split into separate executables

15 files changed, 427 insertions, 584 deletions

diff --git a/.gitignore b/.gitignore
index 4d63b10..db97f5f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
 /freenect-server
+/freenect-server--kinect
+/freenect-server--http
 
 *.o
 .*.mk
\ No newline at end of file
diff --git a/Makefile b/Makefile
index 39e1290..58da358 100644
--- a/Makefile
+++ b/Makefile
@@ -2,14 +2,14 @@ CFLAGS += -g -std=c99 -Wall -Werror -Wextra -pedantic
 CPPFLAGS += -std=c99 -Wall -Werror -Wextra -pedantic
 CPPFLAGS += -D_GNU_SOURCE
 
-all: freenect-server
+all: freenect-server freenect-server--kinect freenect-server--http
 .PHONY: all
 
-freenect-server: main.o thread_kinect.o thread_mpjpeg.o thread_http.o wg.o -lfreenect -lusb-1.0 -lpthread
-	$(CC) $(LDFLAGS) $^ -o $@
+freenect-server--kinect: util.o -lfreenect -lusb-1.0
+freenect-server--http: util.o mpjpeg.o -lpthread
 
 clean:
-	rm -f -- *.o .*.mk freenect-server
+	rm -f -- *.o .*.mk freenect-server freenect-server--kinect freenect-server--http
 .PHONY: clean
 
 .DELETE_ON_ERROR:
diff --git a/freenect-server--http.c b/freenect-server--http.c
new file mode 100644
index 0000000..d966e3b
--- /dev/null
+++ b/freenect-server--http.c
@@ -0,0 +1,172 @@
+#include <error.h>
+#include <errno.h>
+#include <netdb.h> /* for {get,free}addrinfo() */
+#include <stdlib.h> /* for EXIT_FAILURE */
+#include <sys/socket.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/stat.h> /* for open */
+#include <fcntl.h> /* for open */
+
+#include "util.h"
+#include "mpjpeg.h"
+
+struct httpfile {
+	char name[256];
+	struct mpjpeg_stream *stream;
+};
+
+size_t filec = 0;
+struct httpfile *filev = NULL;
+
+struct reader_thread_args {
+	struct mpjpeg_stream *stream;
+	int fd;
+	const char *boundary;
+};
+
+void *reader_thread(void *args_anon) {
+	struct reader_thread_args *args = args_anon;
+	mpjpeg_reader(args->stream, args->fd, args->boundary);
+	return NULL;
+}
+
+void start_mpjpeg_reader(struct mpjpeg_stream *s, int fd, const char *boundary) {
+	struct reader_thread_args *args = xrealloc(NULL, sizeof(struct reader_thread_args));
+	args->stream = s;
+	args->fd = fd;
+	args->boundary = boundary;
+	pthread_t thread;
+	pthread_create(&thread, NULL, reader_thread, args);
+}
+
+void file_add(const char *filename) {
+	struct mpjpeg_stream *stream = xrealloc(NULL, sizeof(struct mpjpeg_stream));
+	init_mpjpeg_stream(stream);
+	int fd = open(filename, O_RDONLY);
+	if (fd < 0)
+		error(EXIT_FAILURE, errno, "opening file: %s", filename);
+	filev = xrealloc(NULL, (++filec)*sizeof(*filev));
+	strncpy(filev[filec-1].name, filename, sizeof(filev[filec-1].name));
+	filev[filec-1].stream = stream;
+	start_mpjpeg_reader(stream, fd, "ffserver" /* FIXME */);
+}
+
+struct mpjpeg_stream *file_get(const char *filename) {
+	for (size_t i = 0; i < filec; i++) {
+		if (strncmp(filename, filev[i].name, sizeof(filev[i].name)) == 0) {
+			return filev[i].stream;
+		}
+	}
+	return NULL;
+}
+
+int tcp4_parse_listen(const char *port) {
+	int r;
+	struct addrinfo *addr = NULL;
+	struct addrinfo hints = { 0 };
+	hints.ai_family = AF_INET;
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_flags = AI_PASSIVE;
+
+	if ((r = getaddrinfo(NULL, port, &hints, &addr)) != 0)
+		error(EXIT_FAILURE, r, _("Could not resolve TCP4 port %s"), port);
+
+	int sock = socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol);
+	if (sock < 0)
+		error(EXIT_FAILURE, errno, _("Could not create a TCP4 socket"));
+
+	int yes = 1;
+	setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
+
+	if (bind(sock, addr->ai_addr, addr->ai_addrlen) < 0)
+		error(EXIT_FAILURE, errno, _("Could not bind to TCP4 port %s"), port);
+
+	if (listen(sock, 5) < 0)
+		error(EXIT_FAILURE, errno, _("Could not listen on TCP4 port %s"), port);
+
+	freeaddrinfo(addr);
+	return sock;
+}
+
+void connection_handler(int fd) {
+	FILE *netstream = fdopen(fd, "r");
