diff options
| -rw-r--r-- | include/tinyalsa/pcm.h | 15 | ||||
| -rw-r--r-- | src/pcm.c | 158 |
2 files changed, 173 insertions, 0 deletions
diff --git a/include/tinyalsa/pcm.h b/include/tinyalsa/pcm.h index 1184d81..5191882 100644 --- a/include/tinyalsa/pcm.h +++ b/include/tinyalsa/pcm.h @@ -264,6 +264,21 @@ unsigned int pcm_params_get_min(const struct pcm_params *pcm_params, enum pcm_pa unsigned int pcm_params_get_max(const struct pcm_params *pcm_params, enum pcm_param param); +/* Converts the pcm parameters to a human readable string. + * The string parameter is a caller allocated buffer of size bytes, + * which is then filled up to size - 1 and null terminated, + * if size is greater than zero. + * The return value is the number of bytes copied to string + * (not including null termination) if less than size; otherwise, + * the number of bytes required for the buffer. + */ +int pcm_params_to_string(struct pcm_params *params, char *string, unsigned int size); + +/* Returns 1 if the pcm_format is present (format bit set) in + * the pcm_params structure; 0 otherwise, or upon unrecognized format. + */ +int pcm_params_format_test(struct pcm_params *params, enum pcm_format format); + struct pcm; struct pcm *pcm_open(unsigned int card, @@ -70,6 +70,83 @@ #define SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP (1<<2) #endif /* SNDRV_PCM_HW_PARAMS_NO_PERIOD_WAKEUP */ +/* Logs information into a string; follows snprintf() in that + * offset may be greater than size, and though no characters are copied + * into string, characters are still counted into offset. */ +#define STRLOG(string, offset, size, ...) \ + do { int temp, clipoffset = offset > size ? size : offset; \ + temp = snprintf(string + clipoffset, size - clipoffset, __VA_ARGS__); \ + if (temp > 0) offset += temp; } while (0) + +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0])) +#endif + +/* refer to SNDRV_PCM_ACCESS_##index in sound/asound.h. */ +static const char * const access_lookup[] = { + "MMAP_INTERLEAVED", + "MMAP_NONINTERLEAVED", + "MMAP_COMPLEX", + "RW_INTERLEAVED", + "RW_NONINTERLEAVED", +}; + +/* refer to SNDRV_PCM_FORMAT_##index in sound/asound.h. */ +static const char * const format_lookup[] = { + /*[0] =*/ "S8", + "U8", + "S16_LE", + "S16_BE", + "U16_LE", + "U16_BE", + "S24_LE", + "S24_BE", + "U24_LE", + "U24_BE", + "S32_LE", + "S32_BE", + "U32_LE", + "U32_BE", + "FLOAT_LE", + "FLOAT_BE", + "FLOAT64_LE", + "FLOAT64_BE", + "IEC958_SUBFRAME_LE", + "IEC958_SUBFRAME_BE", + "MU_LAW", + "A_LAW", + "IMA_ADPCM", + "MPEG", + /*[24] =*/ "GSM", + /* gap */ + [31] = "SPECIAL", + "S24_3LE", + "S24_3BE", + "U24_3LE", + "U24_3BE", + "S20_3LE", + "S20_3BE", + "U20_3LE", + "U20_3BE", + "S18_3LE", + "S18_3BE", + "U18_3LE", + /*[43] =*/ "U18_3BE", +#if 0 + /* recent additions, may not be present on local asound.h */ + "G723_24", + "G723_24_1B", + "G723_40", + "G723_40_1B", + "DSD_U8", + "DSD_U16_LE", +#endif +}; + +/* refer to SNDRV_PCM_SUBFORMAT_##index in sound/asound.h. */ +static const char * const subformat_lookup[] = { + "STD", +}; static inline int param_is_mask(int p) { @@ -798,6 +875,87 @@ unsigned int pcm_params_get_max(const struct pcm_params *pcm_params, return param_get_max(params, p); } +static int pcm_mask_test(const struct pcm_mask *m, unsigned int index) +{ + const