From c8c995bc1ddc34df93049f002432286018c8cc94 Mon Sep 17 00:00:00 2001 From: Felicia Lim Date: Mon, 27 Mar 2017 16:21:20 -0700 Subject: [PATCH] libopus: Add channel mapping 2 support in libopusdec Enables demuxing of Ambisonics content coded with channel mapping 2 Signed-off-by: Michael Niedermayer --- libavcodec/libopusdec.c | 37 ++++++++++++++++++++++++++++--------- 1 file changed, 28 insertions(+), 9 deletions(-) diff --git a/libavcodec/libopusdec.c b/libavcodec/libopusdec.c index e6ca61a78f..9dab0fdf65 100644 --- a/libavcodec/libopusdec.c +++ b/libavcodec/libopusdec.c @@ -57,8 +57,6 @@ static av_cold int libopus_decode_init(AVCodecContext *avc) avc->sample_rate = 48000; avc->sample_fmt = avc->request_sample_fmt == AV_SAMPLE_FMT_FLT ? AV_SAMPLE_FMT_FLT : AV_SAMPLE_FMT_S16; - avc->channel_layout = avc->channels > 8 ? 0 : - ff_vorbis_channel_layouts[avc->channels - 1]; if (avc->extradata_size >= OPUS_HEAD_SIZE) { opus->pre_skip = AV_RL16(avc->extradata + 10); @@ -82,14 +80,35 @@ static av_cold int libopus_decode_init(AVCodecContext *avc) mapping = mapping_arr; } - if (avc->channels > 2 && avc->channels <= 8) { - const uint8_t *vorbis_offset = ff_vorbis_channel_layout_offsets[avc->channels - 1]; - int ch; + if (channel_map == 1) { + avc->channel_layout = avc->channels > 8 ? 0 : + ff_vorbis_channel_layouts[avc->channels - 1]; + if (avc->channels > 2 && avc->channels <= 8) { + const uint8_t *vorbis_offset = ff_vorbis_channel_layout_offsets[avc->channels - 1]; + int ch; - /* Remap channels from Vorbis order to ffmpeg order */ - for (ch = 0; ch < avc->channels; ch++) - mapping_arr[ch] = mapping[vorbis_offset[ch]]; - mapping = mapping_arr; + /* Remap channels from Vorbis order to ffmpeg order */ + for (ch = 0; ch < avc->channels; ch++) + mapping_arr[ch] = mapping[vorbis_offset[ch]]; + mapping = mapping_arr; + } + } else if (channel_map == 2) { + int ambisonic_order = ff_sqrt(avc->channels) - 1; + if (avc->channels != (ambisonic_order + 1) * (ambisonic_order + 1) && + avc->channels != (ambisonic_order + 1) * (ambisonic_order + 1) + 2) { + av_log(avc, AV_LOG_ERROR, + "Channel mapping 2 is only specified for channel counts" + " which can be written as (n + 1)^2 or (n + 2)^2 + 2" + " for nonnegative integer n\n"); + return AVERROR_INVALIDDATA; + } + if (avc->channels > 227) { + av_log(avc, AV_LOG_ERROR, "Too many channels\n"); + return AVERROR_INVALIDDATA; + } + avc->channel_layout = 0; + } else { + avc->channel_layout = 0; } opus->dec = opus_multistream_decoder_create(avc->sample_rate, avc->channels,