+	char *line_buf = NULL;
+	size_t line_cap = 0;
+	ssize_t line_len = 0;
+
+	line_len = getline(&line_buf, &line_cap, netstream);
+	/* expect line to be "GET /path.mjpg HTTP/1.1" */
+	if (strncmp(line_buf, "GET ", 4) != 0) {
+		dprintf(fd,
+		        "HTTP/1.1 405 Method Not Allowed\r\n"
+		        "Allow: GET\r\n"
+		        "\r\n");
+		close(fd);
+		return;
+	}
+	char *version = &line_buf[4];
+	char *path = strsep(&version, " ");
+	if (strcmp(version, "HTTP/1.1\r\n") != 0 && strcmp(version, "HTTP/1.0\r\n")) {
+		close(fd);
+		return;
+	}
+	path = strdupa(path);
+
+	/* run through the rest of the headers */
+	while (strcmp(line_buf, "\r\n") != 0 && line_len >= 0)
+		line_len = getline(&line_buf, &line_cap, netstream);
+
+	struct mpjpeg_stream *vidstream = file_get(path);
+	if (vidstream == NULL) {
+		dprintf(fd,
+		        "HTTP/1.1 404 Not Found\r\n"
+		        "\r\n");
+		return;
+	}
+
+	const char *boundary = "boundary" /* FIXME */;
+	dprintf(fd,
+	        "HTTP/1.1 200 OK\r\n"
+	        "Content-Type: multipart/x-mixed-replace;boundary=%s\r\n"
+	        "\r\n",
+	        boundary);
+	mpjpeg_writer(vidstream, fd, boundary);
+	close(fd);
+}
+
+void *connection_thread(void *arg_anon) {
+	int fd = (int)(intptr_t)arg_anon;
+	connection_handler(fd);
+	return NULL;
+}
+
+void usage() {
+	printf("Usage: %s [-h] PORT [FILENAME...]\n", program_invocation_name);
+}
+
+int main(int argc, char *argv[]) {
+	if (argc < 2) {
+		dup2(2, 1);
+		usage();
+		return EXIT_FAILURE;
+	}
+	if (strcmp(argv[1], "-h") == 0) {
+		usage();
+		return EXIT_SUCCESS;
+	}
+	int sock = tcp4_parse_listen(argv[1]);
+
+	for (int i = 2; i < argc; i++)
+		file_add(argv[i]);
+	
+	while (1) {
+		int conn = accept(sock, NULL, NULL);
+		if (conn < 0)
+			continue;
+		pthread_t thread;
+		pthread_create(&thread, NULL, connection_thread, (void*)(intptr_t)conn);
+	}
+
+	return 0;
+}
diff --git a/freenect-server--kinect.c b/freenect-server--kinect.c
new file mode 100644
index 0000000..1c68fe3
--- /dev/null
+++ b/freenect-server--kinect.c
@@ -0,0 +1,165 @@
+#include <errno.h>
+#include <error.h>
+#include <stdio.h>
+#include <stdlib.h> /* atexit */
+#include <unistd.h> /* dup2 */
+
+#include <libfreenect/libfreenect.h>
+#include <libusb-1.0/libusb.h>
+
+#include "util.h"
+
+FILE *depth_stream = NULL;
+FILE *video_stream = NULL;
+FILE *accel_stream = NULL;
+freenect_context *ctx;
+
+void dump_ffmpeg_24(FILE *stream, uint32_t timestamp UNUSED, void *data,
+                    size_t data_size)
+{
+	fwrite(data, data_size, 1, stream);
+}
+
+void dump_ffmpeg_pad16(FILE *stream, uint32_t timestamp UNUSED, void *data_anon,
+                       size_t data_size)
+{
+	uint16_t* data = data_anon;
+	uint16_t* end = (void*)&((char*)data_anon)[data_size];
+	while (data < end) {
+		uint32_t z = *data;
+		fwrite(((char*)(&z)), 3, 1, stream);
+		data = &data[1];
+	}
+}
+
+void handle_accel(freenect_device *dev UNUSED, freenect_raw_tilt_state* data)
+{
+	printf("handle accel\n");
+	double x, y, z;
+	freenect_get_mks_accel(data, &x, &y, &z);
+	//fprintf(accel_stream, "x=%f\ty=%f\tz=%f\n", x, y, z);
+}
+
+void handle_depth(freenect_device *dev UNUSED, void *depth, uint32_t timestamp)
+{
+	printf("handle depth\n");
+	dump_ffmpeg_pad16(depth_stream, timestamp, depth,
+	                  freenect_find_depth_mode(FREENECT_RESOLUTION_MEDIUM,
+	                                           FREENECT_DEPTH_11BIT).bytes);
+}
+
+void handle_video(freenect_device *dev, void *rgb, uint32_t timestamp)
+{
+	printf("handle video\n");
+	dump_ffmpeg_24(video_stream, timestamp, rgb,
+	               freenect_get_current_video_mode(dev).bytes);
+}
+
+void print_mode(const char *name, freenect_frame_mode mode) {
+	/* This is just a courtesy function to let the user know the mode
+	   if it becomes a bother for maintainability just comment out the
+	   code in its body.  It will only break if struct entries go missing.
