Receive-side ready for multiple channels.
Made path from NetEq to AudioTransport ready for many-channel audio.
If there is one stream, we can handle anything that fits in an
AudioFrame. For many streams, the current limit is 6.
Some multi-channel combinations are not supported: e.g. if we get
stereo audio and attempt to play out 6 channels.
Changes:
* AudioFrameOperations - replaced the MonoTo* and *ToMono methods by
UpmixChannels & DownmixChannels.
* AudioMixer: removed DCHECKs for <= 2 channels and tweaked the mixing
algorithm to handle many channels.
Bug: webrtc:8649
Change-Id: Ib83e16d463694e35658caa09c27849e853d508fb
Reviewed-on: https://webrtc-review.googlesource.com/c/106040
Reviewed-by: Oskar Sundbom <ossu@webrtc.org>
Commit-Queue: Alex Loiko <aleloi@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26446}diff --git a/modules/audio_mixer/audio_frame_manipulator.cc b/modules/audio_mixer/audio_frame_manipulator.cc
index e8a5f75..78c11b1 100644
--- a/modules/audio_mixer/audio_frame_manipulator.cc
+++ b/modules/audio_mixer/audio_frame_manipulator.cc
@@ -9,6 +9,7 @@
*/
#include "modules/audio_mixer/audio_frame_manipulator.h"
+
#include "audio/utility/audio_frame_operations.h"
#include "rtc_base/checks.h"
@@ -55,11 +56,16 @@
void RemixFrame(size_t target_number_of_channels, AudioFrame* frame) {
RTC_DCHECK_GE(target_number_of_channels, 1);
- RTC_DCHECK_LE(target_number_of_channels, 2);
- if (frame->num_channels_ == 1 && target_number_of_channels == 2) {
- AudioFrameOperations::MonoToStereo(frame);
- } else if (frame->num_channels_ == 2 && target_number_of_channels == 1) {
- AudioFrameOperations::StereoToMono(frame);
+ if (frame->num_channels_ == target_number_of_channels) {
+ return;
}
+ if (frame->num_channels_ > target_number_of_channels) {
+ AudioFrameOperations::DownmixChannels(target_number_of_channels, frame);
+ } else if (frame->num_channels_ < target_number_of_channels) {
+ AudioFrameOperations::UpmixChannels(target_number_of_channels, frame);
+ }
+ RTC_DCHECK_EQ(frame->num_channels_, target_number_of_channels)
+ << "Wrong number of channels, " << frame->num_channels_ << " vs "
+ << target_number_of_channels;
}
} // namespace webrtc