i965_encoder: consistently represent framerate as a fraction

Update references in both H.264 encoders (gen6_mfc and gen9_vdenc).

Signed-off-by: Mark Thompson <sw@jkqxz.net>
Reviewed-by: Xiang, Haihao<haihao.xiang@intel.com>

5 files changed, 65 insertions, 33 deletions

diff --git a/src/gen6_mfc_common.c b/src/gen6_mfc_common.c
index 68d030e..15c0637 100644
--- a/src/gen6_mfc_common.c
+++ b/src/gen6_mfc_common.c
@@ -119,16 +119,19 @@ static void intel_mfc_brc_init(struct encode_state *encode_state,
 
         if (i == 0) {
             bitrate = encoder_context->brc.bits_per_second[0];
-            framerate = (double)encoder_context->brc.framerate_per_100s[0] / 100.0;
+            framerate = (double)encoder_context->brc.framerate[0].num / (double)encoder_context->brc.framerate[0].den;
         } else {
             bitrate = (encoder_context->brc.bits_per_second[i] - encoder_context->brc.bits_per_second[i - 1]);
-            framerate = (double)(encoder_context->brc.framerate_per_100s[i] - encoder_context->brc.framerate_per_100s[i - 1]) / 100.0;
+            framerate = ((double)encoder_context->brc.framerate[i].num / (double)encoder_context->brc.framerate[i].den) -
+                ((double)encoder_context->brc.framerate[i - 1].num / (double)encoder_context->brc.framerate[i - 1].den);
         }
 
         if (i == encoder_context->layer.num_layers - 1)
             factor = 1.0;
-        else
-            factor = (double)encoder_context->brc.framerate_per_100s[i] / encoder_context->brc.framerate_per_100s[encoder_context->layer.num_layers - 1];
+        else {
+            factor = ((double)encoder_context->brc.framerate[i].num / (double)encoder_context->brc.framerate[i].den) /
+                ((double)encoder_context->brc.framerate[i - 1].num / (double)encoder_context->brc.framerate[i - 1].den);
+        }
 
         hrd_factor = (double)bitrate / encoder_context->brc.bits_per_second[encoder_context->layer.num_layers - 1];
 
diff --git a/src/gen9_vdenc.c b/src/gen9_vdenc.c
index 8009b31..691faec 100644
--- a/src/gen9_vdenc.c
+++ b/src/gen9_vdenc.c
@@ -851,7 +851,7 @@ gen9_vdenc_update_misc_parameters(VADriverContextP ctx,
     if (vdenc_context->internal_rate_mode != I965_BRC_CQP &&
         encoder_context->brc.need_reset) {
         /* So far, vdenc doesn't support temporal layer */
-        vdenc_context->frames_per_100s = encoder_context->brc.framerate_per_100s[0];
+        vdenc_context->framerate = encoder_context->brc.framerate[0];
 
         vdenc_context->vbv_buffer_size_in_bit = encoder_context->brc.hrd_buffer_size;
         vdenc_context->init_vbv_buffer_fullness_in_bit = encoder_context->brc.hrd_initial_buffer_fullness;
@@ -927,7 +927,8 @@ gen9_vdenc_update_parameters(VADriverContextP ctx,
          !vdenc_context->vbv_buffer_size_in_bit ||
          !vdenc_context->max_bit_rate ||
          !vdenc_context->target_bit_rate ||
-         !vdenc_context->frames_per_100s))
+         !vdenc_context->framerate.num ||
+         !vdenc_context->framerate.den))
         vdenc_context->brc_enabled = 0;
 
     if (!vdenc_context->brc_enabled) {
@@ -1565,7 +1566,8 @@ gen9_vdenc_get_profile_level_max_frame(VADriverContextP ctx,
         tmpf = max_mbps / 172.0;
 
     max_byte_per_frame0 = (uint64_t)(tmpf * bits_per_mb);
-    max_byte_per_frame1 = (uint64_t)(((double)max_mbps * 100) / vdenc_context->frames_per_100s *bits_per_mb);
+    max_byte_per_frame1 = (uint64_t)(((double)max_mbps * vdenc_context->framerate.den) /
+                                     (double)vdenc_context->framerate.num * bits_per_mb);
 
