diff --git a/libavcodec/vaapi_encode.c b/libavcodec/vaapi_encode.c
index 1818da8731..8d1a08d940 100644
--- a/libavcodec/vaapi_encode.c
+++ b/libavcodec/vaapi_encode.c
@@ -2058,6 +2058,8 @@ static av_cold int vaapi_encode_init_slice_structure(AVCodecContext *avctx)
         return 0;
     }
 
+    av_assert0(ctx->slice_block_height > 0 && ctx->slice_block_width > 0);
+
     ctx->slice_block_rows = (avctx->height + ctx->slice_block_height - 1) /
                              ctx->slice_block_height;
     ctx->slice_block_cols = (avctx->width  + ctx->slice_block_width  - 1) /
@@ -2447,6 +2449,20 @@ av_cold int ff_vaapi_encode_init(AVCodecContext *avctx)
     if (err < 0)
         goto fail;
 
+    if (ctx->codec->get_encoder_caps) {
+        err = ctx->codec->get_encoder_caps(avctx);
+        if (err < 0)
+            goto fail;
+    } else {
+        // Assume 16x16 blocks.
+        ctx->surface_width  = FFALIGN(avctx->width,  16);
+        ctx->surface_height = FFALIGN(avctx->height, 16);
+        if (ctx->codec->flags & FLAG_SLICE_CONTROL) {
+            ctx->slice_block_width  = 16;
+            ctx->slice_block_height = 16;
+        }
+    }
+
     err = vaapi_encode_init_rate_control(avctx);
     if (err < 0)
         goto fail;
diff --git a/libavcodec/vaapi_encode.h b/libavcodec/vaapi_encode.h
index 61c5615eb8..f0021acccf 100644
--- a/libavcodec/vaapi_encode.h
+++ b/libavcodec/vaapi_encode.h
@@ -376,6 +376,13 @@ typedef struct VAAPIEncodeType {
     // factor depending on RC mode.
     int default_quality;
 
+    // Determine encode parameters like block sizes for surface alignment
+    // and slices. This may need to query the profile and entrypoint,
+    // which will be available when this function is called. If not set,
+    // assume that all blocks are 16x16 and that surfaces should be
+    // aligned to match this.
+    int (*get_encoder_caps)(AVCodecContext *avctx);
+
     // Perform any extra codec-specific configuration after the
     // codec context is initialised (set up the private data and
     // add any necessary global parameters).
diff --git a/libavcodec/vaapi_encode_h265.c b/libavcodec/vaapi_encode_h265.c
index ea45893508..706ec5d849 100644
--- a/libavcodec/vaapi_encode_h265.c
+++ b/libavcodec/vaapi_encode_h265.c
@@ -55,6 +55,10 @@ typedef struct VAAPIEncodeH265Picture {
 typedef struct VAAPIEncodeH265Context {
     VAAPIEncodeContext common;
 
+    // Encoder features.
+    uint32_t ctu_size;
+    uint32_t min_cb_size;
+
     // User options.
     int qp;
     int aud;
@@ -1091,6 +1095,27 @@ static int vaapi_encode_h265_init_slice_params(AVCodecContext *avctx,
     return 0;
 }
 
+static av_cold int vaapi_encode_h265_get_encoder_caps(AVCodecContext *avctx)
+{
+    VAAPIEncodeContext      *ctx = avctx->priv_data;
+    VAAPIEncodeH265Context *priv = avctx->priv_data;
+
+    if (!priv->ctu_size) {
+        priv->ctu_size     = 32;
+        priv->min_cb_size  = 16;
+    }
+    av_log(avctx, AV_LOG_VERBOSE, "Using CTU size %dx%d, "
+           "min CB size %dx%d.\n", priv->ctu_size, priv->ctu_size,
+           priv->min_cb_size, priv->min_cb_size);
+
+    ctx->surface_width  = FFALIGN(avctx->width,  priv->min_cb_size);
+    ctx->surface_height = FFALIGN(avctx->height, priv->min_cb_size);
+
+    ctx->slice_block_width = ctx->slice_block_height = priv->ctu_size;
+
+    return 0;
+}
+
 static av_cold int vaapi_encode_h265_configure(AVCodecContext *avctx)
 {
     VAAPIEncodeContext      *ctx = avctx->priv_data;
@@ -1160,6 +1185,7 @@ static const VAAPIEncodeType vaapi_encode_type_h265 = {
 
     .default_quality       = 25,
 
+    .get_encoder_caps      = &vaapi_encode_h265_get_encoder_caps,
     .configure             = &vaapi_encode_h265_configure,
 
     .picture_priv_data_size = sizeof(VAAPIEncodeH265Picture),
@@ -1205,12 +1231,6 @@ static av_cold int vaapi_encode_h265_init(AVCodecContext *avctx)
         VA_ENC_PACKED_HEADER_SLICE    | // Slice headers.
         VA_ENC_PACKED_HEADER_MISC;      // SEI
 
-    ctx->surface_width  = FFALIGN(avctx->width,  16);
-    ctx->surface_height = FFALIGN(avctx->height, 16);
-
-    // CTU size is currently hard-coded to 32.
-    ctx->slice_block_width = ctx->slice_block_height = 32;
-
     if (priv->qp > 0)
         ctx->explicit_qp = priv->qp;
 
diff --git a/libavcodec/vaapi_encode_mjpeg.c b/libavcodec/vaapi_encode_mjpeg.c
index 6206b23e5f..87a03f181b 100644
--- a/libavcodec/vaapi_encode_mjpeg.c
+++ b/libavcodec/vaapi_encode_mjpeg.c
@@ -434,6 +434,20 @@ static int vaapi_encode_mjpeg_init_slice_params(AVCodecContext *avctx,
     return 0;
 }
 
