audio: align audio_generic_write with audio_pcm_hw_run_out

The function audio_generic_write should work exactly like
audio_pcm_hw_run_out. It's a very similar function working on a
different buffer.

This patch significantly reduces the number of drop-outs with
the DirectSound backend. To hear the difference start qemu with
-audiodev dsound,id=audio0,out.mixing-engine=off and play a
song in the guest with and without this patch.

Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Message-id: 20200920171729.15861-6-vr_qemu@t-online.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Volker Rümelin 2020-09-20 19:17:26 +02:00 committed by Gerd Hoffmann
parent ac221f45e3
commit 2d8823077e

View File

@ -1484,12 +1484,34 @@ size_t audio_generic_put_buffer_out(HWVoiceOut *hw, void *buf, size_t size)
size_t audio_generic_write(HWVoiceOut *hw, void *buf, size_t size)
{
size_t dst_size, copy_size;
void *dst = hw->pcm_ops->get_buffer_out(hw, &dst_size);
copy_size = MIN(size, dst_size);
size_t total = 0;
memcpy(dst, buf, copy_size);
return hw->pcm_ops->put_buffer_out(hw, dst, copy_size);
while (total < size) {
size_t dst_size = size - total;
size_t copy_size, proc;
void *dst = hw->pcm_ops->get_buffer_out(hw, &dst_size);
if (dst_size == 0) {
break;
}
copy_size = MIN(size - total, dst_size);
if (dst) {
memcpy(dst, (char *)buf + total, copy_size);
}
proc = hw->pcm_ops->put_buffer_out(hw, dst, copy_size);
total += proc;
if (proc == 0 || proc < copy_size) {
break;
}
}
if (hw->pcm_ops->run_buffer_out) {
hw->pcm_ops->run_buffer_out(hw);
}
return total;
}
size_t audio_generic_read(HWVoiceIn *hw, void *buf, size_t size)