recorder: use av_oformat_next to support older FFmpeg
#include "log.h"
static const AVOutputFormat *find_mp4_muxer(void) {
+#if LIBAVFORMAT_VERSION_INT >= AV_VERSION_INT(58, 9, 100)
void *opaque = NULL;
- const AVOutputFormat *oformat;
+#endif
+ const AVOutputFormat *oformat = NULL;
do {
+#if LIBAVFORMAT_VERSION_INT >= AV_VERSION_INT(58, 9, 100)
oformat = av_muxer_iterate(&opaque);
+#else
+ oformat = av_oformat_next(oformat);
+#endif
// until null or with name "mp4"
} while (oformat && strcmp(oformat->name, "mp4"));
return oformat;
