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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 <hardware/audio.h>
     22 #include <utils/Log.h>
     23 
     24 #include "AudioHwDevice.h"
     25 #include "AudioStreamOut.h"
     26 
     27 namespace android {
     28 
     29 // ----------------------------------------------------------------------------
     30 AudioStreamOut::AudioStreamOut(AudioHwDevice *dev, audio_output_flags_t flags)
     31         : audioHwDev(dev)
     32         , stream(NULL)
     33         , flags(flags)
     34         , mFramesWritten(0)
     35         , mFramesWrittenAtStandby(0)
     36         , mRenderPosition(0)
     37         , mRateMultiplier(1)
     38         , mHalFormatHasProportionalFrames(false)
     39         , mHalFrameSize(0)
     40 {
     41 }
     42 
     43 audio_hw_device_t *AudioStreamOut::hwDev() const
     44 {
     45     return audioHwDev->hwDevice();
     46 }
     47 
     48 status_t AudioStreamOut::getRenderPosition(uint64_t *frames)
     49 {
     50     if (stream == NULL) {
     51         return NO_INIT;
     52     }
     53 
     54     uint32_t halPosition = 0;
     55     status_t status = stream->get_render_position(stream, &halPosition);
     56     if (status != NO_ERROR) {
     57         return status;
     58     }
     59 
     60     // Maintain a 64-bit render position using the 32-bit result from the HAL.
     61     // This delta calculation relies on the arithmetic overflow behavior
     62     // of integers. For example (100 - 0xFFFFFFF0) = 116.
     63     uint32_t truncatedPosition = (uint32_t)mRenderPosition;
     64     int32_t deltaHalPosition = (int32_t)(halPosition - truncatedPosition);
     65     if (deltaHalPosition > 0) {
     66         mRenderPosition += deltaHalPosition;
     67     }
     68     // Scale from HAL sample rate to application rate.
     69     *frames = mRenderPosition / mRateMultiplier;
     70 
     71     return status;
     72 }
     73 
     74 // return bottom 32-bits of the render position
     75 status_t AudioStreamOut::getRenderPosition(uint32_t *frames)
     76 {
     77     uint64_t position64 = 0;
     78     status_t status = getRenderPosition(&position64);
     79     if (status == NO_ERROR) {
     80         *frames = (uint32_t)position64;
     81     }
     82     return status;
     83 }
     84 
     85 status_t AudioStreamOut::getPresentationPosition(uint64_t *frames, struct timespec *timestamp)
     86 {
     87     if (stream == NULL) {
     88         return NO_INIT;
     89     }
     90 
     91     uint64_t halPosition = 0;
     92     status_t status = stream->get_presentation_position(stream, &halPosition, timestamp);
     93     if (status != NO_ERROR) {
     94         return status;
     95     }
     96 
     97     // Adjust for standby using HAL rate frames.
     98     // Only apply this correction if the HAL is getting PCM frames.
     99     if (mHalFormatHasProportionalFrames) {
    100         uint64_t adjustedPosition = (halPosition <= mFramesWrittenAtStandby) ?
    101                 0 : (halPosition - mFramesWrittenAtStandby);
    102         // Scale from HAL sample rate to application rate.
    103         *frames = adjustedPosition / mRateMultiplier;
    104     } else {
    105         // For offloaded MP3 and other compressed formats.
    106         *frames = halPosition;
    107     }
    108 
    109     return status;
    110 }
    111 
    112 status_t AudioStreamOut::open(
    113         audio_io_handle_t handle,
    114         audio_devices_t devices,
    115         struct audio_config *config,
    116         const char *address)
    117 {
    118     audio_stream_out_t *outStream;
    119 
    120     audio_output_flags_t customFlags = (config->format == AUDIO_FORMAT_IEC61937)
    121                 ? (audio_output_flags_t)(flags | AUDIO_OUTPUT_FLAG_IEC958_NONAUDIO)
    122                 : flags;
    123 
    124     int status = hwDev()->open_output_stream(
    125             hwDev(),
    126             handle,
    127             devices,
    128             customFlags,
    129             config,
    130             &outStream,
    131             address);
    132     ALOGV("AudioStreamOut::open(), HAL returned "
    133             " stream %p, sampleRate %d, Format %#x, "
    134             "channelMask %#x, status %d",
    135             outStream,
    136             config->sample_rate,
    137             config->format,
    138             config->channel_mask,
    139             status);
    140 
    141     // Some HALs may not recognize AUDIO_FORMAT_IEC61937. But if we declare
    142     // it as PCM then it will probably work.
    143     if (status != NO_ERROR && config->format == AUDIO_FORMAT_IEC61937) {
    144         struct audio_config customConfig = *config;
    145         customConfig.format = AUDIO_FORMAT_PCM_16_BIT;
    146 
    147         status = hwDev()->open_output_stream(
    148                 hwDev(),
    149                 handle,
    150                 devices,
    151                 customFlags,
    152                 &customConfig,
    153                 &outStream,
    154                 address);
    155         ALOGV("AudioStreamOut::open(), treat IEC61937 as PCM, status = %d", status);
    156     }
    157 
    158     if (status == NO_ERROR) {
    159         stream = outStream;
    160         mHalFormatHasProportionalFrames = audio_has_proportional_frames(config->format);
    161         mHalFrameSize = audio_stream_out_frame_size(stream);
    162     }
    163 
    164     return status;
    165 }
    166 
    167 audio_format_t AudioStreamOut::getFormat() const
    168 {
    169     return stream->common.get_format(&stream->common);
    170 }
    171 
    172 uint32_t AudioStreamOut::getSampleRate() const
    173 {
    174     return stream->common.get_sample_rate(&stream->common);
    175 }
    176 
    177 audio_channel_mask_t AudioStreamOut::getChannelMask() const
    178 {
    179     return stream->common.get_channels(&stream->common);
    180 }
    181 
    182 int AudioStreamOut::flush()
    183 {
    184     ALOG_ASSERT(stream != NULL);
    185     mRenderPosition = 0;
    186     mFramesWritten = 0;
    187     mFramesWrittenAtStandby = 0;
    188     if (stream->flush != NULL) {
    189         return stream->flush(stream);
    190     }
    191     return NO_ERROR;
    192 }
    193 
    194 int AudioStreamOut::standby()
    195 {
    196     ALOG_ASSERT(stream != NULL);
    197     mRenderPosition = 0;
    198     mFramesWrittenAtStandby = mFramesWritten;
    199     return stream->common.standby(&stream->common);
    200 }
    201 
    202 ssize_t AudioStreamOut::write(const void *buffer, size_t numBytes)
    203 {
    204     ALOG_ASSERT(stream != NULL);
    205     ssize_t bytesWritten = stream->write(stream, buffer, numBytes);
    206     if (bytesWritten > 0 && mHalFrameSize > 0) {
    207         mFramesWritten += bytesWritten / mHalFrameSize;
    208     }
    209     return bytesWritten;
    210 }
    211 
    212 } // namespace android
    213