diff options
Diffstat (limited to 'media/ffvpx/libavcodec/vlc.h')
| -rw-r--r-- | media/ffvpx/libavcodec/vlc.h | 89 |
1 files changed, 76 insertions, 13 deletions
diff --git a/media/ffvpx/libavcodec/vlc.h b/media/ffvpx/libavcodec/vlc.h index 42ccddf3fc..e63c484755 100644 --- a/media/ffvpx/libavcodec/vlc.h +++ b/media/ffvpx/libavcodec/vlc.h @@ -21,11 +21,16 @@ #include <stdint.h> -#define VLC_TYPE int16_t +// When changing this, be sure to also update tableprint_vlc.h accordingly. +typedef int16_t VLCBaseType; + +typedef struct VLCElem { + VLCBaseType sym, len; +} VLCElem; typedef struct VLC { int bits; - VLC_TYPE (*table)[2]; ///< code, bits + VLCElem *table; int table_size, table_allocated; } VLC; @@ -49,28 +54,73 @@ int ff_init_vlc_sparse(VLC *vlc, int nb_bits, int nb_codes, 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]; \ + static VLCElem table[static_size]; \ (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) @@ -78,4 +128,17 @@ void ff_free_vlc(VLC *vlc); #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 VLCElem table[static_size]; \ + (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 */ |