[FFmpeg-devel] [PATCH] avcodec/aacdec_template: Allow duplicated elements

[Michael Niedermayer]

Such streams are invalid according to
4.5.2.1 Top level payloads for the audio object types AAC main, AAC SSR, AAC LC and AAC LTP
4.5.2.1.1 Definitions
...cIn the raw_data_block(), several instances of the
same syntactic element may occur, but must have a different 4 bit
element_instance_tag, except for data_stream_element()'s and
fill_element()'s.

Fixes: Ticket7477

Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/aacdec_template.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/libavcodec/aacdec_template.c b/libavcodec/aacdec_template.c
index b60b31a92c..dce6035d67 100644
--- a/libavcodec/aacdec_template.c
+++ b/libavcodec/aacdec_template.c
@@ -3161,12 +3161,15 @@ static int aac_decode_frame_int(AVCodecContext *avctx, void *data,
 
         if (elem_type < TYPE_DSE) {
             if (che_presence[elem_type][elem_id]) {
-                av_log(ac->avctx, AV_LOG_ERROR, "channel element %d.%d duplicate\n",
+                int error = che_presence[elem_type][elem_id] > 1;
+                av_log(ac->avctx, error ? AV_LOG_ERROR : AV_LOG_DEBUG, "channel element %d.%d duplicate\n",
                        elem_type, elem_id);
-                err = AVERROR_INVALIDDATA;
-                goto fail;
+                if (error) {
+                    err = AVERROR_INVALIDDATA;
+                    goto fail;
+                }
             }
-            che_presence[elem_type][elem_id] = 1;
+            che_presence[elem_type][elem_id]++;
 
             if (!(che=get_che(ac, elem_type, elem_id))) {
                 av_log(ac->avctx, AV_LOG_ERROR, "channel element %d.%d is not allocated\n",
-- 
2.19.0