Deprecated functions used in examples

When using the ffmpeg_decode example code I get these warnings:

```
main.c: In function ‘main’:
main.c:849:5: warning: ‘av_register_all’ is deprecated [-Wdeprecated-declarations]
av_register_all();
^~~~~~~~~~~~~~~
In file included from main.c:47:0:
/usr/local/include/libavformat/avformat.h:2050:6: note: declared here
void av_register_all(void);
^~~~~~~~~~~~~~~
main.c:876:9: warning: ‘codec’ is deprecated [-Wdeprecated-declarations]
if (fmt_ctx->streams[stream]->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
^~
In file included from main.c:47:0:
/usr/local/include/libavformat/avformat.h:885:21: note: declared here
AVCodecContext *codec;
^~~~~
main.c:887:5: warning: ‘codec’ is deprecated [-Wdeprecated-declarations]
AVCodecContext* codec_ctx = fmt_ctx->streams[stream]->codec;
^~~~~~~~~~~~~~
In file included from main.c:47:0:
/usr/local/include/libavformat/avformat.h:885:21: note: declared here
AVCodecContext *codec;
^~~~~
main.c:948:9: warning: ‘avcodec_decode_audio4’ is deprecated [-Wdeprecated-declarations]
if (avcodec_decode_audio4(codec_ctx, frame, &got_frame, &packet) < 0) {
^~
In file included from /usr/local/include/libavformat/avformat.h:317:0,
from main.c:47:
/usr/local/include/libavcodec/avcodec.h:4779:5: note: declared here
int avcodec_decode_audio4(AVCodecContext *avctx, AVFrame *frame,
^~~~~~~~~~~~~~~~~~~~~
main.c:990:9: warning: ‘av_free_packet’ is deprecated [-Wdeprecated-declarations]
av_free_packet(&packet);
^~~~~~~~~~~~~~
In file included from /usr/local/include/libavformat/avformat.h:317:0,
from main.c:47:
/usr/local/include/libavcodec/avcodec.h:4473:6: note: declared here
void av_free_packet(AVPacket *pkt);
^~~~~~~~~~~~~~
```

I use version 4.2.1 of ffmpeg.

Are there any plans to update the examples?