text: /* Spa
   *
   * Copyright © 2018 Wim Taymans
   *
   * Permission is hereby granted, free of charge, to any person obtaining a
   * copy of this software and associated documentation files (the "Software"),
   * to deal in the Software without restriction, including without limitation
   * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   * and/or sell copies of the Software, and to permit persons to whom the
   * Software is furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice (including the next
   * paragraph) shall be included in all copies or substantial portions of the
   * Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
   * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
   * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   * DEALINGS IN THE SOFTWARE.
   */
  
  #include <errno.h>
  #include <string.h>
  #include <stdio.h>
  
  #include <spa/support/plugin.h>
  #include <spa/support/log.h>
  #include <spa/utils/list.h>
  #include <spa/utils/names.h>
  #include <spa/node/node.h>
  #include <spa/node/io.h>
  #include <spa/node/utils.h>
  #include <spa/param/audio/format-utils.h>
  #include <spa/param/param.h>
  #include <spa/pod/filter.h>
  #include <spa/debug/types.h>
  
  #include "resample.h"
  
  #define NAME "resample"
  
  #define DEFAULT_RATE		48000
  #define DEFAULT_CHANNELS	2
  
  #define MAX_SAMPLES	8192
  #define MAX_BUFFERS	32
  
  struct impl;
  
  struct props {
  	double rate;
  	int quality;
  };
  
  static void props_reset(struct props *props)
  {
  	props->rate = 1.0;
  	props->quality = RESAMPLE_DEFAULT_QUALITY;
  }
  
  struct buffer {
  	uint32_t id;
  #define BUFFER_FLAG_OUT		(1 << 0)
  	uint32_t flags;
  	struct spa_list link;
  	struct spa_buffer *outbuf;
  	struct spa_meta_header *h;
  };
  
  struct port {
  	uint32_t direction;
  	uint32_t id;
  
  	uint64_t info_all;
  	struct spa_port_info info;
  	struct spa_param_info params[8];
  
  	struct spa_io_buffers *io;
  
  	struct spa_audio_info format;
  	uint32_t stride;
  	uint32_t blocks;
  	uint32_t size;
  	unsigned int have_format:1;
  
  	struct buffer buffers[MAX_BUFFERS];
  	uint32_t n_buffers;
  
  	uint32_t offset;
  	struct spa_list queue;
  };
  
  struct impl {
  	struct spa_handle handle;
  	struct spa_node node;
  
  	struct spa_log *log;
  	struct spa_cpu *cpu;
  
  	struct spa_io_position *io_position;
  	struct spa_io_rate_match *io_rate_match;
  
  	uint64_t info_all;
  	struct spa_node_info info;
  	struct props props;
  
  	struct spa_hook_list hooks;
  
  	struct port in_port;
  	struct port out_port;
  
  #define MODE_SPLIT	0
  #define MODE_MERGE	1
  #define MODE_CONVERT	2
  	int mode;
  	unsigned int started:1;
  	unsigned int peaks:1;
  	unsigned int drained:1;
  
  	struct resample resample;
  };
  
  #define CHECK_PORT(this,d,id)		(id == 0)
  #define GET_IN_PORT(this,id)		(&this->in_port)
  #define GET_OUT_PORT(this,id)		(&this->out_port)
  #define GET_PORT(this,d,id)		(d == SPA_DIRECTION_INPUT ? GET_IN_PORT(this,id) : GET_OUT_PORT(this,id))
  
  static int setup_convert(struct impl *this,
  		enum spa_direction direction,
  		const struct spa_audio_info *info)
  {
  	const struct spa_audio_info *src_info, *dst_info;
  	int err;
  
  	if (direction == SPA_DIRECTION_INPUT) {
  		src_info = info;
  		dst_info = &GET_OUT_PORT(this, 0)->format;
  	} else {
  		src_info = &GET_IN_PORT(this, 0)->format;
  		dst_info = info;
  	}
  
  	spa_log_info(this->log, NAME " %p: %s/%d@%d->%s/%d@%d", this,
  			spa_debug_type_find_name(spa_type_audio_format, src_info->info.raw.format),
  			src_info->info.raw.channels,
  			src_info->info.raw.rate,
  			spa_debug_type_find_name(spa_type_audio_format, dst_info->info.raw.format),
  			dst_info->info.raw.channels,
  			dst_info->info.raw.rate);
  
  	if (src_info->info.raw.channels != dst_info->info.raw.channels)
  		return -EINVAL;
  
  	if (this->resample.free)
  		resample_free(&this->resample);
  
  	this->resample.channels = src_info->info.raw.channels;
  	this->resample.i_rate = src_info->info.raw.rate;
  	this->resample.o_rate = dst_info->info.raw.rate;
  	this->resample.log = this->log;
  	this->resample.quality = this->props.quality;
  
