diff --git a/tests/checkasm/Makefile b/tests/checkasm/Makefile
index f768b1144e..7133a6ee66 100644
--- a/tests/checkasm/Makefile
+++ b/tests/checkasm/Makefile
@@ -11,6 +11,7 @@ AVCODECOBJS-$(CONFIG_H264PRED)          += h264pred.o
 AVCODECOBJS-$(CONFIG_H264QPEL)          += h264qpel.o
 AVCODECOBJS-$(CONFIG_LLVIDDSP)          += llviddsp.o
 AVCODECOBJS-$(CONFIG_LLVIDENCDSP)       += llviddspenc.o
+AVCODECOBJS-$(CONFIG_VC1DSP)            += vc1dsp.o
 AVCODECOBJS-$(CONFIG_VP8DSP)            += vp8dsp.o
 AVCODECOBJS-$(CONFIG_VIDEODSP)          += videodsp.o
 
diff --git a/tests/checkasm/checkasm.c b/tests/checkasm/checkasm.c
index 748d6a9f3a..c2efd81b6d 100644
--- a/tests/checkasm/checkasm.c
+++ b/tests/checkasm/checkasm.c
@@ -147,6 +147,9 @@ static const struct {
     #if CONFIG_V210_ENCODER
         { "v210enc", checkasm_check_v210enc },
     #endif
+    #if CONFIG_VC1DSP
+        { "vc1dsp", checkasm_check_vc1dsp },
+    #endif
     #if CONFIG_VP8DSP
         { "vp8dsp", checkasm_check_vp8dsp },
     #endif
diff --git a/tests/checkasm/checkasm.h b/tests/checkasm/checkasm.h
index c3192d8c23..52ab18a5b1 100644
--- a/tests/checkasm/checkasm.h
+++ b/tests/checkasm/checkasm.h
@@ -78,6 +78,7 @@ void checkasm_check_sw_scale(void);
 void checkasm_check_utvideodsp(void);
 void checkasm_check_v210dec(void);
 void checkasm_check_v210enc(void);
+void checkasm_check_vc1dsp(void);
 void checkasm_check_vf_eq(void);
 void checkasm_check_vf_gblur(void);
 void checkasm_check_vf_hflip(void);
diff --git a/tests/checkasm/vc1dsp.c b/tests/checkasm/vc1dsp.c
new file mode 100644
index 0000000000..2fd6c74d6c
--- /dev/null
+++ b/tests/checkasm/vc1dsp.c
@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) 2022 Ben Avison
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <string.h>
+
+#include "checkasm.h"
+
+#include "libavcodec/vc1dsp.h"
+
+#include "libavutil/common.h"
+#include "libavutil/internal.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/mem_internal.h"
+
+#define VC1DSP_TEST(func) { #func, offsetof(VC1DSPContext, func) },
+
+typedef struct {
+    const char *name;
+    size_t offset;
+} test;
+
+#define RANDOMIZE_BUFFER8_MID_WEIGHTED(name, size)  \
+    do {                                            \
+        uint8_t *p##0 = name##0, *p##1 = name##1;   \
+        int i = (size);                             \
+        while (i-- > 0) {                           \
+            int x = 0x80 | (rnd() & 0x7F);          \
+            x >>= rnd() % 9;                        \
+            if (rnd() & 1)                          \
+                x = -x;                             \
+            *p##1++ = *p##0++ = 0x80 + x;           \
+        }                                           \
+    } while (0)
+
+static void check_loop_filter(void)
+{
+    /* Deblocking filter buffers are big enough to hold a 16x16 block,
+     * plus 16 columns left and 4 rows above to hold filter inputs
+     * (depending on whether v or h neighbouring block edge, oversized
+     * horizontally to maintain 16-byte alignment) plus 16 columns and
+     * 4 rows below to catch write overflows */
+    LOCAL_ALIGNED_16(uint8_t, filter_buf0, [24 * 48]);
+    LOCAL_ALIGNED_16(uint8_t, filter_buf1, [24 * 48]);
+
+    VC1DSPContext h;
+
+    const test tests[] = {
+        VC1DSP_TEST(vc1_v_loop_filter4)
+        VC1DSP_TEST(vc1_h_loop_filter4)
+        VC1DSP_TEST(vc1_v_loop_filter8)
+        VC1DSP_TEST(vc1_h_loop_filter8)
+        VC1DSP_TEST(vc1_v_loop_filter16)
+        VC1DSP_TEST(vc1_h_loop_filter16)
+    };
+
+    ff_vc1dsp_init(&h);
+
+    for (size_t t = 0; t < FF_ARRAY_ELEMS(tests); ++t) {
+        void (*func)(uint8_t *, ptrdiff_t, int) = *(void **)((intptr_t) &h + tests[t].offset);
+        declare_func_emms(AV_CPU_FLAG_MMX, void, uint8_t *, ptrdiff_t, int);
+        if (check_func(func, "vc1dsp.%s", tests[t].name)) {
+            for (int count = 1000; count > 0; --count) {
+                int pq = rnd() % 31 + 1;
+                RANDOMIZE_BUFFER8_MID_WEIGHTED(filter_buf, 24 * 48);
+                call_ref(filter_buf0 + 4 * 48 + 16, 48, pq);
+                call_new(filter_buf1 + 4 * 48 + 16, 48, pq);
+                if (memcmp(filter_buf0, filter_buf1, 24 * 48))
+                    fail();
+            }
+        }
+        for (int j = 0; j < 24; ++j)
+            for (int i = 0; i < 48; ++i)
+                filter_buf1[j * 48 + i] = 0x60 + 0x40 * (i >= 16 && j >= 4);
+        if (check_func(func, "vc1dsp.%s_bestcase", tests[t].name))
+            bench_new(filter_buf1 + 4 * 48 + 16, 48, 1);
+        if (check_func(func, "vc1dsp.%s_worstcase", tests[t].name))
+            bench_new(filter_buf1 + 4 * 48 + 16, 48, 31);
+    }
+}
+
+void checkasm_check_vc1dsp(void)
+{
+    check_loop_filter();
+    report("loop_filter");
+}
diff --git a/tests/fate/checkasm.mak b/tests/fate/checkasm.mak
index 6db8f09d12..99e6bb13c4 100644
--- a/tests/fate/checkasm.mak
+++ b/tests/fate/checkasm.mak
@@ -32,6 +32,7 @@ FATE_CHECKASM = fate-checkasm-aacpsdsp                                  \
                 fate-checkasm-utvideodsp                                \
                 fate-checkasm-v210dec                                   \
                 fate-checkasm-v210enc                                   \
+                fate-checkasm-vc1dsp                                    \
                 fate-checkasm-vf_blend                                  \
                 fate-checkasm-vf_colorspace                             \
                 fate-checkasm-vf_eq                                     \