X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Flcldec.c;h=d4fe65ccebb4d5bfc9abc4c5150e6cdf1e400e58;hb=8d872e8ac9d17dd004af60787cd69eac69ef8891;hp=5225ff0552572bc3dcc263e07a8e9f819a8dd039;hpb=e4f141ad60afbd721e494975677fbfd8e0ebcb22;p=ffmpeg

diff --git a/libavcodec/lcldec.c b/libavcodec/lcldec.c
index 5225ff05525..d4fe65ccebb 100644
--- a/libavcodec/lcldec.c
+++ b/libavcodec/lcldec.c
@@ -73,7 +73,7 @@ typedef struct LclDecContext {
 
 
 /**
- * \param srcptr compressed source buffer, must be padded with at least 4 extra bytes
+ * \param srcptr compressed source buffer, must be padded with at least 5 extra bytes
  * \param destptr must be padded sufficiently for av_memcpy_backptr
  */
 static unsigned int mszh_decomp(const unsigned char * srcptr, int srclen, unsigned char * destptr, unsigned int destsize)
@@ -81,31 +81,36 @@ static unsigned int mszh_decomp(const unsigned char * srcptr, int srclen, unsign
     unsigned char *destptr_bak = destptr;
     unsigned char *destptr_end = destptr + destsize;
     const unsigned char *srcptr_end = srcptr + srclen;
-    unsigned char mask = 0;
-    unsigned char maskbit = 0;
-    unsigned int ofs, cnt;
+    unsigned mask = *srcptr++;
+    unsigned maskbit = 0x80;
 
     while (srcptr < srcptr_end && destptr < destptr_end) {
-        if (maskbit == 0) {
-            mask = *srcptr++;
-            maskbit = 8;
-            continue;
-        }
-        if ((mask & (1 << (--maskbit))) == 0) {
-            if (destptr_end - destptr < 4)
-                break;
+        if (!(mask & maskbit)) {
             memcpy(destptr, srcptr, 4);
             destptr += 4;
             srcptr += 4;
         } else {
-            ofs = bytestream_get_le16(&srcptr);
-            cnt = (ofs >> 11) + 1;
+            unsigned ofs = bytestream_get_le16(&srcptr);
+            unsigned cnt = (ofs >> 11) + 1;
             ofs &= 0x7ff;
+            ofs = FFMIN(ofs, destptr - destptr_bak);
             cnt *= 4;
             cnt = FFMIN(cnt, destptr_end - destptr);
             av_memcpy_backptr(destptr, ofs, cnt);
             destptr += cnt;
         }
+        maskbit >>= 1;
+        if (!maskbit) {
+            mask = *srcptr++;
+            while (!mask) {
+                if (destptr_end - destptr < 32 || srcptr_end - srcptr < 32) break;
+                memcpy(destptr, srcptr, 32);
+                destptr += 32;
+                srcptr += 32;
+                mask = *srcptr++;
+            }
+            maskbit = 0x80;
+        }
     }
 
     return destptr - destptr_bak;
@@ -119,6 +124,7 @@ static unsigned int mszh_decomp(const unsigned char * srcptr, int srclen, unsign
  * \param offset offset in decomp_buf
  * \param expected expected decompressed length
  */
+#if CONFIG_ZLIB_DECODER
 static int zlib_decomp(AVCodecContext *avctx, const uint8_t *src, int src_len, int offset, int expected)
 {
     LclDecContext *c = avctx->priv_data;
@@ -143,6 +149,7 @@ static int zlib_decomp(AVCodecContext *avctx, const uint8_t *src, int src_len, i
     }
     return c->zstream.total_out;
 }
+#endif
 
 
 /*
@@ -446,22 +453,11 @@ static av_cold int decode_init(AVCodecContext *avctx)
     unsigned int max_basesize = FFALIGN(avctx->width, 4) * FFALIGN(avctx->height, 4) + AV_LZO_OUTPUT_PADDING;
     unsigned int max_decomp_size;
 
-    c->pic.data[0] = NULL;
-
-#if CONFIG_ZLIB_DECODER
-    // Needed if zlib unused or init aborted before inflateInit
-    memset(&c->zstream, 0, sizeof(z_stream));
-#endif
-
     if (avctx->extradata_size < 8) {
         av_log(avctx, AV_LOG_ERROR, "Extradata size too small.\n");
         return 1;
     }
 
-    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
-        return 1;
-    }
-
     /* Check codec type */
     if ((avctx->codec_id == CODEC_ID_MSZH  && avctx->extradata[7] != CODEC_MSZH) ||
         (avctx->codec_id == CODEC_ID_ZLIB  && avctx->extradata[7] != CODEC_ZLIB)) {
@@ -512,7 +508,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
     }
 
     /* Detect compression method */
-    c->compression = avctx->extradata[5];
+    c->compression = (int8_t)avctx->extradata[5];
     switch (avctx->codec_id) {
     case CODEC_ID_MSZH:
         switch (c->compression) {
@@ -583,6 +579,7 @@ static av_cold int decode_init(AVCodecContext *avctx)
         zret = inflateInit(&c->zstream);
         if (zret != Z_OK) {
             av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
+            av_freep(&c->decomp_buf);
             return 1;
         }
     }
@@ -600,10 +597,12 @@ static av_cold int decode_end(AVCodecContext *avctx)
 {
     LclDecContext * const c = avctx->priv_data;
 
+    av_freep(&c->decomp_buf);
     if (c->pic.data[0])
         avctx->release_buffer(avctx, &c->pic);
 #if CONFIG_ZLIB_DECODER
-    inflateEnd(&c->zstream);
+    if (avctx->codec_id == CODEC_ID_ZLIB)
+        inflateEnd(&c->zstream);
 #endif
 
     return 0;