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      1 /*
      2  * Copyright (C) 2015 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #ifndef ANDROID_BUFFER_PROVIDERS_H
     18 #define ANDROID_BUFFER_PROVIDERS_H
     19 
     20 #include <stdint.h>
     21 #include <sys/types.h>
     22 
     23 #include <media/AudioBufferProvider.h>
     24 #include <media/AudioResamplerPublic.h>
     25 #include <system/audio.h>
     26 #include <system/audio_effect.h>
     27 #include <utils/StrongPointer.h>
     28 
     29 // external forward declaration from external/sonic/sonic.h
     30 struct sonicStreamStruct;
     31 typedef struct sonicStreamStruct *sonicStream;
     32 
     33 namespace android {
     34 
     35 class EffectBufferHalInterface;
     36 class EffectHalInterface;
     37 class EffectsFactoryHalInterface;
     38 
     39 // ----------------------------------------------------------------------------
     40 
     41 class PassthruBufferProvider : public AudioBufferProvider {
     42 public:
     43     PassthruBufferProvider() : mTrackBufferProvider(NULL) { }
     44 
     45     virtual ~PassthruBufferProvider() { }
     46 
     47     // call this to release the buffer to the upstream provider.
     48     // treat it as an audio discontinuity for future samples.
     49     virtual void reset() { }
     50 
     51     // set the upstream buffer provider. Consider calling "reset" before this function.
     52     virtual void setBufferProvider(AudioBufferProvider *p) {
     53         mTrackBufferProvider = p;
     54     }
     55 
     56 protected:
     57     AudioBufferProvider *mTrackBufferProvider;
     58 };
     59 
     60 // Base AudioBufferProvider class used for DownMixerBufferProvider, RemixBufferProvider,
     61 // and ReformatBufferProvider.
     62 // It handles a private buffer for use in converting format or channel masks from the
     63 // input data to a form acceptable by the mixer.
     64 // TODO: Make a ResamplerBufferProvider when integers are entirely removed from the
     65 // processing pipeline.
     66 class CopyBufferProvider : public PassthruBufferProvider {
     67 public:
     68     // Use a private buffer of bufferFrameCount frames (each frame is outputFrameSize bytes).
     69     // If bufferFrameCount is 0, no private buffer is created and in-place modification of
     70     // the upstream buffer provider's buffers is performed by copyFrames().
     71     CopyBufferProvider(size_t inputFrameSize, size_t outputFrameSize,
     72             size_t bufferFrameCount);
     73     virtual ~CopyBufferProvider();
     74 
     75     // Overrides AudioBufferProvider methods
     76     virtual status_t getNextBuffer(Buffer *buffer);
     77     virtual void releaseBuffer(Buffer *buffer);
     78 
     79     // Overrides PassthruBufferProvider
     80     virtual void reset();
     81 
     82     // this function should be supplied by the derived class.  It converts
     83     // #frames in the *src pointer to the *dst pointer.  It is public because
     84     // some providers will allow this to work on arbitrary buffers outside
     85     // of the internal buffers.
     86     virtual void copyFrames(void *dst, const void *src, size_t frames) = 0;
     87 
     88 protected:
     89     const size_t         mInputFrameSize;
     90     const size_t         mOutputFrameSize;
     91 private:
     92     AudioBufferProvider::Buffer mBuffer;
     93     const size_t         mLocalBufferFrameCount;
     94     void                *mLocalBufferData;
     95     size_t               mConsumed;
     96 };
     97 
     98 // DownmixerBufferProvider derives from CopyBufferProvider to provide
     99 // position dependent downmixing by an Audio Effect.
    100 class DownmixerBufferProvider : public CopyBufferProvider {
    101 public:
    102     DownmixerBufferProvider(audio_channel_mask_t inputChannelMask,
    103             audio_channel_mask_t outputChannelMask, audio_format_t format,
    104             uint32_t sampleRate, int32_t sessionId, size_t bufferFrameCount);
    105     virtual ~DownmixerBufferProvider();
    106     //Overrides
    107     virtual void copyFrames(void *dst, const void *src, size_t frames);
    108 
    109     bool isValid() const { return mDownmixInterface.get() != NULL; }
    110     static status_t init();
    111     static bool isMultichannelCapable() { return sIsMultichannelCapable; }
    112 
    113 protected:
    114     sp<EffectsFactoryHalInterface> mEffectsFactory;
    115     sp<EffectHalInterface> mDownmixInterface;
    116     size_t mInFrameSize;
    117     size_t mOutFrameSize;
    118     sp<EffectBufferHalInterface> mInBuffer;
    119     sp<EffectBufferHalInterface> mOutBuffer;
    120     effect_config_t    mDownmixConfig;
    121 
    122     // effect descriptor for the downmixer used by the mixer
    123     static effect_descriptor_t sDwnmFxDesc;
    124     // indicates whether a downmix effect has been found and is usable by this mixer
    125     static bool                sIsMultichannelCapable;
    126     // FIXME: should we allow effects outside of the framework?
