Revert "[audio_core] Fix audio effects timing."
This reverts commit 874da3cff7f72c23f325899945a81ed5af945414.
Reason for revert: This CL currently interacts badly with chrome audio on Astro. Reverting for now until we can get to the bottom of things.
Original change's description:
> [audio_core] Fix audio effects timing.
>
> Fix a sign error which was causing us to compensate for delay
> introduced by audio effects in the wrong direction, effectively
> shifting the audio out by 2x the amount introduced by the effects,
> instead of canceling it out as it should have.
>
> Tests: Verified timing on scope using pulse-gen test app with a GPIO
> reference.
> Change-Id: Ib63a2d410fccf818bc2703f357b8d7d0e978c08f
> Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/378087
> Commit-Queue: Martin Puryear <mpuryear@google.com>
> Reviewed-by: Dustin Green <dustingreen@google.com>
> Reviewed-by: Tim Detwiler <tjdetwiler@google.com>
> Testability-Review: Tim Detwiler <tjdetwiler@google.com>
TBR=johngro@google.com,tjdetwiler@google.com,mpuryear@google.com,dustingreen@google.com
Change-Id: I9d2bbd0a497833aa7bc3e82322ce26348ae736ad
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/378012
Reviewed-by: John Grossman <johngro@google.com>
Commit-Queue: John Grossman <johngro@google.com>
diff --git a/src/media/audio/audio_core/effects_stage.cc b/src/media/audio/audio_core/effects_stage.cc
index 60ad6ac..f927149 100644
--- a/src/media/audio/audio_core/effects_stage.cc
+++ b/src/media/audio/audio_core/effects_stage.cc
@@ -113,15 +113,11 @@
auto snapshot = source_->ReferenceClockToFractionalFrames();
// Update our timeline function to include the latency introduced by these effects.
- //
- // Our effects shift incoming audio into the future by "delay_frames".
- // So input frame[N] corresponds to output frame[N + delay_frames].
int64_t delay_frames = effects_processor_->delay_frames();
- auto delay_frac_frames = FractionalFrames<int64_t>(delay_frames);
-
- auto source_frac_frame_to_dest_frac_frame =
- TimelineFunction(delay_frac_frames.raw_value(), 0, TimelineRate(1, 1));
- snapshot.timeline_function = source_frac_frame_to_dest_frac_frame * snapshot.timeline_function;
+ auto delay_frac_frames = FractionalFrames<int64_t>(-delay_frames);
+ auto delay_function = TimelineFunction(delay_frac_frames.raw_value(), 0, TimelineRate(1, 1));
+ snapshot.timeline_function =
+ TimelineFunction::Compose(delay_function, snapshot.timeline_function);
return snapshot;
}
diff --git a/src/media/audio/audio_core/effects_stage_unittest.cc b/src/media/audio/audio_core/effects_stage_unittest.cc
index df5cf21..97819b7 100644
--- a/src/media/audio/audio_core/effects_stage_unittest.cc
+++ b/src/media/audio/audio_core/effects_stage_unittest.cc
@@ -182,20 +182,17 @@
});
auto effects_stage = EffectsStage::Create(effects, stream);
- // Since our effect introduces 13 frames of latency, the incoming source frame at time 0 can only
- // emerge from the effect in output frame 13.
- // Conversely, output frame 0 was produced based on the source frame at time -13.
- auto ref_clock_to_output_frac_frame =
- effects_stage->ReferenceClockToFractionalFrames().timeline_function;
- EXPECT_EQ(FractionalFrames<int64_t>::FromRaw(ref_clock_to_output_frac_frame.Apply(0)),
- FractionalFrames<int64_t>(13));
+ // Since our effect is introducing 13 frames of latency, the frame at time 0 is now actually frame
+ // -13, and the actual frame 0 will occur once it makes its way through the effect.
+ auto timeline_function = effects_stage->ReferenceClockToFractionalFrames().timeline_function;
+ EXPECT_EQ(FractionalFrames<int64_t>::FromRaw(timeline_function.Apply(0)),
+ FractionalFrames<int64_t>(-13));
- // Similarly, at the time we produce output frame 0, we had to draw upon the source frame from
- // time -13. Use a fuzzy compare to allow for slight rounding errors.
- int64_t frame_13_time = (zx::sec(-13).to_nsecs()) / kDefaultFormat.frames_per_second();
+ // Similarly, at the time we'd normally expect frame 13, we should instead be seeing frame 0. Use
+ // a fuzzy compare to allow for slight rounding errors.
+ int64_t frame_13_time = (zx::sec(13).to_nsecs()) / kDefaultFormat.frames_per_second();
auto frame_13_frac_frames =
- FractionalFrames<int64_t>::FromRaw(ref_clock_to_output_frac_frame.Apply(frame_13_time))
- .Absolute();
+ FractionalFrames<int64_t>::FromRaw(timeline_function.Apply(frame_13_time)).Absolute();
EXPECT_LE(frame_13_frac_frames.raw_value(), 1);
}