     /* TODO: check VAEncMiscParameterTypeMaxFrameSize */
     ret = (unsigned int)MIN(max_byte_per_frame0, max_byte_per_frame1);
@@ -1586,12 +1588,12 @@ gen9_vdenc_calculate_initial_qp(VADriverContextP ctx,
 
     frame_size = (vdenc_context->frame_width * vdenc_context->frame_height * 3 / 2);
     qp = (int)(1.0 / 1.2 * pow(10.0,
-                               (log10(frame_size * 2.0 / 3.0 * ((float)vdenc_context->frames_per_100s) /
-                                      ((float)(vdenc_context->target_bit_rate * 1000) * 100)) - x0) *
+                               (log10(frame_size * 2.0 / 3.0 * vdenc_context->framerate.num /
+                                      ((double)vdenc_context->target_bit_rate * 1000.0 * vdenc_context->framerate.den)) - x0) *
                                (y1 - y0) / (x1 - x0) + y0) + 0.5);
     qp += 2;
-    delat_qp = (int)(9 - (vdenc_context->vbv_buffer_size_in_bit * ((float)vdenc_context->frames_per_100s) /
-                          ((float)(vdenc_context->target_bit_rate * 1000) * 100)));
+    delat_qp = (int)(9 - (vdenc_context->vbv_buffer_size_in_bit * ((double)vdenc_context->framerate.num) /
+                          ((double)vdenc_context->target_bit_rate * 1000.0 * vdenc_context->framerate.den)));
     if (delat_qp > 0)
         qp += delat_qp;
 
@@ -1615,7 +1617,8 @@ gen9_vdenc_update_huc_brc_init_dmem(VADriverContextP ctx,
     double input_bits_per_frame, bps_ratio;
     int i;
 
-    vdenc_context->brc_init_reset_input_bits_per_frame = ((double)(vdenc_context->max_bit_rate * 1000) * 100) / vdenc_context->frames_per_100s;
+    vdenc_context->brc_init_reset_input_bits_per_frame =
+        ((double)vdenc_context->max_bit_rate * 1000.0 * vdenc_context->framerate.den) / vdenc_context->framerate.num;
     vdenc_context->brc_init_current_target_buf_full_in_bits = vdenc_context->brc_init_reset_input_bits_per_frame;
     vdenc_context->brc_target_size = vdenc_context->init_vbv_buffer_fullness_in_bit;
 
@@ -1645,8 +1648,8 @@ gen9_vdenc_update_huc_brc_init_dmem(VADriverContextP ctx,
     else if (vdenc_context->internal_rate_mode == I965_BRC_VBR)
         dmem->brc_flag |= 0x20;
 
-    dmem->frame_rate_m = vdenc_context->frames_per_100s;
-    dmem->frame_rate_d = 100;
+    dmem->frame_rate_m = vdenc_context->framerate.num;
+    dmem->frame_rate_d = vdenc_context->framerate.den;
 
     dmem->profile_level_max_frame = gen9_vdenc_get_profile_level_max_frame(ctx, encoder_context, seq_param->level_idc);
 
@@ -1656,8 +1659,9 @@ gen9_vdenc_update_huc_brc_init_dmem(VADriverContextP ctx,
     dmem->min_qp = 10;
     dmem->max_qp = 51;
 
-    input_bits_per_frame = ((double)vdenc_context->max_bit_rate * 1000 * 100) / vdenc_context->frames_per_100s;
-    bps_ratio = input_bits_per_frame / ((double)vdenc_context->vbv_buffer_size_in_bit * 100 / vdenc_context->frames_per_100s);
+    input_bits_per_frame = ((double)vdenc_context->max_bit_rate * 1000.0 * vdenc_context->framerate.den) / vdenc_context->framerate.num;
+    bps_ratio = input_bits_per_frame /
+        ((double)vdenc_context->vbv_buffer_size_in_bit * vdenc_context->framerate.den / vdenc_context->framerate.num);
 
