avcodec/s302menc: set supported channel layouts by codec

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavcodec/s302menc.c

@@ -175,4 +175,9 @@ AVCodec ff_s302m_encoder = {
                                                             AV_SAMPLE_FMT_NONE },
     .capabilities          = AV_CODEC_CAP_VARIABLE_FRAME_SIZE | AV_CODEC_CAP_EXPERIMENTAL,
     .supported_samplerates = (const int[]) { 48000, 0 },
+    .channel_layouts       = (const uint64_t[]) { AV_CH_LAYOUT_STEREO,
+                                                  AV_CH_LAYOUT_QUAD,
+                                                  AV_CH_LAYOUT_5POINT1_BACK,
+                                                  AV_CH_LAYOUT_5POINT1_BACK | AV_CH_LAYOUT_STEREO_DOWNMIX,
+                                                  0 },
 };