The Linux Manuals (man pages) document is an important part of Linux documents. Linux Manuals are organized as several sections. Each section has a group of commands for a specific area in Linux usage, administration or development.
snd_pcm_hw_param_last – refine config space and return maximum value Synopsis int snd_pcm_hw_param_last(struct snd_pcm_substream *pcm, struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var, int *dir); Arguments pcm PCM instance params the hw_params instance var parameter to retrieve dir pointer to the direction (-1,0,1) or NULL Description Inside configuration space defined by params remove from var all values < maximum….
snd_pcm_hw_param_first – refine config space and return minimum value Synopsis int snd_pcm_hw_param_first(struct snd_pcm_substream *pcm, struct snd_pcm_hw_params *params, snd_pcm_hw_param_t var, int *dir); Arguments pcm PCM instance params the hw_params instance var parameter to retrieve dir pointer to the direction (-1,0,1) or NULL Description Inside configuration space defined by params remove from var all values > minimum….
snd_pcm_hw_constraint_step – add a hw constraint step rule Synopsis int snd_pcm_hw_constraint_step(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, unsigned long step); Arguments runtime PCM runtime instance cond condition bits var hw_params variable to apply the step constraint step step size Return Zero if successful, or a negative error code on failure. Copyright
snd_pcm_hw_constraint_single – Constrain parameter to a single value Synopsis int snd_pcm_hw_constraint_single(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var, unsigned int val); Arguments runtime PCM runtime instance var The hw_params variable to constrain val The value to constrain to Return Positive if the value is changed, zero if it’s not changed, or a negative error code. Copyright
snd_pcm_hw_constraint_ratnums – apply ratnums constraint to a parameter Synopsis int snd_pcm_hw_constraint_ratnums(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, const struct snd_pcm_hw_constraint_ratnums *r); Arguments runtime PCM runtime instance cond condition bits var hw_params variable to apply the ratnums constraint r struct snd_ratnums constriants Return Zero if successful, or a negative error code on failure. Copyright
snd_pcm_hw_constraint_ratdens – apply ratdens constraint to a parameter Synopsis int snd_pcm_hw_constraint_ratdens(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, const struct snd_pcm_hw_constraint_ratdens *r); Arguments runtime PCM runtime instance cond condition bits var hw_params variable to apply the ratdens constraint r struct snd_ratdens constriants Return Zero if successful, or a negative error code on failure. Copyright
snd_pcm_hw_constraint_ranges – apply list of range constraints to a parameter Synopsis int snd_pcm_hw_constraint_ranges(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, const struct snd_pcm_hw_constraint_ranges *r); Arguments runtime PCM runtime instance cond condition bits var hw_params variable to apply the list of range constraints r ranges Description Apply the list of range constraints to an interval parameter….
snd_pcm_hw_constraint_pow2 – add a hw constraint power-of-2 rule Synopsis int snd_pcm_hw_constraint_pow2(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var); Arguments runtime PCM runtime instance cond condition bits var hw_params variable to apply the power-of-2 constraint Return Zero if successful, or a negative error code on failure. Copyright
snd_pcm_hw_constraint_msbits – add a hw constraint msbits rule Synopsis int snd_pcm_hw_constraint_msbits(struct snd_pcm_runtime *runtime, unsigned int cond, unsigned int width, unsigned int msbits); Arguments runtime PCM runtime instance cond condition bits width sample bits width msbits msbits width Description This constraint will set the number of most significant bits (msbits) if a sample format with the…
snd_pcm_hw_constraint_minmax – apply a min/max range constraint to an interval Synopsis int snd_pcm_hw_constraint_minmax(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var, unsigned int min, unsigned int max); Arguments runtime PCM runtime instance var hw_params variable to apply the range min the minimal value max the maximal value Description Apply the min/max range constraint to an interval parameter. Return Positive…
snd_pcm_hw_constraint_mask64 – apply the given bitmap mask constraint Synopsis int snd_pcm_hw_constraint_mask64(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var, u_int64_t mask); Arguments runtime PCM runtime instance var hw_params variable to apply the mask mask the 64bit bitmap mask Description Apply the constraint of the given bitmap mask to a 64-bit mask parameter. Return Zero if successful, or a negative…
snd_pcm_hw_constraint_list – apply a list of constraints to a parameter Synopsis int snd_pcm_hw_constraint_list(struct snd_pcm_runtime *runtime, unsigned int cond, snd_pcm_hw_param_t var, const struct snd_pcm_hw_constraint_list *l); Arguments runtime PCM runtime instance cond condition bits var hw_params variable to apply the list constraint l list Description Apply the list of constraints to an interval parameter. Return Zero if…
snd_pcm_hw_constraint_integer – apply an integer constraint to an interval Synopsis int snd_pcm_hw_constraint_integer(struct snd_pcm_runtime *runtime, snd_pcm_hw_param_t var); Arguments runtime PCM runtime instance var hw_params variable to apply the integer constraint Description Apply the constraint of integer to an interval parameter. Return Positive if the value is changed, zero if it’s not changed, or a negative error…
snd_pcm_group_for_each_entry – iterate over the linked substreams Synopsis snd_pcm_group_for_each_entry(s, substream); Arguments s the iterator substream the substream Description Iterate over the all linked substreams to the given substream. When substream isn’t linked with any others, this gives returns substream itself once. Copyright
snd_pcm_gettime – Fill the timespec depending on the timestamp mode Synopsis void snd_pcm_gettime(struct snd_pcm_runtime *runtime, struct timespec *tv); Arguments runtime PCM runtime instance tv timespec to fill Copyright
snd_pcm_format_width – return the bit-width of the format Synopsis int snd_pcm_format_width(snd_pcm_format_t format); Arguments format the format to check Return The bit-width of the format, or a negative error code if unknown format. Copyright
snd_pcm_format_unsigned – Check the PCM format is unsigned linear Synopsis int snd_pcm_format_unsigned(snd_pcm_format_t format); Arguments format the format to check Return 1 if the given PCM format is unsigned linear, 0 if signed linear, and a negative error code for non-linear formats. Copyright
snd_pcm_format_size – return the byte size of samples on the given format Synopsis ssize_t snd_pcm_format_size(snd_pcm_format_t format, size_t samples); Arguments format the format to check samples sampling rate Return The byte size of the given samples for the format, or a negative error code if unknown format. Copyright
snd_pcm_format_silence_64 – return the silent data in 8 bytes array Synopsis const unsigned char *snd_pcm_format_silence_64(snd_pcm_format_t format); Arguments format the format to check Return The format pattern to fill or NULL if error. Copyright
snd_pcm_format_signed – Check the PCM format is signed linear Synopsis int snd_pcm_format_signed(snd_pcm_format_t format); Arguments format the format to check Return 1 if the given PCM format is signed linear, 0 if unsigned linear, and a negative error code for non-linear formats. Copyright