[FFmpeg-devel] [PATCH] avformat/aacdec: resync to the next aac sample on invalid data instead of aborting

James Almer jamrial at gmail.com
Sat Jul 20 16:13:08 EEST 2019


Should fix ticket #6634

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavformat/aacdec.c | 44 +++++++++++++++++++++++++++++---------------
 1 file changed, 29 insertions(+), 15 deletions(-)

diff --git a/libavformat/aacdec.c b/libavformat/aacdec.c
index 8a5450880b..5b00b3f664 100644
--- a/libavformat/aacdec.c
+++ b/libavformat/aacdec.c
@@ -80,10 +80,31 @@ static int adts_aac_probe(const AVProbeData *p)
         return 0;
 }
 
+static int adts_aac_resync(AVFormatContext *s)
+{
+    uint16_t state;
+
+    // skip data until an ADTS frame is found
+    state = avio_r8(s->pb);
+    while (!avio_feof(s->pb) && avio_tell(s->pb) < s->probesize) {
+        state = (state << 8) | avio_r8(s->pb);
+        if ((state >> 4) != 0xFFF)
+            continue;
+        avio_seek(s->pb, -2, SEEK_CUR);
+        break;
+    }
+    if (s->pb->eof_reached)
+        return AVERROR_EOF;
+    if ((state >> 4) != 0xFFF)
+        return AVERROR_INVALIDDATA;
+
+    return 0;
+}
+
 static int adts_aac_read_header(AVFormatContext *s)
 {
     AVStream *st;
-    uint16_t state;
+    int ret;
 
     st = avformat_new_stream(s, NULL);
     if (!st)
@@ -101,17 +122,9 @@ static int adts_aac_read_header(AVFormatContext *s)
         avio_seek(s->pb, cur, SEEK_SET);
     }
 
-    // skip data until the first ADTS frame is found
-    state = avio_r8(s->pb);
-    while (!avio_feof(s->pb) && avio_tell(s->pb) < s->probesize) {
-        state = (state << 8) | avio_r8(s->pb);
-        if ((state >> 4) != 0xFFF)
-            continue;
-        avio_seek(s->pb, -2, SEEK_CUR);
-        break;
-    }
-    if ((state >> 4) != 0xFFF)
-        return AVERROR_INVALIDDATA;
+    ret = adts_aac_resync(s);
+    if (ret < 0)
+        return ret;
 
     // LCM of all possible ADTS sample rates
     avpriv_set_pts_info(st, 64, 1, 28224000);
@@ -177,9 +190,10 @@ retry:
         }
         if (!ff_id3v2_match(pkt->data, ID3v2_DEFAULT_MAGIC)) {
             av_packet_unref(pkt);
-            return AVERROR_INVALIDDATA;
-        }
-        ret = handle_id3(s, pkt);
+            ret = adts_aac_resync(s);
+        } else
+            ret = handle_id3(s, pkt);
+
         if (ret < 0)
             return ret;
 
-- 
2.22.0



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