fftools/ffmpeg: calculate the time interval to get the first decoded …

…frame

Signed-off-by: Linjie Fu <linjie.justin.fu@gmail.com>

fftools/ffmpeg.c

@@ -109,6 +109,9 @@
 const char program_name[] = "ffmpeg";
 const int program_birth_year = 2000;
 
+int64_t program_start_time = 0;
+int64_t got_output_time = 0;
+
 static FILE *vstats_file;
 
 const char *const forced_keyframes_const_names[] = {
@@ -2462,6 +2465,11 @@ static int decode_video(InputStream *ist, AVPacket *pkt, int *got_output, int64_
     if (!*got_output || ret < 0)
         return ret;
 
+    if (got_output_time == 0) {
+        got_output_time = av_gettime_relative() - program_start_time;
+        av_log(NULL, AV_LOG_ERROR, "first time to got frame, it takes %lld us\n", got_output_time);
+    }
+
     if(ist->top_field_first>=0)
         decoded_frame->top_field_first = ist->top_field_first;
 
@@ -4220,13 +4228,16 @@ static int get_input_packet_mt(InputFile *f, AVPacket **pkt)
 static int get_input_packet(InputFile *f, AVPacket **pkt)
 {
     if (f->rate_emu) {
+        av_log(NULL, AV_LOG_INFO, "get_input_packet here.\n");
         int i;
         for (i = 0; i < f->nb_streams; i++) {
             InputStream *ist = input_streams[f->ist_index + i];
             int64_t pts = av_rescale(ist->dts, 1000000, AV_TIME_BASE);
             int64_t now = av_gettime_relative() - ist->start;
-            if (pts > now)
+            if (pts > now) {
+                av_log(NULL, AV_LOG_INFO, "pts > now, return EAGAIN.\n");
                 return AVERROR(EAGAIN);
+            }
         }
     }
 
@@ -4970,6 +4981,8 @@ int main(int argc, char **argv)
 
     init_dynload();
 
+    program_start_time = av_gettime_relative();
+
     register_exit(ffmpeg_cleanup);
 
     setvbuf(stderr,NULL,_IONBF,0); /* win32 runtime needs this */