diff --git a/libavcodec/proresenc_kostya.c b/libavcodec/proresenc_kostya.c
index 06d5aa31e8..81f3865ea6 100644
--- a/libavcodec/proresenc_kostya.c
+++ b/libavcodec/proresenc_kostya.c
@@ -51,9 +51,11 @@ enum {
 
 enum {
     QUANT_MAT_PROXY = 0,
+    QUANT_MAT_PROXY_CHROMA,
     QUANT_MAT_LT,
     QUANT_MAT_STANDARD,
     QUANT_MAT_HQ,
+    QUANT_MAT_XQ_LUMA,
     QUANT_MAT_DEFAULT,
 };
 
@@ -68,6 +70,16 @@ static const uint8_t prores_quant_matrices[][64] = {
         13, 63, 63, 63, 63, 63, 63, 63,
         63, 63, 63, 63, 63, 63, 63, 63,
     },
+    { // proxy chromas
+        4,  7,  9, 11, 13, 14, 63, 63,
+        7,  7, 11, 12, 14, 63, 63, 63,
+        9, 11, 13, 14, 63, 63, 63, 63,
+        11, 11, 13, 14, 63, 63, 63, 63,
+        11, 13, 14, 63, 63, 63, 63, 63,
+        13, 14, 63, 63, 63, 63, 63, 63,
+        13, 63, 63, 63, 63, 63, 63, 63,
+        63, 63, 63, 63, 63, 63, 63, 63
+    },
     { // LT
          4,  5,  6,  7,  9, 11, 13, 15,
          5,  5,  7,  8, 11, 13, 15, 17,
@@ -98,6 +110,16 @@ static const uint8_t prores_quant_matrices[][64] = {
          4,  4,  4,  4,  5,  5,  6,  7,
          4,  4,  4,  4,  5,  6,  7,  7,
     },
+    { // XQ luma
+        2,  2,  2,  2,  2,  2,  2,  2,
+        2,  2,  2,  2,  2,  2,  2,  2,
+        2,  2,  2,  2,  2,  2,  2,  2,
+        2,  2,  2,  2,  2,  2,  2,  3,
+        2,  2,  2,  2,  2,  2,  3,  3,
+        2,  2,  2,  2,  2,  3,  3,  3,
+        2,  2,  2,  2,  3,  3,  3,  4,
+        2,  2,  2,  2,  3,  3,  4,  4,
+    },
     { // codec default
          4,  4,  4,  4,  4,  4,  4,  4,
          4,  4,  4,  4,  4,  4,  4,  4,
@@ -125,6 +147,7 @@ static const struct prores_profile {
     int         max_quant;
     int         br_tab[NUM_MB_LIMITS];
     int         quant;
+    int         quant_chroma;
 } prores_profile_info[6] = {
     {
         .full_name = "proxy",
@@ -133,6 +156,7 @@ static const struct prores_profile {
         .max_quant = 8,
         .br_tab    = { 300, 242, 220, 194 },
         .quant     = QUANT_MAT_PROXY,
+        .quant_chroma = QUANT_MAT_PROXY_CHROMA,
     },
     {
         .full_name = "LT",
@@ -141,6 +165,7 @@ static const struct prores_profile {
         .max_quant = 9,
         .br_tab    = { 720, 560, 490, 440 },
         .quant     = QUANT_MAT_LT,
+        .quant_chroma = QUANT_MAT_LT,
     },
     {
         .full_name = "standard",
@@ -149,6 +174,7 @@ static const struct prores_profile {
         .max_quant = 6,
         .br_tab    = { 1050, 808, 710, 632 },
         .quant     = QUANT_MAT_STANDARD,
+        .quant_chroma = QUANT_MAT_STANDARD,
     },
     {
         .full_name = "high quality",
@@ -157,6 +183,7 @@ static const struct prores_profile {
         .max_quant = 6,
         .br_tab    = { 1566, 1216, 1070, 950 },
         .quant     = QUANT_MAT_HQ,
+        .quant_chroma = QUANT_MAT_HQ,
     },
     {
         .full_name = "4444",
@@ -165,6 +192,7 @@ static const struct prores_profile {
         .max_quant = 6,
         .br_tab    = { 2350, 1828, 1600, 1425 },
         .quant     = QUANT_MAT_HQ,
+        .quant_chroma = QUANT_MAT_HQ,
     },
     {
         .full_name = "4444XQ",
@@ -172,7 +200,8 @@ static const struct prores_profile {
         .min_quant = 1,
         .max_quant = 6,
         .br_tab    = { 3525, 2742, 2400, 2137 },
-        .quant     = QUANT_MAT_HQ,
+        .quant     = QUANT_MAT_HQ, /* Fix me : use QUANT_MAT_XQ_LUMA */
+        .quant_chroma = QUANT_MAT_HQ,
     }
 };
 
