[FFmpeg-devel] [PATCH 2/9] avformat/matroskadec: Read RealAudio extradata directly

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Thu Aug 5 08:42:37 EEST 2021


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

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
---
 libavformat/matroskadec.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index fdfcc86aeb..1977240cf9 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)
-- 
2.30.2



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