X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fqtrle.c;h=c051d056a48f77a676b86aedef8693e128e7b84b;hb=7ff1a4b10f2d7f9a4ae1c72e1259b4ed7d13e316;hp=5acd2eb3ae36f67d75a7b9b66251d017a4c8eda3;hpb=b4581e9394c9f97d08af814d09337ed16f21cfe0;p=ffmpeg

diff --git a/libavcodec/qtrle.c b/libavcodec/qtrle.c
index 5acd2eb3ae3..c051d056a48 100644
--- a/libavcodec/qtrle.c
+++ b/libavcodec/qtrle.c
@@ -56,7 +56,7 @@ typedef struct QtrleContext {
 static void qtrle_decode_1bpp(QtrleContext *s, int row_ptr, int lines_to_change)
 {
     int rle_code;
-    int pixel_ptr = 0;
+    int pixel_ptr;
     int row_inc = s->frame.linesize[0];
     unsigned char pi0, pi1;  /* 2 8-pixel values */
     unsigned char *rgb = s->frame.data[0];
@@ -69,9 +69,11 @@ static void qtrle_decode_1bpp(QtrleContext *s, int row_ptr, int lines_to_change)
      * would not be counted, so we count one more.
      * See: https://ffmpeg.org/trac/ffmpeg/ticket/226
      * In the following decoding loop, row_ptr will be the position of the
-     * _next_ row. */
-    lines_to_change++;
+     * current row. */
 
+    row_ptr  -= row_inc;
+    pixel_ptr = row_ptr;
+    lines_to_change++;
     while (lines_to_change) {
         skip     =              bytestream2_get_byte(&s->g);
         rle_code = (signed char)bytestream2_get_byte(&s->g);
@@ -79,8 +81,8 @@ static void qtrle_decode_1bpp(QtrleContext *s, int row_ptr, int lines_to_change)
             break;
         if(skip & 0x80) {
             lines_to_change--;
-            pixel_ptr = row_ptr + 2 * (skip & 0x7f);
             row_ptr += row_inc;
+            pixel_ptr = row_ptr + 2 * (skip & 0x7f);
         } else
             pixel_ptr += 2 * skip;
         CHECK_PIXEL_PTR(0);  /* make sure pixel_ptr is positive */