1 files changed, 171 insertions, 0 deletions
diff --git a/libaudio/ReSampler.cpp b/libaudio/ReSampler.cpp
new file mode 100644
index 0000000..aa1d5e0
--- /dev/null
+++ b/libaudio/ReSampler.cpp
@@ -0,0 +1,171 @@
+/*
+** Copyright 2011, The Android Open-Source Project
+**
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+**
+**     http://www.apache.org/licenses/LICENSE-2.0
+**
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*/
+
+//#define LOG_NDEBUG 0
+#define LOG_TAG "ReSampler"
+
+#include <utils/Log.h>
+#include "ReSampler.h"
+
+namespace android_audio_legacy {
+
+
+//------------------------------------------------------------------------------
+// speex based resampler
+//------------------------------------------------------------------------------
+
+#define RESAMPLER_QUALITY 2
+
+ReSampler::ReSampler(uint32_t inSampleRate,
+                                    uint32_t outSampleRate,
+                                    uint32_t channelCount,
+                                    BufferProvider* provider)
+    :  mStatus(NO_INIT), mSpeexResampler(NULL), mProvider(provider),
+       mInSampleRate(inSampleRate), mOutSampleRate(outSampleRate), mChannelCount(channelCount),
+       mInBuf(NULL), mInBufSize(0)
+{
+    LOGV("ReSampler() cstor %p In SR %d Out SR %d channels %d",
+         this, mInSampleRate, mOutSampleRate, mChannelCount);
+
+    if (mProvider == NULL) {
+        return;
+    }
+
+    int error;
+    mSpeexResampler = speex_resampler_init(channelCount,
+                                      inSampleRate,
+                                      outSampleRate,
+                                      RESAMPLER_QUALITY,
+                                      &error);
+    if (mSpeexResampler == NULL) {
+        LOGW("ReSampler: Cannot create speex resampler: %s", speex_resampler_strerror(error));
+        return;
+    }
+
+    reset();
+
+    int frames = speex_resampler_get_input_latency(mSpeexResampler);
+    mSpeexDelayNs = (int32_t)((1000000000 * (int64_t)frames) / mInSampleRate);
+    frames = speex_resampler_get_output_latency(mSpeexResampler);
+    mSpeexDelayNs += (int32_t)((1000000000 * (int64_t)frames) / mOutSampleRate);
+
+    mStatus = NO_ERROR;
+}
+
+ReSampler::~ReSampler()
+{
+    free(mInBuf);
+
+    if (mSpeexResampler != NULL) {
+        speex_resampler_destroy(mSpeexResampler);
+    }
+}
+
+void ReSampler::reset()
+{
+    mFramesIn = 0;
+    mFramesRq = 0;
+
+    if (mSpeexResampler != NULL) {
+        speex_resampler_reset_mem(mSpeexResampler);
+    }
+}
+
+int32_t ReSampler::delayNs()
+{
+    int32_t delay = (int32_t)((1000000000 * (int64_t)mFramesIn) / mInSampleRate);
+    delay += mSpeexDelayNs;
+
+    return delay;
+}
+
+// outputs a number of frames less or equal to *outFrameCount and updates *outFrameCount
+// with the actual number of frames produced.
+int ReSampler::resample(int16_t *out, size_t *outFrameCount)
+{
+    if (mStatus != NO_ERROR) {
+        return mStatus;
+    }
+
+    if (out == NULL || outFrameCount == NULL) {
+        return BAD_VALUE;
+    }
+
+    size_t framesRq = *outFrameCount;
+    // update and cache the number of frames needed at the input sampling rate to produce
+    // the number of frames requested at the output sampling rate
+    if (framesRq != mFramesRq) {
+        mFramesNeeded = (framesRq * mOutSampleRate) / mInSampleRate + 1;
+        mFramesRq = framesRq;
+    }
+
+    size_t framesWr = 0;
+    size_t inFrames = 0;
+    while (framesWr < framesRq) {
+        if (mFramesIn < mFramesNeeded) {
+            // make sure that the number of frames present in mInBuf (mFramesIn) is at least
+            // the number of frames needed to produce the number of frames requested at
+            // the output sampling rate
+            if (mInBufSize < mFramesNeeded) {
+                mInBufSize = mFramesNeeded;
+                mInBuf = (int16_t *)realloc(mInBuf, mInBufSize * mChannelCount * sizeof(int16_t));
+            }
+            BufferProvider::Buffer buf;
+            buf.frameCount = mFramesNeeded - mFramesIn;
+            mProvider->getNextBuffer(&buf);
+            if (buf.raw == NULL) {
+                break;
+            }
+            memcpy(mInBuf + mFramesIn * mChannelCount,
+                    buf.raw,
+                    buf.frameCount * mChannelCount * sizeof(int16_t));
+            mFramesIn += buf.frameCount;
+            mProvider->releaseBuffer(&buf);
+        }
+
+        size_t outFrames = framesRq - framesWr;
+        inFrames = mFramesIn;
+        if (mChannelCount == 1) {
+            speex_resampler_process_int(mSpeexResampler,
+                                        0,
+                                        mInBuf,
+                                        &inFrames,
+                                        out + framesWr * mChannelCount,
+                                        &outFrames);
+        } else {
+            speex_resampler_process_interleaved_int(mSpeexResampler,
+                                        mInBuf,
+                                        &inFrames,
+                                        out + framesWr * mChannelCount,
+                                        &outFrames);
+        }
+        framesWr += outFrames;
+        mFramesIn -= inFrames;
+        LOGW_IF((framesWr != framesRq) && (mFramesIn != 0),
+                "ReSampler::resample() remaining %d frames in and %d frames out",
+                mFramesIn, (framesRq - framesWr));
+    }
+    if (mFramesIn) {
+        memmove(mInBuf,
+                mInBuf + inFrames * mChannelCount,
+                mFramesIn * mChannelCount * sizeof(int16_t));
+    }
+    *outFrameCount = framesWr;
+
+    return NO_ERROR;
+}
+
+}; // namespace android_audio_legacy