prores: only call get_buffer once per frame

[ffmpeg] / libavcodec / xxan.c

diff --git a/libavcodec/xxan.c b/libavcodec/xxan.c
index 10ec53f4677453b1e96cfdc687ca9a36be25c05c..938a5581c49a8ff89b9ac6adf4dfb8c7fd77f2cc 100644 (file)
--- a/libavcodec/xxan.c
+++ b/libavcodec/xxan.c
@@ -129,7 +129,9 @@ static int xan_unpack(uint8_t *dest, const int dest_len,
                 if (size + size2 > dest_end - dest)
                     break;
             }
-            if (src + size > src_end || dest + size + size2 > dest_end)
+            if (src + size > src_end ||
+                dest + size + size2 > dest_end ||
+                dest + size - orig_dest < back )
                 return -1;
             bytestream_get_buffer(&src, dest, size);
             dest += size;
@@ -194,6 +196,8 @@ static int xan_decode_chroma(AVCodecContext *avctx, AVPacket *avpkt)
     if (mode) {
         for (j = 0; j < avctx->height >> 1; j++) {
             for (i = 0; i < avctx->width >> 1; i++) {
+                if (src_end - src < 1)
+                    return 0;
                 val = *src++;
                 if (val) {
                     val  = AV_RL16(table + (val << 1));
@@ -202,8 +206,6 @@ static int xan_decode_chroma(AVCodecContext *avctx, AVPacket *avpkt)
                     U[i] = uval | (uval >> 5);
                     V[i] = vval | (vval >> 5);
                 }
-                if (src == src_end)
-                    return 0;
             }
             U += s->pic.linesize[1];
             V += s->pic.linesize[2];
@@ -214,6 +216,8 @@ static int xan_decode_chroma(AVCodecContext *avctx, AVPacket *avpkt)
 
         for (j = 0; j < avctx->height >> 2; j++) {
             for (i = 0; i < avctx->width >> 1; i += 2) {
+                if (src_end - src < 1)
+                    return 0;
                 val = *src++;
                 if (val) {
                     val  = AV_RL16(table + (val << 1));
@@ -302,6 +306,9 @@ static int xan_decode_frame_type0(AVCodecContext *avctx, AVPacket *avpkt)
                               corr_end - corr_off);
         if (dec_size < 0)
             dec_size = 0;
+        else
+            dec_size = FFMIN(dec_size, s->buffer_size/2 - 1);
+
         for (i = 0; i < dec_size; i++)
             s->y_buffer[i*2+1] = (s->y_buffer[i*2+1] + (s->scratch_buffer[i] << 1)) & 0x3F;
     }
@@ -415,15 +422,14 @@ static av_cold int xan_decode_end(AVCodecContext *avctx)
 }
 
 AVCodec ff_xan_wc4_decoder = {
-    "xan_wc4",
-    AVMEDIA_TYPE_VIDEO,
-    CODEC_ID_XAN_WC4,
-    sizeof(XanContext),
-    xan_decode_init,
-    NULL,
-    xan_decode_end,
-    xan_decode_frame,
-    CODEC_CAP_DR1,
+    .name           = "xan_wc4",
+    .type           = AVMEDIA_TYPE_VIDEO,
+    .id             = CODEC_ID_XAN_WC4,
+    .priv_data_size = sizeof(XanContext),
+    .init           = xan_decode_init,
+    .close          = xan_decode_end,
+    .decode         = xan_decode_frame,
+    .capabilities   = CODEC_CAP_DR1,
     .long_name = NULL_IF_CONFIG_SMALL("Wing Commander IV / Xxan"),
 };