imc: set channels to 1 instead of validating it

libavcodec/imc.c

@@ -175,8 +175,10 @@ static av_cold int imc_decode_init(AVCodecContext *avctx)
     IMCContext *q = avctx->priv_data;
     double r1, r2;
 
-    if ((avctx->codec_id == AV_CODEC_ID_IMC && avctx->channels != 1)
-        || (avctx->codec_id == AV_CODEC_ID_IAC && avctx->channels > 2)) {
+    if (avctx->codec_id == AV_CODEC_ID_IMC)
+        avctx->channels = 1;
+
+    if (avctx->channels > 2) {
         av_log_ask_for_sample(avctx, "Number of channels is not supported\n");
         return AVERROR_PATCHWELCOME;
     }