Set Beam Software VB palette opaque.

[ffmpeg] / libavcodec / vble.c

diff --git a/libavcodec/vble.c b/libavcodec/vble.c
index f354faa41f31fe3d92bd020f6fbd9a584902ede7..b27ec32a383578e3df5e6d2b11a6e31007ed8086 100644 (file)
--- a/libavcodec/vble.c
+++ b/libavcodec/vble.c
@@ -33,53 +33,51 @@ typedef struct {
     AVCodecContext *avctx;
 
     int            size;
-    int            flags;
-    uint8_t        *len;
-    uint8_t        *val;
+    uint8_t        *val; ///< This array first holds the lengths of vlc symbols and then their value.
 } VBLEContext;
 
-static uint8_t vble_read_reverse_unary(GetBitContext *gb)
-{
-    /* At most we need to read 9 bits total to get indices up to 8 */
-    uint8_t val = show_bits(gb, 8);
-
-    if (val) {
-        val = 7 - av_log2_16bit(av_reverse[val]);
-        skip_bits(gb, val + 1);
-        return val;
-    } else {
-        skip_bits(gb, 8);
-        if (get_bits1(gb))
-            return 8;
-    }
-
-    /* Return something larger than 8 on error */
-    return UINT8_MAX;
-}
-
 static int vble_unpack(VBLEContext *ctx, GetBitContext *gb)
 {
     int i;
+    int allbits = 0;
+    static const uint8_t LUT[256] = {
+        8,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        7,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        6,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+        5,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,4,0,1,0,2,0,1,0,3,0,1,0,2,0,1,0,
+    };
 
     /* Read all the lengths in first */
     for (i = 0; i < ctx->size; i++) {
-        ctx->len[i] = vble_read_reverse_unary(gb);
-
-        if (ctx->len[i] == UINT8_MAX)
-            return -1;
+        /* At most we need to read 9 bits total to get indices up to 8 */
+        int val = show_bits(gb, 8);
+
+        // read reverse unary
+        if (val) {
+            val = LUT[val];
+            skip_bits(gb, val + 1);
+            ctx->val[i] = val;
+        } else {
+            skip_bits(gb, 8);
+            if (!get_bits1(gb))
+                return -1;
+            ctx->val[i] = 8;
+        }
+        allbits += ctx->val[i];
     }
 
-    /* For any values that have length 0 */
-    memset(ctx->val, 0, ctx->size);
+    /* Check we have enough bits left */
+    if (get_bits_left(gb) < allbits)
+        return -1;
 
     for (i = 0; i < ctx->size; i++) {
-        /* Check we have enough bits left */
-        if (get_bits_left(gb) < ctx->len[i])
-            return -1;
-
         /* get_bits can't take a length of 0 */
-        if (ctx->len[i])
-            ctx->val[i] = (1 << ctx->len[i]) + get_bits(gb, ctx->len[i]) - 1;
+        if (ctx->val[i])
+            ctx->val[i] = (1 << ctx->val[i]) + get_bits(gb, ctx->val[i]) - 1;
     }
 
     return 0;
@@ -91,7 +89,6 @@ static void vble_restore_plane(VBLEContext *ctx, int plane, int offset,
     AVFrame *pic = ctx->avctx->coded_frame;
     uint8_t *dst = pic->data[plane];
     uint8_t *val = ctx->val + offset;
-    uint8_t *len = ctx->len + offset;
     uint8_t a, b, c;
     int stride = pic->linesize[plane];
     int i, j;
@@ -116,7 +113,6 @@ static void vble_restore_plane(VBLEContext *ctx, int plane, int offset,
         }
         dst += stride;
         val += width;
-        len += width;
     }
 }
 
@@ -167,7 +163,7 @@ static int vble_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
     vble_restore_plane(ctx, 0, offset, avctx->width, avctx->height);
 
     /* Chroma */
-    if (!(ctx->flags & CODEC_FLAG_GRAY)) {
+    if (!(ctx->avctx->flags & CODEC_FLAG_GRAY)) {
         offset += avctx->width * avctx->height;
         vble_restore_plane(ctx, 1, offset, width_uv, height_uv);
 
@@ -190,7 +186,6 @@ static av_cold int vble_decode_close(AVCodecContext *avctx)
         avctx->release_buffer(avctx, pic);
 
     av_freep(&avctx->coded_frame);
-    av_freep(&ctx->len);
     av_freep(&ctx->val);
 
     return 0;
@@ -202,7 +197,6 @@ static av_cold int vble_decode_init(AVCodecContext *avctx)
 
     /* Stash for later use */
     ctx->avctx = avctx;
-    ctx->flags = avctx->flags;
 
     avctx->pix_fmt = PIX_FMT_YUV420P;
     avctx->bits_per_raw_sample = 8;
@@ -216,14 +210,6 @@ static av_cold int vble_decode_init(AVCodecContext *avctx)
     ctx->size = avpicture_get_size(avctx->pix_fmt,
                                    avctx->width, avctx->height);
 
-    ctx->len = av_malloc(ctx->size * sizeof(*ctx->len));
-
-    if (!ctx->len) {
-        av_log(avctx, AV_LOG_ERROR, "Could not allocate lengths buffer.\n");
-        vble_decode_close(avctx);
-        return AVERROR(ENOMEM);
-    }
-
     ctx->val = av_malloc(ctx->size * sizeof(*ctx->val));
 
     if (!ctx->val) {