if (st->codec->extradata[19] == st->codec->channels - coupled_stream_counts[st->codec->channels] &&
st->codec->extradata[20] == coupled_stream_counts[st->codec->channels] &&
- memcmp(&st->codec->extradata[21], channel_map_a[st->codec->channels], st->codec->channels) == 0) {
+ memcmp(&st->codec->extradata[21], channel_map_a[st->codec->channels-1], st->codec->channels) == 0) {
*q++ = st->codec->channels;
} else if (st->codec->channels >= 2 && st->codec->extradata[19] == st->codec->channels &&
st->codec->extradata[20] == 0 &&
- memcmp(&st->codec->extradata[21], channel_map_b[st->codec->channels], st->codec->channels) == 0) {
+ memcmp(&st->codec->extradata[21], channel_map_b[st->codec->channels-1], st->codec->channels) == 0) {
*q++ = st->codec->channels | 0x80;
} else {
/* Unsupported, could write an extended descriptor here */