     if (bps_ratio < 0.1)
         bps_ratio = 0.1;
diff --git a/src/gen9_vdenc.h b/src/gen9_vdenc.h
index e790497..41e4362 100644
--- a/src/gen9_vdenc.h
+++ b/src/gen9_vdenc.h
@@ -741,7 +741,7 @@ struct gen9_vdenc_context
     uint32_t    min_bit_rate;           /* in kbps */
     uint64_t    init_vbv_buffer_fullness_in_bit;
     uint64_t    vbv_buffer_size_in_bit;
-    uint32_t    frames_per_100s;
+    struct intel_fraction framerate;
     uint32_t    gop_size;
     uint32_t    ref_dist;
     uint32_t    brc_target_size;
diff --git a/src/i965_encoder.c b/src/i965_encoder.c
index d874322..3aaac34 100644
--- a/src/i965_encoder.c
+++ b/src/i965_encoder.c
@@ -42,6 +42,17 @@
 
 #include "i965_post_processing.h"
 
+static struct intel_fraction
+reduce_fraction(struct intel_fraction f)
+{
+    unsigned int a = f.num, b = f.den, c;
+    while ((c = a % b)) {
+        a = b;
+        b = c;
+    }
+    return (struct intel_fraction) { f.num / b, f.den / b };
+}
+
 static VAStatus
 clear_border(struct object_surface *obj_surface)
 {
@@ -306,8 +317,9 @@ intel_encoder_check_brc_h264_sequence_parameter(VADriverContextP ctx,
                                                 struct intel_encoder_context *encoder_context)
 {
     VAEncSequenceParameterBufferH264 *seq_param = (VAEncSequenceParameterBufferH264 *)encode_state->seq_param_ext->buffer;
+    struct intel_fraction framerate;
+    unsigned int bits_per_second;
     unsigned short num_pframes_in_gop, num_bframes_in_gop;
-    unsigned int bits_per_second, framerate_per_100s;
 
     if (!encoder_context->is_new_sequence)
         return VA_STATUS_SUCCESS;
@@ -315,10 +327,13 @@ intel_encoder_check_brc_h264_sequence_parameter(VADriverContextP ctx,
     assert(seq_param);
     bits_per_second = seq_param->bits_per_second; // for the highest layer
 
-    if (!seq_param->num_units_in_tick || !seq_param->time_scale)
-        framerate_per_100s = 3000;
-    else
-        framerate_per_100s = seq_param->time_scale * 100 / (2 * seq_param->num_units_in_tick); // for the highest layer
+    if (!seq_param->num_units_in_tick || !seq_param->time_scale) {
+        framerate = (struct intel_fraction) { 30, 1 };
+    } else {
+        // for the highest layer
+        framerate = (struct intel_fraction) { seq_param->time_scale, 2 * seq_param->num_units_in_tick };
+    }
+    framerate = reduce_fraction(framerate);
 
     encoder_context->brc.num_iframes_in_gop = 1; // Always 1
 
@@ -326,7 +341,7 @@ intel_encoder_check_brc_h264_sequence_parameter(VADriverContextP ctx,
         if (seq_param->ip_period == 0)
             goto error;
 
-        encoder_context->brc.gop_size = (unsigned int)(framerate_per_100s / 100.0 + 0.5); // fake
+        encoder_context->brc.gop_size = (framerate.num + framerate.den - 1) / framerate.den; // fake
         num_pframes_in_gop = (encoder_context->brc.gop_size +
                               seq_param->ip_period - 1) / seq_param->ip_period - 1;
     } else if (seq_param->intra_period == 1) { // E.g. IDRIII...
@@ -347,11 +362,12 @@ intel_encoder_check_brc_h264_sequence_parameter(VADriverContextP ctx,
     if (num_pframes_in_gop != encoder_context->brc.num_pframes_in_gop ||
         num_bframes_in_gop != encoder_context->brc.num_bframes_in_gop ||
         bits_per_second != encoder_context->brc.bits_per_second[encoder_context->layer.num_layers - 1] ||
-        framerate_per_100s != encoder_context->brc.framerate_per_100s[encoder_context->layer.num_layers - 1]) {
+        framerate.num != encoder_context->brc.framerate[encoder_context->layer.num_layers - 1].num ||
+        framerate.den != encoder_context->brc.framerate[encoder_context->layer.num_layers - 1].den) {
         encoder_context->brc.num_pframes_in_gop = num_pframes_in_gop;
         encoder_context->brc.num_bframes_in_gop = num_bframes_in_gop;
         encoder_context->brc.bits_per_second[encoder_context->layer.num_layers - 1] = bits_per_second;
-        encoder_context->brc.framerate_per_100s[encoder_context->layer.num_layers - 1] = framerate_per_100s;
+        encoder_context->brc.framerate[encoder_context->layer.num_layers - 1] = framerate;
         encoder_context->brc.need_reset = 1;
     }
 
