X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fmjpegdec.c;h=f26e8a3f9ac053c6124d4e0126d157837bc8f835;hb=4205010240fe013eaef25e6b8b86e7361dfbd27f;hp=8bf2fdfcc14583b8e453a4fb3300e4024d0dcba1;hpb=e5623aafd8f6cba710f714e1d22c13d4a699792b;p=ffmpeg

diff --git a/libavcodec/mjpegdec.c b/libavcodec/mjpegdec.c
index 8bf2fdfcc14..f26e8a3f9ac 100644
--- a/libavcodec/mjpegdec.c
+++ b/libavcodec/mjpegdec.c
@@ -188,6 +188,10 @@ int ff_mjpeg_decode_dqt(MJpegDecodeContext *s)
         /* read quant table */
         for (i = 0; i < 64; i++) {
             s->quant_matrixes[index][i] = get_bits(&s->gb, pr ? 16 : 8);
+            if (s->quant_matrixes[index][i] == 0) {
+                av_log(s->avctx, AV_LOG_ERROR, "dqt: 0 quant value\n");
+                return AVERROR_INVALIDDATA;
+            }
         }
 
         // XXX FIXME fine-tune, and perhaps add dc too
@@ -682,7 +686,7 @@ static inline int mjpeg_decode_dc(MJpegDecodeContext *s, int dc_index)
 
 /* decode block and dequantize */
 static int decode_block(MJpegDecodeContext *s, int16_t *block, int component,
-                        int dc_index, int ac_index, int16_t *quant_matrix)
+                        int dc_index, int ac_index, uint16_t *quant_matrix)
 {
     int code, i, j, level, val;
 
@@ -732,7 +736,7 @@ static int decode_block(MJpegDecodeContext *s, int16_t *block, int component,
 
 static int decode_dc_progressive(MJpegDecodeContext *s, int16_t *block,
                                  int component, int dc_index,
-                                 int16_t *quant_matrix, int Al)
+                                 uint16_t *quant_matrix, int Al)
 {
     int val;
     s->bdsp.clear_block(block);
@@ -750,7 +754,7 @@ static int decode_dc_progressive(MJpegDecodeContext *s, int16_t *block,
 /* decode block and dequantize - progressive JPEG version */
 static int decode_block_progressive(MJpegDecodeContext *s, int16_t *block,
                                     uint8_t *last_nnz, int ac_index,
-                                    int16_t *quant_matrix,
+                                    uint16_t *quant_matrix,
                                     int ss, int se, int Al, int *EOBRUN)
 {
     int code, i, j, level, val, run;
@@ -848,7 +852,7 @@ for (; ; i++) {                                                     \
 /* decode block and dequantize - progressive JPEG refinement pass */
 static int decode_block_refinement(MJpegDecodeContext *s, int16_t *block,
                                    uint8_t *last_nnz,
-                                   int ac_index, int16_t *quant_matrix,
+                                   int ac_index, uint16_t *quant_matrix,
                                    int ss, int se, int Al, int *EOBRUN)
 {
     int code, i = ss, j, sign, val, run;
@@ -1379,7 +1383,7 @@ static int mjpeg_decode_scan_progressive_ac(MJpegDecodeContext *s, int ss,
     int mb_x, mb_y;
     int EOBRUN = 0;
     int c = s->comp_index[0];
-    int16_t *quant_matrix = s->quant_matrixes[s->quant_sindex[0]];
+    uint16_t *quant_matrix = s->quant_matrixes[s->quant_sindex[0]];
 
     av_assert0(ss>=0 && Ah>=0 && Al>=0);
     if (se < ss || se > 63) {