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      1 /*
      2 **
      3 ** Copyright 2015, The Android Open Source Project
      4 **
      5 ** Licensed under the Apache License, Version 2.0 (the "License");
      6 ** you may not use this file except in compliance with the License.
      7 ** You may obtain a copy of the License at
      8 **
      9 **     http://www.apache.org/licenses/LICENSE-2.0
     10 **
     11 ** Unless required by applicable law or agreed to in writing, software
     12 ** distributed under the License is distributed on an "AS IS" BASIS,
     13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14 ** See the License for the specific language governing permissions and
     15 ** limitations under the License.
     16 */
     17 
     18 #define LOG_TAG "AudioFlinger"
     19 //#define LOG_NDEBUG 0
     20 
     21 #include <media/audiohal/DeviceHalInterface.h>
     22 #include <media/audiohal/StreamHalInterface.h>
     23 #include <system/audio.h>
     24 #include <utils/Log.h>
     25 
     26 #include "AudioHwDevice.h"
     27 #include "AudioStreamOut.h"
     28 
     29 namespace android {
     30 
     31 // ----------------------------------------------------------------------------
     32 AudioStreamOut::AudioStreamOut(AudioHwDevice *dev, audio_output_flags_t flags)
     33         : audioHwDev(dev)
     34         , stream(NULL)
     35         , flags(flags)
     36         , mFramesWritten(0)
     37         , mFramesWrittenAtStandby(0)
     38         , mRenderPosition(0)
     39         , mRateMultiplier(1)
     40         , mHalFormatHasProportionalFrames(false)
     41         , mHalFrameSize(0)
     42 {
     43 }
     44 
     45 AudioStreamOut::~AudioStreamOut()
     46 {
     47 }
     48 
     49 sp<DeviceHalInterface> AudioStreamOut::hwDev() const
     50 {
     51     return audioHwDev->hwDevice();
     52 }
     53 
     54 status_t AudioStreamOut::getRenderPosition(uint64_t *frames)
     55 {
     56     if (stream == 0) {
     57         return NO_INIT;
     58     }
     59 
     60     uint32_t halPosition = 0;
     61     status_t status = stream->getRenderPosition(&halPosition);
     62     if (status != NO_ERROR) {
     63         return status;
     64     }
     65 
     66     // Maintain a 64-bit render position using the 32-bit result from the HAL.
     67     // This delta calculation relies on the arithmetic overflow behavior
     68     // of integers. For example (100 - 0xFFFFFFF0) = 116.
     69     uint32_t truncatedPosition = (uint32_t)mRenderPosition;
     70     int32_t deltaHalPosition = (int32_t)(halPosition - truncatedPosition);
     71     if (deltaHalPosition > 0) {
     72         mRenderPosition += deltaHalPosition;
     73     }
     74     // Scale from HAL sample rate to application rate.
     75     *frames = mRenderPosition / mRateMultiplier;
     76 
     77     return status;
     78 }
     79 
     80 // return bottom 32-bits of the render position
     81 status_t AudioStreamOut::getRenderPosition(uint32_t *frames)
     82 {
     83     uint64_t position64 = 0;
     84     status_t status = getRenderPosition(&position64);
     85     if (status == NO_ERROR) {
     86         *frames = (uint32_t)position64;
     87     }
     88     return status;
     89 }
     90 
     91 status_t AudioStreamOut::getPresentationPosition(uint64_t *frames, struct timespec *timestamp)
     92 {
     93     if (stream == 0) {
     94         return NO_INIT;
     95     }
     96 
     97     uint64_t halPosition = 0;
     98     status_t status = stream->getPresentationPosition(&halPosition, timestamp);
     99     if (status != NO_ERROR) {
    100         return status;
    101     }
    102 
    103     // Adjust for standby using HAL rate frames.
    104     // Only apply this correction if the HAL is getting PCM frames.
    105     if (mHalFormatHasProportionalFrames) {
    106         uint64_t adjustedPosition = (halPosition <= mFramesWrittenAtStandby) ?
