lavc/aac_ac3_parser: avoid zeroing codec parameters if we haven't read a frame

This caused issues when seeking in some unusual MPEGTS files

diff --git a/libavcodec/aac_ac3_parser.c b/libavcodec/aac_ac3_parser.c
index 2f7d56807c2bc56f6e9aef57881e15a4b99a56fd..6a76eb8ec2123f63b5d9204869c826a22ef56ea4 100644 (file)
--- a/libavcodec/aac_ac3_parser.c
+++ b/libavcodec/aac_ac3_parser.c
@@ -34,6 +34,7 @@ int ff_aac_ac3_parse(AVCodecParserContext *s1,
     ParseContext *pc = &s->pc;
     int len, i;
     int new_frame_start;
+    int got_frame = 0;
 
 get_next:
     i=END_NOT_FOUND;
@@ -51,6 +52,7 @@ get_next:
             if(len<=0){
                 i=END_NOT_FOUND;
             }else{
+                got_frame = 1;
                 s->state=0;
                 i-= s->header_size -1;
                 s->remaining_size = len;
@@ -76,6 +78,7 @@ get_next:
     if(s->codec_id)
         avctx->codec_id = s->codec_id;
 
+    if (got_frame) {
     /* Due to backwards compatible HE-AAC the sample rate, channel count,
        and total number of samples found in an AAC ADTS header are not
        reliable. Bit rate is still accurate because the total frame duration in
@@ -101,6 +104,7 @@ get_next:
     }
 
     avctx->bit_rate = s->bit_rate;
+    }
 
     return i;
 }