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      1 /*
      2  * Copyright (C) 2014 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 /* This file contains shared utility functions to handle the tinyalsa
     18  * implementation for Android internal audio, generally in the hardware layer.
     19  * Some routines may log a fatal error on failure, as noted.
     20  */
     21 
     22 #ifndef ANDROID_AUDIO_ALSAOPS_H
     23 #define ANDROID_AUDIO_ALSAOPS_H
     24 
     25 #include <log/log.h>
     26 
     27 #include <system/audio.h>
     28 #include <tinyalsa/asoundlib.h>
     29 
     30 __BEGIN_DECLS
     31 
     32 /* Converts audio_format to pcm_format.
     33  * Parameters:
     34  *  format  the audio_format_t to convert
     35  *
     36  * Logs a fatal error if format is not a valid convertible audio_format_t.
     37  */
     38 static inline enum pcm_format pcm_format_from_audio_format(audio_format_t format)
     39 {
     40     switch (format) {
     41 #if HAVE_BIG_ENDIAN
     42     case AUDIO_FORMAT_PCM_16_BIT:
     43         return PCM_FORMAT_S16_BE;
     44     case AUDIO_FORMAT_PCM_24_BIT_PACKED:
     45         return PCM_FORMAT_S24_3BE;
     46     case AUDIO_FORMAT_PCM_32_BIT:
     47         return PCM_FORMAT_S32_BE;
     48     case AUDIO_FORMAT_PCM_8_24_BIT:
     49         return PCM_FORMAT_S24_BE;
     50 #else
     51     case AUDIO_FORMAT_PCM_16_BIT:
     52         return PCM_FORMAT_S16_LE;
     53     case AUDIO_FORMAT_PCM_24_BIT_PACKED:
     54         return PCM_FORMAT_S24_3LE;
     55     case AUDIO_FORMAT_PCM_32_BIT:
     56         return PCM_FORMAT_S32_LE;
     57     case AUDIO_FORMAT_PCM_8_24_BIT:
     58         return PCM_FORMAT_S24_LE;
     59 #endif
     60     case AUDIO_FORMAT_PCM_FLOAT:  /* there is no equivalent for float */
     61     default:
     62         LOG_ALWAYS_FATAL("pcm_format_from_audio_format: invalid audio format %#x", format);
     63         return 0;
     64     }
     65 }
     66 
     67 /* Converts pcm_format to audio_format.
     68  * Parameters:
     69  *  format  the pcm_format to convert
     70  *
     71  * Logs a fatal error if format is not a valid convertible pcm_format.
     72  */
     73 static inline audio_format_t audio_format_from_pcm_format(enum pcm_format format)
     74 {
     75     switch (format) {
     76 #if HAVE_BIG_ENDIAN
     77     case PCM_FORMAT_S16_BE:
     78         return AUDIO_FORMAT_PCM_16_BIT;
     79     case PCM_FORMAT_S24_3BE:
     80         return AUDIO_FORMAT_PCM_24_BIT_PACKED;
     81     case PCM_FORMAT_S24_BE:
     82         return AUDIO_FORMAT_PCM_8_24_BIT;
     83     case PCM_FORMAT_S32_BE:
     84         return AUDIO_FORMAT_PCM_32_BIT;
     85 #else
     86     case PCM_FORMAT_S16_LE:
     87         return AUDIO_FORMAT_PCM_16_BIT;
     88     case PCM_FORMAT_S24_3LE:
     89         return AUDIO_FORMAT_PCM_24_BIT_PACKED;
     90     case PCM_FORMAT_S24_LE:
     91         return AUDIO_FORMAT_PCM_8_24_BIT;
     92     case PCM_FORMAT_S32_LE:
     93         return AUDIO_FORMAT_PCM_32_BIT;
     94 #endif
     95     default:
     96         LOG_ALWAYS_FATAL("audio_format_from_pcm_format: invalid pcm format %#x", format);
     97         return 0;
     98     }
     99 }
    100 
    101 __END_DECLS
    102 
    103 #endif /* ANDROID_AUDIO_ALSAOPS_H */
    104