  	if (this->peaks)
  		err = resample_peaks_init(&this->resample);
  	else
  		err = resample_native_init(&this->resample);
  
  	return err;
  }
  
  static int impl_node_enum_params(void *object, int seq,
  				 uint32_t id, uint32_t start, uint32_t num,
  				 const struct spa_pod *filter)
  {
  	return -ENOTSUP;
  }
  
  static int apply_props(struct impl *this, const struct spa_pod *param)
  {
  	struct spa_pod_prop *prop;
  	struct spa_pod_object *obj = (struct spa_pod_object *) param;
  	struct props *p = &this->props;
  
  	SPA_POD_OBJECT_FOREACH(obj, prop) {
  		switch (prop->key) {
  		case SPA_PROP_rate:
  			if (spa_pod_get_double(&prop->value, &p->rate) == 0) {
  				resample_update_rate(&this->resample, p->rate);
  			}
  			break;
  		case SPA_PROP_quality:
  			spa_pod_get_int(&prop->value, &p->quality);
  			break;
  		default:
  			break;
  		}
  	}
  	return 0;
  }
  
  static int impl_node_set_param(void *object, uint32_t id, uint32_t flags,
  			       const struct spa_pod *param)
  {
  	struct impl *this = object;
  	int res = 0;
  
  	spa_return_val_if_fail(this != NULL, -EINVAL);
  
  	switch (id) {
  	case SPA_PARAM_Props:
  		apply_props(this, param);
  		break;
  	default:
  		return -ENOTSUP;
  	}
  
  	return res;
  }
  
  static int impl_node_set_io(void *object, uint32_t id, void *data, size_t size)
  {
  	struct impl *this = object;
  
  	spa_return_val_if_fail(this != NULL, -EINVAL);
  
  	spa_log_debug(this->log, NAME " %p: io %d %p/%zd", this, id, data, size);
  
  	switch (id) {
  	case SPA_IO_Position:
  		this->io_position = data;
  		break;
  	default:
  		return -ENOENT;
  	}
  	return 0;
  }
  
  static void update_rate_match(struct impl *this)
  {
  	if (this->io_rate_match) {
  		this->io_rate_match->delay = resample_delay(&this->resample);
  		if (SPA_LIKELY(this->io_position))
  			this->io_rate_match->size = resample_in_len(&this->resample,
  					this->io_position->clock.duration);
  	}
  }
  
  static void reset_node(struct impl *this)
  {
  	struct port *outport, *inport;
  	outport = GET_OUT_PORT(this, 0);
  	inport = GET_IN_PORT(this, 0);
  
  	resample_reset(&this->resample);
  	outport->offset = 0;
  	inport->offset = 0;
  }
  
  static int impl_node_send_command(void *object, const struct spa_command *command)
  {
  	struct impl *this = object;
  
  	spa_return_val_if_fail(this != NULL, -EINVAL);
  	spa_return_val_if_fail(command != NULL, -EINVAL);
  
  	switch (SPA_NODE_COMMAND_ID(command)) {
  	case SPA_NODE_COMMAND_Start:
  		this->started = true;
  		resample_update_rate(&this->resample, 1.0);
  		update_rate_match(this);
  		break;
  	case SPA_NODE_COMMAND_Suspend:
  	case SPA_NODE_COMMAND_Flush:
  		reset_node(this);
  		SPA_FALLTHROUGH;
  	case SPA_NODE_COMMAND_Pause:
  		this->started = false;
  		break;
  	default:
  		return -ENOTSUP;
  	}
  	return 0;
  }
  
  static void emit_node_info(struct impl *this, bool full)
  {
  	if (full)
  		this->info.change_mask = this->info_all;
  
  	if (this->info.change_mask) {
  		spa_node_emit_info(&this->hooks, &this->info);
  		this->info.change_mask = 0;
  	}
  }
  
  static void emit_port_info(struct impl *this, struct port *port, bool full)
  {
  	if (full)
  		port->info.change_mask = port->info_all;
  	if (port->info.change_mask) {
  		spa_node_emit_port_info(&this->hooks,
  				port->direction, port->id, &port->info);
  		port->info.change_mask = 0;
  	}
  }
  
  static int
  impl_node_add_listener(void *object,
  		struct spa_hook *listener,
  		const struct spa_node_events *events,
  		void *data)
  {
  	struct impl *this = object;
  	struct spa_hook_list save;
  
  	spa_return_val_if_fail(this != NULL, -EINVAL);
  
  	spa_hook_list_isolate(&this->hooks, &save, listener, events, data);
  
