diff options
Diffstat (limited to 'libavcodec/qtrle.c')
| -rw-r--r-- | libavcodec/qtrle.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/libavcodec/qtrle.c b/libavcodec/qtrle.c index c7a04c0..e84a63b 100644 --- a/libavcodec/qtrle.c +++ b/libavcodec/qtrle.c @@ -72,6 +72,15 @@ static void qtrle_decode_1bpp(QtrleContext *s, int stream_ptr, int row_ptr, int unsigned char *rgb = s->frame.data[0]; int pixel_limit = s->frame.linesize[0] * s->avctx->height; int skip; + /* skip & 0x80 appears to mean 'start a new line', which can be interpreted + * as 'go to next line' during the decoding of a frame but is 'go to first + * line' at the beginning. Since we always interpret it as 'go to next line' + * in the decoding loop (which makes code simpler/faster), the first line + * 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++; while (lines_to_change) { CHECK_STREAM_PTR(2); @@ -81,8 +90,8 @@ static void qtrle_decode_1bpp(QtrleContext *s, int stream_ptr, int row_ptr, int break; if(skip & 0x80) { lines_to_change--; - row_ptr += row_inc; pixel_ptr = row_ptr + 2 * (skip & 0x7f); + row_ptr += row_inc; } else pixel_ptr += 2 * skip; CHECK_PIXEL_PTR(0); /* make sure pixel_ptr is positive */ |
