diff --git a/mp4.t b/mp4.t
new file mode 100644
index 0000000..7d72822
--- /dev/null
+++ b/mp4.t
@@ -0,0 +1,116 @@
+#!/usr/bin/perl
+
+# (C) Sergey Kandaurov
+# (C) Nginx, Inc.
+
+# Tests for mp4 module.
+# Ensures that requested stream duration is given with sane accuracy.
+
+###############################################################################
+
+use warnings;
+use strict;
+
+use Test::More;
+
+BEGIN { use FindBin; chdir($FindBin::Bin); }
+
+use lib 'lib';
+use Test::Nginx;
+
+###############################################################################
+
+select STDERR; $| = 1;
+select STDOUT; $| = 1;
+
+my $t = Test::Nginx->new()->has(qw/http mp4/)->has_daemon('ffprobe ffmpeg')
+	->plan(12)->write_file_expand('nginx.conf', <<'EOF');
+
+%%TEST_GLOBALS%%
+
+daemon off;
+
+events {
+}
+
+http {
+    %%TEST_GLOBALS_HTTP%%
+
+    server {
+        listen       127.0.0.1:8080;
+        server_name  localhost;
+
+        location / {
+            mp4;
+        }
+    }
+}
+
+EOF
+
+system('ffmpeg -loglevel quiet -y '
+	. '-f lavfi -i testsrc=duration=10:size=320x200:rate=15 '
+	. '-f lavfi -i testsrc=duration=20:size=320x200:rate=15 '
+	. '-map 0:0 -map 1:0 -pix_fmt yuv420p -g 15 -c:v libx264 '
+	. "${\($t->testdir())}/test.mp4") == 0
+	or die "Can't create mp4 file: $!";
+
+$t->run();
+
+###############################################################################
+
+is(durations($t, 0.0), '10.0 20.0', 'start zero');
+is(durations($t, 2), '8.0 18.0', 'start integer');
+is(durations($t, 7.1), '2.9 12.9', 'start float');
+
+SKIP: {
+skip 'no end argument support', 7 unless $t->has_version('1.5.13');
+
+is(durations($t, 6, 9), '3.0 3.0', 'start end integer');
+is(durations($t, 2.7, 5.6), '2.9 2.9', 'start end float');
+
+is(durations($t, undef, 9), '9.0 9.0', 'end integer');
+is(durations($t, undef, 5.6), '5.6 5.6', 'end float');
+
+# invalid range results in ignoring end argument
+
+like(http_head('/test.mp4?start=1&end=1'), qr/200 OK/, 'zero range');
+like(http_head('/test.mp4?start=1&end=0'), qr/200 OK/, 'negative range');
+
+# start/end values exceeding file duration
+
+like(http_head("/test.mp4?end=11"), qr!HTTP/1.1 500!, 'end beyond EOF');
+
+}
+
+like(http_head("/test.mp4?start=21"), qr!HTTP/1.1 500!, 'start beyond EOF');
+
+# check for alerts, e.g., "zero buf in output", shouldn't be any
+
+like(`grep -F '[alert]' ${\($t->testdir())}/error.log`, qr/^$/s, 'no alerts');
+
+###############################################################################
+
+sub durations {
+	my ($t, $start, $end) = @_;
+	my $path = $t->{_testdir} . '/frag.mp4';
+
+	my $uri = '/test.mp4';
+	if (defined $start) {
+		$uri .= "?start=$start";
+		if (defined $end) {
+			$uri .= "&end=$end";
+		}
+
+	} elsif (defined $end) {
+		$uri .= "?end=$end";
+	}
+
+	$t->write_file('frag.mp4', Test::Nginx::http_content(http_get($uri)));
+
+	my $r = `ffprobe -show_streams $path 2>/dev/null`;
+	Test::Nginx::log_core('||', $r);
+	sprintf "%.1f %.1f", $r =~ /duration=(\d+\.\d+)/g;
+}
+
+###############################################################################