From 79b057f1b7dd7ff05829089d2009c7172b13704b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20Ekstr=C3=B6m?= <jeebjp@gmail.com>
Date: Thu, 11 Jun 2020 00:07:15 +0300
Subject: [PATCH] avcodec/mpeg4audio: add newer channel_coding mappings

Additionally, add comments regarding their definitions. Based on
ARIB STD-B32, which bases on 14496-3:2009 and 14496-3:2009/AMD4.
---
 libavcodec/mpeg4audio.c | 17 +++++++++++++++--
 libavcodec/mpeg4audio.h |  2 +-
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/libavcodec/mpeg4audio.c b/libavcodec/mpeg4audio.c
index 0d83fb8d25..77cf2fb61c 100644
--- a/libavcodec/mpeg4audio.c
+++ b/libavcodec/mpeg4audio.c
@@ -64,8 +64,21 @@ const int avpriv_mpeg4audio_sample_rates[16] = {
     24000, 22050, 16000, 12000, 11025, 8000, 7350
 };
 
-const uint8_t ff_mpeg4audio_channels[8] = {
-    0, 1, 2, 3, 4, 5, 6, 8
+const uint8_t ff_mpeg4audio_channels[14] = {
+    0,
+    1, // mono (1/0)
+    2, // stereo (2/0)
+    3, // 3/0
+    4, // 3/1
+    5, // 3/2
+    6, // 3/2.1
+    8, // 5/2.1
+    0,
+    0,
+    0,
+    7, // 3/3.1
+    8, // 3/2/2.1
+    24 // 3/3/3 - 5/2/3 - 3/0/0.2
 };
 
 static inline int get_object_type(GetBitContext *gb)
diff --git a/libavcodec/mpeg4audio.h b/libavcodec/mpeg4audio.h
index 4b390e0f42..c4cdc1508c 100644
--- a/libavcodec/mpeg4audio.h
+++ b/libavcodec/mpeg4audio.h
@@ -46,7 +46,7 @@ typedef struct MPEG4AudioConfig {
 } MPEG4AudioConfig;
 
 extern av_export_avcodec const int avpriv_mpeg4audio_sample_rates[16];
-extern const uint8_t ff_mpeg4audio_channels[8];
+extern const uint8_t ff_mpeg4audio_channels[14];
 
 /**
  * Parse MPEG-4 systems extradata from a potentially unaligned GetBitContext to retrieve audio configuration.