unsigned int bitshift = 5; /* for 32 bit integer */ + const unsigned int bitmask = (1 << bitshift) - 1; + unsigned int element; + + element = index >> bitshift; + if (element >= ARRAY_SIZE(m->bits)) + return 0; /* for safety, but should never occur */ + return (m->bits[element] >> (index & bitmask)) & 1; +} + +static int pcm_mask_to_string(const struct pcm_mask *m, char *string, unsigned int size, + char *mask_name, + const char * const *bit_array_name, size_t bit_array_size) +{ + unsigned int i; + unsigned int offset = 0; + + if (m == NULL) + return 0; + if (bit_array_size < 32) { + STRLOG(string, offset, size, "%12s:\t%#08x\n", mask_name, m->bits[0]); + } else { /* spans two or more bitfields, print with an array index */ + for (i = 0; i < (bit_array_size + 31) >> 5; ++i) { + STRLOG(string, offset, size, "%9s[%d]:\t%#08x\n", + mask_name, i, m->bits[i]); + } + } + for (i = 0; i < bit_array_size; ++i) { + if (pcm_mask_test(m, i)) { + STRLOG(string, offset, size, "%12s \t%s\n", "", bit_array_name[i]); + } + } + return offset; +} + +int pcm_params_to_string(struct pcm_params *params, char *string, unsigned int size) +{ + const struct pcm_mask *m; + unsigned int min, max; + unsigned int clipoffset, offset; + + m = pcm_params_get_mask(params, PCM_PARAM_ACCESS); + offset = pcm_mask_to_string(m, string, size, + "Access", access_lookup, ARRAY_SIZE(access_lookup)); + m = pcm_params_get_mask(params, PCM_PARAM_FORMAT); + clipoffset = offset > size ? size : offset; + offset += pcm_mask_to_string(m, string + clipoffset, size - clipoffset, + "Format", format_lookup, ARRAY_SIZE(format_lookup)); + m = pcm_params_get_mask(params, PCM_PARAM_SUBFORMAT); + clipoffset = offset > size ? size : offset; + offset += pcm_mask_to_string(m, string + clipoffset, size - clipoffset, + "Subformat", subformat_lookup, ARRAY_SIZE(subformat_lookup)); + min = pcm_params_get_min(params, PCM_PARAM_RATE); + max = pcm_params_get_max(params, PCM_PARAM_RATE); + STRLOG(string, offset, size, " Rate:\tmin=%uHz\tmax=%uHz\n", min, max); + min = pcm_params_get_min(params, PCM_PARAM_CHANNELS); + max = pcm_params_get_max(params, PCM_PARAM_CHANNELS); + STRLOG(string, offset, size, " Channels:\tmin=%u\t\tmax=%u\n", min, max); + min = pcm_params_get_min(params, PCM_PARAM_SAMPLE_BITS); + max = pcm_params_get_max(params, PCM_PARAM_SAMPLE_BITS); + STRLOG(string, offset, size, " Sample bits:\tmin=%u\t\tmax=%u\n", min, max); + min = pcm_params_get_min(params, PCM_PARAM_PERIOD_SIZE); + max = pcm_params_get_max(params, PCM_PARAM_PERIOD_SIZE); + STRLOG(string, offset, size, " Period size:\tmin=%u\t\tmax=%u\n", min, max); + min = pcm_params_get_min(params, PCM_PARAM_PERIODS); + max = pcm_params_get_max(params, PCM_PARAM_PERIODS); + STRLOG(string, offset, size, "Period count:\tmin=%u\t\tmax=%u\n", min, max); + return offset; +} + +int pcm_params_format_test(struct pcm_params *params, enum pcm_format format) +{ + unsigned int alsa_format = pcm_format_to_alsa(format); + + if (alsa_format == SNDRV_PCM_FORMAT_S16_LE && format != PCM_FORMAT_S16_LE) + return 0; /* caution: format not recognized is equivalent to S16_LE */ + return pcm_mask_test(pcm_params_get_mask(params, PCM_PARAM_FORMAT), alsa_format); +} + /** Closes a PCM returned by @ref pcm_open. * @param pcm A PCM returned by @ref pcm_open. * May not be NULL. |