electronicarts: Check packet sizes before reading

[ffmpeg] / libavcodec / mss12.h

diff --git a/libavcodec/mss12.h b/libavcodec/mss12.h
index 383d86c90449bf92f7f35ecb0adf76eac7046cf4..5b1fee8913e2dc3307c4e41189110b9b806cbad8 100644 (file)
--- a/libavcodec/mss12.h
+++ b/libavcodec/mss12.h
@@ -26,8 +26,10 @@
 #ifndef AVCODEC_MSS12_H
 #define AVCODEC_MSS12_H
 
+#include "libavutil/intreadwrite.h"
 #include "avcodec.h"
 #include "get_bits.h"
+#include "bytestream.h"
 
 #define MODEL_MIN_SYMS    2
 #define MODEL_MAX_SYMS  256
@@ -36,17 +38,19 @@
 #define THRESH_HIGH      50
 
 typedef struct Model {
-    int cum_prob[MODEL_MAX_SYMS + 1];
-    int weights[MODEL_MAX_SYMS + 1];
-    int idx2sym[MODEL_MAX_SYMS + 1];
-    int sym2idx[MODEL_MAX_SYMS + 1];
+    int16_t cum_prob[MODEL_MAX_SYMS + 1];
+    int16_t weights[MODEL_MAX_SYMS + 1];
+    uint8_t idx2sym[MODEL_MAX_SYMS + 1];
     int num_syms;
     int thr_weight, threshold;
 } Model;
 
 typedef struct ArithCoder {
     int low, high, value;
-    GetBitContext *gb;
+    union {
+        GetBitContext *gb;
+        GetByteContext *gB;
+    } gbc;
     int (*get_model_sym)(struct ArithCoder *c, Model *m);
     int (*get_number)   (struct ArithCoder *c, int n);
 } ArithCoder;
@@ -55,29 +59,75 @@ typedef struct PixContext {
     int cache_size, num_syms;
     uint8_t cache[12];
     Model cache_model, full_model;
-    Model sec_models[4][8][4];
+    Model sec_models[15][4];
+    int special_initial_cache;
 } PixContext;
 
+struct MSS12Context;
+
+typedef struct SliceContext {
+    struct MSS12Context *c;
+    Model      intra_region, inter_region;
+    Model      pivot, edge_mode, split_mode;
+    PixContext intra_pix_ctx, inter_pix_ctx;
+} SliceContext;
+
 typedef struct MSS12Context {
     AVCodecContext *avctx;
-    uint8_t        *pic_start;
-    int            pic_stride;
-    uint8_t        *mask;
-    int            mask_linesize;
     uint32_t       pal[256];
+    uint8_t        *pal_pic;
+    uint8_t        *last_pal_pic;
+    int            pal_stride;
+    uint8_t        *mask;
+    int            mask_stride;
+    uint8_t        *rgb_pic;
+    uint8_t        *last_rgb_pic;
+    int            rgb_stride;
     int            free_colours;
     int            keyframe;
-    Model          intra_region, inter_region;
-    Model          pivot, edge_mode, split_mode;
-    PixContext     intra_pix_ctx, inter_pix_ctx;
+    int            mvX, mvY;
     int            corrupted;
+    int            slice_split;
+    int            full_model_syms;
 } MSS12Context;
 
-int ff_mss12_decode_rect(MSS12Context *ctx, ArithCoder *acoder,
+int ff_mss12_decode_rect(SliceContext *ctx, ArithCoder *acoder,
                          int x, int y, int width, int height);
 void ff_mss12_model_update(Model *m, int val);
-void ff_mss12_codec_reset(MSS12Context *ctx);
-av_cold int ff_mss12_decode_init(AVCodecContext *avctx, int version);
-av_cold int ff_mss12_decode_end(AVCodecContext *avctx);
+void ff_mss12_slicecontext_reset(SliceContext *sc);
+int ff_mss12_decode_init(MSS12Context *c, int version,
+                         SliceContext *sc1, SliceContext *sc2);
+int ff_mss12_decode_end(MSS12Context *ctx);
+
+#define ARITH_GET_BIT(VERSION)                                          \
+static int arith ## VERSION ## _get_bit(ArithCoder *c)                  \
+{                                                                       \
+    int range = c->high - c->low + 1;                                   \
+    int bit   = 2 * c->value - c->low >= c->high;                       \
+                                                                        \
+    if (bit)                                                            \
+        c->low += range >> 1;                                           \
+    else                                                                \
+        c->high = c->low + (range >> 1) - 1;                            \
+                                                                        \
+    arith ## VERSION ## _normalise(c);                                  \
+                                                                        \
+    return bit;                                                         \
+}
+
+#define ARITH_GET_MODEL_SYM(VERSION)                                    \
+static int arith ## VERSION ## _get_model_sym(ArithCoder *c, Model *m)  \
+{                                                                       \
+    int idx, val;                                                       \
+                                                                        \
+    idx = arith ## VERSION ## _get_prob(c, m->cum_prob);                \
+                                                                        \
+    val = m->idx2sym[idx];                                              \
+    ff_mss12_model_update(m, idx);                                      \
+                                                                        \
+    arith ## VERSION ## _normalise(c);                                  \
+                                                                        \
+    return val;                                                         \
+}
 
 #endif /* AVCODEC_MSS12_H */