diff --git a/packages/core/src/bridge/highway/video-upload.ts b/packages/core/src/bridge/highway/video-upload.ts
index 4f60cb2c..94c8e743 100644
--- a/packages/core/src/bridge/highway/video-upload.ts
+++ b/packages/core/src/bridge/highway/video-upload.ts
@@ -460,10 +460,14 @@ export async function uploadVideoMsgInfo(
             fileHash: video.md5Hex,
             fileSha1: video.sha1Hex,
             fileName: 'nya.mp4',
-            type: { type: 2, picFormat: 0, videoFormat: video.videoFormat, voiceFormat: 0 },
-            height: video.height,
-            width: video.width,
-            time: video.duration,
+            // NapCat sends type.videoFormat=0 and width/height/time=0
+            // for the main video sub-file (only the thumb carries
+            // dimensions). The QQ NT server treats non-zero values
+            // here as a schema mismatch on c2c sends.
+            type: { type: 2, picFormat: 0, videoFormat: 0, voiceFormat: 0 },
+            height: 0,
+            width: 0,
+            time: 0,
             original: 0,
           },
           subFileType: 0,
diff --git a/packages/core/src/bridge/proto/highway.ts b/packages/core/src/bridge/proto/highway.ts
index 9f5a5d75..2346dc81 100644
--- a/packages/core/src/bridge/proto/highway.ts
+++ b/packages/core/src/bridge/proto/highway.ts
@@ -234,35 +234,17 @@ export const NTV2UploadInfoSchema = {
   subFileType: { field: 2, type: 'uint32' as const },
 } satisfies ProtoSchema;
 
-export const NTV2PicReserveC2CSchema = {
-  subType: { field: 1, type: 'uint32' as const },
-} satisfies ProtoSchema;
-
-export const NTV2PicReserveTroopSchema = {
-  subType: { field: 1, type: 'uint32' as const },
-} satisfies ProtoSchema;
-
-export const NTV2PicExtBizInfoSchema = {
-  bizType:      { field: 1, type: 'uint32' as const },
-  textSummary:  { field: 2, type: 'string' as const },
-  reserveC2c:   { field: 11, type: 'message' as const, schema: NTV2PicReserveC2CSchema },
-  reserveTroop: { field: 12, type: 'message' as const, schema: NTV2PicReserveTroopSchema },
-} satisfies ProtoSchema;
-
-export const NTV2VideoExtBizInfoSchema = {
-  bytesPbReserve: { field: 3, type: 'bytes' as const },
-} satisfies ProtoSchema;
-
-export const NTV2PttExtBizInfoSchema = {
-  bytesReserve:      { field: 11, type: 'bytes' as const },
-  bytesPbReserve:    { field: 12, type: 'bytes' as const },
-  bytesGeneralFlags: { field: 13, type: 'bytes' as const },
-} satisfies ProtoSchema;
-
+// The NTV2 upload request + response carry the same ExtBizInfo shape that
+// element-side incoming-message decoding uses. Pulling those schemas in
+// directly (instead of redefining stub copies) keeps the round-trip
+// `server response → finalizeMediaMsgInfo → commonElem.pbElem` from
+// silently dropping fields the QQ NT server later validates against —
+// the video `fromScene`/`toScene` drop was already responsible for c2c
+// `result=79` rejections on `send_private_msg [{type:'video'}]`.
 export const NTV2ExtBizInfoSchema = {
-  pic:      { field: 1, type: 'message' as const, schema: NTV2PicExtBizInfoSchema },
-  video:    { field: 2, type: 'message' as const, schema: NTV2VideoExtBizInfoSchema },
-  ptt:      { field: 3, type: 'message' as const, schema: NTV2PttExtBizInfoSchema },
+  pic:      { field: 1, type: 'message' as const, schema: PicExtBizInfoSchema },
+  video:    { field: 2, type: 'message' as const, schema: VideoExtBizInfoSchema },
+  ptt:      { field: 3, type: 'message' as const, schema: PttExtBizInfoSchema },
   busiType: { field: 10, type: 'uint32' as const },
 } satisfies ProtoSchema;