avcodec/codec: add doxy to AVCodec.decode()

[ffmpeg] / libavcodec / webp.c

diff --git a/libavcodec/webp.c b/libavcodec/webp.c
index 077bb06f85a7c21e5e94b83aba997213a98ea80c..6de6a5c036d1b76ebf8e80e9ac0f8bfa4e8fda91 100644 (file)
--- a/libavcodec/webp.c
+++ b/libavcodec/webp.c
@@ -232,44 +232,6 @@ static void image_ctx_free(ImageContext *img)
     memset(img, 0, sizeof(*img));
 }
 
-
-/* Differs from get_vlc2() in the following ways:
- *   - codes are bit-reversed
- *   - assumes 8-bit table to make reversal simpler
- *   - assumes max depth of 2 since the max code length for WebP is 15
- */
-static av_always_inline int webp_get_vlc(GetBitContext *gb, VLC_TYPE (*table)[2])
-{
-    int n, nb_bits;
-    unsigned int index;
-    int code;
-
-    OPEN_READER(re, gb);
-    UPDATE_CACHE(re, gb);
-
-    index = SHOW_UBITS(re, gb, 8);
-    index = ff_reverse[index];
-    code  = table[index][0];
-    n     = table[index][1];
-
-    if (n < 0) {
-        LAST_SKIP_BITS(re, gb, 8);
-        UPDATE_CACHE(re, gb);
-
-        nb_bits = -n;
-
-        index = SHOW_UBITS(re, gb, nb_bits);
-        index = (ff_reverse[index] >> (8 - nb_bits)) + code;
-        code  = table[index][0];
-        n     = table[index][1];
-    }
-    SKIP_BITS(re, gb, n);
-
-    CLOSE_READER(re, gb);
-
-    return code;
-}
-
 static int huff_reader_get_symbol(HuffReader *r, GetBitContext *gb)
 {
     if (r->simple) {
@@ -278,10 +240,10 @@ static int huff_reader_get_symbol(HuffReader *r, GetBitContext *gb)
         else
             return r->simple_symbols[get_bits1(gb)];
     } else
-        return webp_get_vlc(gb, r->vlc.table);
+        return get_vlc2(gb, r->vlc.table, 8, 2);
 }
 
-static int huff_reader_build_canonical(HuffReader *r, int *code_lengths,
+static int huff_reader_build_canonical(HuffReader *r, const uint8_t *code_lengths,
                                        int alphabet_size)
 {
     int len = 0, sym, code = 0, ret;
@@ -332,7 +294,7 @@ static int huff_reader_build_canonical(HuffReader *r, int *code_lengths,
 
     ret = init_vlc(&r->vlc, 8, alphabet_size,
                    code_lengths, sizeof(*code_lengths), sizeof(*code_lengths),
-                   codes, sizeof(*codes), sizeof(*codes), 0);
+                   codes, sizeof(*codes), sizeof(*codes), INIT_VLC_OUTPUT_LE);
     if (ret < 0) {
         av_free(codes);
         return ret;
@@ -362,13 +324,12 @@ static int read_huffman_code_normal(WebPContext *s, HuffReader *hc,
                                     int alphabet_size)
 {
     HuffReader code_len_hc = { { 0 }, 0, 0, { 0 } };
-    int *code_lengths = NULL;
-    int code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 };
+    uint8_t *code_lengths;
+    uint8_t code_length_code_lengths[NUM_CODE_LENGTH_CODES] = { 0 };
     int i, symbol, max_symbol, prev_code_len, ret;
     int num_codes = 4 + get_bits(&s->gb, 4);
 
-    if (num_codes > NUM_CODE_LENGTH_CODES)
-        return AVERROR_INVALIDDATA;
+    av_assert1(num_codes <= NUM_CODE_LENGTH_CODES);
 
     for (i = 0; i < num_codes; i++)
         code_length_code_lengths[code_length_code_order[i]] = get_bits(&s->gb, 3);
@@ -376,9 +337,9 @@ static int read_huffman_code_normal(WebPContext *s, HuffReader *hc,
     ret = huff_reader_build_canonical(&code_len_hc, code_length_code_lengths,
                                       NUM_CODE_LENGTH_CODES);
     if (ret < 0)
-        goto finish;
+        return ret;
 
-    code_lengths = av_mallocz_array(alphabet_size, sizeof(*code_lengths));
+    code_lengths = av_mallocz(alphabet_size);
     if (!code_lengths) {
         ret = AVERROR(ENOMEM);
         goto finish;
@@ -1412,8 +1373,11 @@ static int webp_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
             return AVERROR_INVALIDDATA;
         chunk_size += chunk_size & 1;
 
-        if (bytestream2_get_bytes_left(&gb) < chunk_size)
-            return AVERROR_INVALIDDATA;
+        if (bytestream2_get_bytes_left(&gb) < chunk_size) {
+           /* we seem to be running out of data, but it could also be that the
+              bitstream has trailing junk leading to bogus chunk_size. */
+            break;
+        }
 
         switch (chunk_type) {
         case MKTAG('V', 'P', '8', ' '):