@@ -36,6 +36,12 @@ typedef struct {

     AVRational        pixel_aspect;

 } BufferSourceContext;

+#define CHECK_PARAM_CHANGE(s, c, width, height, format)\

+    if (c->w != width || c->h != height || c->pix_fmt != format) {\

+        av_log(s, AV_LOG_ERROR, "Changing frame properties on the fly is not supported.\n");\

+        return AVERROR(EINVAL);\

+    }

+

 int av_vsrc_buffer_add_frame(AVFilterContext *buffer_filter, AVFrame *frame,

                              int64_t pts, AVRational pixel_aspect)

 {

@@ -49,6 +55,8 @@ int av_vsrc_buffer_add_frame(AVFilterContext *buffer_filter, AVFrame *frame,

         //return -1;

     }

+    CHECK_PARAM_CHANGE(buffer_filter, c, frame->width, frame->height, frame->format);

+

     c->buf = avfilter_get_video_buffer(buffer_filter->outputs[0], AV_PERM_WRITE,

                                        c->w, c->h);

     av_image_copy(c->buf->data, c->buf->linesize, frame->data, frame->linesize,

@@ -73,6 +81,8 @@ int av_buffersrc_buffer(AVFilterContext *s, AVFilterBufferRef *buf)

         return AVERROR(EINVAL);

     }

+    CHECK_PARAM_CHANGE(s, c, buf->video->w, buf->video->h, buf->format);

+

     c->buf = buf;

     return 0;