X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=bitstream.c;fp=bitstream.c;h=d9d5233a9cde81ad2265ab06fe425f549ab85c51;hp=dedcdead5bc77bb12880ec9342dc95a39e6cd615;hb=5a8158c86d30905b0684fdf4e74a9bb1d1ba767b;hpb=232020d1a15641c8a492c07f79f59df7d4d279ea diff --git a/bitstream.c b/bitstream.c index dedcdead..d9d5233a 100644 --- a/bitstream.c +++ b/bitstream.c @@ -163,3 +163,42 @@ void free_vlc(struct vlc *vlc) { freep(&vlc->table); } + +/** + * Parse a vlc code. + * + * \param gbc The getbit context structure. + * + * \param bits The number of bits which will be read at once, must be + * identical to nb_bits in init_vlc(). + * + * \param max_depth The number of times bits bits must be read to completely + * read the longest vlc code = (max_vlc_length + bits - 1) / bits. + * + * \return The vlc code. + */ +int get_vlc(struct getbit_context *gbc, VLC_TYPE(*table)[2], int bits, + int max_depth) +{ + int n, idx, nb_bits, code; + + idx = show_bits(gbc, bits); + code = table[idx][0]; + n = table[idx][1]; + if (max_depth > 1 && n < 0) { + skip_bits(gbc, bits); + nb_bits = -n; + idx = show_bits(gbc, nb_bits) + code; + code = table[idx][0]; + n = table[idx][1]; + if (max_depth > 2 && n < 0) { + skip_bits(gbc, nb_bits); + nb_bits = -n; + idx = show_bits(gbc, nb_bits) + code; + code = table[idx][0]; + n = table[idx][1]; + } + } + skip_bits(gbc, n); + return code; +}