+	*/
+	printf("%s Mode: {%d, %d, {%d}, %d, %d, %d, %d, %d, %d, %d}\n", name,
+	       mode.reserved, (int)mode.resolution, (int)mode.video_format, mode.bytes, mode.width,
+	       mode.height, mode.data_bits_per_pixel, mode.padding_bits_per_pixel,
+	       mode.framerate, mode.is_valid);
+}
+
+void cleanup() {
+	if (ctx)
+		freenect_shutdown(ctx);
+	if (video_stream)
+		fclose(video_stream);
+	if (depth_stream)
+		fclose(depth_stream);
+	if (accel_stream)
+		fclose(accel_stream);
+}
+
+void usage() {
+	printf("Usage: %s [-h] [-v video.rgb24] [-d depth.rgb24] [-a accel.txt]\n", program_invocation_name);
+}
+
+int main(int argc, char *argv[]) {
+	int res = 0;
+	freenect_device *dev;
+
+	atexit(cleanup);
+
+	for (int i = 1; i < argc; i++) {
+		if (argv[i][0] == '-' && argv[i][1] != '\0' && argv[i][2] == '\0') {
+			switch (argv[i][1]) {
+			case 'h':
+				usage();
+				return EXIT_SUCCESS;
+			case 'v':
+				i++;
+				video_stream = fopen(argv[i], "w");
+				break;
+			case 'd':
+				i++;
+				depth_stream = fopen(argv[i], "w");
+				break;
+			case 'a':
+				i++;
+				accel_stream = fopen(argv[i], "w");
+				break;
+			default:
+				dup2(2, 1);
+				usage();
+				return EXIT_FAILURE;
+			}
+		} else {
+			dup2(2, 1);
+			usage();
+			return EXIT_FAILURE;
+		}
+	}
+					
+	res = freenect_init(&ctx, 0);
+	if (res) {
+		error(EXIT_FAILURE, 0, "freenect_init: %s", libusb_strerror(res));
+	}
+
+	freenect_device_flags devices = 0;
+	if (video_stream || depth_stream)
+		devices |= FREENECT_DEVICE_CAMERA;
+	if (accel_stream)
+		devices |= FREENECT_DEVICE_MOTOR;
+
+	freenect_select_subdevices(ctx, devices);
+	if ((res = freenect_open_device(ctx, &dev, 0))) {
+		error(EXIT_FAILURE, 0, "freenect_open_device: %s", libusb_strerror(res));
+	}
+
+	if (video_stream) {
+		print_mode("Video", freenect_find_video_mode(FREENECT_RESOLUTION_MEDIUM, FREENECT_VIDEO_RGB));
+		freenect_set_video_mode(dev, freenect_find_video_mode(FREENECT_RESOLUTION_MEDIUM, FREENECT_VIDEO_RGB));
+		freenect_start_video(dev);
+		freenect_set_video_callback(dev, handle_video);
+	}
+
+	if (depth_stream) {
+		print_mode("Depth", freenect_find_depth_mode(FREENECT_RESOLUTION_MEDIUM, FREENECT_DEPTH_11BIT));
+		freenect_set_depth_mode(dev, freenect_find_depth_mode(FREENECT_RESOLUTION_MEDIUM, FREENECT_DEPTH_11BIT));
+		freenect_start_depth(dev);
+		freenect_set_depth_callback(dev, handle_depth);
+	}
+
+	if (accel_stream) {
+	}
+
+	while (freenect_process_events(ctx) >= 0) {
+		if (accel_stream) {
+			freenect_raw_tilt_state* state;
+			freenect_update_tilt_state(dev);
+			state = freenect_get_tilt_state(dev);
+			handle_accel(dev, state);
+		}
+	}
+
+	freenect_stop_depth(dev);
+	freenect_stop_video(dev);
+	freenect_close_device(dev);
+}
diff --git a/freenect-server.sh b/freenect-server.sh
new file mode 100644
index 0000000..b2f3d7c
--- /dev/null
+++ b/freenect-server.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+mkfifo video.rgb24
+mkfifo depth.rgb24
+mkfifo video.mjpg
+mkfifo depth.mjpg
+
+pids=()
+./freenect-server--kinect -v video.rgb24 -d depth.rgb24 &
+pids+=($!)
+./freenect-server--http 8090 video.mjpg depth.mjpg &
+pids+=($!)
+ffmpeg -pix_fmt rgb24 -s 640x480 -f rawvideo -i video.rgb24 -f mpjpeg - > video.mjpg &
+pids+=($!)
+ffmpeg -pix_fmt rgb24 -s 640x480 -f rawvideo -i depth.rgb24 -f mpjpeg - > depth.mjpg &
+pids+=($!)
