[FFmpeg-cvslog] Fix multi-channel encoding with libfaac.

[Carl Eugen Hoyos]

ffmpeg | branch: master | Carl Eugen Hoyos <cehoyos at ag.or.at> | Wed Jan 25 03:51:49 2012 +0100| [7988dd1b9a1a5013a77d90cb7105c8a83d836756] | committer: Carl Eugen Hoyos

Fix multi-channel encoding with libfaac.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7988dd1b9a1a5013a77d90cb7105c8a83d836756
---

 libavcodec/libfaac.c |   10 ++++++++++
 1 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/libavcodec/libfaac.c b/libavcodec/libfaac.c
index 4758cf7..31dc1a4 100644
--- a/libavcodec/libfaac.c
+++ b/libavcodec/libfaac.c
@@ -31,6 +31,13 @@ typedef struct FaacAudioContext {
     faacEncHandle faac_handle;
 } FaacAudioContext;
 
+static const int channel_maps[][6] = {
+    { 2, 0, 1 },          //< C L R
+    { 2, 0, 1, 3 },       //< C L R Cs
+    { 2, 0, 1, 3, 4 },    //< C L R Ls Rs
+    { 2, 0, 1, 4, 5, 3 }, //< C L R Ls Rs LFE
+};
+
 static av_cold int Faac_encode_init(AVCodecContext *avctx)
 {
     FaacAudioContext *s = avctx->priv_data;
@@ -86,6 +93,9 @@ static av_cold int Faac_encode_init(AVCodecContext *avctx)
     }
     faac_cfg->outputFormat = 1;
     faac_cfg->inputFormat = FAAC_INPUT_16BIT;
+    if (avctx->channels > 2)
+        memcpy(faac_cfg->channel_map, channel_maps[avctx->channels-3],
+               avctx->channels * sizeof(int));
 
     avctx->frame_size = samples_input / avctx->channels;