[FFmpeg-cvslog] m4vdec: Check for non-startcode 00 00 00 sequences in probe

Michael Niedermayer git at videolan.org
Thu Mar 16 02:45:40 EET 2017


ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Sun Sep  7 16:39:39 2014 +0200| [e5b019725f53b79159931d3a7317107cbbfd0860] | committer: Diego Biurrun

m4vdec: Check for non-startcode 00 00 00 sequences in probe

This makes the m4v detection less trigger-happy.

Bug-Id: 949
Signed-off-by: Diego Biurrun <diego at biurrun.de>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=e5b019725f53b79159931d3a7317107cbbfd0860
---

 libavformat/m4vdec.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/libavformat/m4vdec.c b/libavformat/m4vdec.c
index 4a0af3c..9d69dcc 100644
--- a/libavformat/m4vdec.c
+++ b/libavformat/m4vdec.c
@@ -33,16 +33,18 @@ static int mpeg4video_probe(AVProbeData *probe_packet)
 
     for (i = 0; i < probe_packet->buf_size; i++) {
         temp_buffer = (temp_buffer << 8) + probe_packet->buf[i];
-        if ((temp_buffer & 0xffffff00) != 0x100)
+        if (temp_buffer & 0xfffffe00)
+            continue;
+        if (temp_buffer < 2)
             continue;
 
         if (temp_buffer == VOP_START_CODE)
             VOP++;
         else if (temp_buffer == VISUAL_OBJECT_START_CODE)
             VISO++;
-        else if (temp_buffer < 0x120)
+        else if (temp_buffer >= 0x100 && temp_buffer < 0x120)
             VO++;
-        else if (temp_buffer < 0x130)
+        else if (temp_buffer >= 0x120 && temp_buffer < 0x130)
             VOL++;
         else if (!(0x1AF < temp_buffer && temp_buffer < 0x1B7) &&
                  !(0x1B9 < temp_buffer && temp_buffer < 0x1C4))



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