avcodec/videotoolboxenc: Use BufNode as sourceFrameRefcon

ExtraSEI is used as the sourceFrameRefcon of VTCompressionSessionEncodeFrame.
It cannot hold other information which is necessary to fix another issue
in the following patch.

This patch also fixed leak of ExtraSEI on the error path of
vtenc_output_callback.

Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>

libavcodec/videotoolboxenc.c

@@ -347,8 +347,7 @@ static void set_async_error(VTEncContext *vtctx, int err)
 
     while (info) {
         BufNode *next = info->next;
-        CFRelease(info->cm_buffer);
-        av_free(info);
+        vtenc_free_buf_node(info);
         info = next;
     }
 
@@ -438,19 +437,8 @@ static int vtenc_q_pop(VTEncContext *vtctx, bool wait, CMSampleBufferRef *buf, E
     return 0;
 }
 
-static void vtenc_q_push(VTEncContext *vtctx, CMSampleBufferRef buffer, ExtraSEI *sei)
+static void vtenc_q_push(VTEncContext *vtctx, BufNode *info)
 {
-    BufNode *info = av_malloc(sizeof(BufNode));
-    if (!info) {
-        set_async_error(vtctx, AVERROR(ENOMEM));
-        return;
-    }
-
-    CFRetain(buffer);
-    info->cm_buffer = buffer;
-    info->sei = sei;
-    info->next = NULL;
-
     pthread_mutex_lock(&vtctx->lock);
 
     if (!vtctx->q_head) {
@@ -726,6 +714,22 @@ static int set_extradata(AVCodecContext *avctx, CMSampleBufferRef sample_buffer)
     return 0;
 }
 
+static void vtenc_free_buf_node(BufNode *info)
+{
+    if (!info)
+        return;
+
+    if (info->sei) {
+        av_free(info->sei->data);
+        av_free(info->sei);
+    }
+
+    if (info->cm_buffer)
+        CFRelease(info->cm_buffer);
+
+    av_free(info);
+}
+
 static void vtenc_output_callback(
     void *ctx,
     void *sourceFrameCtx,
@@ -735,13 +739,15 @@ static void vtenc_output_callback(
 {
     AVCodecContext *avctx = ctx;
     VTEncContext   *vtctx = avctx->priv_data;
-    ExtraSEI *sei = sourceFrameCtx;
+    BufNode *info = sourceFrameCtx;
 
     if (vtctx->async_error) {
+        vtenc_free_buf_node(info);
         return;
     }
 
     if (status) {
+        vtenc_free_buf_node(info);
         av_log(avctx, AV_LOG_ERROR, "Error encoding frame: %d\n", (int)status);
         set_async_error(vtctx, AVERROR_EXTERNAL);
         return;
@@ -751,15 +757,19 @@ static void vtenc_output_callback(
         return;
     }
 
+    CFRetain(sample_buffer);
+    info->cm_buffer = sample_buffer;
+
     if (!avctx->extradata && (avctx->flags & AV_CODEC_FLAG_GLOBAL_HEADER)) {
         int set_status = set_extradata(avctx, sample_buffer);
         if (set_status) {
+            vtenc_free_buf_node(info);
             set_async_error(vtctx, set_status);
             return;
         }
     }
 
-    vtenc_q_push(vtctx, sample_buffer, sei);
+    vtenc_q_push(vtctx, info);
 }
 
 static int get_length_code_size(
@@ -2565,19 +2575,23 @@ static int vtenc_send_frame(AVCodecContext *avctx,
                             const AVFrame  *frame)
 {
     CMTime time;
-    CFDictionaryRef frame_dict;
+    CFDictionaryRef frame_dict = NULL;
     CVPixelBufferRef cv_img = NULL;
     AVFrameSideData *side_data = NULL;
+    BufNode *node = av_mallocz(sizeof(*node));
     ExtraSEI *sei = NULL;
-    int status = create_cv_pixel_buffer(avctx, frame, &cv_img);
+    int status;
 
-    if (status) return status;
+    if (!node)
+        return AVERROR(ENOMEM);
+
+    status = create_cv_pixel_buffer(avctx, frame, &cv_img);
+    if (status)
+        goto out;
 
     status = create_encoder_dict_h264(frame, &frame_dict);
-    if (status) {
-        CFRelease(cv_img);
-        return status;
-    }
+    if (status)
+        goto out;
 
 #if CONFIG_ATSC_A53
     side_data = av_frame_get_side_data(frame, AV_FRAME_DATA_A53_CC);
@@ -2587,6 +2601,7 @@ static int vtenc_send_frame(AVCodecContext *avctx,
             status = AVERROR(ENOMEM);
             goto out;
         }
+        node->sei = sei;
         status = ff_alloc_a53_sei(frame, 0, &sei->data, &sei->size);
         if (status < 0) {
             av_free(sei);
@@ -2602,7 +2617,7 @@ static int vtenc_send_frame(AVCodecContext *avctx,
         time,
         kCMTimeInvalid,
         frame_dict,
-        sei,
+        node,
         NULL
     );
 
@@ -2616,7 +2631,10 @@ static int vtenc_send_frame(AVCodecContext *avctx,
 out:
     if (frame_dict)
         CFRelease(frame_dict);
-    CFRelease(cv_img);
+    if (cv_img)
+        CFRelease(cv_img);
+    if (status)
+        vtenc_free_buf_node(node);
 
     return status;
 }
@@ -2701,6 +2719,10 @@ static int vtenc_populate_extradata(AVCodecContext   *avctx,
     CVPixelBufferRef pix_buf = NULL;
     CMTime time;
     CMSampleBufferRef buf = NULL;
+    BufNode *node = av_mallocz(sizeof(*node));
+
+    if (!node)
+        return AVERROR(ENOMEM);
 
     status = vtenc_create_encoder(avctx,
                                   codec_type,
@@ -2736,7 +2758,7 @@ static int vtenc_populate_extradata(AVCodecContext   *avctx,
                                              time,
                                              kCMTimeInvalid,
                                              NULL,
-                                             NULL,
+                                             node,
                                              NULL);
 
     if (status) {
@@ -2747,6 +2769,7 @@ static int vtenc_populate_extradata(AVCodecContext   *avctx,
         status = AVERROR_EXTERNAL;
         goto pe_cleanup;
     }
+    node = NULL;
 
     //Populates extradata - output frames are flushed and param sets are available.
     status = VTCompressionSessionCompleteFrames(vtctx->session,
@@ -2780,6 +2803,8 @@ pe_cleanup:
     vtctx->frame_ct_out = 0;
 
     av_assert0(status != 0 || (avctx->extradata && avctx->extradata_size > 0));
+    if (!status)
+        vtenc_free_buf_node(node);
 
     return status;
 }