    127     // We need to here. A special ioId that must be <= -2 so it does not map to a session.
    128     static const int32_t SESSION_ID_INVALID_AND_IGNORED = -2;
    129 };
    130 
    131 // RemixBufferProvider derives from CopyBufferProvider to perform an
    132 // upmix or downmix to the proper channel count and mask.
    133 class RemixBufferProvider : public CopyBufferProvider {
    134 public:
    135     RemixBufferProvider(audio_channel_mask_t inputChannelMask,
    136             audio_channel_mask_t outputChannelMask, audio_format_t format,
    137             size_t bufferFrameCount);
    138     //Overrides
    139     virtual void copyFrames(void *dst, const void *src, size_t frames);
    140 
    141 protected:
    142     const audio_format_t mFormat;
    143     const size_t         mSampleSize;
    144     const size_t         mInputChannels;
    145     const size_t         mOutputChannels;
    146     int8_t               mIdxAry[sizeof(uint32_t) * 8]; // 32 bits => channel indices
    147 };
    148 
    149 // ReformatBufferProvider derives from CopyBufferProvider to convert the input data
    150 // to an acceptable mixer input format type.
    151 class ReformatBufferProvider : public CopyBufferProvider {
    152 public:
    153     ReformatBufferProvider(int32_t channelCount,
    154             audio_format_t inputFormat, audio_format_t outputFormat,
    155             size_t bufferFrameCount);
    156     virtual void copyFrames(void *dst, const void *src, size_t frames);
    157 
    158 protected:
    159     const uint32_t       mChannelCount;
    160     const audio_format_t mInputFormat;
    161     const audio_format_t mOutputFormat;
    162 };
    163 
    164 // ClampFloatBufferProvider derives from CopyBufferProvider to clamp floats inside -3db
    165 class ClampFloatBufferProvider : public CopyBufferProvider {
    166 public:
    167     ClampFloatBufferProvider(int32_t channelCount,
    168             size_t bufferFrameCount);
    169     virtual void copyFrames(void *dst, const void *src, size_t frames);
    170 
    171 protected:
    172     const uint32_t       mChannelCount;
    173 };
    174 
    175 // TimestretchBufferProvider derives from PassthruBufferProvider for time stretching
    176 class TimestretchBufferProvider : public PassthruBufferProvider {
    177 public:
    178     TimestretchBufferProvider(int32_t channelCount,
    179             audio_format_t format, uint32_t sampleRate,
    180             const AudioPlaybackRate &playbackRate);
    181     virtual ~TimestretchBufferProvider();
    182 
    183     // Overrides AudioBufferProvider methods
    184     virtual status_t getNextBuffer(Buffer* buffer);
    185     virtual void releaseBuffer(Buffer* buffer);
    186 
    187     // Overrides PassthruBufferProvider
    188     virtual void reset();
    189 
    190     virtual status_t setPlaybackRate(const AudioPlaybackRate &playbackRate);
    191 
    192     // processes frames
    193     // dstBuffer is where to place the data
    194     // dstFrames [in/out] is the desired frames (return with actual placed in buffer)
    195     // srcBuffer is the source data
    196     // srcFrames [in/out] is the available source frames (return with consumed)
    197     virtual void processFrames(void *dstBuffer, size_t *dstFrames,
    198             const void *srcBuffer, size_t *srcFrames);
    199 
    200 protected:
    201     const uint32_t       mChannelCount;
    202     const audio_format_t mFormat;
    203     const uint32_t       mSampleRate; // const for now (TODO change this)
    204     const size_t         mFrameSize;
    205     AudioPlaybackRate    mPlaybackRate;
    206 
    207 private:
    208     AudioBufferProvider::Buffer mBuffer;          // for upstream request
    209     size_t               mLocalBufferFrameCount;  // size of local buffer
    210     void                *mLocalBufferData;        // internally allocated buffer for data returned
    211                                                   // to caller
    212     size_t               mRemaining;              // remaining data in local buffer
    213     sonicStream          mSonicStream;            // handle to sonic timestretch object
    214     //FIXME: this dependency should be abstracted out
    215     bool                 mFallbackFailErrorShown; // log fallback error only once
    216     bool                 mAudioPlaybackRateValid; // flag for current parameters validity
    217 };
    218 
    219 // ----------------------------------------------------------------------------
    220 } // namespace android
    221 
    222 #endif // ANDROID_BUFFER_PROVIDERS_H
    223