Go to the documentation of this file.
21 #ifdef BITSTREAM_TEMPLATE_LE
22 # define BS_SUFFIX_LOWER _le
23 # define BS_SUFFIX_UPPER LE
25 # define BS_SUFFIX_LOWER _be
26 # define BS_SUFFIX_UPPER BE
29 #define BS_JOIN(x, y, z) x ## y ## z
30 #define BS_JOIN3(x, y, z) BS_JOIN(x, y, z)
31 #define BS_FUNC(x) BS_JOIN3(bits_, x, BS_SUFFIX_LOWER)
33 #define BSCTX BS_JOIN3(Bitstream, Context, BS_SUFFIX_UPPER)
52 #if !UNCHECKED_BITSTREAM_READER
53 if (bc->ptr >= bc->buffer_end)
57 #ifdef BITSTREAM_TEMPLATE_LE
77 #if !UNCHECKED_BITSTREAM_READER
78 if (bc->ptr >= bc->buffer_end)
82 #ifdef BITSTREAM_TEMPLATE_LE
83 bc->bits |= (uint64_t)
AV_RL32(bc->ptr) << bc->bits_valid;
85 bc->bits |= (uint64_t)
AV_RB32(bc->ptr) << (32 - bc->bits_valid);
102 unsigned int bit_size)
104 unsigned int buffer_size;
106 if (bit_size > INT_MAX - 7 || !
buffer) {
113 buffer_size = (bit_size + 7) >> 3;
116 bc->buffer_end =
buffer + buffer_size;
117 bc->ptr = bc->buffer;
118 bc->size_in_bits = bit_size;
136 unsigned int byte_size)
138 if (byte_size > INT_MAX / 8)
148 return (bc->ptr - bc->buffer) * 8 - bc->bits_valid;
156 return bc->size_in_bits;
164 return (bc->buffer - bc->ptr) * 8 + bc->size_in_bits + bc->bits_valid;
171 #ifdef BITSTREAM_TEMPLATE_LE
172 return bc->bits & (UINT64_MAX >> (64 - n));
174 return bc->bits >> (64 - n);
180 #ifdef BITSTREAM_TEMPLATE_LE
220 if (n > bc->bits_valid) {
254 if (n > bc->bits_valid) {
255 left = bc->bits_valid;
266 #ifdef BITSTREAM_TEMPLATE_LE
284 #ifdef BITSTREAM_TEMPLATE_LE
326 if (n > bc->bits_valid)
377 if (n < bc->bits_valid)
385 unsigned int skip = n / 8;
401 bc->ptr = bc->buffer;
427 int sign = ~cache >> 31;
430 return ((((uint32_t)(sign ^ cache)) >> (32 - n)) ^ sign) - sign;
459 return (
val ^ sign) - sign;
488 return table[idx].sym;
503 int bits,
int max_depth)
508 int n =
table[idx].len;
510 if (max_depth > 1 && n < 0) {
513 if (max_depth > 2 && n < 0) {
527 #undef BS_SUFFIX_UPPER
528 #undef BS_SUFFIX_LOWER
static uint64_t BS_FUNC() read_64(BSCTX *bc, unsigned int n)
Return n bits from the buffer, n has to be in the 0-64 range.
static int BS_FUNC() size(const BSCTX *bc)
Return buffer size in bits.
static uint32_t BS_FUNC() read_nz(BSCTX *bc, unsigned int n)
Return n bits from the buffer, n has to be in the 1-32 range.
static int BS_FUNC() decode210(BSCTX *bc)
Return decoded truncated unary code for the values 2, 1, 0.
static const uint16_t table[]
static int BS_FUNC() init(BSCTX *bc, const uint8_t *buffer, unsigned int bit_size)
Initialize BitstreamContext.
static int BS_FUNC() priv_refill_64(BSCTX *bc)
static uint32_t BS_FUNC() peek(BSCTX *bc, unsigned int n)
Return n bits from the buffer but do not change the buffer state.
static int BS_FUNC() peek_signed(BSCTX *bc, unsigned int n)
Return n bits from the buffer as a signed integer, do not change the buffer state.
static int32_t BS_FUNC() read_signed_nz(BSCTX *bc, unsigned int n)
Return n bits from the buffer as a signed integer, n has to be in the 1-32 range.
static int BS_FUNC() read_xbits(BSCTX *bc, unsigned int n)
Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).
static int BS_FUNC() left(const BSCTX *bc)
Return the number of the bits left in a buffer.
static uint32_t BS_FUNC() peek_nz(BSCTX *bc, unsigned int n)
Return n bits from the buffer but do not change the buffer state.
static double val(void *priv, double ch)
static uint64_t BS_FUNC() read_63(BSCTX *bc, unsigned int n)
Return n bits from the buffer, n has to be in the 0-63 range.
static unsigned int BS_FUNC() read_bit(BSCTX *bc)
Return one bit from the buffer.
static int32_t BS_FUNC() read_signed(BSCTX *bc, unsigned int n)
Return n bits from the buffer as a signed integer.
static int BS_FUNC() tell(const BSCTX *bc)
Return number of bits already read.
static void BS_FUNC() seek(BSCTX *bc, unsigned pos)
Seek to the given bit position.
static uint64_t BS_FUNC() priv_val_get(BSCTX *bc, unsigned int n)
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
static const uint8_t *BS_FUNC() align(BSCTX *bc)
Skip bits to a byte boundary.
static uint64_t BS_FUNC() priv_val_show(BSCTX *bc, unsigned int n)
static int BS_FUNC() peek_signed_nz(BSCTX *bc, unsigned int n)
Return n bits from the buffer as a signed integer, do not change the buffer state.
#define av_assert2(cond)
assert() equivalent, that does lie in speed critical code.
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code
const uint8_t * buffer_end
static int BS_FUNC() skip_1stop_8data(BSCTX *s)
static int BS_FUNC() priv_set_idx(BSCTX *bc, int code, int *n, int *nb_bits, const VLCElem *table)
Return the LUT element for the given bitstream configuration.
static int BS_FUNC() decode012(BSCTX *bc)
Return decoded truncated unary code for the values 0, 1, 2.
static int BS_FUNC() apply_sign(BSCTX *bc, int val)
static void BS_FUNC() priv_skip_remaining(BSCTX *bc, unsigned int n)
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
the frame and frame reference mechanism is intended to as much as expensive copies of that data while still allowing the filters to produce correct results The data is stored in buffers represented by AVFrame structures Several references can point to the same frame buffer
static av_const int sign_extend(int val, unsigned bits)
static int BS_FUNC() init8(BSCTX *bc, const uint8_t *buffer, unsigned int byte_size)
Initialize BitstreamContext.
static int BS_FUNC() priv_refill_32(BSCTX *bc)
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
static void BS_FUNC() skip(BSCTX *bc, unsigned int n)
Skip n bits in the buffer.
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_RB64
static uint32_t BS_FUNC() read(BSCTX *bc, unsigned int n)
Return n bits from the buffer, n has to be in the 0-32 range.
static int BS_FUNC() read_vlc(BSCTX *bc, const VLCElem *table, int bits, int max_depth)
Parse a vlc code.