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