From fcf3e06fe406823214e95993e210ac2cc2bfa6b4 Mon Sep 17 00:00:00 2001 From: Felicia Date: Mon, 6 Feb 2017 15:49:36 -0800 Subject: [PATCH] libopus: decode ambisonics with non-diegetic sources Channel mapping 2 additionally supports a non-diegetic stereo track appended to the end of a full-order ambisonics signal, such that the total channel count is either (n + 1) ^ 2, or (n + 1) ^ 2 + 2 where n is the ambisonics order Signed-off-by: Michael Niedermayer --- libavcodec/opus.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/libavcodec/opus.c b/libavcodec/opus.c index 1eeb92c5bd..07e70fd7a4 100644 --- a/libavcodec/opus.c +++ b/libavcodec/opus.c @@ -373,10 +373,12 @@ av_cold int ff_opus_parse_extradata(AVCodecContext *avctx, channel_reorder = channel_reorder_vorbis; } else if (map_type == 2) { int ambisonic_order = ff_sqrt(channels) - 1; - if (channels != (ambisonic_order + 1) * (ambisonic_order + 1)) { + if (channels != ((ambisonic_order + 1) * (ambisonic_order + 1)) && + channels != ((ambisonic_order + 1) * (ambisonic_order + 1) + 2)) { av_log(avctx, AV_LOG_ERROR, "Channel mapping 2 is only specified for channel counts" - " which can be written as (n + 1)^2 for nonnegative integer n\n"); + " which can be written as (n + 1)^2 or (n + 1)^2 + 2" + " for nonnegative integer n\n"); return AVERROR_INVALIDDATA; } layout = 0;