alsa-utils/axfer/xfer.c

//
// xfer.c - receiver/transmiter of data frames.
//
// Copyright (c) 2018 Takashi Sakamoto <o-takashi@sakamocchi.jp>
//
// Licensed under the terms of the GNU General Public License, version 2.

#include "xfer.h"
#include "misc.h"

#include <stdio.h>

static const char *const xfer_type_labels[] = {
	[XFER_TYPE_LIBASOUND] = "libasound",
#if WITH_FFADO
	[XFER_TYPE_LIBFFADO] = "libffado",
#endif
};

enum xfer_type xfer_type_from_label(const char *label)
{
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(xfer_type_labels); ++i) {
		if (!strcmp(xfer_type_labels[i], label))
			return i;
	}

	return XFER_TYPE_UNSUPPORTED;
}

const char *xfer_label_from_type(enum xfer_type type)
{
	return xfer_type_labels[type];
}

int xfer_context_init(struct xfer_context *xfer, enum xfer_type type,
		      snd_pcm_stream_t direction, int argc, char *const *argv)
{
	struct {
		enum xfer_type type;
		const struct xfer_data *data;
	} *entry, entries[] = {
		{XFER_TYPE_LIBASOUND, &xfer_libasound},
#if WITH_FFADO
		{XFER_TYPE_LIBFFADO, &xfer_libffado},
#endif
	};
	unsigned int i;
	int err;

	assert(xfer);
	assert(direction >= SND_PCM_STREAM_PLAYBACK);
	assert(direction <= SND_PCM_STREAM_CAPTURE);

	for (i = 0; i < ARRAY_SIZE(entries); ++i) {
		if (entries[i].type == type)
			break;
	}
	if (i == ARRAY_SIZE(entries))
		return -EINVAL;
	entry = &entries[i];

	xfer->direction = direction;
	xfer->type = type;
	xfer->ops = &entry->data->ops;

	xfer->private_data = malloc(entry->data->private_size);
	if (xfer->private_data == NULL)
		return -ENOMEM;
	memset(xfer->private_data, 0, entry->data->private_size);

	err = xfer->ops->init(xfer, direction);
	if (err < 0)
		return err;

	err = xfer_options_parse_args(xfer, entry->data, argc, argv);
	if (err < 0)
		return err;

	return xfer->ops->validate_opts(xfer);
}

void xfer_context_destroy(struct xfer_context *xfer)
{
	unsigned int i;

	assert(xfer);

	if (!xfer->ops)
		return;

	if (xfer->ops->destroy)
		xfer->ops->destroy(xfer);
	if (xfer->private_data)
		free(xfer->private_data);

	if (xfer->paths) {
		for (i = 0; i < xfer->path_count; ++i)
			free(xfer->paths[i]);
		free(xfer->paths);
	}

	xfer->paths = NULL;

	free(xfer->sample_format_literal);
	xfer->sample_format_literal = NULL;

	free(xfer->cntr_format_literal);
	xfer->cntr_format_literal = NULL;
}

int xfer_context_pre_process(struct xfer_context *xfer,
			     snd_pcm_format_t *format,
			     unsigned int *samples_per_frame,
			     unsigned int *frames_per_second,
			     snd_pcm_access_t *access,
			     snd_pcm_uframes_t *frames_per_buffer)
{
	int err;

	assert(xfer);
	assert(format);
	assert(samples_per_frame);
	assert(frames_per_second);
	assert(access);
	assert(frames_per_buffer);

	if (!xfer->ops)
		return -ENXIO;

	if (xfer->direction == SND_PCM_STREAM_CAPTURE) {
		// For capture direction, use values in options if given.
		if (xfer->sample_format != SND_PCM_FORMAT_UNKNOWN)
			*format = xfer->sample_format;
		if (xfer->samples_per_frame > 0)
			*samples_per_frame = xfer->samples_per_frame;
		if (xfer->frames_per_second > 0)
			*frames_per_second = xfer->frames_per_second;
	} else if (xfer->direction == SND_PCM_STREAM_PLAYBACK) {
		// For playback direction, check values in given options so that
		// they don't mismatch to parameters from media container.
		if (*format != xfer->sample_format) {
			// Not initial value.
			if (xfer->sample_format != SND_PCM_FORMAT_UNKNOWN) {
				fprintf(stderr,
					"Sample format mismatch: %s is given "
					"but %s by files\n",
					snd_pcm_format_name(xfer->sample_format),
					snd_pcm_format_name(*format));
				return -EINVAL;
			}
		}

		if (*samples_per_frame != xfer->samples_per_frame) {
			// Not initial value.
			if (xfer->samples_per_frame > 0) {
				fprintf(stderr,
					"The number of channels mismatch: %u "
					"is given but %u by files\n",
					xfer->samples_per_frame,
					*samples_per_frame);
				return -EINVAL;
			}
		}

		if (*frames_per_second != xfer->frames_per_second) {
			// Not initial value.
			if (xfer->frames_per_second != 8000) {
				fprintf(stderr,
					"Sampling rate mismatch: %u is given "
					"but %u by files\n",
					xfer->frames_per_second,
					*frames_per_second);
				return -EINVAL;
			}
		}
	}

	err = xfer->ops->pre_process(xfer, format, samples_per_frame,
				     frames_per_second, access,
				     frames_per_buffer);
	if (err < 0)
		return err;

	assert(*format >= SND_PCM_FORMAT_S8);
	assert(*format <= SND_PCM_FORMAT_LAST);
	assert(*samples_per_frame > 0);
	assert(*frames_per_second > 0);
	assert(*access >= SND_PCM_ACCESS_MMAP_INTERLEAVED);
	assert(*access <= SND_PCM_ACCESS_LAST);
	assert(*frames_per_buffer > 0);

	xfer->sample_format = *format;
	xfer->samples_per_frame = *samples_per_frame;
	xfer->frames_per_second = *frames_per_second;

	if (xfer->direction == SND_PCM_STREAM_CAPTURE) {
		err = xfer_options_fixup_paths(xfer);
		if (err < 0)
			return err;
	}

	if (xfer->verbose > 1) {
		fprintf(stderr, "Transfer: %s\n",
			xfer_type_labels[xfer->type]);
		fprintf(stderr, "  access: %s\n",
			snd_pcm_access_name(*access));
		fprintf(stderr, "  sample format: %s\n",
			snd_pcm_format_name(*format));
		fprintf(stderr, "  bytes/sample: %u\n",
		       snd_pcm_format_physical_width(*format) / 8);
		fprintf(stderr, "  samples/frame: %u\n",
			*samples_per_frame);
		fprintf(stderr, "  frames/second: %u\n",
			*frames_per_second);
		fprintf(stderr, "  frames/buffer: %lu\n",
			*frames_per_buffer);
	}

	return 0;
}

int xfer_context_process_frames(struct xfer_context *xfer,
				struct mapper_context *mapper,
				struct container_context *cntrs,
				unsigned int *frame_count)
{
	assert(xfer);
	assert(mapper);
	assert(cntrs);
	assert(frame_count);

	if (!xfer->ops)
		return -ENXIO;

	return xfer->ops->process_frames(xfer, frame_count, mapper, cntrs);
}

void xfer_context_pause(struct xfer_context *xfer, bool enable)
{
	assert(xfer);

	if (!xfer->ops)
		return;

	xfer->ops->pause(xfer, enable);
}

void xfer_context_post_process(struct xfer_context *xfer)
{
	assert(xfer);

	if (!xfer->ops)
		return;

	xfer->ops->post_process(xfer);
}