avfilter/vf_framerate: change blend factor precision

This is done mainly in preparation for the SIMD patches.

- for the 8-bit input, decrease the blend factor precision to 7-bit.
- for the 16-bit input, increase the blend factor precision to 15-bit.
- make sure the blend functions are not called with 0 or maximum blending
  factors, because we don't want the signed factor integers to overflow.

Fate test changes are due to different rounding.

Signed-off-by: Marton Balint <cus@passwd.hu>

4 files changed, 109 insertions, 111 deletions

diff --git a/libavfilter/vf_framerate.c b/libavfilter/vf_framerate.c
index 2a6d692..8119fe2 100644
--- a/libavfilter/vf_framerate.c
+++ b/libavfilter/vf_framerate.c
@@ -43,7 +43,10 @@
                           const uint8_t *src2, ptrdiff_t src2_linesize, \
                           uint8_t *dst, ptrdiff_t dst_linesize, \
                           ptrdiff_t width, ptrdiff_t height, \
-                          int factor1, int factor2, int half, int shift
+                          int factor1, int factor2, int half
+
+#define BLEND_FACTOR_DEPTH8   7
+#define BLEND_FACTOR_DEPTH16 15
 
 typedef void (*blend_func)(BLEND_FUNC_PARAMS);
 
@@ -53,10 +56,8 @@ typedef struct FrameRateContext {
     AVRational dest_frame_rate;         ///< output frames per second
     int flags;                          ///< flags affecting frame rate conversion algorithm
     double scene_score;                 ///< score that denotes a scene change has happened
-    int interp_start;                   ///< start of range to apply linear interpolation (same bitdepth as input)
-    int interp_end;                     ///< end of range to apply linear interpolation (same bitdepth as input)
-    int interp_start_param;             ///< start of range to apply linear interpolation
-    int interp_end_param;               ///< end of range to apply linear interpolation
+    int interp_start;                   ///< start of range to apply linear interpolation
+    int interp_end;                     ///< end of range to apply linear interpolation
 
     int line_size[4];                   ///< bytes of pixel data per line for each plane
     int vsub;
@@ -67,7 +68,7 @@ typedef struct FrameRateContext {
     av_pixelutils_sad_fn sad;           ///< Sum of the absolute difference function (scene detect only)
     double prev_mafd;                   ///< previous MAFD                           (scene detect only)
 
-    int max;
+    int blend_factor_max;
     int bitdepth;
     AVFrame *work;
 
@@ -92,8 +93,8 @@ typedef struct FrameRateContext {
 static const AVOption framerate_options[] = {
     {"fps",                 "required output frames per second rate", OFFSET(dest_frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="50"},             0,       INT_MAX, V|F },
 
-    {"interp_start",        "point to start linear interpolation",    OFFSET(interp_start_param),AV_OPT_TYPE_INT,    {.i64=15},                 0,       255,     V|F },
-    {"interp_end",          "point to end linear interpolation",      OFFSET(interp_end_param),  AV_OPT_TYPE_INT,    {.i64=240},                0,       255,     V|F },
+    {"interp_start",        "point to start linear interpolation",    OFFSET(interp_start),    AV_OPT_TYPE_INT,      {.i64=15},                 0,       255,     V|F },
+    {"interp_end",          "point to end linear interpolation",      OFFSET(interp_end),      AV_OPT_TYPE_INT,      {.i64=240},                0,       255,     V|F },
     {"scene",               "scene change level",                     OFFSET(scene_score),     AV_OPT_TYPE_DOUBLE,   {.dbl=8.2},                0,       INT_MAX, V|F },
 
     {"flags",               "set flags",                              OFFSET(flags),           AV_OPT_TYPE_FLAGS,    {.i64=1},                  0,       INT_MAX, V|F, "flags" },
@@ -210,7 +211,7 @@ static int filter_slice(AVFilterContext *ctx, void *arg, int job, int nb_jobs)
                  cpy_src2_data, cpy_src2_line_size,
                  cpy_dst_data,  cpy_dst_line_size,
                  cpy_line_width, end - start,
-                 src1_factor, src2_factor, s->max / 2, s->bitdepth);
+                 src1_factor, src2_factor, s->blend_factor_max >> 1);
     }
 
     return 0;
@@ -235,7 +236,7 @@ static int blend_frames(AVFilterContext *ctx, int interpolate)
         td.copy_src1 = s->f0;
         td.copy_src2 = s->f1;
         td.src2_factor = interpolate;
-        td.src1_factor = s->max - td.src2_factor;
+        td.src1_factor = s->blend_factor_max - td.src2_factor;
 