+static av_cold int vaapi_encode_mjpeg_get_encoder_caps(AVCodecContext *avctx)
+{
+    VAAPIEncodeContext *ctx = avctx->priv_data;
+    const AVPixFmtDescriptor *desc;
+
+    desc = av_pix_fmt_desc_get(ctx->input_frames->sw_format);
+    av_assert0(desc);
+
+    ctx->surface_width  = FFALIGN(avctx->width,  8 << desc->log2_chroma_w);
+    ctx->surface_height = FFALIGN(avctx->height, 8 << desc->log2_chroma_h);
+
+    return 0;
+}
+
 static av_cold int vaapi_encode_mjpeg_configure(AVCodecContext *avctx)
 {
     VAAPIEncodeContext       *ctx = avctx->priv_data;
@@ -483,6 +497,7 @@ static const VAAPIEncodeType vaapi_encode_type_mjpeg = {
     .flags                 = FLAG_CONSTANT_QUALITY_ONLY |
                              FLAG_INTRA_ONLY,
 
+    .get_encoder_caps      = &vaapi_encode_mjpeg_get_encoder_caps,
     .configure             = &vaapi_encode_mjpeg_configure,
 
     .default_quality       = 80,
@@ -509,9 +524,6 @@ static av_cold int vaapi_encode_mjpeg_init(AVCodecContext *avctx)
     ctx->desired_packed_headers =
         VA_ENC_PACKED_HEADER_RAW_DATA;
 
-    ctx->surface_width  = FFALIGN(avctx->width,  8);
-    ctx->surface_height = FFALIGN(avctx->height, 8);
-
     return ff_vaapi_encode_init(avctx);
 }
 
diff --git a/libavcodec/vaapi_encode_mpeg2.c b/libavcodec/vaapi_encode_mpeg2.c
index d084d8c4b9..f8809b08ab 100644
--- a/libavcodec/vaapi_encode_mpeg2.c
+++ b/libavcodec/vaapi_encode_mpeg2.c
@@ -623,9 +623,6 @@ static av_cold int vaapi_encode_mpeg2_init(AVCodecContext *avctx)
     ctx->desired_packed_headers = VA_ENC_PACKED_HEADER_SEQUENCE |
                                   VA_ENC_PACKED_HEADER_PICTURE;
 
-    ctx->surface_width  = FFALIGN(avctx->width,  16);
-    ctx->surface_height = FFALIGN(avctx->height, 16);
-
     return ff_vaapi_encode_init(avctx);
 }
 
diff --git a/libavcodec/vaapi_encode_vp8.c b/libavcodec/vaapi_encode_vp8.c
index 7d4578f674..ab3c84a618 100644
--- a/libavcodec/vaapi_encode_vp8.c
+++ b/libavcodec/vaapi_encode_vp8.c
@@ -210,9 +210,6 @@ static av_cold int vaapi_encode_vp8_init(AVCodecContext *avctx)
     // adding them anyway.
     ctx->desired_packed_headers = 0;
 
-    ctx->surface_width  = FFALIGN(avctx->width,  16);
-    ctx->surface_height = FFALIGN(avctx->height, 16);
-
     return ff_vaapi_encode_init(avctx);
 }
 
diff --git a/libavcodec/vaapi_encode_vp9.c b/libavcodec/vaapi_encode_vp9.c
index be706e3bd6..837adaa825 100644
--- a/libavcodec/vaapi_encode_vp9.c
+++ b/libavcodec/vaapi_encode_vp9.c
@@ -184,6 +184,17 @@ static int vaapi_encode_vp9_init_picture_params(AVCodecContext *avctx,
     return 0;
 }
 
+static av_cold int vaapi_encode_vp9_get_encoder_caps(AVCodecContext *avctx)
+{
+    VAAPIEncodeContext *ctx = avctx->priv_data;
+
+    // Surfaces must be aligned to 64x64 superblock boundaries.
+    ctx->surface_width  = FFALIGN(avctx->width,  64);
+    ctx->surface_height = FFALIGN(avctx->height, 64);
+
+    return 0;
+}
+
 static av_cold int vaapi_encode_vp9_configure(AVCodecContext *avctx)
 {
     VAAPIEncodeContext     *ctx = avctx->priv_data;
@@ -231,6 +242,7 @@ static const VAAPIEncodeType vaapi_encode_type_vp9 = {
 
     .picture_priv_data_size = sizeof(VAAPIEncodeVP9Picture),
 
+    .get_encoder_caps      = &vaapi_encode_vp9_get_encoder_caps,
     .configure             = &vaapi_encode_vp9_configure,
 
     .sequence_params_size  = sizeof(VAEncSequenceParameterBufferVP9),
@@ -251,10 +263,6 @@ static av_cold int vaapi_encode_vp9_init(AVCodecContext *avctx)
     // can write its own headers and there is no metadata to include.
     ctx->desired_packed_headers = 0;
 
-    // Surfaces must be aligned to superblock boundaries.
-    ctx->surface_width  = FFALIGN(avctx->width,  64);
-    ctx->surface_height = FFALIGN(avctx->height, 64);
-
     return ff_vaapi_encode_init(avctx);
 }
 
