+---------------------+
in:default--[48000Hz fltp:stereo]--default| Parsed_showvolume_0 |default--[41x240 1:1 rgba]--auto_scaler_0:default
                                          |    (showvolume)     |
                                          +---------------------+

+------------------+
| Parsed_nullsrc_1 |default--[320x240 1:1 yuv420p]--Parsed_overlay_6:main
|    (nullsrc)     |
+------------------+

                                            +---------------+
in1:default--[1280x720 1:1 yuv420p]--default| Parsed_fifo_2 |default--[1280x720 1:1 yuv420p]--Parsed_setpts_3:default
                                            |    (fifo)     |
                                            +---------------+

                                                      +-----------------+
Parsed_fifo_2:default--[1280x720 1:1 yuv420p]--default| Parsed_setpts_3 |default--[1280x720 1:1 yuv420p]--Parsed_scale_4:default
                                                      |    (setpts)     |
                                                      +-----------------+

                                                        +----------------+
Parsed_setpts_3:default--[1280x720 1:1 yuv420p]--default| Parsed_scale_4 |default--[320x240 4:3 yuva420p]--Parsed_overlay_5:main
                                                        |    (scale)     |
                                                        +----------------+

                                                       +------------------+
Parsed_scale_4:default--[320x240 4:3 yuva420p]-----main| Parsed_overlay_5 |default--[320x240 4:3 yuva420p]--Parsed_overlay_6:overlay
auto_scaler_0:default---[41x240 1:1 yuva420p]---overlay|    (overlay)     |
                                                       +------------------+

                                                         +------------------+
Parsed_nullsrc_1:default--[320x240 1:1 yuv420p]------main| Parsed_overlay_6 |default--[320x240 1:1 yuv420p]--out:default
Parsed_overlay_5:default--[320x240 4:3 yuva420p]--overlay|    (overlay)     |
                                                         +------------------+

+-----------+
|    in     |default--[48000Hz fltp:stereo]--Parsed_showvolume_0:default
| (abuffer) |
+-----------+

+----------+
|   in1    |default--[1280x720 1:1 yuv420p]--Parsed_fifo_2:default
| (buffer) |
+----------+

                                                        +--------------+
Parsed_overlay_6:default--[320x240 1:1 yuv420p]--default|     out      |
                                                        | (buffersink) |
                                                        +--------------+

                                                       +---------------+
Parsed_showvolume_0:default--[41x240 1:1 rgba]--default| auto_scaler_0 |default--[41x240 1:1 yuva420p]--Parsed_overlay_5:overlay
                                                       |    (scale)    |
                                                       +---------------+