if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
get_channel_idx(&mapping, &out_ch_idx, separator, MAX_CH) < 0) {
av_log(ctx, AV_LOG_ERROR, err);
if (get_channel_idx(&mapping, &in_ch_idx, '-', MAX_CH) < 0 ||
get_channel_idx(&mapping, &out_ch_idx, separator, MAX_CH) < 0) {
av_log(ctx, AV_LOG_ERROR, err);