commit 7fc97ba08e2850f3f16db704b78ce78e3dbe1ff0
author Glenn Kasten <gkasten@google.com> Tue Jul 16 17:18:58 2013 -0700
committer Glenn Kasten <gkasten@google.com> Thu Jul 25 12:22:18 2013 -0700
tree ada9fda1321150cc75295eece5f7f82e35f0c9f3
parent fc5ea08326b510c6f82f71845d95a8758a6ab698

HAL stream format for mixer output threads must be stereo 16-bit PCM

Direct and tunnel output threads can support various HAL stream formats,
included encoded.  But currently there are stereo 16-bit PCM assumptions
in several places for mixer and duplicating output threads:
 - mMixBuffer and mixBuffer()
 - AudioMixer including resampler
 - FastMixer's mixBuffer
 - effects
 - NBAIO_Format
 - anywhere FCC_2 is used
 - possibly other places

Until those assumptions are removed, this CL enforces stereo 16-bit
PCM in mixer and duplicating threads at the place where the HAL format
is read.  It was already being checked in checkForNewParameters_l(),
but not in readOutputParameters().

Change-Id: Ibe344cc922743da234299097aa1bb1f54795cc9b

services/audioflinger/Threads.cpp

diff --git a/services/audioflinger/Threads.cpp b/services/audioflinger/Threads.cpp
index f27d908..0928923 100644
--- a/services/audioflinger/Threads.cpp
+++ b/services/audioflinger/Threads.cpp
@@ -1430,10 +1430,25 @@
 
 void AudioFlinger::PlaybackThread::readOutputParameters()
 {
+    // unfortunately we have no way of recovering from errors here, hence the LOG_FATAL
     mSampleRate = mOutput->stream->common.get_sample_rate(&mOutput->stream->common);
     mChannelMask = mOutput->stream->common.get_channels(&mOutput->stream->common);
+    if (!audio_is_output_channel(mChannelMask)) {
+        LOG_FATAL("HAL channel mask %#x not valid for output", mChannelMask);
+    }
+    if ((mType == MIXER || mType == DUPLICATING) && mChannelMask != AUDIO_CHANNEL_OUT_STEREO) {
+        LOG_FATAL("HAL channel mask %#x not supported for mixed output; "
+                "must be AUDIO_CHANNEL_OUT_STEREO", mChannelMask);
+    }
     mChannelCount = (uint16_t)popcount(mChannelMask);
     mFormat = mOutput->stream->common.get_format(&mOutput->stream->common);
+    if (!audio_is_valid_format(mFormat)) {
+        LOG_FATAL("HAL format %d not valid for output", mFormat);
+    }
+    if ((mType == MIXER || mType == DUPLICATING) && mFormat != AUDIO_FORMAT_PCM_16_BIT) {
+        LOG_FATAL("HAL format %d not supported for mixed output; must be AUDIO_FORMAT_PCM_16_BIT",
+                mFormat);
+    }
     mFrameSize = audio_stream_frame_size(&mOutput->stream->common);
     mFrameCount = mOutput->stream->common.get_buffer_size(&mOutput->stream->common) / mFrameSize;
     if (mFrameCount & 15) {