    107                 0 : (halPosition - mFramesWrittenAtStandby);
    108         // Scale from HAL sample rate to application rate.
    109         *frames = adjustedPosition / mRateMultiplier;
    110     } else {
    111         // For offloaded MP3 and other compressed formats.
    112         *frames = halPosition;
    113     }
    114 
    115     return status;
    116 }
    117 
    118 status_t AudioStreamOut::open(
    119         audio_io_handle_t handle,
    120         audio_devices_t devices,
    121         struct audio_config *config,
    122         const char *address)
    123 {
    124     sp<StreamOutHalInterface> outStream;
    125 
    126     audio_output_flags_t customFlags = (config->format == AUDIO_FORMAT_IEC61937)
    127                 ? (audio_output_flags_t)(flags | AUDIO_OUTPUT_FLAG_IEC958_NONAUDIO)
    128                 : flags;
    129 
    130     int status = hwDev()->openOutputStream(
    131             handle,
    132             devices,
    133             customFlags,
    134             config,
    135             address,
    136             &outStream);
    137     ALOGV("AudioStreamOut::open(), HAL returned "
    138             " stream %p, sampleRate %d, Format %#x, "
    139             "channelMask %#x, status %d",
    140             outStream.get(),
    141             config->sample_rate,
    142             config->format,
    143             config->channel_mask,
    144             status);
    145 
    146     // Some HALs may not recognize AUDIO_FORMAT_IEC61937. But if we declare
    147     // it as PCM then it will probably work.
    148     if (status != NO_ERROR && config->format == AUDIO_FORMAT_IEC61937) {
    149         struct audio_config customConfig = *config;
    150         customConfig.format = AUDIO_FORMAT_PCM_16_BIT;
    151 
    152         status = hwDev()->openOutputStream(
    153                 handle,
    154                 devices,
    155                 customFlags,
    156                 &customConfig,
    157                 address,
    158                 &outStream);
    159         ALOGV("AudioStreamOut::open(), treat IEC61937 as PCM, status = %d", status);
    160     }
    161 
    162     if (status == NO_ERROR) {
    163         stream = outStream;
    164         mHalFormatHasProportionalFrames = audio_has_proportional_frames(config->format);
    165         status = stream->getFrameSize(&mHalFrameSize);
    166     }
    167 
    168     return status;
    169 }
    170 
    171 audio_format_t AudioStreamOut::getFormat() const
    172 {
    173     audio_format_t result;
    174     return stream->getFormat(&result) == OK ? result : AUDIO_FORMAT_INVALID;
    175 }
    176 
    177 uint32_t AudioStreamOut::getSampleRate() const
    178 {
    179     uint32_t result;
    180     return stream->getSampleRate(&result) == OK ? result : 0;
    181 }
    182 
    183 audio_channel_mask_t AudioStreamOut::getChannelMask() const
    184 {
    185     audio_channel_mask_t result;
    186     return stream->getChannelMask(&result) == OK ? result : AUDIO_CHANNEL_INVALID;
    187 }
    188 
    189 int AudioStreamOut::flush()
    190 {
    191     mRenderPosition = 0;
    192     mFramesWritten = 0;
    193     mFramesWrittenAtStandby = 0;
    194     status_t result = stream->flush();
    195     return result != INVALID_OPERATION ? result : NO_ERROR;
    196 }
    197 
    198 int AudioStreamOut::standby()
    199 {
    200     mRenderPosition = 0;
    201     mFramesWrittenAtStandby = mFramesWritten;
    202     return stream->standby();
    203 }
    204 
    205 ssize_t AudioStreamOut::write(const void *buffer, size_t numBytes)
    206 {
    207     size_t bytesWritten;
    208     status_t result = stream->write(buffer, numBytes, &bytesWritten);
    209     if (result == OK && bytesWritten > 0 && mHalFrameSize > 0) {
    210         mFramesWritten += bytesWritten / mHalFrameSize;
    211     }
    212     return result == OK ? bytesWritten : result;
    213 }
    214 
    215 } // namespace android
    216