         // get work-space for output frame
         s->work = ff_get_video_buffer(outlink, outlink->w, outlink->h);
@@ -255,7 +256,7 @@ static int process_work_frame(AVFilterContext *ctx)
 {
     FrameRateContext *s = ctx->priv;
     int64_t work_pts;
-    int interpolate;
+    int64_t interpolate, interpolate8;
     int ret;
 
     if (!s->f1)
@@ -274,18 +275,19 @@ static int process_work_frame(AVFilterContext *ctx)
         if (work_pts >= s->pts1 + s->delta && s->flush)
             return 0;
 
-        interpolate = av_rescale(work_pts - s->pts0, s->max, s->delta);
-        ff_dlog(ctx, "process_work_frame() interpolate:%d/%d\n", interpolate, s->max);
-        if (interpolate > s->interp_end) {
+        interpolate = av_rescale(work_pts - s->pts0, s->blend_factor_max, s->delta);
+        interpolate8 = av_rescale(work_pts - s->pts0, 256, s->delta);
+        ff_dlog(ctx, "process_work_frame() interpolate: %"PRId64"/256\n", interpolate8);
+        if (interpolate >= s->blend_factor_max || interpolate8 > s->interp_end) {
             s->work = av_frame_clone(s->f1);
-        } else if (interpolate < s->interp_start) {
+        } else if (interpolate <= 0 || interpolate8 < s->interp_start) {
             s->work = av_frame_clone(s->f0);
         } else {
             ret = blend_frames(ctx, interpolate);
             if (ret < 0)
                 return ret;
             if (ret == 0)
-                s->work = av_frame_clone(interpolate > (s->max >> 1) ? s->f1 : s->f0);
+                s->work = av_frame_clone(interpolate > (s->blend_factor_max >> 1) ? s->f1 : s->f0);
         }
     }
 
@@ -337,12 +339,8 @@ static void blend_frames_c(BLEND_FUNC_PARAMS)
 {
     int line, pixel;
     for (line = 0; line < height; line++) {
-        for (pixel = 0; pixel < width; pixel++) {
-            // integer version of (src1 * factor1) + (src2 * factor2) + 0.5
-            // 0.5 is for rounding
-            // 128 is the integer representation of 0.5 << 8
-            dst[pixel] = ((src1[pixel] * factor1) + (src2[pixel] * factor2) + 128) >> 8;
-        }
+        for (pixel = 0; pixel < width; pixel++)
+            dst[pixel] = ((src1[pixel] * factor1) + (src2[pixel] * factor2) + half) >> BLEND_FACTOR_DEPTH8;
         src1 += src1_linesize;
         src2 += src2_linesize;
         dst  += dst_linesize;
@@ -361,7 +359,7 @@ static void blend_frames16_c(BLEND_FUNC_PARAMS)
     dst_linesize /= 2;
     for (line = 0; line < height; line++) {
         for (pixel = 0; pixel < width; pixel++)
-            dstw[pixel] = ((src1w[pixel] * factor1) + (src2w[pixel] * factor2) + half) >> shift;
+            dstw[pixel] = ((src1w[pixel] * factor1) + (src2w[pixel] * factor2) + half) >> BLEND_FACTOR_DEPTH16;
         src1w += src1_linesize;
         src2w += src2_linesize;
         dstw  += dst_linesize;
@@ -382,8 +380,6 @@ static int config_input(AVFilterLink *inlink)
 
     s->bitdepth = pix_desc->comp[0].depth;
     s->vsub = pix_desc->log2_chroma_h;
-    s->interp_start = s->interp_start_param << (s->bitdepth - 8);
-    s->interp_end = s->interp_end_param << (s->bitdepth - 8);
 
     s->sad = av_pixelutils_get_sad_fn(3, 3, 2, s); // 8x8 both sources aligned
     if (!s->sad)
@@ -391,11 +387,13 @@ static int config_input(AVFilterLink *inlink)
 
     s->srce_time_base = inlink->time_base;
 
-    s->max = 1 << (s->bitdepth);
-    if (s->bitdepth == 8)
+    if (s->bitdepth == 8) {
+        s->blend_factor_max = 1 << BLEND_FACTOR_DEPTH8;
         s->blend = blend_frames_c;
-    else
+    } else {
+        s->blend_factor_max = 1 << BLEND_FACTOR_DEPTH16;
         s->blend = blend_frames16_c;
+    }
 
