X-Git-Url: http://git.meshlink.io/?p=utcp;a=blobdiff_plain;f=stream.c;fp=stream.c;h=378809cc509865e234179df6364342387786ddda;hp=0000000000000000000000000000000000000000;hb=0c3abf9e3538c482639ed32b0e85104495db5b4f;hpb=68103ae7c369fdccd59b71afb554079d9e6c798d

diff --git a/stream.c b/stream.c
new file mode 100644
index 0000000..378809c
--- /dev/null
+++ b/stream.c
@@ -0,0 +1,156 @@
+#define _GNU_SOURCE
+
+#include <stdio.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <string.h>
+#include <getopt.h>
+#include <err.h>
+#include <time.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[]) {
+	static const struct option longopts[] = {
+		{"verify", 0, NULL, 'v'},
+		{"rate", 1, NULL, 'r'},
+		{"fps", 1, NULL, 'f'},
+		{"total", 1, NULL, 't'},
+		{NULL, 0, NULL, 0},
+	};
+
+	int opt;
+	bool verify = false;
+	float rate = 1e6;
+	float fps = 60;
+	float total = 1.0 / 0.0;
+
+	while((opt = getopt_long(argc, argv, "vr:f:t:", longopts, &optind)) != -1) {
+		switch(opt) {
+		case 'v':
+			verify = true;
+			break;
+
+		case 'r':
+			rate = atof(optarg);
+			break;
+
+		case 'f':
+			fps = atof(optarg);
+			break;
+
+		case 't':
+			total = atof(optarg);
+			break;
+
+		default:
+			fprintf(stderr, "Usage: %s [-v] [-r bitrate] [-f frames_per_second]\n", argv[0]);
+			return 1;
+		}
+	}
+
+	size_t framesize = rate / fps / 8;
+	framesize &= ~0xf;
+	long interval = 1e9 / fps;
+
+	if(!framesize || interval <= 0) {
+		err(1, "invalid parameters");
+	}
+
+	char *buf = malloc(framesize + 16);
+
+	if(!buf) {
+		err(1, "malloc(%zu)", framesize);
+	}
+
+	uint64_t counter = 0;
+	struct timespec now, next = {0};
+	clock_gettime(CLOCK_REALTIME, &now);
+
+	while(total > 0) {
+		if(!verify) {
+			size_t tosend = framesize;
+			char *p = buf;
+
+			memcpy(buf, &now, sizeof(now));
+
+			for(uint64_t *q = (uint64_t *)(buf + sizeof(now)); (char *)q < buf + framesize; q++) {
+				*q = counter++;
+			}
+
+			while(tosend) {
+				ssize_t sent = write(1, p, tosend);
+
+				if(sent <= 0) {
+					err(1, "write(1, %p, %zu)", p, tosend);
+				}
+
+				tosend -= sent;
+				p += sent;
+			}
+
+			next = now;
+			next.tv_nsec += interval;
+
+			while(next.tv_nsec >= 1000000000) {
+				next.tv_nsec -= 1000000000;
+				next.tv_sec++;
+			}
+
+			clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &next, NULL);
+			now = next;
+			total -= framesize;
+		} else {
+			struct timespec *ts = (struct timespec *)buf;
+			size_t toread = sizeof(*ts);
+			char *p = buf;
+
+			while(toread) {
+				ssize_t result = read(0, p, toread);
+
+				if(result <= 0) {
+					err(1, "read(1, %p, %zu)", p, toread);
+				}
+
+				toread -= result;
+				p += result;
+			}
+
+			clock_gettime(CLOCK_REALTIME, &now);
+
+			toread = framesize - sizeof(now);
+
+			while(toread) {
+				ssize_t result = read(0, p, toread);
+
+				if(result <= 0) {
+					err(1, "read(1, %p, %zu)", p, toread);
+				}
+
+				toread -= result;
+				p += result;
+			}
+
+			clock_gettime(CLOCK_REALTIME, &next);
+
+			for(uint64_t *q = (uint64_t *)(buf + sizeof(now)); (char *)q < buf + framesize; q++) {
+				if(*q != counter++) {
+					uint64_t offset = (counter - 1) * 8;
+					offset += ((counter * 8) / (framesize - sizeof(now))) * sizeof(now);
+					err(1, "verification failed at offset %lu", offset);
+				}
+			}
+
+			float dt1 = now.tv_sec - ts->tv_sec + 1e-9 * (now.tv_nsec - ts->tv_nsec);
+			float dt2 = next.tv_sec - now.tv_sec + 1e-9 * (next.tv_nsec - now.tv_nsec);
+
+			fprintf(stderr, "\rDelay: %8.3f ms, burst bandwidth: %8.0f Mbit/s", dt1 * 1e3, (framesize - sizeof(now)) / dt2 * 8 / 1e6);
+
+			total -= framesize;
+		}
+	}
+
+	if(verify) {
+		fprintf(stderr, "\n");
+	}
+}