[FFmpeg-devel] [PATCH v2 4/4] avformat/movenc: handle EAC-3 extension bits for Atmos

[James Almer]

From: nyanmisaka <nst799610810 at gmail.com>

Fixes commit #9996.

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavformat/movenc.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index 7bcdc2463d..cd5b45f6fe 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -393,6 +393,8 @@ struct eac3_info {
         uint16_t chan_loc;
         /* if there is no dependent substream, then one bit reserved instead */
     } substream[1]; /* TODO: support 8 independent substreams */
+    /* indicates the decoding complexity, 8 bits */
+    uint8_t complexity_index_type_a;
 };
 
 static int mov_write_ac3_tag(AVFormatContext *s, AVIOContext *pb, MOVTrack *track)
@@ -474,6 +476,8 @@ static int handle_eac3(MOVMuxContext *mov, AVPacket *pkt, MOVTrack *track)
     info->data_rate = FFMAX(info->data_rate, hdr->bit_rate / 1000);
     info->ac3_bit_rate_code = FFMAX(info->ac3_bit_rate_code,
                                     hdr->ac3_bit_rate_code);
+    info->complexity_index_type_a = hdr->complexity_index_type_a;
+
     num_blocks = hdr->num_blocks;
 
     if (!info->ec3_done) {
@@ -601,7 +605,7 @@ static int mov_write_eac3_tag(AVFormatContext *s, AVIOContext *pb, MOVTrack *tra
     }
 
     info = track->eac3_priv;
-    size = 2 + ((34 * (info->num_ind_sub + 1) + 7) >> 3);
+    size = 2 + (4 * (info->num_ind_sub + 1)) + (2 * !!info->complexity_index_type_a);
     buf = av_malloc(size);
     if (!buf) {
         return AVERROR(ENOMEM);
@@ -626,6 +630,11 @@ static int mov_write_eac3_tag(AVFormatContext *s, AVIOContext *pb, MOVTrack *tra
             put_bits(&pbc, 9, info->substream[i].chan_loc);
         }
     }
+    if (info->complexity_index_type_a) {
+        put_bits(&pbc, 7, 0); /* reserved */
+        put_bits(&pbc, 1, 1); // flag_eac3_extension_type_a
+        put_bits(&pbc, 8, info->complexity_index_type_a);
+    }
     flush_put_bits(&pbc);
     size = put_bytes_output(&pbc);
 
-- 
2.49.0