     return 0;
 }
diff --git a/tests/ref/fate/filter-framerate-12bit-down b/tests/ref/fate/filter-framerate-12bit-down
index 49dcb1e..25a3c0a 100644
--- a/tests/ref/fate/filter-framerate-12bit-down
+++ b/tests/ref/fate/filter-framerate-12bit-down
@@ -4,52 +4,52 @@
 #dimensions 0: 320x240
 #sar 0: 1/1
 0,          0,          0,        1,   307200, 0xb49cf016
-0,          1,          1,        1,   307200, 0xc3be6971
-0,          2,          2,        1,   307200, 0x4d458da1
-0,          3,          3,        1,   307200, 0xb49ed940
-0,          4,          4,        1,   307200, 0x1577849f
+0,          1,          1,        1,   307200, 0xbccf696d
+0,          2,          2,        1,   307200, 0x709c8dd1
+0,          3,          3,        1,   307200, 0xb948d907
+0,          4,          4,        1,   307200, 0x850f849a
 0,          5,          5,        1,   307200, 0xaf71e7fc
-0,          6,          6,        1,   307200, 0x1290a487
-0,          7,          7,        1,   307200, 0xaf0cf5ee
-0,          8,          8,        1,   307200, 0x6ffb3abb
-0,          9,          9,        1,   307200, 0x9e65597e
+0,          6,          6,        1,   307200, 0x0a1ba486
+0,          7,          7,        1,   307200, 0x0601f62a
+0,          8,          8,        1,   307200, 0x2c6d3a59
+0,          9,          9,        1,   307200, 0xed03597b
 0,         10,         10,        1,   307200, 0x9f84df5d
-0,         11,         11,        1,   307200, 0xf60b8c87
-0,         12,         12,        1,   307200, 0xe2eac3a7
-0,         13,         13,        1,   307200, 0x2c4ac771
-0,         14,         14,        1,   307200, 0xf4d9003d
+0,         11,         11,        1,   307200, 0x9fbe8c84
+0,         12,         12,        1,   307200, 0x8f7bc394
+0,         13,         13,        1,   307200, 0x5113c787
+0,         14,         14,        1,   307200, 0x41e8002f
 0,         15,         15,        1,   307200, 0xab2162fc
-0,         16,         16,        1,   307200, 0xdc90848a
-0,         17,         17,        1,   307200, 0x29f79f4b
-0,         18,         18,        1,   307200, 0x45b1e01b
-0,         19,         19,        1,   307200, 0x43baddc2
+0,         16,         16,        1,   307200, 0xbf8f847c
+0,         17,         17,        1,   307200, 0x832d9ef7
+0,         18,         18,        1,   307200, 0xd2f5e043
+0,         19,         19,        1,   307200, 0xceeaddb8
 0,         20,         20,        1,   307200, 0xf2b12fe5
-0,         21,         21,        1,   307200, 0x1de67e13
-0,         22,         22,        1,   307200, 0xfc1f7774
-0,         23,         23,        1,   307200, 0x5552e7f2
-0,         24,         24,        1,   307200, 0xb1d60366
+0,         21,         21,        1,   307200, 0xf3477e11
+0,         22,         22,        1,   307200, 0xdf387773
+0,         23,         23,        1,   307200, 0x273be7e2
+0,         24,         24,        1,   307200, 0x68cd0360
 0,         25,         25,        1,   307200, 0x4693ab03
-0,         26,         26,        1,   307200, 0x7295ef7a
-0,         27,         27,        1,   307200, 0xf442a5df
-0,         28,         28,        1,   307200, 0x01e0dbb8
-0,         29,         29,        1,   307200, 0xf10c3549
+0,         26,         26,        1,   307200, 0xe2baef73
+0,         27,         27,        1,   307200, 0x0c9fa60a
+0,         28,         28,        1,   307200, 0x6e4ddbc5
+0,         29,         29,        1,   307200, 0xd1b2353c
 0,         30,         30,        1,   307200, 0x8a512668
-0,         31,         31,        1,   307200, 0x69e7b43e
-0,         32,         32,        1,   307200, 0x6c5343ca
-0,         33,         33,        1,   307200, 0xf323456c
-0,         34,         34,        1,   307200, 0xeead5632
+0,         31,         31,        1,   307200, 0x7224b439
+0,         32,         32,        1,   307200, 0x7a9243e2
+0,         33,         33,        1,   307200, 0x9a7e4553
+0,         34,         34,        1,   307200, 0x4d795626
 0,         35,         35,        1,   307200, 0x4e24d659
-0,         36,         36,        1,   307200, 0x7a25b546
-0,         37,         37,        1,   307200, 0x9b7e8e8f
-0,         38,         38,        1,   307200, 0x9d059d4c
