diff --git a/src/video_core/host_shaders/astc_decoder.comp b/src/video_core/host_shaders/astc_decoder.comp
index 2248a92a46..58dccb545f 100644
--- a/src/video_core/host_shaders/astc_decoder.comp
+++ b/src/video_core/host_shaders/astc_decoder.comp
@@ -296,14 +296,19 @@ uint ExtractBits(uvec4 payload, int offset, int bits) {
     if (bits > 32) {
         return 0;
     }
-    const int last_offset = offset + bits - 1;
+    if (offset >= 128) {
+        return 0;
+    }
+    const int avail_bits = min(bits, 128 - offset);
+    const int last_offset = offset + avail_bits - 1;
     const int shifted_offset = offset >> 5;
     if ((last_offset >> 5) == shifted_offset) {
-        return bitfieldExtract(payload[shifted_offset], offset & 31, bits);
+        return bitfieldExtract(payload[shifted_offset], offset & 31, avail_bits);
     }
     const int first_bits = 32 - (offset & 31);
     const int result_first = int(bitfieldExtract(payload[shifted_offset], offset & 31, first_bits));
-    const int result_second = int(bitfieldExtract(payload[shifted_offset + 1], 0, bits - first_bits));
+    const int result_second =
+        int(bitfieldExtract(payload[shifted_offset + 1], 0, avail_bits - first_bits));
     return result_first | (result_second << first_bits);
 }
 
diff --git a/src/video_core/texture_cache/util.cpp b/src/video_core/texture_cache/util.cpp
index e55d0752ec..25cf6e33b1 100644
--- a/src/video_core/texture_cache/util.cpp
+++ b/src/video_core/texture_cache/util.cpp
@@ -950,7 +950,7 @@ void ConvertImage(std::span<const u8> input, const ImageInfo& info, std::span<u8
                 tile_size.height, output.subspan(output_offset));
 
             output_offset += copy.image_extent.width * copy.image_extent.height *
-                             copy.image_subresource.num_layers *
+                             copy.image_extent.depth * copy.image_subresource.num_layers *
                              BytesPerBlock(PixelFormat::A8B8G8R8_UNORM);
         } else if (astc) {
             // BC1 uses 0.5 bytes per texel
@@ -985,7 +985,7 @@ void ConvertImage(std::span<const u8> input, const ImageInfo& info, std::span<u8
         } else {
             DecompressBCn(input_offset, output.subspan(output_offset), copy, info.format);
             output_offset += copy.image_extent.width * copy.image_extent.height *
-                             copy.image_subresource.num_layers *
+                             copy.image_extent.depth * copy.image_subresource.num_layers *
                              ConvertedBytesPerBlock(info.format);
         }