  	emit_node_info(this, true);
  	emit_port_info(this, GET_IN_PORT(this, 0), true);
  	emit_port_info(this, GET_OUT_PORT(this, 0), true);
  
  	spa_hook_list_join(&this->hooks, &save);
  
  	return 0;
  }
  
  static int
  impl_node_set_callbacks(void *object,
  			const struct spa_node_callbacks *callbacks,
  			void *user_data)
  {
  	return 0;
  }
  
  static int impl_node_add_port(void *object, enum spa_direction direction, uint32_t port_id,
  		const struct spa_dict *props)
  {
  	return -ENOTSUP;
  }
  
  static int
  impl_node_remove_port(void *object, enum spa_direction direction, uint32_t port_id)
  {
  	return -ENOTSUP;
  }
  
  static int port_enum_formats(void *object,
  			     enum spa_direction direction, uint32_t port_id,
  			     uint32_t index,
  			     struct spa_pod **param,
  			     struct spa_pod_builder *builder)
  {
  	struct impl *this = object;
  	struct port *other;
  	struct spa_pod_frame f;
  
  	other = GET_PORT(this, SPA_DIRECTION_REVERSE(direction), 0);
  
  	switch (index) {
  	case 0:
  		if (other->have_format) {
  			spa_pod_builder_push_object(builder, &f,
  				SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat);
  			spa_pod_builder_add(builder,
  				SPA_FORMAT_mediaType,      SPA_POD_Id(SPA_MEDIA_TYPE_audio),
  				SPA_FORMAT_mediaSubtype,   SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
  				SPA_FORMAT_AUDIO_format,   SPA_POD_Id(SPA_AUDIO_FORMAT_F32P),
  				SPA_FORMAT_AUDIO_rate,     SPA_POD_CHOICE_RANGE_Int(
  								other->format.info.raw.rate, 1, INT32_MAX),
  				SPA_FORMAT_AUDIO_channels, SPA_POD_Int(other->format.info.raw.channels),
  				0);
  			spa_pod_builder_prop(builder, SPA_FORMAT_AUDIO_position, 0);
  			spa_pod_builder_array(builder, sizeof(uint32_t), SPA_TYPE_Id,
  					other->format.info.raw.channels, other->format.info.raw.position);
  			*param = spa_pod_builder_pop(builder, &f);
  		} else {
  			*param = spa_pod_builder_add_object(builder,
  				SPA_TYPE_OBJECT_Format, SPA_PARAM_EnumFormat,
  				SPA_FORMAT_mediaType,      SPA_POD_Id(SPA_MEDIA_TYPE_audio),
  				SPA_FORMAT_mediaSubtype,   SPA_POD_Id(SPA_MEDIA_SUBTYPE_raw),
  				SPA_FORMAT_AUDIO_format,   SPA_POD_Id(SPA_AUDIO_FORMAT_F32P),
  				SPA_FORMAT_AUDIO_rate,     SPA_POD_CHOICE_RANGE_Int(DEFAULT_RATE, 1, INT32_MAX),
  				SPA_FORMAT_AUDIO_channels, SPA_POD_CHOICE_RANGE_Int(DEFAULT_CHANNELS, 1, INT32_MAX));
  		}
  		break;
  	default:
  		return 0;
  	}
  	return 1;
  }
  
  static int
  impl_node_port_enum_params(void *object, int seq,
  			   enum spa_direction direction, uint32_t port_id,
  			   uint32_t id, uint32_t start, uint32_t num,
  			   const struct spa_pod *filter)
  {
  	struct impl *this = object;
  	struct port *port, *other;
  	struct spa_pod *param;
  	struct spa_pod_builder b = { 0 };
  	uint8_t buffer[1024];
  	struct spa_result_node_params result;
  	uint32_t count = 0;
  	int res;
  
  	spa_return_val_if_fail(this != NULL, -EINVAL);
  	spa_return_val_if_fail(num != 0, -EINVAL);
  
  	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);
  
  	port = GET_PORT(this, direction, port_id);
  	other = GET_PORT(this, SPA_DIRECTION_REVERSE(direction), port_id);
  
  	spa_log_debug(this->log, "%p: enum params port %d.%d %d %u",
  			this, direction, port_id, seq, id);
  
  	result.id = id;
  	result.next = start;
        next:
  	result.index = result.next++;
  
  	spa_pod_builder_init(&b, buffer, sizeof(buffer));
  
  	switch (id) {
  	case SPA_PARAM_EnumFormat:
  		if ((res = port_enum_formats(this, direction, port_id,
  						result.index, &param, &b)) <= 0)
  			return res;
  		break;
  	case SPA_PARAM_Format:
  		if (!port->have_format)
  			return -EIO;
  		if (result.index > 0)
  			return 0;
  
