CI: Add tests for negative stride

3 files changed, 55 insertions, 1 deletions

diff --git a/tools/dav1d.c b/tools/dav1d.c
index bb1f4fd..5087180 100644
--- a/tools/dav1d.c
+++ b/tools/dav1d.c
@@ -29,6 +29,7 @@
 #include "vcs_version.h"
 #include "cli_config.h"
 
+#include <assert.h>
 #include <errno.h>
 #include <inttypes.h>
 #include <math.h>
@@ -139,6 +140,47 @@ static void print_stats(const int istty, const unsigned n, const unsigned num,
     fputs(buf, stderr);
 }
 
+static int picture_alloc(Dav1dPicture *const p, void *const _) {
+    const int hbd = p->p.bpc > 8;
+    const int aligned_w = (p->p.w + 127) & ~127;
+    const int aligned_h = (p->p.h + 127) & ~127;
+    const int has_chroma = p->p.layout != DAV1D_PIXEL_LAYOUT_I400;
+    const int ss_ver = p->p.layout == DAV1D_PIXEL_LAYOUT_I420;
+    const int ss_hor = p->p.layout != DAV1D_PIXEL_LAYOUT_I444;
+    ptrdiff_t y_stride = aligned_w << hbd;
+    ptrdiff_t uv_stride = has_chroma ? y_stride >> ss_hor : 0;
+    /* Due to how mapping of addresses to sets works in most L1 and L2 cache
+     * implementations, strides of multiples of certain power-of-two numbers
+     * may cause multiple rows of the same superblock to map to the same set,
+     * causing evictions of previous rows resulting in a reduction in cache
+     * hit rate. Avoid that by slightly padding the stride when necessary. */
+    if (!(y_stride & 1023))
+        y_stride += DAV1D_PICTURE_ALIGNMENT;
+    if (!(uv_stride & 1023) && has_chroma)
+        uv_stride += DAV1D_PICTURE_ALIGNMENT;
+    p->stride[0] = -y_stride;
+    p->stride[1] = -uv_stride;
+    const size_t y_sz = y_stride * aligned_h;
+    const size_t uv_sz = uv_stride * (aligned_h >> ss_ver);
+    const size_t pic_size = y_sz + 2 * uv_sz;
+
+    uint8_t *const buf = malloc(pic_size + DAV1D_PICTURE_ALIGNMENT * 2);
+    if (!buf) return DAV1D_ERR(ENOMEM);
+    p->allocator_data = buf;
+
+    const ptrdiff_t align_m1 = DAV1D_PICTURE_ALIGNMENT - 1;
+    uint8_t *const data = (uint8_t *)(((ptrdiff_t)buf + align_m1) & ~align_m1);
+    p->data[0] = data + y_sz - y_stride;
+    p->data[1] = has_chroma ? data + y_sz + uv_sz * 1 - uv_stride : NULL;
+    p->data[2] = has_chroma ? data + y_sz + uv_sz * 2 - uv_stride : NULL;
+
+    return 0;
+}
+
+static void picture_release(Dav1dPicture *const p, void *const _) {
+    free(p->allocator_data);
+}
+
 int main(const int argc, char *const *const argv) {
     const int istty = isatty(fileno(stderr));
     int res = 0;
@@ -162,6 +204,10 @@ int main(const int argc, char *const *const argv) {
     }
 
     parse(argc, argv, &cli_settings, &lib_settings);
+    if (cli_settings.neg_stride) {
+        lib_settings.allocator.alloc_picture_callback = picture_alloc;
+        lib_settings.allocator.release_picture_callback = picture_release;
+    }
 
     if ((res = input_open(&in, cli_settings.demuxer,
                           cli_settings.inputfile,
diff --git a/tools/dav1d_cli_parse.c b/tools/dav1d_cli_parse.c
index ab38400..7b24aa4 100644
--- a/tools/dav1d_cli_parse.c
+++ b/tools/dav1d_cli_parse.c
@@ -58,6 +58,7 @@ enum {
     ARG_ALL_LAYERS,
     ARG_SIZE_LIMIT,
     ARG_CPU_MASK,
+    ARG_NEG_STRIDE,
 };
 
 static const struct option long_opts[] = {
@@ -80,6 +81,7 @@ static const struct option long_opts[] = {
     { "alllayers",      1, NULL, ARG_ALL_LAYERS },
     { "sizelimit",      1, NULL, ARG_SIZE_LIMIT },
     { "cpumask",        1, NULL, ARG_CPU_MASK },
+    { "negstride",      0, NULL, ARG_NEG_STRIDE },
     { NULL,             0, NULL, 0 },
 };
 
@@ -130,7 +132,9 @@ static void usage(const char *const app, const char *const reason, ...) {
             " --alllayers $num:     output all spatial layers of a scalable AV1 bitstream (default: 1)\n"
             " --sizelimit $num:     stop decoding if the frame size exceeds the specified limit\n"
             " --verify $md5:        verify decoded md5. implies --muxer md5, no output\n"
-            " --cpumask $mask:      restrict permitted CPU instruction sets (0" ALLOWED_CPU_MASKS "; default: -1)\n");
+            " --cpumask $mask:      restrict permitted CPU instruction sets (0" ALLOWED_CPU_MASKS "; default: -1)\n"
+            " --negstride:          use negative picture strides\n"
+            "                       this is mostly meant as a developer option\n");
     exit(1);
 }
 
@@ -338,6 +342,9 @@ void parse(const int argc, char *const *const argv,
             dav1d_set_cpu_flags_mask(parse_enum(optarg, cpu_mask_tbl, ARRAY_SIZE(cpu_mask_tbl),
                                                 ARG_CPU_MASK, argv[0]));
             break;
+        case ARG_NEG_STRIDE:
+            cli_settings->neg_stride = 1;
+            break;
         default:
             usage(argv[0], NULL);
         }
diff --git a/tools/dav1d_cli_parse.h b/tools/dav1d_cli_parse.h
index 11e88e1..50cfeb8 100644
--- a/tools/dav1d_cli_parse.h
+++ b/tools/dav1d_cli_parse.h
@@ -46,6 +46,7 @@ typedef struct {
     } realtime;
     double realtime_fps;
     unsigned realtime_cache;
+    int neg_stride;
 } CLISettings;
 
 void parse(const int argc, char *const *const argv,