@@ -392,8 +408,9 @@ intel_encoder_check_brc_vp8_sequence_parameter(VADriverContextP ctx,
     num_pframes_in_gop = encoder_context->brc.gop_size - 1;
     bits_per_second = seq_param->bits_per_second;       // for the highest layer
 
-    if (!encoder_context->brc.framerate_per_100s[encoder_context->layer.num_layers - 1]) {
-        encoder_context->brc.framerate_per_100s[encoder_context->layer.num_layers - 1] = 3000;  // for the highest layer
+    if (!encoder_context->brc.framerate[encoder_context->layer.num_layers - 1].num) {
+        // for the highest layer
+        encoder_context->brc.framerate[encoder_context->layer.num_layers - 1] = (struct intel_fraction) { 30, 1 };
         encoder_context->brc.need_reset = 1;
     }
 
@@ -480,7 +497,7 @@ intel_encoder_check_framerate_parameter(VADriverContextP ctx,
                                         struct intel_encoder_context *encoder_context,
                                         VAEncMiscParameterFrameRate *misc)
 {
-    int framerate_per_100s;
+    struct intel_fraction framerate;
     int temporal_id = 0;
 
     if (encoder_context->layer.num_layers >= 2)
@@ -490,12 +507,14 @@ intel_encoder_check_framerate_parameter(VADriverContextP ctx,
         return;
 
     if (misc->framerate & 0xffff0000)
-        framerate_per_100s = (misc->framerate & 0xffff) * 100 / ((misc->framerate >> 16) & 0xffff);
+        framerate = (struct intel_fraction) { misc->framerate & 0xffff, misc->framerate >> 16 & 0xffff };
     else
-        framerate_per_100s = misc->framerate * 100;
+        framerate = (struct intel_fraction) { misc->framerate, 1 };
+    framerate = reduce_fraction(framerate);
 
-    if (encoder_context->brc.framerate_per_100s[temporal_id] != framerate_per_100s) {
-        encoder_context->brc.framerate_per_100s[temporal_id] = framerate_per_100s;
+    if (encoder_context->brc.framerate[temporal_id].num != framerate.num ||
+        encoder_context->brc.framerate[temporal_id].den != framerate.den) {
+        encoder_context->brc.framerate[temporal_id] = framerate;
         encoder_context->brc.need_reset = 1;
     }
 }
diff --git a/src/i965_encoder.h b/src/i965_encoder.h
index 0b636d6..7016975 100644
--- a/src/i965_encoder.h
+++ b/src/i965_encoder.h
@@ -55,6 +55,12 @@ struct intel_roi
     char  value;
 };
 
+struct intel_fraction
+{
+    unsigned int num;
+    unsigned int den;
+};
+
 struct intel_encoder_context
 {
     struct hw_context base;
@@ -80,7 +86,7 @@ struct intel_encoder_context
         unsigned short num_pframes_in_gop;
         unsigned short num_bframes_in_gop;
         unsigned int bits_per_second[MAX_TEMPORAL_LAYERS];
-        unsigned int framerate_per_100s[MAX_TEMPORAL_LAYERS];
+        struct intel_fraction framerate[MAX_TEMPORAL_LAYERS];
         unsigned int mb_rate_control[MAX_TEMPORAL_LAYERS];
         unsigned int target_percentage[MAX_TEMPORAL_LAYERS];
         unsigned int hrd_buffer_size;