fix(ffmpeg): when disabled LV_FFMPEG_AV_DUMP_FORMAT makes av_log quiet (#2838)

* fix(Kconfig) remove duplicate LV_BUILD_EXAMPLES configuration

* feat(refr) add reset of FPS statistics

* fix(ffmpeg) when disabled LV_FFMPEG_AV_DUMP_FORMAT makes av_log quiet

Signed-off-by: _VIFEXTech <1290176185@qq.com>

* docs(ffmpeg) add example code

Co-authored-by: pengyiqiang <pengyiqiang@xiaomi.com>

docs/libs/ffmpeg.md

@@ -22,7 +22,14 @@ Enable `LV_USE_FFMPEG` in `lv_conf.h`.
 See the examples below.
 
 Note that, the FFmpeg extension doesn't use LVGL's file system. 
-You can simply pass the path to the font as usual on your operating system or platform.
+You can simply pass the path to the image or video as usual on your operating system or platform.
+
+## Example
+```eval_rst
+
+.. include:: ../../examples/libs/ffmpeg/index.rst
+
+```
 
 ## API
 

examples/libs/ffmpeg/index.rst

@@ -0,0 +1,12 @@
+Decode image
+"""""""""""""""""""""""""""""""""""""
+
+.. lv_example:: libs/ffmpeg/lv_example_ffmpeg_1
+  :language: c
+
+Decode video
+"""""""""""""""""""""""""""""""""""
+
+.. lv_example:: libs/ffmpeg/lv_example_ffmpeg_2
+  :language: c
+

src/extra/libs/ffmpeg/lv_ffmpeg.c

@@ -117,6 +117,10 @@ void lv_ffmpeg_init(void)
     lv_img_decoder_set_info_cb(dec, decoder_info);
     lv_img_decoder_set_open_cb(dec, decoder_open);
     lv_img_decoder_set_close_cb(dec, decoder_close);
+
+#if LV_FFMPEG_AV_DUMP_FORMAT == 0
+    av_log_set_level(AV_LOG_QUIET);
+#endif
 }
 
 int lv_ffmpeg_get_frame_num(const char * path)