+/* check that a given sample format is supported by the encoder */
+static int check_sample_fmt(AVCodec *codec, enum AVSampleFormat sample_fmt)
+{
+ const enum AVSampleFormat *p = codec->sample_fmts;
+
+ while (*p != AV_SAMPLE_FMT_NONE) {
+ if (*p == sample_fmt)
+ return 1;
+ p++;
+ }
+ return 0;
+}
+
+/* just pick the highest supported samplerate */
+static int select_sample_rate(AVCodec *codec)
+{
+ const int *p;
+ int best_samplerate = 0;
+
+ if (!codec->supported_samplerates)
+ return 44100;
+
+ p = codec->supported_samplerates;
+ while (*p) {
+ best_samplerate = FFMAX(*p, best_samplerate);
+ p++;
+ }
+ return best_samplerate;
+}
+
+/* select layout with the highest channel count */
+static int select_channel_layout(AVCodec *codec)
+{
+ const uint64_t *p;
+ uint64_t best_ch_layout = 0;
+ int best_nb_channels = 0;
+
+ if (!codec->channel_layouts)
+ return AV_CH_LAYOUT_STEREO;
+
+ p = codec->channel_layouts;
+ while (*p) {
+ int nb_channels = av_get_channel_layout_nb_channels(*p);
+
+ if (nb_channels > best_nb_channels) {
+ best_ch_layout = *p;
+ best_nb_channels = nb_channels;
+ }
+ p++;
+ }
+ return best_ch_layout;
+}
+