.c b/client/src/audio.c
index 03314bfa..89eb390a 100644
--- a/client/src/audio.c
+++ b/client/src/audio.c
@@ -131,10 +131,21 @@ void playbackStopNL(void)
   }
 }
 
-static int playbackPullFrames(uint8_t ** data, int frames)
+static int playbackPullFrames(uint8_t * dst, int frames)
 {
   if (audio.playback.buffer)
-    *data = ringbuffer_consume(audio.playback.buffer, &frames);
+  {
+    frames = min(frames, ringbuffer_getCount(audio.playback.buffer));
+    for(int fetched = 0; fetched < frames; )
+    {
+      int       copy = frames - fetched;
+      uint8_t *  src = ringbuffer_consume(audio.playback.buffer, &copy);
+
+      memcpy(dst, src, copy * audio.playback.stride);
+      dst     += copy * audio.playback.stride;
+      fetched += copy;
+    }
+  }
   else
     frames = 0;