[FFmpeg-devel] [PATCH] avformat/m4vdec: use avpriv_find_start_code in mpeg4video_probe()

[zhaoxiu.zeng]

>From 7d57cb0e822ac755ba7e3d9c09d90bf62c7da24d Mon Sep 17 00:00:00 2001
From: Zeng Zhaoxiu <zhaoxiu.zeng at gmail.com>
Date: Sun, 15 Mar 2015 11:59:27 +0800
Subject: [PATCH 4/7] avformat/m4vdec: use avpriv_find_start_code in
 mpeg4video_probe()

Signed-off-by: Zeng Zhaoxiu <zhaoxiu.zeng at gmail.com>
---
 libavformat/m4vdec.c | 17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

diff --git a/libavformat/m4vdec.c b/libavformat/m4vdec.c
index d8ee530..aa0ee36 100644
--- a/libavformat/m4vdec.c
+++ b/libavformat/m4vdec.c
@@ -21,6 +21,7 @@
 
 #include "avformat.h"
 #include "rawdec.h"
+#include "libavcodec/internal.h"
 
 #define VISUAL_OBJECT_START_CODE       0x000001b5
 #define VOP_START_CODE                 0x000001b6
@@ -29,22 +30,20 @@ static int mpeg4video_probe(AVProbeData *probe_packet)
 {
     uint32_t temp_buffer = -1;
     int VO = 0, VOL = 0, VOP = 0, VISO = 0, res = 0;
-    int i;
+    const uint8_t *ptr = probe_packet->buf, *end = ptr + probe_packet->buf_size;
 
-    for (i = 0; i < probe_packet->buf_size; i++) {
-        temp_buffer = (temp_buffer << 8) + probe_packet->buf[i];
-        if (temp_buffer & 0xfffffe00)
-            continue;
-        if (temp_buffer < 2)
-            continue;
+    while (ptr < end) {
+        ptr = avpriv_find_start_code(ptr, end, &temp_buffer);
+        if ((temp_buffer & 0xffffff00) != 0x100)
+            break;
 
         if (temp_buffer == VOP_START_CODE)
             VOP++;
         else if (temp_buffer == VISUAL_OBJECT_START_CODE)
             VISO++;
-        else if (temp_buffer >= 0x100 && temp_buffer < 0x120)
+        else if (temp_buffer < 0x120)
             VO++;
-        else if (temp_buffer >= 0x120 && temp_buffer < 0x130)
+        else if (temp_buffer < 0x130)
             VOL++;
         else if (!(0x1AF < temp_buffer && temp_buffer < 0x1B7) &&
                  !(0x1B9 < temp_buffer && temp_buffer < 0x1C4))
-- 
2.1.0