  		param = spa_format_audio_raw_build(&b, id, &port->format.info.raw);
  		break;
  	case SPA_PARAM_Buffers:
  	{
  		uint32_t buffers, size;
  
  		if (!port->have_format)
  			return -EIO;
  		if (result.index > 0)
  			return 0;
  
  		if (other->n_buffers > 0) {
  			buffers = other->n_buffers;
  			size = other->size / other->stride * 2;
  		}
  		else {
  			buffers = 1;
  			size = MAX_SAMPLES*2 * other->stride;
  		}
  
  		param = spa_pod_builder_add_object(&b,
  			SPA_TYPE_OBJECT_ParamBuffers, id,
  			SPA_PARAM_BUFFERS_buffers, SPA_POD_CHOICE_RANGE_Int(buffers, 1, MAX_BUFFERS),
  			SPA_PARAM_BUFFERS_blocks,  SPA_POD_Int(port->blocks),
  			SPA_PARAM_BUFFERS_size,    SPA_POD_CHOICE_RANGE_Int(
  							size * port->stride,
  							16 * port->stride,
  							INT32_MAX),
  			SPA_PARAM_BUFFERS_stride,  SPA_POD_Int(port->stride),
  			SPA_PARAM_BUFFERS_align,   SPA_POD_Int(16));
  		break;
  	}
  	case SPA_PARAM_Meta:
  		switch (result.index) {
  		case 0:
  			param = spa_pod_builder_add_object(&b,
  				SPA_TYPE_OBJECT_ParamMeta, id,
  				SPA_PARAM_META_type, SPA_POD_Id(SPA_META_Header),
  				SPA_PARAM_META_size, SPA_POD_Int(sizeof(struct spa_meta_header)));
  			break;
  		default:
  			return 0;
  		}
  		break;
  	case SPA_PARAM_IO:
  		switch (result.index) {
  		case 0:
  			param = spa_pod_builder_add_object(&b,
  				SPA_TYPE_OBJECT_ParamIO, id,
  				SPA_PARAM_IO_id,   SPA_POD_Id(SPA_IO_Buffers),
  				SPA_PARAM_IO_size, SPA_POD_Int(sizeof(struct spa_io_buffers)));
  			break;
  		default:
  			return 0;
  		}
  		break;
  	default:
  		return -ENOENT;
  	}
  
  	if (spa_pod_filter(&b, &result.param, param, filter) < 0)
  		goto next;
  
  	spa_node_emit_result(&this->hooks, seq, 0, SPA_RESULT_TYPE_NODE_PARAMS, &result);
  
  	if (++count != num)
  		goto next;
  
  	return 0;
  }
  
  static int clear_buffers(struct impl *this, struct port *port)
  {
  	if (port->n_buffers > 0) {
  		spa_log_debug(this->log, NAME " %p: clear buffers %p", this, port);
  		port->n_buffers = 0;
  		spa_list_init(&port->queue);
  	}
  	return 0;
  }
  
  static int port_set_format(void *object,
  			   enum spa_direction direction,
  			   uint32_t port_id,
  			   uint32_t flags,
  			   const struct spa_pod *format)
  {
  	struct impl *this = object;
  	struct port *port, *other;
  	int res = 0;
  
  	port = GET_PORT(this, direction, port_id);
  	other = GET_PORT(this, SPA_DIRECTION_REVERSE(direction), port_id);
  
  	if (format == NULL) {
  		if (port->have_format) {
  			port->have_format = false;
  			clear_buffers(this, port);
  		}
  	} else {
  		struct spa_audio_info info = { 0 };
  
  		if ((res = spa_format_parse(format, &info.media_type, &info.media_subtype)) < 0)
  			return res;
  
  		if (info.media_type != SPA_MEDIA_TYPE_audio ||
  		    info.media_subtype != SPA_MEDIA_SUBTYPE_raw)
  			return -EINVAL;
  
  		if (spa_format_audio_raw_parse(format, &info.info.raw) < 0)
  			return -EINVAL;
  
  		if (info.info.raw.format != SPA_AUDIO_FORMAT_F32P)
  			return -EINVAL;
  
  		port->stride = sizeof(float);
  		port->blocks = info.info.raw.channels;
  
  		if (other->have_format) {
  			if ((res = setup_convert(this, direction, &info)) < 0)
  				return res;
  		}
  		port->format = info;
  		port->have_format = true;
  
  		spa_log_debug(this->log, NAME " %p: set format on port %d %d", this, port_id, res);
  	}
  
  	port->info.change_mask |= SPA_PORT_CHANGE_MASK_PARAMS;
  	if (port->have_format) {
  		port->params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
  		port->params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
  	} else {
  		port->params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_READWRITE);
  		port->params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, SPA_PARAM_INFO_READ);
  	}
  	emit_port_info(this, port, false);
  
