[FFmpeg-cvslog] avcodec/mlpdec: update matrix encoding only if it changed

[Paul B Mahol]

ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sat Sep  4 15:04:27 2021 +0200| [114634a51a7ca2ea4d375d62eba55123ce2262d5] | committer: Paul B Mahol

avcodec/mlpdec: update matrix encoding only if it changed

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=114634a51a7ca2ea4d375d62eba55123ce2262d5
---

 libavcodec/mlpdec.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/libavcodec/mlpdec.c b/libavcodec/mlpdec.c
index 6c2940903f..d56e214e1e 100644
--- a/libavcodec/mlpdec.c
+++ b/libavcodec/mlpdec.c
@@ -73,6 +73,7 @@ typedef struct SubStream {
     uint64_t    mask;
     /// The matrix encoding mode for this substream
     enum AVMatrixEncoding matrix_encoding;
+    enum AVMatrixEncoding prev_matrix_encoding;
 
     /// Channel coding parameters for channels in the substream
     ChannelParams channel_params[MAX_CHANNELS];
@@ -1123,8 +1124,12 @@ static int output_data(MLPDecodeContext *m, unsigned int substr,
                                                     is32);
 
     /* Update matrix encoding side data */
-    if ((ret = ff_side_data_update_matrix_encoding(frame, s->matrix_encoding)) < 0)
-        return ret;
+    if (s->matrix_encoding != s->prev_matrix_encoding) {
+        if ((ret = ff_side_data_update_matrix_encoding(frame, s->matrix_encoding)) < 0)
+            return ret;
+
+        s->prev_matrix_encoding = s->matrix_encoding;
+    }
 
     *got_frame_ptr = 1;
 
@@ -1353,6 +1358,7 @@ static void mlp_decode_flush(AVCodecContext *avctx)
         SubStream *s = &m->substream[substr];
 
         s->lossless_check_data = 0xffffffff;
+        s->prev_matrix_encoding = 0;
     }
 }