[vlc-commits] coreaudio: update the play date until the first rendering

[Thomas Guillem]

vlc/vlc-3.0 | branch: master | Thomas Guillem <thomas at gllm.fr> | Fri Sep 27 13:35:00 2019 +0200| [5e13b2ca197648f58f078605abe3921846480483] | committer: Thomas Guillem

coreaudio: update the play date until the first rendering

cf. fe2e9755088a0061518514f3b7bf3601f4813794

Only the first play date was handled. This is OK in most cases but not as
accurate as handling the date until the playback is truly started.

This previous commit and this commit were inspired by the pulse module.

(cherry picked from commit 53787c8fe097499049996457e56762a75bd5fd4c)
Signed-off-by: Thomas Guillem <thomas at gllm.fr>

> http://git.videolan.org/gitweb.cgi/vlc/vlc-3.0.git/?a=commit;h=5e13b2ca197648f58f078605abe3921846480483
---

 modules/audio_output/coreaudio_common.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/modules/audio_output/coreaudio_common.c b/modules/audio_output/coreaudio_common.c
index a7bcff42de..d727b02134 100644
--- a/modules/audio_output/coreaudio_common.c
+++ b/modules/audio_output/coreaudio_common.c
@@ -257,6 +257,15 @@ drop:
     lock_unlock(p_sys);
 }
 
+static mtime_t
+ca_GetLatencyLocked(audio_output_t *p_aout)
+{
+    struct aout_sys_common *p_sys = (struct aout_sys_common *) p_aout->sys;
+
+    const int64_t i_out_frames = BytesToFrames(p_sys, p_sys->i_out_size);
+    return FramesToUs(p_sys, i_out_frames + p_sys->i_render_frames);
+}
+
 int
 ca_TimeGet(audio_output_t *p_aout, mtime_t *delay)
 {
@@ -277,10 +286,8 @@ ca_TimeGet(audio_output_t *p_aout, mtime_t *delay)
     const mtime_t i_render_time_us = HostTimeToTick(p_sys->i_render_host_time);
     const mtime_t i_render_delay = i_render_time_us - mdate();
 
-    const int64_t i_out_frames = BytesToFrames(p_sys, p_sys->i_out_size);
-    *delay = FramesToUs(p_sys, i_out_frames + p_sys->i_render_frames)
-           + p_sys->i_dev_latency_us + i_render_delay;
-
+    *delay = ca_GetLatencyLocked(p_aout) + i_render_delay
+           + p_sys->i_dev_latency_us;
     lock_unlock(p_sys);
     return 0;
 }
@@ -355,10 +362,14 @@ ca_Play(audio_output_t * p_aout, block_t * p_block)
 
     lock_lock(p_sys);
 
-    if (p_sys->i_first_render_host_time == 0)
+    if (p_sys->i_render_host_time == 0)
     {
-        /* Setup the first render time */
-        p_sys->i_first_render_host_time = TickToHostTime(date);
+        /* Setup the first render time, this date must be updated until the
+         * first (non-silence/zero) frame is rendered by the render callback.
+         * Once the rendering is truly started, the date can be ignored. */
+
+        const mtime_t first_render_time = p_block->i_pts - ca_GetLatencyLocked(p_aout);
+        p_sys->i_first_render_host_time = TickToHostTime(first_render_time);
     }
 
     do