+
+cleanup() {
+	kill -- "${pids[@]}"
+	rm -f {video,depth}.{rgb24,mjpg}
+}
+trap cleanup EXIT
+
+wait
diff --git a/main.c b/main.c
deleted file mode 100644
index 9af7dd7..0000000
--- a/main.c
+++ /dev/null
@@ -1,218 +0,0 @@
-/*
- * This file is part of the OpenKinect Project. http://www.openkinect.org
- *
- * Copyright (c) 2010 Brandyn White (bwhite@dappervision.com)
- * Copyright (c) 2016 Luke Shumaker (lukeshu@sbcglobal.net)
- *
- * This code is licensed to you under the terms of the Apache License, version
- * 2.0, or, at your option, the terms of the GNU General Public License,
- * version 2.0. See the APACHE20 and GPL2 files for the text of the licenses,
- * or the following URLs:
- * http://www.apache.org/licenses/LICENSE-2.0
- * http://www.gnu.org/licenses/gpl-2.0.txt
- *
- * If you redistribute this file in source form, modified or unmodified, you
- * may:
- *   1) Leave this header intact and distribute it under the same terms,
- *      accompanying it with the APACHE20 and GPL20 files, or
- *   2) Delete the Apache 2.0 clause and accompany it with the GPL2 file, or
- *   3) Delete the GPL v2 clause and accompany it with the APACHE20 file
- * In all cases you must keep the copyright notice intact and include a copy
- * of the CONTRIB file.
- *
- * Binary distributions must follow the binary distribution requirements of
- * either License.
- */
-
-#include <stdio.h>
-
-#include <errno.h>
-#include <error.h>
-#include <pthread.h>
-#include <signal.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include <sys/wait.h>
-
-#include "main.h"
-#include "wg.h"
-
-volatile sig_atomic_t running = 1;
-static struct wg wg;
-
-void * xrealloc(void *ptr, size_t size)
-{
-	void *ret = realloc(ptr, size);
-	if (ret == NULL) {
-		if (ptr==NULL)
-			error(1, errno, "Could not allocate memory");
-		else
-			error(1, errno, "Could not re-allocate memory");
-	}
-	return ret;
-}
-
-static
-void start_ffmpeg(int in, int out) {
-	switch (fork()) {
-	case -1: /* error */
-		error(1, errno, "fork");
-	case 0: /* child */
-		dup2(in, 0);
-		dup2(out, 1);
-		for (int fd = 3; fd < 30; fd++)
-			close(fd);
-		execlp("ffmpeg",
-		       "ffmpeg",
-		       "-pix_fmt", "rgb24", "-s", "640x480", "-f", "rawvideo", "-i", "/dev/stdin",
-		       "-f", "mpjpeg", "-",
-		       NULL);
-		error(1, errno, "execlp: ffmpeg");
-	default: /* parent */
-		close(in);
-		close(out);
-	}
-}
-
-struct thread_kinect_args {
-	int video_fd;
-	int depth_fd;
-	int accel_fd;
-};
-static
-void* start_kinect_inner(void *args_anon) {
-	pthread_setname_np(pthread_self(), "kinect");
-	struct thread_kinect_args *args = args_anon;
-	thread_kinect(args->video_fd, args->depth_fd, args->accel_fd);
-	wg_sub(&wg, 1);
-	finish(0);
-	return NULL;
-}
-static
-void start_kinect(int video_fd, int depth_fd, int accel_fd) {
-
-	static struct thread_kinect_args args;
-	args.video_fd = video_fd;
-	args.depth_fd = depth_fd;
-	args.accel_fd = accel_fd;
-
-	static pthread_t thread;
-	wg_add(&wg, 1);
-	pthread_create(&thread, NULL, start_kinect_inner, &args);
-}
-
-struct thread_mpjpeg_args {
-	struct mpjpeg_stream *s;
-	int fd;
-	const char *boundary;
-};
-static
-void *start_mpjpeg_reader_inner(void *args_anon) {
-	pthread_setname_np(pthread_self(), "mpjpeg-reader");
-	struct thread_mpjpeg_args *args = args_anon;
-	thread_mpjpeg_reader(args->s, args->fd, args->boundary);
-	wg_sub(&wg, 1);
-	return NULL;
-}
-static
-void start_mpjpeg_reader(struct mpjpeg_stream *s, int fd, const char *boundary) {
-	struct thread_mpjpeg_args *args = xrealloc(NULL, sizeof(struct thread_mpjpeg_args));
-	args->s = s;
-	args->fd = fd;
-	args->boundary = boundary;
-	wg_add(&wg, 1);
-	static pthread_t thread;
-	pthread_create(&thread, NULL, start_mpjpeg_reader_inner, args);
