[FFmpeg-cvslog] avformat/matroskadec: Read RealAudio extradata directly

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Wed Aug  4 22:20:46 2021 +0200| [e75ab15fd4579e7b4d5b12d756caeee338f0f62c] | committer: Andreas Rheinhardt

avformat/matroskadec: Read RealAudio extradata directly

Don't use the avio-API to read a few bytes at fixed offsets.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e75ab15fd4579e7b4d5b12d756caeee338f0f62c
---

 libavformat/matroskadec.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 01104dbda7..c33128f528 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -2660,18 +2660,18 @@ static int matroska_parse_tracks(AVFormatContext *s)
                     codec_id == AV_CODEC_ID_ATRAC3 ||
                     codec_id == AV_CODEC_ID_SIPR)
                       && track->codec_priv.data) {
+            const uint8_t *ptr = track->codec_priv.data;
             int flavor;
 
-            ffio_init_context(&b, track->codec_priv.data,
-                              track->codec_priv.size,
-                              0, NULL, NULL, NULL, NULL);
-            avio_skip(&b, 22);
-            flavor                       = avio_rb16(&b);
-            track->audio.coded_framesize = avio_rb32(&b);
-            avio_skip(&b, 12);
-            track->audio.sub_packet_h    = avio_rb16(&b);
-            track->audio.frame_size      = avio_rb16(&b);
-            track->audio.sub_packet_size = avio_rb16(&b);
+            if (track->codec_priv.size < 46)
+                return AVERROR_INVALIDDATA;
+            ptr += 22;
+            flavor                       = bytestream_get_be16(&ptr);
+            track->audio.coded_framesize = bytestream_get_be32(&ptr);
+            ptr += 12;
+            track->audio.sub_packet_h    = bytestream_get_be16(&ptr);
+            track->audio.frame_size      = bytestream_get_be16(&ptr);
+            track->audio.sub_packet_size = bytestream_get_be16(&ptr);
             if (track->audio.coded_framesize <= 0 ||
                 track->audio.sub_packet_h    <= 0 ||
                 track->audio.frame_size      <= 0)