[FFmpeg-cvslog] avformat/aacdec: factorize the adts frame resync code
James Almer
git at videolan.org
Sun Jul 21 03:51:00 EEST 2019
ffmpeg | branch: master | James Almer <jamrial at gmail.com> | Sat Jul 20 10:13:08 2019 -0300| [a38eab8b7501440f872ff1af8a0c5482b7b3e532] | committer: James Almer
avformat/aacdec: factorize the adts frame resync code
Signed-off-by: James Almer <jamrial at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a38eab8b7501440f872ff1af8a0c5482b7b3e532
---
libavformat/aacdec.c | 37 +++++++++++++++++++++++++------------
1 file changed, 25 insertions(+), 12 deletions(-)
diff --git a/libavformat/aacdec.c b/libavformat/aacdec.c
index 8a5450880b..262614fdd9 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);
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