-}
-
-struct thread_http_args {
-	struct wg *wg;
-	struct mpjpeg_stream *video;
-	struct mpjpeg_stream *depth;
-};
-static
-void *start_http_inner(void *args_anon) {
-	pthread_setname_np(pthread_self(), "http-listener");
-	struct thread_http_args *args = args_anon;
-	thread_http_listener(args->wg, args->video, args->depth);
-	wg_sub(&wg, 1);
-	finish(0);
-	return NULL;
-}
-static
-void start_http(struct wg *awg,
-                struct mpjpeg_stream *video,
-                struct mpjpeg_stream *depth) {
-	static struct thread_http_args args;
-	args.wg = awg;
-	args.video = video;
-	args.depth = depth;
-
-	static pthread_t thread;
-	wg_add(&wg, 1);
-	pthread_create(&thread, NULL, start_http_inner, &args);
-}
-
-static
-void sigchld_handler(int sig UNUSED)
-{
-	int status;
-	while (waitpid(-1, &status, WNOHANG) > 0) {}
-}
-
-void finish(int sig)
-{
-	if (sig != 0)
-		printf("Caught signal %d\n", sig);
-	running = 0;
-	close(httpsock);
-	kill(getpid(), SIGHUP);
-}
-
-int main(int argc UNUSED, char **argv UNUSED)
-{
-	int kinect_video_fds[2];
-	int kinect_depth_fds[2];
-	int kinect_accel_fds[2];
-	int mpjpeg_video_fds[2];
-	int mpjpeg_depth_fds[2];
-	struct mpjpeg_stream mpjpeg_video;
-	struct mpjpeg_stream mpjpeg_depth;
-
-	struct sigaction act_chld;
-	sigemptyset (&act_chld.sa_mask);
-	act_chld.sa_flags = SA_RESTART;
-	act_chld.sa_handler = sigchld_handler;
-	if (sigaction(SIGCHLD, &act_chld, 0)) {
-		error(EXIT_FAILURE, errno, _("Could not set up SIGCHLD handler"));
-	}
-
-	struct sigaction act_exit;
-	sigemptyset (&act_exit.sa_mask);
-	act_exit.sa_flags = 0;
-	act_exit.sa_handler = finish;
-	sigaction(SIGINT, &act_exit, 0);
-	sigaction(SIGQUIT, &act_exit, 0);
-	sigaction(SIGTERM, &act_exit, 0);
-
-	if (pipe(kinect_video_fds) == -1) error(1, errno, "pipe");
-	if (pipe(kinect_depth_fds) == -1) error(1, errno, "pipe");
-	if (pipe(kinect_accel_fds) == -1) error(1, errno, "pipe");
-	if (pipe(mpjpeg_video_fds) == -1) error(1, errno, "pipe");
-	if (pipe(mpjpeg_depth_fds) == -1) error(1, errno, "pipe");
-	init_mpjpeg_stream(&mpjpeg_video);
-	init_mpjpeg_stream(&mpjpeg_depth);
-
-	wg_init(&wg);
-	start_kinect(kinect_video_fds[1],
-	                    kinect_depth_fds[1],
-	                    kinect_accel_fds[1]);
-	start_mpjpeg_reader(&mpjpeg_video, mpjpeg_video_fds[0], "ffserver");
-	start_mpjpeg_reader(&mpjpeg_depth, mpjpeg_depth_fds[0], "ffserver");
-	start_http(&wg, &mpjpeg_video, &mpjpeg_depth);
-	/* never call exit() after we've started ffmpeg */
-	start_ffmpeg(kinect_video_fds[0], mpjpeg_video_fds[1]);
-	start_ffmpeg(kinect_depth_fds[0], mpjpeg_depth_fds[1]);
-	wg_wait(&wg);
-	return 0;
-}
diff --git a/main.h b/main.h
deleted file mode 100644
index 73fa96e..0000000
--- a/main.h
+++ /dev/null
@@ -1,41 +0,0 @@
-#pragma once
-
-#include <signal.h> /* for sig_atomic_t */
-#include <string.h> /* for memset(3) */
-
-#define UNUSED __attribute__((__unused__))
-#define ZERO(x) memset(&(x), 0, sizeof(x))
-
-#ifndef _
-#define _(str) str
-#endif
-
-extern volatile sig_atomic_t running;
-extern int httpsock;
-
-struct frame {
-	ssize_t len;
-	size_t cap;
-	char *data;
-};
-
-struct mpjpeg_stream {
-	struct frame a;
-	struct frame b;
-
-	struct frame *front;
-	struct frame *back;
-	pthread_mutex_t frontlock;
-};
-
-struct wg;
-
-void finish(int sig);
-void thread_kinect(int video_fd, int depth_fd, int accel_fd);
-void thread_http_listen(int fd);
-void thread_mpjpeg_reader(struct mpjpeg_stream *s, int fd, const char *boundary);
-void thread_mpjpeg_writer(struct mpjpeg_stream *s, int fd, const char *boundary);
-void thread_http_listener(struct wg *wg, struct mpjpeg_stream *video, struct mpjpeg_stream *depth);
-void init_mpjpeg_stream();
-
-void * xrealloc(void *ptr, size_t size);