  	return res;
  }
  
  static int
  impl_node_port_set_param(void *object,
  			 enum spa_direction direction, uint32_t port_id,
  			 uint32_t id, uint32_t flags,
  			 const struct spa_pod *param)
  {
  	spa_return_val_if_fail(object != NULL, -EINVAL);
  
  	spa_return_val_if_fail(CHECK_PORT(object, direction, port_id), -EINVAL);
  
  	if (id == SPA_PARAM_Format) {
  		return port_set_format(object, direction, port_id, flags, param);
  	}
  	else
  		return -ENOENT;
  }
  
  static int
  impl_node_port_use_buffers(void *object,
  			   enum spa_direction direction,
  			   uint32_t port_id,
  			   uint32_t flags,
  			   struct spa_buffer **buffers,
  			   uint32_t n_buffers)
  {
  	struct impl *this = object;
  	struct port *port;
  	uint32_t i, j, size = SPA_ID_INVALID;
  
  	spa_return_val_if_fail(this != NULL, -EINVAL);
  
  	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);
  
  	port = GET_PORT(this, direction, port_id);
  
  	spa_return_val_if_fail(port->have_format, -EIO);
  
  	spa_log_debug(this->log, NAME " %p: use buffers %d on port %d:%d", this,
  			n_buffers, direction, port_id);
  
  	clear_buffers(this, port);
  
  	for (i = 0; i < n_buffers; i++) {
  		struct buffer *b;
  		struct spa_data *d = buffers[i]->datas;
  
  		b = &port->buffers[i];
  		b->id = i;
  		b->flags = 0;
  		b->outbuf = buffers[i];
  		b->h = spa_buffer_find_meta_data(buffers[i], SPA_META_Header, sizeof(*b->h));
  
  		for (j = 0; j < buffers[i]->n_datas; j++) {
  			if (size == SPA_ID_INVALID)
  				size = d[j].maxsize;
  			else
  				if (size != d[j].maxsize) {
  					spa_log_error(this->log, NAME " %p: invalid size %d on buffer %p", this,
  						      size, buffers[i]);
  					return -EINVAL;
  				}
  
  			if (d[j].data == NULL) {
  				spa_log_error(this->log, NAME " %p: invalid memory on buffer %p", this,
  					      buffers[i]);
  				return -EINVAL;
  			}
  		}
  
  		if (direction == SPA_DIRECTION_OUTPUT)
  			spa_list_append(&port->queue, &b->link);
  		else
  			SPA_FLAG_SET(b->flags, BUFFER_FLAG_OUT);
  
  		port->offset = 0;
  	}
  	port->n_buffers = n_buffers;
  	port->size = size;
  
  	return 0;
  }
  
  static int
  impl_node_port_set_io(void *object,
  		      enum spa_direction direction, uint32_t port_id,
  		      uint32_t id, void *data, size_t size)
  {
  	struct impl *this = object;
  	struct port *port;
  
  	spa_return_val_if_fail(this != NULL, -EINVAL);
  
  	spa_return_val_if_fail(CHECK_PORT(this, direction, port_id), -EINVAL);
  
  	spa_log_trace_fp(this->log, NAME " %p: %d:%d io %d", this, direction, port_id, id);
  
  	port = GET_PORT(this, direction, port_id);
  
  	switch (id) {
  	case SPA_IO_Buffers:
  		port->io = data;
  		break;
  	case SPA_IO_RateMatch:
  		this->io_rate_match = data;
  		break;
  	default:
  		return -ENOENT;
  	}
  	return 0;
  }
  
  static void recycle_buffer(struct impl *this, uint32_t id)
  {
  	struct port *port = GET_OUT_PORT(this, 0);
  	struct buffer *b = &port->buffers[id];
  
  	if (SPA_FLAG_IS_SET(b->flags, BUFFER_FLAG_OUT)) {
  		spa_list_append(&port->queue, &b->link);
  		SPA_FLAG_CLEAR(b->flags, BUFFER_FLAG_OUT);
  		spa_log_trace_fp(this->log, NAME " %p: recycle buffer %d", this, id);
  	}
  }
  
  static struct buffer *peek_buffer(struct impl *this, struct port *port)
  {
  	struct buffer *b;
  
  	if (spa_list_is_empty(&port->queue))
  		return NULL;
  
  	b = spa_list_first(&port->queue, struct buffer, link);
  	return b;
  }
  
  static void dequeue_buffer(struct impl *this, struct buffer *b)
  {
  	spa_list_remove(&b->link);
  	SPA_FLAG_SET(b->flags, BUFFER_FLAG_OUT);
  }
  
