alsa-utils/axfer/xfer-libasound.h
Takashi Sakamoto d010fe8bcf axfer: add options for software parameters of PCM substream
In ALSA PCM interface, some parameters are used to configure runtime of
PCM substream independently of actual hardware. These parameters are
mainly used to decide the detailed timing to start/stop PCM substream and
release I/O blocking state of application. These parameters are
represented and delivered by a structure.

In alsa-lib PCM API, the structure is hidden from userspace applications.
The applications can set/get actual parameters by helper functions.

In aplay, three of the parameters are configurable. This commit adds
support for them. When no options are given, default values are used.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-11-13 12:04:47 +01:00

68 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
//
// xfer-libasound.h - a header for receiver/transmitter of frames by alsa-lib.
//
// Copyright (c) 2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>
//
// Licensed under the terms of the GNU General Public License, version 2.
#ifndef __ALSA_UTILS_AXFER_XFER_LIBASOUND__H_
#define __ALSA_UTILS_AXFER_XFER_LIBASOUND__H_
#include "xfer.h"
#define logging(state, ...) \
snd_output_printf(state->log, __VA_ARGS__)
struct xfer_libasound_ops;
struct libasound_state {
snd_pcm_t *handle;
snd_output_t *log;
snd_pcm_hw_params_t *hw_params;
snd_pcm_sw_params_t *sw_params;
const struct xfer_libasound_ops *ops;
void *private_data;
bool verbose;
char *node_literal;
unsigned int msec_per_period;
unsigned int msec_per_buffer;
unsigned int frames_per_period;
unsigned int frames_per_buffer;
unsigned int msec_for_avail_min;
unsigned int msec_for_start_threshold;
unsigned int msec_for_stop_threshold;
bool finish_at_xrun:1;
bool nonblock:1;
bool mmap:1;
bool test_nowait:1;
bool use_waiter:1;
};
// For internal use in 'libasound' module.
struct xfer_libasound_ops {
int (*pre_process)(struct libasound_state *state);
int (*process_frames)(struct libasound_state *state,
unsigned int *frame_count,
struct mapper_context *mapper,
struct container_context *cntrs);
void (*post_process)(struct libasound_state *state);
unsigned int private_size;
};
extern const struct xfer_libasound_ops xfer_libasound_irq_rw_ops;
extern const struct xfer_libasound_ops xfer_libasound_irq_mmap_r_ops;
extern const struct xfer_libasound_ops xfer_libasound_irq_mmap_w_ops;
#endif