diff --git a/thread_mpjpeg.c b/mpjpeg.c
index 410faa0..dd4b96e 100644
--- a/thread_mpjpeg.c
+++ b/mpjpeg.c
@@ -1,15 +1,17 @@
 /* Copyright 2016 Luke Shumaker */
 
-#include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 
-#include "main.h"
+#include "mpjpeg.h"
+#include "util.h"
+
+#define STARTS_WITH(str, prefix) strncmp(str, prefix, sizeof(prefix)-1)
 
 static
-char *format_boundary(const char *old) {
+char *boundary_line(const char *old) {
 	size_t len = strlen(old);
 	char *new = xrealloc(NULL, len+5);
 	new[0] = '-';
@@ -21,11 +23,9 @@ char *format_boundary(const char *old) {
 	return new;
 }
 
-#define STARTS_WITH(str, prefix) strncmp(str, prefix, sizeof(prefix)-1)
-
-void thread_mpjpeg_reader(struct mpjpeg_stream *s, int fd, const char *boundary) {
+void mpjpeg_reader(struct mpjpeg_stream *s, int fd, const char *boundary) {
 	FILE *stream = fdopen(fd, "r");
-	boundary = format_boundary(boundary);
+	boundary = boundary_line(boundary);
 
 	char *line_buf = NULL;
 	size_t line_cap = 0;
@@ -67,7 +67,7 @@ void thread_mpjpeg_reader(struct mpjpeg_stream *s, int fd, const char *boundary)
 
 }
 
-void thread_mpjpeg_writer(struct mpjpeg_stream *s, int fd, const char *boundary) {
+void mpjpeg_writer(struct mpjpeg_stream *s, int fd, const char *boundary) {
 	struct frame myframe = { 0 };
 	struct frame *lastframe = NULL;
 	while(1) {
diff --git a/mpjpeg.h b/mpjpeg.h
new file mode 100644
index 0000000..7a51006
--- /dev/null
+++ b/mpjpeg.h
@@ -0,0 +1,22 @@
+#pragma once
+
+#include <pthread.h>
+
+struct frame {
+	ssize_t len;
+	size_t cap;
+	char *data;
+};
+
+struct mpjpeg_stream {
+	struct frame a;
+	struct frame b;
+
+	struct frame *front;
+	struct frame *back;
+	pthread_mutex_t frontlock;
+};
+
+void mpjpeg_reader(struct mpjpeg_stream *s, int fd, const char *boundary);
+void mpjpeg_writer(struct mpjpeg_stream *s, int fd, const char *boundary);
+void init_mpjpeg_stream();
diff --git a/thread_http.c b/thread_http.c
deleted file mode 100644
index 353ad0f..0000000
--- a/thread_http.c
+++ /dev/null
@@ -1,129 +0,0 @@
-#include <error.h>
-#include <errno.h>
-#include <netdb.h> /* for {get,free}addrinfo() */
-#include <stdlib.h> /* for EXIT_FAILURE */
-#include <sys/socket.h>
-#include <stdio.h>
-#include <unistd.h>
-
-#include "main.h"
-#include "wg.h"
-
-static
-int tcp4_parse_listen(const char *port) {
-	int r;
-	struct addrinfo *addr = NULL;
-	struct addrinfo hints = { 0 };
-	hints.ai_family = AF_INET;
-	hints.ai_socktype = SOCK_STREAM;
-	hints.ai_flags = AI_PASSIVE;
-
-	if ((r = getaddrinfo(NULL, port, &hints, &addr)) != 0)
-		error(EXIT_FAILURE, r, _("Could not resolve TCP4 port %s"), port);
-
-	int sock = socket(addr->ai_family, addr->ai_socktype, addr->ai_protocol);
-	if (sock < 0)
-		error(EXIT_FAILURE, errno, _("Could not create a TCP4 socket"));
-
-	int yes = 1;
-	setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &yes, sizeof(yes));
-
-	if (bind(sock, addr->ai_addr, addr->ai_addrlen) < 0)
-		error(EXIT_FAILURE, errno, _("Could not bind to TCP4 port %s"), port);
-
-	if (listen(sock, 5) < 0)
-		error(EXIT_FAILURE, errno, _("Could not listen on TCP4 port %s"), port);
-
-	freeaddrinfo(addr);
-	return sock;
-}
-
-static struct wg *wg;
-static struct mpjpeg_stream *video;
-static struct mpjpeg_stream *depth;
-
-static
-void thread_http_connection(int fd) {
-	FILE *stream = fdopen(fd, "r");
-	char *line_buf = NULL;
-	size_t line_cap = 0;
-	getline(&line_buf, &line_cap, stream);
-	/* expect line to be "GET /kinect-(video|depth).mjpg HTTP/1.1" */
-	if (strncmp(line_buf, "GET ", 4) != 0) {
-		dprintf(fd,
-		        "HTTP/1.1 405 Method Not Allowed\r\n"
-		        "Allow: GET\r\n"
-		        "\r\n");
-		close(fd);
-		return;
-	}
-	char *version = &line_buf[4];
-	char *path = strsep(&version, " ");