-0,         39,         39,        1,   307200, 0x21c4a16f
+0,         36,         36,        1,   307200, 0xa230b54b
+0,         37,         37,        1,   307200, 0x14598ea5
+0,         38,         38,        1,   307200, 0x21619cf3
+0,         39,         39,        1,   307200, 0x5220a167
 0,         40,         40,        1,   307200, 0xb6505ff0
-0,         41,         41,        1,   307200, 0x12562a42
-0,         42,         42,        1,   307200, 0x3335e451
-0,         43,         43,        1,   307200, 0x6f1274cf
-0,         44,         44,        1,   307200, 0xa52e71d2
+0,         41,         41,        1,   307200, 0x0a482a3d
+0,         42,         42,        1,   307200, 0x6bdce40c
+0,         43,         43,        1,   307200, 0x3c6074f3
+0,         44,         44,        1,   307200, 0x369c71c8
 0,         45,         45,        1,   307200, 0x4fda2634
-0,         46,         46,        1,   307200, 0x5b48d624
-0,         47,         47,        1,   307200, 0xa9505af8
-0,         48,         48,        1,   307200, 0xc2624880
-0,         49,         49,        1,   307200, 0x4eb317a5
+0,         46,         46,        1,   307200, 0x4df2d619
+0,         47,         47,        1,   307200, 0x21205aab
+0,         48,         48,        1,   307200, 0xe00f48c2
+0,         49,         49,        1,   307200, 0xe3b11798
diff --git a/tests/ref/fate/filter-framerate-12bit-up b/tests/ref/fate/filter-framerate-12bit-up
index ef709a8..15bf9be 100644
--- a/tests/ref/fate/filter-framerate-12bit-up
+++ b/tests/ref/fate/filter-framerate-12bit-up
@@ -4,62 +4,62 @@
 #dimensions 0: 320x240
 #sar 0: 1/1
 0,          0,          0,        1,   307200, 0xb49cf016
-0,          1,          1,        1,   307200, 0xbe4390ed
-0,          2,          2,        1,   307200, 0xe4ca172c
+0,          1,          1,        1,   307200, 0x95d191b2
+0,          2,          2,        1,   307200, 0x20e5173b
 0,          3,          3,        1,   307200, 0x5378b13c
-0,          4,          4,        1,   307200, 0xe742454c
-0,          5,          5,        1,   307200, 0x68f620cd
+0,          4,          4,        1,   307200, 0x3e304543
+0,          5,          5,        1,   307200, 0x2f131cdb
 0,          6,          6,        1,   307200, 0x83dbe321
-0,          7,          7,        1,   307200, 0x7135c77d
-0,          8,          8,        1,   307200, 0xc69a864a
+0,          7,          7,        1,   307200, 0xb81fc682
+0,          8,          8,        1,   307200, 0xb32a8644
 0,          9,          9,        1,   307200, 0xc5c8b0f8
-0,         10,         10,        1,   307200, 0xf6ee5d1c
-0,         11,         11,        1,   307200, 0xab36763c
+0,         10,         10,        1,   307200, 0x27945d0a
+0,         11,         11,        1,   307200, 0x444c7640
 0,         12,         12,        1,   307200, 0xcba4c6bb
-0,         13,         13,        1,   307200, 0xb379c679
-0,         14,         14,        1,   307200, 0x63339757
+0,         13,         13,        1,   307200, 0xf923c7a3
+0,         14,         14,        1,   307200, 0x88149757
 0,         15,         15,        1,   307200, 0x4bdfd3ca
-0,         16,         16,        1,   307200, 0x14e09691
-0,         17,         17,        1,   307200, 0x5dc7c711
+0,         16,         16,        1,   307200, 0x1c279695
+0,         17,         17,        1,   307200, 0x634cc809
 0,         18,         18,        1,   307200, 0xda8c6c41
-0,         19,         19,        1,   307200, 0xe187c6b6
-0,         20,         20,        1,   307200, 0x5d8b76ab
+0,         19,         19,        1,   307200, 0x2136c986
+0,         20,         20,        1,   307200, 0x457576a8
 0,         21,         21,        1,   307200, 0xe2337c57
-0,         22,         22,        1,   307200, 0x492117d7
-0,         23,         23,        1,   307200, 0xf0df5ea3
+0,         22,         22,        1,   307200, 0x8ed517c9
+0,         23,         23,        1,   307200, 0x4fd35f99
 0,         24,         24,        1,   307200, 0x4237e892
-0,         25,         25,        1,   307200, 0x4f61a7d7
-0,         26,         26,        1,   307200, 0x2ba55745
+0,         25,         25,        1,   307200, 0x1383a9d8
+0,         26,         26,        1,   307200, 0xc7195735
