const void *codes, int codes_wrap, int codes_size,
const void *symbols, int symbols_wrap, int symbols_size,
int flags);
+
+/**
+ * Build VLC decoding tables suitable for use with get_vlc2()
+ *
+ * This function takes lengths and symbols and calculates the codes from them.
+ * For this the input lengths and symbols have to be sorted according to "left
+ * nodes in the corresponding tree first".
+ *
+ * @param[in,out] vlc The VLC to be initialized; table and table_allocated
+ * must have been set when initializing a static VLC,
+ * otherwise this will be treated as uninitialized.
+ * @param[in] nb_bits The number of bits to use for the VLC table;
+ * higher values take up more memory and cache, but
+ * allow to read codes with fewer reads.
+ * @param[in] nb_codes The number of provided length and (if supplied) symbol
+ * entries.
+ * @param[in] lens The lengths of the codes. Entries > 0 correspond to
+ * valid codes; entries == 0 will be skipped and entries
+ * with len < 0 indicate that the tree is incomplete and
+ * has an open end of length -len at this position.
+ * @param[in] lens_wrap Stride (in bytes) of the lengths.
+ * @param[in] symbols The symbols, i.e. what is returned from get_vlc2()
+ * when the corresponding code is encountered.
+ * May be NULL, then 0, 1, 2, 3, 4,... will be used.
+ * @param[in] symbols_wrap Stride (in bytes) of the symbols.
+ * @param[in] symbols_size Size of the symbols. 1 and 2 are supported.
+ * @param[in] offset An offset to apply to all the valid symbols.
+ * @param[in] flags A combination of the INIT_VLC_* flags; notice that
+ * INIT_VLC_INPUT_LE is pointless and ignored.
+ */
+int ff_init_vlc_from_lengths(VLC *vlc, int nb_bits, int nb_codes,
+ const int8_t *lens, int lens_wrap,
+ const void *symbols, int symbols_wrap, int symbols_size,
+ int offset, int flags, void *logctx);
+
void ff_free_vlc(VLC *vlc);
-#define INIT_VLC_LE 2
+/* If INIT_VLC_INPUT_LE is set, the LSB bit of the codes used to
+ * initialize the VLC table is the first bit to be read. */
+#define INIT_VLC_INPUT_LE 2
+/* If set the VLC is intended for a little endian bitstream reader. */
+#define INIT_VLC_OUTPUT_LE 8
+#define INIT_VLC_LE (INIT_VLC_INPUT_LE | INIT_VLC_OUTPUT_LE)
#define INIT_VLC_USE_NEW_STATIC 4
+#define INIT_VLC_STATIC_OVERLONG (1 | INIT_VLC_USE_NEW_STATIC)
-#define INIT_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, h, i, j, static_size) \
+#define INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, \
+ h, i, j, flags, static_size) \
do { \
static VLC_TYPE table[static_size][2]; \
(vlc)->table = table; \
(vlc)->table_allocated = static_size; \
ff_init_vlc_sparse(vlc, bits, a, b, c, d, e, f, g, h, i, j, \
- INIT_VLC_USE_NEW_STATIC); \
+ flags | INIT_VLC_USE_NEW_STATIC); \
} while (0)
+#define INIT_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, h, i, j, static_size) \
+ INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, \
+ h, i, j, 0, static_size)
+
#define INIT_LE_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, h, i, j, static_size) \
- do { \
- static VLC_TYPE table[static_size][2]; \
- (vlc)->table = table; \
- (vlc)->table_allocated = static_size; \
- ff_init_vlc_sparse(vlc, bits, a, b, c, d, e, f, g, h, i, j, \
- INIT_VLC_USE_NEW_STATIC | INIT_VLC_LE); \
- } while (0)
+ INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, \
+ h, i, j, INIT_VLC_LE, static_size)
+
+#define INIT_CUSTOM_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, flags, static_size) \
+ INIT_CUSTOM_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, \
+ NULL, 0, 0, flags, static_size)
#define INIT_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size) \
INIT_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, NULL, 0, 0, static_size)
#define INIT_LE_VLC_STATIC(vlc, bits, a, b, c, d, e, f, g, static_size) \
INIT_LE_VLC_SPARSE_STATIC(vlc, bits, a, b, c, d, e, f, g, NULL, 0, 0, static_size)
+#define INIT_VLC_STATIC_FROM_LENGTHS(vlc, bits, nb_codes, lens, len_wrap, \
+ symbols, symbols_wrap, symbols_size, \
+ offset, flags, static_size) \
+ do { \
+ static VLC_TYPE table[static_size][2]; \
+ (vlc)->table = table; \
+ (vlc)->table_allocated = static_size; \
+ ff_init_vlc_from_lengths(vlc, bits, nb_codes, lens, len_wrap, \
+ symbols, symbols_wrap, symbols_size, \
+ offset, flags | INIT_VLC_USE_NEW_STATIC, \
+ NULL); \
+ } while (0)
+
#endif /* AVCODEC_VLC_H */
projects / ffmpeg / blobdiff