diff options
Diffstat (limited to 'modules/usbaudio/audio_format.c')
| -rw-r--r-- | modules/usbaudio/audio_format.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/modules/usbaudio/audio_format.c b/modules/usbaudio/audio_format.c new file mode 100644 index 0000000..63b1ba8 --- /dev/null +++ b/modules/usbaudio/audio_format.c @@ -0,0 +1,110 @@ +/* + * Copyright (C) 2014 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#define LOG_TAG "audio_format" +/*#define LOG_NDEBUG 0*/ + +#include "audio_format.h" + +#include <tinyalsa/asoundlib.h> + +#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) + +/* + * Maps from bit position in pcm_mask to PCM_ format constants. + */ +int8_t const pcm_format_value_map[50] = { + PCM_FORMAT_S8, /* 00 - SNDRV_PCM_FORMAT_S8 */ + PCM_FORMAT_INVALID, /* 01 - SNDRV_PCM_FORMAT_U8 */ + PCM_FORMAT_S16_LE, /* 02 - SNDRV_PCM_FORMAT_S16_LE */ + PCM_FORMAT_INVALID, /* 03 - SNDRV_PCM_FORMAT_S16_BE */ + PCM_FORMAT_INVALID, /* 04 - SNDRV_PCM_FORMAT_U16_LE */ + PCM_FORMAT_INVALID, /* 05 - SNDRV_PCM_FORMAT_U16_BE */ + PCM_FORMAT_S24_3LE, /* 06 - SNDRV_PCM_FORMAT_S24_LE */ + PCM_FORMAT_INVALID, /* 07 - SNDRV_PCM_FORMAT_S24_BE */ + PCM_FORMAT_INVALID, /* 08 - SNDRV_PCM_FORMAT_U24_LE */ + PCM_FORMAT_INVALID, /* 09 - SNDRV_PCM_FORMAT_U24_BE */ + PCM_FORMAT_S32_LE, /* 10 - SNDRV_PCM_FORMAT_S32_LE */ + PCM_FORMAT_INVALID, /* 11 - SNDRV_PCM_FORMAT_S32_BE */ + PCM_FORMAT_INVALID, /* 12 - SNDRV_PCM_FORMAT_U32_LE */ + PCM_FORMAT_INVALID, /* 13 - SNDRV_PCM_FORMAT_U32_BE */ + PCM_FORMAT_INVALID, /* 14 - SNDRV_PCM_FORMAT_FLOAT_LE */ + PCM_FORMAT_INVALID, /* 15 - SNDRV_PCM_FORMAT_FLOAT_BE */ + PCM_FORMAT_INVALID, /* 16 - SNDRV_PCM_FORMAT_FLOAT64_LE */ + PCM_FORMAT_INVALID, /* 17 - SNDRV_PCM_FORMAT_FLOAT64_BE */ + PCM_FORMAT_INVALID, /* 18 - SNDRV_PCM_FORMAT_IEC958_SUBFRAME_LE */ + PCM_FORMAT_INVALID, /* 19 - SNDRV_PCM_FORMAT_IEC958_SUBFRAME_BE */ + PCM_FORMAT_INVALID, /* 20 - SNDRV_PCM_FORMAT_MU_LAW */ + PCM_FORMAT_INVALID, /* 21 - SNDRV_PCM_FORMAT_A_LAW */ + PCM_FORMAT_INVALID, /* 22 - SNDRV_PCM_FORMAT_IMA_ADPCM */ + PCM_FORMAT_INVALID, /* 23 - SNDRV_PCM_FORMAT_MPEG */ + PCM_FORMAT_INVALID, /* 24 - SNDRV_PCM_FORMAT_GSM */ + PCM_FORMAT_INVALID, /* 25 -> 30 (not assigned) */ + PCM_FORMAT_INVALID, + PCM_FORMAT_INVALID, + PCM_FORMAT_INVALID, + PCM_FORMAT_INVALID, + PCM_FORMAT_INVALID, + PCM_FORMAT_INVALID, /* 31 - SNDRV_PCM_FORMAT_SPECIAL */ + PCM_FORMAT_S24_3LE, /* 32 - SNDRV_PCM_FORMAT_S24_3LE */ /* ??? */ + PCM_FORMAT_INVALID, /* 33 - SNDRV_PCM_FORMAT_S24_3BE */ + PCM_FORMAT_INVALID, /* 34 - SNDRV_PCM_FORMAT_U24_3LE */ + PCM_FORMAT_INVALID, /* 35 - SNDRV_PCM_FORMAT_U24_3BE */ + PCM_FORMAT_INVALID, /* 36 - SNDRV_PCM_FORMAT_S20_3LE */ + PCM_FORMAT_INVALID, /* 37 - SNDRV_PCM_FORMAT_S20_3BE */ + PCM_FORMAT_INVALID, /* 38 - SNDRV_PCM_FORMAT_U20_3LE */ + PCM_FORMAT_INVALID, /* 39 - SNDRV_PCM_FORMAT_U20_3BE */ + PCM_FORMAT_INVALID, /* 40 - SNDRV_PCM_FORMAT_S18_3LE */ + PCM_FORMAT_INVALID, /* 41 - SNDRV_PCM_FORMAT_S18_3BE */ + PCM_FORMAT_INVALID, /* 42 - SNDRV_PCM_FORMAT_U18_3LE */ + PCM_FORMAT_INVALID, /* 43 - SNDRV_PCM_FORMAT_U18_3BE */ + PCM_FORMAT_INVALID, /* 44 - SNDRV_PCM_FORMAT_G723_24 */ + PCM_FORMAT_INVALID, /* 45 - SNDRV_PCM_FORMAT_G723_24_1B */ + PCM_FORMAT_INVALID, /* 46 - SNDRV_PCM_FORMAT_G723_40 */ + PCM_FORMAT_INVALID, /* 47 - SNDRV_PCM_FORMAT_G723_40_1B */ + PCM_FORMAT_INVALID, /* 48 - SNDRV_PCM_FORMAT_DSD_U8 */ + PCM_FORMAT_INVALID /* 49 - SNDRV_PCM_FORMAT_DSD_U16_LE */ +}; + +/* + * Scans the provided format mask and returns the first non-8 bit sample + * format supported by the devices. + */ +enum pcm_format get_pcm_format_for_mask(struct pcm_mask* mask) +{ + int num_slots = ARRAY_SIZE(mask->bits); + int bits_per_slot = sizeof(mask->bits[0]) * 8; + + int table_size = ARRAY_SIZE(pcm_format_value_map); + + int slot_index, bit_index, table_index; + table_index = 0; + int num_written = 0; + for (slot_index = 0; slot_index < num_slots && table_index < table_size; slot_index++) { + unsigned bit_mask = 1; + for (bit_index = 0; bit_index < bits_per_slot && table_index < table_size; bit_index++) { + /* skip any 8-bit formats */ + if (table_index >= 2 && (mask->bits[slot_index] & bit_mask) != 0) { + /* just return the first one which will be at least 16-bit */ + return (int)pcm_format_value_map[table_index]; + } + bit_mask <<= 1; + table_index++; + } + } + + return PCM_FORMAT_INVALID; +} |