-	if (strcmp(version, "HTTP/1.1\r\n") != 0 && strcmp(version, "HTTP/1.0\r\n")) {
-		close(fd);
-		return;
-	}
-	path = strdupa(path);
-
-	/* run through the rest of the headers */
-	while (strcmp(line_buf, "\r\n") != 0)
-		getline(&line_buf, &line_cap, stream);
-
-	const char *boundary = "boundary";
-	if (strcmp(path, "/kinect-video.mjpg") == 0) {
-		dprintf(fd,
-		        "HTTP/1.1 200 OK\r\n"
-		        "Content-Type: multipart/x-mixed-replace;boundary=%s\r\n"
-		        "\r\n",
-		        boundary);
-		thread_mpjpeg_writer(video, fd, boundary);
-	} else if (strcmp(path, "/kinect-depth.mjpg") == 0) {
-		dprintf(fd,
-		        "HTTP/1.1 200 OK\r\n"
-		        "Content-Type: multipart/x-mixed-replace;boundary=%s\r\n"
-		        "\r\n",
-		        boundary);
-		thread_mpjpeg_writer(depth, fd, boundary);
-	} else {
-		printf("not found url: %s\n", path);
-		dprintf(fd,
-		        "HTTP/1.1 404 Not Found\r\n"
-		        "\r\n");
-	}
-	close(fd);
-}
-
-static
-void *start_http_connection_inner(void *arg_anon) {
-	pthread_setname_np(pthread_self(), "http-connection");
-	int fd = (int)(intptr_t)arg_anon;
-	thread_http_connection(fd);
-	wg_sub(wg, 1);
-	return NULL;
-}
-
-int httpsock = 0;
-
-static
-void start_http_connection(int fd) {
-	wg_add(wg, 1);
-	pthread_t thread;
-	pthread_create(&thread, NULL, start_http_connection_inner, (void*)(intptr_t)fd);
-}
-
-void thread_http_listener(struct wg *awg,
-                          struct mpjpeg_stream *avideo,
-                          struct mpjpeg_stream *adepth) {
-		wg = awg;
-		video = avideo;
-		depth = adepth;
-		httpsock = tcp4_parse_listen("8090");
-	
-	while (running) {
-		int conn = accept(httpsock, NULL, NULL);
-		if (conn < 0)
-			continue;
-		start_http_connection(conn);
-	}
-	finish(0);
-}
diff --git a/thread_kinect.c b/thread_kinect.c
deleted file mode 100644
index bd70679..0000000
--- a/thread_kinect.c
+++ /dev/null
@@ -1,122 +0,0 @@
-#include <error.h>
-#include <libfreenect/libfreenect.h>
-#include <libusb-1.0/libusb.h>
-#include <pthread.h>
-#include <stdio.h>
-#include <unistd.h>
-
-#include "main.h"
-
-FILE *depth_stream = NULL;
-FILE *video_stream = NULL;
-FILE *accel_stream = NULL;
-
-static
-void dump_ffmpeg_24(FILE *stream, uint32_t timestamp UNUSED, void *data,
-                    size_t data_size)
-{
-	fwrite(data, data_size, 1, stream);
-}
-
-static
-void dump_ffmpeg_pad16(FILE *stream, uint32_t timestamp UNUSED, void *data_anon,
-                       size_t data_size)
-{
-	uint16_t* data = data_anon;
-	uint16_t* end = (void*)&((char*)data_anon)[data_size];
-	while (data < end) {
-		uint32_t z = *data;
-		fwrite(((char*)(&z)), 3, 1, stream);
-		data = &data[1];
-	}
-}
-
-static
-void handle_accel(freenect_device *dev UNUSED, freenect_raw_tilt_state* data)
-{
-	double x, y, z;
-	freenect_get_mks_accel(data, &x, &y, &z);
-	//fprintf(accel_stream, "x=%f\ty=%f\tz=%f\n", x, y, z);
-}
-
-static
-void handle_depth(freenect_device *dev UNUSED, void *depth, uint32_t timestamp)
-{
-	printf("handle depth\n");
-	dump_ffmpeg_pad16(depth_stream, timestamp, depth,
-	                  freenect_find_depth_mode(FREENECT_RESOLUTION_MEDIUM,
-	                                           FREENECT_DEPTH_11BIT).bytes);
-}
-
-static
-void handle_video(freenect_device *dev, void *rgb, uint32_t timestamp)
-{
-	printf("handle depth\n");
-	dump_ffmpeg_24(video_stream, timestamp, rgb,
-	               freenect_get_current_video_mode(dev).bytes);
-}
-
-static
-void print_mode(const char *name, freenect_frame_mode mode) {
-	/* This is just a courtesy function to let the user know the mode
-	   if it becomes a bother for maintainability just comment out the
-	   code in its body.  It will only break if struct entries go missing.
