rawdec: don't set codec timebase.

It's not supposed to be set outside of lavc. Set r_frame_rate and
avg_frame_rate instead.

libavformat/rawdec.c

@@ -159,7 +159,7 @@ int ff_raw_video_read_header(AVFormatContext *s,
         goto fail;
     }
 
-    st->codec->time_base = (AVRational){framerate.den, framerate.num};
+    st->r_frame_rate = st->avg_frame_rate = framerate;
     avpriv_set_pts_info(st, 64, 1, 1200000);
 
 fail:

tests/ref/fate/h264-lossless

 0, 0, 460800, 0x7731dd2f
-0, 1500, 460800, 0x944b8c64
-0, 3000, 460800, 0xbe833041
-0, 4500, 460800, 0xbe95d96a
-0, 6000, 460800, 0xfe7ea5e6
-0, 7500, 460800, 0x381743c7
-0, 9000, 460800, 0x63fcc2e9
-0, 10500, 460800, 0x79574960
-0, 12000, 460800, 0xdab9e18a
-0, 13500, 460800, 0xd88e8fe8
+0, 3600, 460800, 0x944b8c64
+0, 7200, 460800, 0xbe833041
+0, 10800, 460800, 0xbe95d96a
+0, 14400, 460800, 0xfe7ea5e6
+0, 18000, 460800, 0x381743c7
+0, 21600, 460800, 0x63fcc2e9
+0, 25200, 460800, 0x79574960
+0, 28800, 460800, 0xdab9e18a
+0, 32400, 460800, 0xd88e8fe8