[FFmpeg-cvslog] avformat/iamf: document the expandable channel layouts

[James Almer]

ffmpeg | branch: master | James Almer <jamrial at gmail.com> | Mon Dec 30 16:53:57 2024 -0300| [c089c158d6c5b75fc8d88846487c4bae2e99e4b5] | committer: James Almer

avformat/iamf: document the expandable channel layouts

Signed-off-by: James Almer <jamrial at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c089c158d6c5b75fc8d88846487c4bae2e99e4b5
---

 libavformat/iamf.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/libavformat/iamf.c b/libavformat/iamf.c
index 0e17dd592d..03c2c239e2 100644
--- a/libavformat/iamf.c
+++ b/libavformat/iamf.c
@@ -46,55 +46,68 @@ const AVChannelLayout ff_iamf_scalable_ch_layouts[10] = {
 };
 
 const AVChannelLayout ff_iamf_expanded_scalable_ch_layouts[13] = {
+    // The low-frequency effects subset (LFE) of "Loudspeaker configuration for Sound System J"
     {
         .nb_channels = 1,
         .order       = AV_CHANNEL_ORDER_NATIVE,
         .u.mask      = AV_CH_LOW_FREQUENCY,
     },
+    // The surround subset (Ls/Rs) of "Loudspeaker configuration for Sound System I"
     {
         .nb_channels = 2,
         .order       = AV_CHANNEL_ORDER_NATIVE,
         .u.mask      = AV_CH_SIDE_LEFT | AV_CH_SIDE_RIGHT,
     },
+    // The side surround subset (Lss/Rss) of "Loudspeaker configuration for Sound System J"
     {
         .nb_channels = 2,
         .order       = AV_CHANNEL_ORDER_NATIVE,
         .u.mask      = AV_CH_SIDE_LEFT | AV_CH_SIDE_RIGHT,
     },
+    // The rear surround subset (Lrs/Rrs) of "Loudspeaker configuration for Sound System J"
     {
         .nb_channels = 2,
         .order       = AV_CHANNEL_ORDER_NATIVE,
         .u.mask      = AV_CH_BACK_LEFT | AV_CH_BACK_RIGHT,
     },
+    // The top front subset (Ltf/Rtf) of "Loudspeaker configuration for Sound System J"
     {
         .nb_channels = 2,
         .order       = AV_CHANNEL_ORDER_NATIVE,
         .u.mask      = AV_CH_TOP_FRONT_LEFT | AV_CH_TOP_FRONT_RIGHT,
     },
+    // The top back subset (Ltb/Rtb) of "Loudspeaker configuration for Sound System J"
     {
         .nb_channels = 2,
         .order       = AV_CHANNEL_ORDER_NATIVE,
         .u.mask      = AV_CH_TOP_BACK_LEFT | AV_CH_TOP_BACK_RIGHT,
     },
+    // The top 4 channels (Ltf/Rtf/Ltb/Rtb) of "Loudspeaker configuration for Sound System J"
     {
         .nb_channels = 4,
         .order       = AV_CHANNEL_ORDER_NATIVE,
         .u.mask      = AV_CH_TOP_FRONT_LEFT | AV_CH_TOP_FRONT_RIGHT |
                        AV_CH_TOP_BACK_LEFT | AV_CH_TOP_BACK_RIGHT,
     },
+    // The front 3 channels (L/C/R)  of "Loudspeaker configuration for Sound System J"
     AV_CHANNEL_LAYOUT_SURROUND,
+    // Subset of "Loudspeaker configuration for Sound System H"
     AV_CHANNEL_LAYOUT_9POINT1POINT6,
+    // Front subset of "Loudspeaker configuration for Sound System H"
     AV_CHANNEL_LAYOUT_STEREO,
+    // The side subset (SiL/SiR) of "Loudspeaker configuration for Sound System H"
     {
         .nb_channels = 2,
         .order       = AV_CHANNEL_ORDER_NATIVE,
         .u.mask      = AV_CH_SIDE_LEFT | AV_CH_SIDE_RIGHT,
     },
+    // The top side subset (TpSiL/TpSiR) of "Loudspeaker configuration for Sound System H"
     {
         .nb_channels = 2,
         .order       = AV_CHANNEL_ORDER_NATIVE,
         .u.mask      = AV_CH_TOP_SIDE_LEFT | AV_CH_TOP_SIDE_RIGHT,
     },
+    // The top 6 channels (TpFL/TpFR/TpSiL/TpSiR/TpBL/TpBR) of "Loudspeaker configuration for Sound System H"
     {
         .nb_channels = 6,
         .order       = AV_CHANNEL_ORDER_NATIVE,