-	*/
-	printf("%s Mode: {%d, %d, {%d}, %d, %d, %d, %d, %d, %d, %d}\n", name,
-	       mode.reserved, (int)mode.resolution, (int)mode.video_format, mode.bytes, mode.width,
-	       mode.height, mode.data_bits_per_pixel, mode.padding_bits_per_pixel,
-	       mode.framerate, mode.is_valid);
-}
-
-void thread_kinect(int video_fd, int depth_fd, int accel_fd) {
-	int res = 0;
-
-	freenect_context *ctx;
-	freenect_device *dev;
-
-	pthread_setname_np(pthread_self(), "libusb");
-	res = freenect_init(&ctx, 0);
-	pthread_setname_np(pthread_self(), "kinect");
-	if (res) {
-		error(0, 0, "freenect_init: %s", libusb_strerror(res));
-		goto end;
-	}
-
-	freenect_select_subdevices(ctx, (freenect_device_flags)(FREENECT_DEVICE_CAMERA | FREENECT_DEVICE_MOTOR));
-	if ((res = freenect_open_device(ctx, &dev, 0))) {
-		error(0, 0, "freenect_open_device: %s", libusb_strerror(res));
-		goto end; 
-	}
-
-	print_mode("Depth", freenect_find_depth_mode(FREENECT_RESOLUTION_MEDIUM, FREENECT_DEPTH_11BIT));
-	freenect_set_depth_mode(dev, freenect_find_depth_mode(FREENECT_RESOLUTION_MEDIUM, FREENECT_DEPTH_11BIT));
-	freenect_start_depth(dev);
-
-	print_mode("Video", freenect_find_video_mode(FREENECT_RESOLUTION_MEDIUM, FREENECT_VIDEO_RGB));
-	freenect_set_video_mode(dev, freenect_find_video_mode(FREENECT_RESOLUTION_MEDIUM, FREENECT_VIDEO_RGB));
-	freenect_start_video(dev);
-
-	depth_stream = fdopen(depth_fd, "w");
-	video_stream = fdopen(video_fd, "w");
-	accel_stream = fdopen(accel_fd, "w");
-
-	freenect_set_depth_callback(dev, handle_depth);
-	freenect_set_video_callback(dev, handle_video);
-
-	while (running && freenect_process_events(ctx) >= 0) {
-		freenect_raw_tilt_state* state;
-		freenect_update_tilt_state(dev);
-		state = freenect_get_tilt_state(dev);
-		handle_accel(dev, state);
-	}
-
-	freenect_stop_depth(dev);
-	freenect_stop_video(dev);
-	freenect_close_device(dev);
-
- end:
-	freenect_shutdown(ctx);
-	close(video_fd);
-	close(depth_fd);
-	close(accel_fd);
-}
diff --git a/util.c b/util.c
new file mode 100644
index 0000000..22b6dc6
--- /dev/null
+++ b/util.c
@@ -0,0 +1,17 @@
+#include <stdlib.h>
+#include <error.h>
+#include <errno.h>
+
+#include "util.h"
+
+void *xrealloc(void *ptr, size_t size)
+{
+	void *ret = realloc(ptr, size);
+	if (ret == NULL) {
+		if (ptr==NULL)
+			error(1, errno, "Could not allocate memory");
+		else
+			error(1, errno, "Could not re-allocate memory");
+	}
+	return ret;
+}
diff --git a/util.h b/util.h
new file mode 100644
index 0000000..0eb8c19
--- /dev/null
+++ b/util.h
@@ -0,0 +1,13 @@
+#pragma once
+
+#include <signal.h> /* for sig_atomic_t */
+#include <string.h> /* for memset(3) */
+
+#define UNUSED __attribute__((__unused__))
+#define ZERO(x) memset(&(x), 0, sizeof(x))
+
+#ifndef _
+#define _(str) str
+#endif
+
+void * xrealloc(void *ptr, size_t size);
diff --git a/wg.c b/wg.c
deleted file mode 100644
index 3208aa1..0000000
--- a/wg.c
+++ /dev/null
@@ -1,43 +0,0 @@
-#include <unistd.h>
-#include <error.h>
-#include <errno.h>
-
-#include "wg.h"
-
-/* Thread management tools modeled on https://golang.org/pkg/sync/#WaitGroup */
-
-/* pthread_cond_t is overly complicated. Just use a self-pipe. */
-
-void wg_init(struct wg *wg) {
-	wg->count = 0;
-	pthread_mutex_init(&wg->lock, NULL);
-	int fds[2];
-	if (pipe(fds) != 0)
-		error(1, errno, "pipe");
-	wg->fd_wait = fds[0];
-	wg->fd_signal = fds[1];
-}
-
-void wg_add(struct wg *wg, unsigned int n) {
-	pthread_mutex_lock(&wg->lock);
-	wg->count += n;
-	pthread_mutex_unlock(&wg->lock);
-}
-
-void wg_sub(struct wg *wg, unsigned int n) {
-	pthread_mutex_lock(&wg->lock);
-	wg->count -= n;
-	if (wg->count == 0)
-		write(wg->fd_signal, " ", 1);
-	pthread_mutex_unlock(&wg->lock);
-}
-
-void wg_wait(struct wg *wg) {
-	char b;
- retry:
-	if (read(wg->fd_wait, &b, 1) == -1) {
-		if (errno == EINTR)
-			goto retry;
-		error(1, errno, "wg_wait");
-	}
-}
diff --git a/wg.h b/wg.h
deleted file mode 100644
index 777e8a3..0000000
--- a/wg.h
+++ /dev/null
@@ -1,19 +0,0 @@
-#pragma once
-
-#include <pthread.h>
-
-/* Thread management tools modeled on https://golang.org/pkg/sync/#WaitGroup */
-
-/* pthread_cond_t is overly complicated. Just use a self-pipe. */
-
-struct wg {
-	int count;
-	pthread_mutex_t lock;
-	int fd_wait;
-	int fd_signal;
-};
-
-void wg_init(struct wg *);
-void wg_add(struct wg *, unsigned int);
-void wg_sub(struct wg *, unsigned int);
-void wg_wait(struct wg*);