@@ -200,8 +229,10 @@ typedef struct ProresContext {
     DECLARE_ALIGNED(16, int16_t, blocks)[MAX_PLANES][64 * 4 * MAX_MBS_PER_SLICE];
     DECLARE_ALIGNED(16, uint16_t, emu_buf)[16*16];
     int16_t quants[MAX_STORED_Q][64];
+    int16_t quants_chroma[MAX_STORED_Q][64];
     int16_t custom_q[64];
     const uint8_t *quant_mat;
+    const uint8_t *quant_chroma_mat;
     const uint8_t *scantable;
 
     void (*fdct)(FDCTDSPContext *fdsp, const uint16_t *src,
@@ -527,6 +558,7 @@ static int encode_slice(AVCodecContext *avctx, const AVFrame *pic,
     ptrdiff_t linesize;
     int plane_factor, is_chroma;
     uint16_t *qmat;
+    uint16_t *qmat_chroma;
 
     if (ctx->pictures_per_frame == 1)
         line_add = 0;
@@ -535,12 +567,17 @@ static int encode_slice(AVCodecContext *avctx, const AVFrame *pic,
 
     if (ctx->force_quant) {
         qmat = ctx->quants[0];
+        qmat_chroma = ctx->quants_chroma[0];
     } else if (quant < MAX_STORED_Q) {
         qmat = ctx->quants[quant];
+        qmat_chroma = ctx->quants_chroma[quant];
     } else {
         qmat = ctx->custom_q;
-        for (i = 0; i < 64; i++)
+        qmat_chroma = ctx->custom_q;
+        for (i = 0; i < 64; i++) {
             qmat[i] = ctx->quant_mat[i] * quant;
+            qmat_chroma[i] = ctx->quant_chroma_mat[i] * quant;
+        }
     }
 
     for (i = 0; i < ctx->num_planes; i++) {
@@ -569,10 +606,17 @@ static int encode_slice(AVCodecContext *avctx, const AVFrame *pic,
                            pwidth, avctx->height / ctx->pictures_per_frame,
                            ctx->blocks[0], ctx->emu_buf,
                            mbs_per_slice, num_cblocks, is_chroma);
-            sizes[i] = encode_slice_plane(ctx, pb, src, linesize,
-                                          mbs_per_slice, ctx->blocks[0],
-                                          num_cblocks, plane_factor,
-                                          qmat);
+            if (!is_chroma) {/* luma quant */
+                sizes[i] = encode_slice_plane(ctx, pb, src, linesize,
+                                              mbs_per_slice, ctx->blocks[0],
+                                              num_cblocks, plane_factor,
+                                              qmat);
+            } else { /* chroma plane */
+                sizes[i] = encode_slice_plane(ctx, pb, src, linesize,
+                                              mbs_per_slice, ctx->blocks[0],
+                                              num_cblocks, plane_factor,
+                                              qmat_chroma);
+            }
         } else {
             get_alpha_data(ctx, src, linesize, xp, yp,
                            pwidth, avctx->height / ctx->pictures_per_frame,
@@ -771,6 +815,7 @@ static int find_slice_quant(AVCodecContext *avctx,
     int slice_bits[TRELLIS_WIDTH], slice_score[TRELLIS_WIDTH];
     int overquant;
     uint16_t *qmat;
+    uint16_t *qmat_chroma;
     int linesize[4], line_add;
     int alpha_bits = 0;
 