  static int impl_node_port_reuse_buffer(void *object, uint32_t port_id, uint32_t buffer_id)
  {
  	struct impl *this = object;
  
  	spa_return_val_if_fail(this != NULL, -EINVAL);
  
  	spa_return_val_if_fail(CHECK_PORT(this, SPA_DIRECTION_OUTPUT, port_id), -EINVAL);
  
  	recycle_buffer(this, buffer_id);
  
  	return 0;
  }
  
  static int impl_node_process(void *object)
  {
  	struct impl *this = object;
  	struct port *outport, *inport;
  	struct spa_io_buffers *outio, *inio;
  	struct buffer *sbuf, *dbuf;
  	struct spa_buffer *sb, *db;
  	uint32_t i, size, in_len, out_len, maxsize, max;
  #ifndef FASTPATH
  	uint32_t pin_len, pout_len;
  #endif
  	int res = 0;
  	const void **src_datas;
  	void **dst_datas;
  	bool flush_out = false;
  	bool flush_in = false;
  	bool draining = false;
  
  	spa_return_val_if_fail(this != NULL, -EINVAL);
  
  	outport = GET_OUT_PORT(this, 0);
  	inport = GET_IN_PORT(this, 0);
  
  	outio = outport->io;
  	inio = inport->io;
  
  	spa_return_val_if_fail(outio != NULL, -EIO);
  	spa_return_val_if_fail(inio != NULL, -EIO);
  
  	spa_log_trace_fp(this->log, NAME " %p: status %p %d %d -> %p %d %d", this,
  			inio, inio->status, inio->buffer_id,
  			outio, outio->status, outio->buffer_id);
  
  	if (SPA_UNLIKELY(outio->status == SPA_STATUS_HAVE_DATA))
  		return SPA_STATUS_HAVE_DATA;
  	/* recycle */
  	if (SPA_LIKELY(outio->buffer_id < outport->n_buffers)) {
  		recycle_buffer(this, outio->buffer_id);
  		outio->buffer_id = SPA_ID_INVALID;
  	}
  	if (SPA_UNLIKELY(inio->status != SPA_STATUS_HAVE_DATA)) {
  		if (inio->status != SPA_STATUS_DRAINED || this->drained)
  			return outio->status = inio->status;
  
  		inio->buffer_id = 0;
  		inport->buffers[0].outbuf->datas[0].chunk->size = 0;
  	}
  
  	if (SPA_UNLIKELY(inio->buffer_id >= inport->n_buffers))
  		return inio->status = -EINVAL;
  
  	if (SPA_UNLIKELY((dbuf = peek_buffer(this, outport)) == NULL))
  		return outio->status = -EPIPE;
  
  	sbuf = &inport->buffers[inio->buffer_id];
  
  	sb = sbuf->outbuf;
  	db = dbuf->outbuf;
  
  	size = sb->datas[0].chunk->size;
  	maxsize = db->datas[0].maxsize;
  
  	if (SPA_LIKELY(this->io_position))
  		max = this->io_position->clock.duration;
  	else
  		max = maxsize / sizeof(float);
  
  	switch (this->mode) {
  	case MODE_SPLIT:
  		/* in split mode we need to output exactly the size of the
  		 * duration so we don't try to flush early */
  		maxsize = SPA_MIN(maxsize, max * sizeof(float));
  		flush_out = false;
  		break;
  	case MODE_MERGE:
  	default:
  		/* in merge mode we consume one duration of samples and
  		 * always output the resulting data */
  		flush_out = true;
  		break;
  	}
  	if (size == 0) {
  		size = sb->datas[0].maxsize;
  		memset(sb->datas[0].data, 0, size);
  		inport->offset = 0;
  		flush_in = draining = true;
  	}
  
  	in_len = (size - inport->offset) / sizeof(float);
  	out_len = (maxsize - outport->offset) / sizeof(float);
  
  	src_datas = alloca(sizeof(void*) * this->resample.channels);
  	dst_datas = alloca(sizeof(void*) * this->resample.channels);
  
  	for (i = 0; i < sb->n_datas; i++)
  		src_datas[i] = SPA_MEMBER(sb->datas[i].data, inport->offset, void);
  	for (i = 0; i < db->n_datas; i++)
  		dst_datas[i] = SPA_MEMBER(db->datas[i].data, outport->offset, void);
  
  #ifndef FASTPATH
  	pin_len = in_len;
  	pout_len = out_len;
  #endif
  
  	resample_process(&this->resample, src_datas, &in_len, dst_datas, &out_len);
  