 0,         27,         27,        1,   307200, 0x0e058165
-0,         28,         28,        1,   307200, 0xe371f352
-0,         29,         29,        1,   307200, 0xab562bfe
+0,         28,         28,        1,   307200, 0x0b81f345
+0,         29,         29,        1,   307200, 0x2ddf2f0a
 0,         30,         30,        1,   307200, 0x0b58bcf7
-0,         31,         31,        1,   307200, 0xf1a04a1e
-0,         32,         32,        1,   307200, 0xb466f1d6
+0,         31,         31,        1,   307200, 0x1b684a1d
+0,         32,         32,        1,   307200, 0x1e44f1cf
 0,         33,         33,        1,   307200, 0x3ed6b5d8
-0,         34,         34,        1,   307200, 0x05091a43
-0,         35,         35,        1,   307200, 0xbfb20efc
+0,         34,         34,        1,   307200, 0x00881a40
+0,         35,         35,        1,   307200, 0x2c3d1406
 0,         36,         36,        1,   307200, 0xbd67248a
-0,         37,         37,        1,   307200, 0x58001b29
-0,         38,         38,        1,   307200, 0x6ec5bbb1
+0,         37,         37,        1,   307200, 0x46261913
+0,         38,         38,        1,   307200, 0xe5b2bbaa
 0,         39,         39,        1,   307200, 0x0e4455cd
-0,         40,         40,        1,   307200, 0x5c2c3213
-0,         41,         41,        1,   307200, 0x976f6900
+0,         40,         40,        1,   307200, 0xb4943212
+0,         41,         41,        1,   307200, 0xf96b6808
 0,         42,         42,        1,   307200, 0x58adad3f
-0,         43,         43,        1,   307200, 0x8dbb14f0
-0,         44,         44,        1,   307200, 0x49163226
+0,         43,         43,        1,   307200, 0x978413f0
+0,         44,         44,        1,   307200, 0x0037320a
 0,         45,         45,        1,   307200, 0xaac8e1ca
-0,         46,         46,        1,   307200, 0x07cc8404
-0,         47,         47,        1,   307200, 0xbf85c994
+0,         46,         46,        1,   307200, 0xc3578407
+0,         47,         47,        1,   307200, 0xfc29c675
 0,         48,         48,        1,   307200, 0x22ed5b5a
-0,         49,         49,        1,   307200, 0x1bf7df1e
-0,         50,         50,        1,   307200, 0x3a21b4d2
+0,         49,         49,        1,   307200, 0x6d58e21e
+0,         50,         50,        1,   307200, 0xbf62b4c3
 0,         51,         51,        1,   307200, 0xbd5edb2d
-0,         52,         52,        1,   307200, 0x336a8437
-0,         53,         53,        1,   307200, 0x02c7e528
+0,         52,         52,        1,   307200, 0x55528432
+0,         53,         53,        1,   307200, 0xa3f1e514
 0,         54,         54,        1,   307200, 0xba073e6f
-0,         55,         55,        1,   307200, 0x9e25ddfe
-0,         56,         56,        1,   307200, 0x8cf55128
+0,         55,         55,        1,   307200, 0x29b8df00
+0,         56,         56,        1,   307200, 0x1517512b
 0,         57,         57,        1,   307200, 0x4e740b42
-0,         58,         58,        1,   307200, 0x8e7e705c
+0,         58,         58,        1,   307200, 0xbd6b7053
 0,         59,         59,        1,   307200, 0xe73f29ef
diff --git a/tests/ref/fate/filter-framerate-up b/tests/ref/fate/filter-framerate-up
index 15bf6d8..a276bf6 100644
--- a/tests/ref/fate/filter-framerate-up
+++ b/tests/ref/fate/filter-framerate-up
@@ -4,12 +4,12 @@
 #dimensions 0: 320x240
 #sar 0: 1/1
 0,          0,          0,        1,   115200, 0x3744b3ed
-0,          1,          1,        1,   115200, 0xc44bdc65
+0,          1,          1,        1,   115200, 0xec1fdfa0
 0,          2,          2,        1,   115200, 0xa17f0d74
 0,          3,          3,        1,   115200, 0xd72532a9
-0,          4,          4,        1,   115200, 0x232d6368
+0,          4,          4,        1,   115200, 0x032e60f8
 0,          5,          5,        1,   115200, 0x6e318ba0
-0,          6,          6,        1,   115200, 0x247e846e
+0,          6,          6,        1,   115200, 0x76018292
 0,          7,          7,        1,   115200, 0x89e27599
 0,          8,          8,        1,   115200, 0x68536eac
-0,          9,          9,        1,   115200, 0x97e45fec
+0,          9,          9,        1,   115200, 0xc3ac62a8