@@ -825,12 +870,17 @@ static int find_slice_quant(AVCodecContext *avctx,
     for (q = min_quant; q <= max_quant; q++) {
         bits  = alpha_bits;
         error = 0;
-        for (i = 0; i < ctx->num_planes - !!ctx->alpha_bits; i++) {
+        bits += estimate_slice_plane(ctx, &error, 0,
+                                     src, linesize[0],
+                                     mbs_per_slice,
+                                     num_cblocks[0], plane_factor[0],
+                                     ctx->quants[q], td); /* estimate luma plane */
+        for (i = 1; i < ctx->num_planes - !!ctx->alpha_bits; i++) { /* estimate chroma plane */
             bits += estimate_slice_plane(ctx, &error, i,
                                          src, linesize[i],
                                          mbs_per_slice,
                                          num_cblocks[i], plane_factor[i],
-                                         ctx->quants[q], td);
+                                         ctx->quants_chroma[q], td);
         }
         if (bits > 65000 * 8)
             error = SCORE_LIMIT;
@@ -848,17 +898,26 @@ static int find_slice_quant(AVCodecContext *avctx,
             error = 0;
             if (q < MAX_STORED_Q) {
                 qmat = ctx->quants[q];
+                qmat_chroma = ctx->quants_chroma[q];
             } else {
                 qmat = td->custom_q;
-                for (i = 0; i < 64; i++)
+                qmat_chroma = td->custom_q;
+                for (i = 0; i < 64; i++) {
                     qmat[i] = ctx->quant_mat[i] * q;
+                    qmat_chroma[i] = ctx->quant_chroma_mat[i] * q;
+                }
             }
-            for (i = 0; i < ctx->num_planes - !!ctx->alpha_bits; i++) {
+            bits += estimate_slice_plane(ctx, &error, 0,
+                                         src, linesize[0],
+                                         mbs_per_slice,
+                                         num_cblocks[0], plane_factor[0],
+                                         qmat, td);/* estimate luma plane */
+            for (i = 1; i < ctx->num_planes - !!ctx->alpha_bits; i++) { /* estimate chroma plane */
                 bits += estimate_slice_plane(ctx, &error, i,
                                              src, linesize[i],
                                              mbs_per_slice,
                                              num_cblocks[i], plane_factor[i],
-                                             qmat, td);
+                                             qmat_chroma, td);
             }
             if (bits <= ctx->bits_per_mb * mbs_per_slice)
                 break;
@@ -1194,10 +1253,13 @@ FF_ENABLE_DEPRECATION_WARNINGS
     ctx->slices_per_picture = ctx->mb_height * ctx->slices_width;
     ctx->pictures_per_frame = 1 + interlaced;
 
-    if (ctx->quant_sel == -1)
+    if (ctx->quant_sel == -1) {
         ctx->quant_mat = prores_quant_matrices[ctx->profile_info->quant];
-    else
+        ctx->quant_chroma_mat = prores_quant_matrices[ctx->profile_info->quant_chroma];
+    } else {
         ctx->quant_mat = prores_quant_matrices[ctx->quant_sel];
+        ctx->quant_chroma_mat = prores_quant_matrices[ctx->quant_sel];
+    }
 
     if (strlen(ctx->vendor) != 4) {
         av_log(avctx, AV_LOG_ERROR, "vendor ID should be 4 bytes\n");
@@ -1222,8 +1284,10 @@ FF_ENABLE_DEPRECATION_WARNINGS
         min_quant = ctx->profile_info->min_quant;
         max_quant = ctx->profile_info->max_quant;
         for (i = min_quant; i < MAX_STORED_Q; i++) {
-            for (j = 0; j < 64; j++)
+            for (j = 0; j < 64; j++) {
                 ctx->quants[i][j] = ctx->quant_mat[j] * i;
+                ctx->quants_chroma[i][j] = ctx->quant_chroma_mat[j] * i;
+            }
         }
 
         ctx->slice_q = av_malloc(ctx->slices_per_picture * sizeof(*ctx->slice_q));
@@ -1254,6 +1318,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
         }
     } else {
         int ls = 0;
+        int ls_chroma = 0;
 
         if (ctx->force_quant > 64) {
             av_log(avctx, AV_LOG_ERROR, "too large quantiser, maximum is 64\n");
@@ -1262,12 +1327,14 @@ FF_ENABLE_DEPRECATION_WARNINGS
 
         for (j = 0; j < 64; j++) {
             ctx->quants[0][j] = ctx->quant_mat[j] * ctx->force_quant;
+            ctx->quants_chroma[0][j] = ctx->quant_chroma_mat[j] * ctx->force_quant;
             ls += av_log2((1 << 11)  / ctx->quants[0][j]) * 2 + 1;
+            ls_chroma += av_log2((1 << 11)  / ctx->quants_chroma[0][j]) * 2 + 1;
         }
 
-        ctx->bits_per_mb = ls * 8;
+        ctx->bits_per_mb = ls * 4 + ls_chroma * 4;
         if (ctx->chroma_factor == CFACTOR_Y444)
-            ctx->bits_per_mb += ls * 4;
+            ctx->bits_per_mb += ls_chroma * 4;
     }
 
     ctx->frame_size_upper_bound = (ctx->pictures_per_frame *