  #ifndef FASTPATH
  	spa_log_trace_fp(this->log, NAME " %p: in %d/%d %zd %d out %d/%d %zd %d max:%d",
  			this, pin_len, in_len, size / sizeof(float), inport->offset,
  			pout_len, out_len, maxsize / sizeof(float), outport->offset,
  			max);
  #endif
  
  	for (i = 0; i < db->n_datas; i++) {
  		db->datas[i].chunk->size = outport->offset + (out_len * sizeof(float));
  		db->datas[i].chunk->offset = 0;
  	}
  
  	inport->offset += in_len * sizeof(float);
  	if (inport->offset >= size || flush_in) {
  		inio->status = SPA_STATUS_NEED_DATA;
  		inport->offset = 0;
  		SPA_FLAG_SET(res, inio->status);
  		spa_log_trace_fp(this->log, NAME " %p: return input buffer of %zd samples", this, size / sizeof(float));
  	}
  
  	outport->offset += out_len * sizeof(float);
  	if (outport->offset > 0 && (outport->offset >= maxsize || flush_out)) {
  		outio->status = SPA_STATUS_HAVE_DATA;
  		outio->buffer_id = dbuf->id;
  		spa_log_trace_fp(this->log, NAME " %p: have output buffer of %zd samples", this, outport->offset / sizeof(float));
  		dequeue_buffer(this, dbuf);
  		outport->offset = 0;
  		this->drained = draining;
  		SPA_FLAG_SET(res, SPA_STATUS_HAVE_DATA);
  	}
  	if (out_len == 0 && this->peaks) {
  		outio->status = SPA_STATUS_HAVE_DATA;
  		outio->buffer_id = SPA_ID_INVALID;
  		SPA_FLAG_SET(res, SPA_STATUS_HAVE_DATA);
  		spa_log_trace_fp(this->log, NAME " %p: no output buffer", this);
  	}
  
  	if (this->io_rate_match) {
  		if (SPA_FLAG_IS_SET(this->io_rate_match->flags, SPA_IO_RATE_MATCH_FLAG_ACTIVE))
  			resample_update_rate(&this->resample, this->io_rate_match->rate);
  		else
  			resample_update_rate(&this->resample, 1.0);
  		this->io_rate_match->delay = resample_delay(&this->resample);
  		this->io_rate_match->size = resample_in_len(&this->resample, max - outport->offset / sizeof(float));
  	}
  	return res;
  }
  
  static const struct spa_node_methods impl_node = {
  	SPA_VERSION_NODE_METHODS,
  	.add_listener = impl_node_add_listener,
  	.set_callbacks = impl_node_set_callbacks,
  	.enum_params = impl_node_enum_params,
  	.set_param = impl_node_set_param,
  	.set_io = impl_node_set_io,
  	.send_command = impl_node_send_command,
  	.add_port = impl_node_add_port,
  	.remove_port = impl_node_remove_port,
  	.port_enum_params = impl_node_port_enum_params,
  	.port_set_param = impl_node_port_set_param,
  	.port_use_buffers = impl_node_port_use_buffers,
  	.port_set_io = impl_node_port_set_io,
  	.port_reuse_buffer = impl_node_port_reuse_buffer,
  	.process = impl_node_process,
  };
  
  static int impl_get_interface(struct spa_handle *handle, const char *type, void **interface)
  {
  	struct impl *this;
  
  	spa_return_val_if_fail(handle != NULL, -EINVAL);
  	spa_return_val_if_fail(interface != NULL, -EINVAL);
  
  	this = (struct impl *) handle;
  
  	if (strcmp(type, SPA_TYPE_INTERFACE_Node) == 0)
  		*interface = &this->node;
  	else
  		return -ENOENT;
  
  	return 0;
  }
  
  static int impl_clear(struct spa_handle *handle)
  {
  	struct impl *this;
  
  	spa_return_val_if_fail(handle != NULL, -EINVAL);
  
  	this = (struct impl *) handle;
  
  	if (this->resample.free)
  		resample_free(&this->resample);
  	return 0;
  }
  
  static size_t
  impl_get_size(const struct spa_handle_factory *factory,
  	      const struct spa_dict *params)
  {
  	return sizeof(struct impl);
  }
  
  static int
  impl_init(const struct spa_handle_factory *factory,
  	  struct spa_handle *handle,
  	  const struct spa_dict *info,
  	  const struct spa_support *support,
  	  uint32_t n_support)
  {
  	struct impl *this;
  	struct port *port;
  	const char *str;
  
  	spa_return_val_if_fail(factory != NULL, -EINVAL);
  	spa_return_val_if_fail(handle != NULL, -EINVAL);
  
  	handle->get_interface = impl_get_interface;
  	handle->clear = impl_clear;
  
  	this = (struct impl *) handle;
  
  	this->log = spa_support_find(support, n_support, SPA_TYPE_INTERFACE_Log);
  	this->cpu = spa_support_find(support, n_support, SPA_TYPE_INTERFACE_CPU);
  
  	if (this->cpu)
  		this->resample.cpu_flags = spa_cpu_get_flags(this->cpu);
  
  	props_reset(&this->props);
  
  	if (info != NULL) {
  		if ((str = spa_dict_lookup(info, "resample.quality")) != NULL)
  			this->props.quality = atoi(str);
  		if ((str = spa_dict_lookup(info, "resample.peaks")) != NULL)
  			this->peaks = strcmp(str, "true") == 0 || atoi(str) == 1;
  		if ((str = spa_dict_lookup(info, "factory.mode")) != NULL) {
  			if (strcmp(str, "split") == 0)
  				this->mode = MODE_SPLIT;
  			else if (strcmp(str, "merge") == 0)
  				this->mode = MODE_MERGE;
  			else
  				this->mode = MODE_CONVERT;
  		}
  	}
  	spa_log_debug(this->log, "mode:%d", this->mode);
  
  	this->node.iface = SPA_INTERFACE_INIT(
  			SPA_TYPE_INTERFACE_Node,
  			SPA_VERSION_NODE,
  			&impl_node, this);
  
  	spa_hook_list_init(&this->hooks);
  
  	this->info = SPA_NODE_INFO_INIT();
  	this->info_all = SPA_NODE_CHANGE_MASK_FLAGS;
  	this->info.max_input_ports = 1;
  	this->info.max_output_ports = 1;
  	this->info.flags = SPA_NODE_FLAG_RT;
  
  	port = GET_OUT_PORT(this, 0);
  	port->direction = SPA_DIRECTION_OUTPUT;
  	port->id = 0;
  	port->info_all = SPA_PORT_CHANGE_MASK_FLAGS |
  		SPA_PORT_CHANGE_MASK_PARAMS;
  	port->info = SPA_PORT_INFO_INIT();
  	port->info.flags = 0;
  	port->params[0] = SPA_PARAM_INFO(SPA_PARAM_EnumFormat, SPA_PARAM_INFO_READ);
  	port->params[1] = SPA_PARAM_INFO(SPA_PARAM_Meta, SPA_PARAM_INFO_READ);
  	port->params[2] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
  	port->params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
  	port->params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
  	port->info.params = port->params;
  	port->info.n_params = 5;
  	spa_list_init(&port->queue);
  
  	port = GET_IN_PORT(this, 0);
  	port->direction = SPA_DIRECTION_INPUT;
  	port->id = 0;
  	port->info_all = SPA_PORT_CHANGE_MASK_FLAGS |
  		SPA_PORT_CHANGE_MASK_PARAMS;
  	port->info = SPA_PORT_INFO_INIT();
  	port->info.flags = SPA_PORT_FLAG_DYNAMIC_DATA;
  	port->params[0] = SPA_PARAM_INFO(SPA_PARAM_EnumFormat, SPA_PARAM_INFO_READ);
  	port->params[1] = SPA_PARAM_INFO(SPA_PARAM_Meta, SPA_PARAM_INFO_READ);
  	port->params[2] = SPA_PARAM_INFO(SPA_PARAM_IO, SPA_PARAM_INFO_READ);
  	port->params[3] = SPA_PARAM_INFO(SPA_PARAM_Format, SPA_PARAM_INFO_WRITE);
  	port->params[4] = SPA_PARAM_INFO(SPA_PARAM_Buffers, 0);
  	port->info.params = port->params;
  	port->info.n_params = 5;
  	spa_list_init(&port->queue);
  
  	return 0;
  }
  
  static const struct spa_interface_info impl_interfaces[] = {
  	{SPA_TYPE_INTERFACE_Node,},
  };
  
  static int
  impl_enum_interface_info(const struct spa_handle_factory *factory,
  			 const struct spa_interface_info **info,
  			 uint32_t *index)
  {
  	spa_return_val_if_fail(factory != NULL, -EINVAL);
  	spa_return_val_if_fail(info != NULL, -EINVAL);
  	spa_return_val_if_fail(index != NULL, -EINVAL);
  
  	switch (*index) {
  	case 0:
  		*info = &impl_interfaces[*index];
  		break;
  	default:
  		return 0;
  	}
  	(*index)++;
  	return 1;
  }
  
  const struct spa_handle_factory spa_resample_factory = {
  	SPA_VERSION_HANDLE_FACTORY,
  	SPA_NAME_AUDIO_PROCESS_RESAMPLE,
  	NULL,
  	impl_get_size,
  	impl_init,
  	impl_enum_interface_info,
  };
  