GPAC
Open Source Multimedia Framework. For more information, check out http://gpac.wp.mines-telecom.fr
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BitStream object. More...
Enumerations | |
enum | { GF_BITSTREAM_READ = 0, GF_BITSTREAM_WRITE } |
Functions | |
GF_BitStream * | gf_bs_new (const char *buffer, u64 size, u32 mode) |
bitstream constructor More... | |
GF_BitStream * | gf_bs_from_file (FILE *f, u32 mode) |
bitstream constructor from file handle More... | |
void | gf_bs_del (GF_BitStream *bs) |
bitstream constructor from file handle More... | |
GF_Err | gf_bs_set_output_buffering (GF_BitStream *bs, u32 size) |
sets bitstream write cache size More... | |
u32 | gf_bs_get_output_buffering (GF_BitStream *bs) |
gets bitstream write cache size More... | |
u32 | gf_bs_read_int (GF_BitStream *bs, u32 nBits) |
integer reading More... | |
u64 | gf_bs_read_long_int (GF_BitStream *bs, u32 nBits) |
large integer reading More... | |
Float | gf_bs_read_float (GF_BitStream *bs) |
float reading More... | |
Double | gf_bs_read_double (GF_BitStream *bs) |
double reading More... | |
u32 | gf_bs_read_data (GF_BitStream *bs, char *data, u32 nbBytes) |
data reading More... | |
u32 | gf_bs_read_u8 (GF_BitStream *bs) |
align char reading More... | |
u32 | gf_bs_read_u8_until_delimiter (GF_BitStream *bs, u8 delimiter, u8 *out, u32 max_length) |
align char reading until reaching the given value More... | |
u32 | gf_bs_read_u16 (GF_BitStream *bs) |
align short reading More... | |
u32 | gf_bs_read_u24 (GF_BitStream *bs) |
align 24-bit integer reading More... | |
u32 | gf_bs_read_u32 (GF_BitStream *bs) |
align integer reading More... | |
u64 | gf_bs_read_u64 (GF_BitStream *bs) |
align large integer reading More... | |
u32 | gf_bs_read_u32_le (GF_BitStream *bs) |
little endian integer reading More... | |
u16 | gf_bs_read_u16_le (GF_BitStream *bs) |
little endian integer reading More... | |
u32 | gf_bs_read_vluimsbf5 (GF_BitStream *bs) |
variable length integer reading More... | |
u32 | gf_bs_get_bit_offset (GF_BitStream *bs) |
bit position More... | |
u32 | gf_bs_get_bit_position (GF_BitStream *bs) |
current bit position More... | |
void | gf_bs_write_int (GF_BitStream *bs, s32 value, s32 nBits) |
integer writing More... | |
void | gf_bs_write_long_int (GF_BitStream *bs, s64 value, s32 nBits) |
large integer writing More... | |
void | gf_bs_write_float (GF_BitStream *bs, Float value) |
float writing More... | |
void | gf_bs_write_double (GF_BitStream *bs, Double value) |
double writing More... | |
u32 | gf_bs_write_data (GF_BitStream *bs, const char *data, u32 nbBytes) |
data writing More... | |
void | gf_bs_write_u8 (GF_BitStream *bs, u32 value) |
align char writing More... | |
void | gf_bs_write_u16 (GF_BitStream *bs, u32 value) |
align short writing More... | |
void | gf_bs_write_u24 (GF_BitStream *bs, u32 value) |
align 24-bits integer writing More... | |
void | gf_bs_write_u32 (GF_BitStream *bs, u32 value) |
align integer writing More... | |
void | gf_bs_write_u64 (GF_BitStream *bs, u64 value) |
align large integer writing More... | |
void | gf_bs_write_u32_le (GF_BitStream *bs, u32 value) |
little endian integer writing More... | |
void | gf_bs_write_u16_le (GF_BitStream *bs, u32 value) |
little endian short writing More... | |
u32 | gf_bs_write_byte (GF_BitStream *bs, u8 byte, u32 count) |
write byte multiple times More... | |
void | gf_bs_set_eos_callback (GF_BitStream *bs, void(*EndOfStream)(void *par), void *par) |
end of bitstream management More... | |
u8 | gf_bs_align (GF_BitStream *bs) |
bitstream alignment More... | |
u64 | gf_bs_available (GF_BitStream *bs) |
capacity query More... | |
void | gf_bs_get_content (GF_BitStream *bs, char **output, u32 *outSize) |
buffer fetching More... | |
void | gf_bs_skip_bytes (GF_BitStream *bs, u64 nbBytes) |
byte skipping More... | |
GF_Err | gf_bs_seek (GF_BitStream *bs, u64 offset) |
bitstream seeking More... | |
void | gf_bs_truncate (GF_BitStream *bs) |
bitstream truncation More... | |
u32 | gf_bs_peek_bits (GF_BitStream *bs, u32 numBits, u32 byte_offset) |
bit peeking More... | |
u8 | gf_bs_bits_available (GF_BitStream *bs) |
bit reservoir query More... | |
u64 | gf_bs_get_position (GF_BitStream *bs) |
position query More... | |
u64 | gf_bs_get_size (GF_BitStream *bs) |
size query More... | |
u64 | gf_bs_get_refreshed_size (GF_BitStream *bs) |
file-based size query More... | |
GF_Err | gf_bs_transfer (GF_BitStream *dst, GF_BitStream *src) |
transfer content from source bitstream to destination bitstream More... | |
void | gf_bs_flush (GF_BitStream *bs) |
Flushes bitstream contet to disk. More... | |
void | gf_bs_reassign (GF_BitStream *bs, FILE *stream) |
Reassigns FILE object for stream-based bitstreams. More... | |
This section documents the bitstream object of the GPAC framework.
Constructs a bitstream from a buffer (read or write mode)
buffer | buffer to read or write. In WRITE mode, this can be NULL to let the bitstream object dynamically allocate memory, in which case the size param is ignored. |
size | size of the buffer given. |
mode | operation mode for this bitstream: GF_BITSTREAM_READ for read, GF_BITSTREAM_WRITE for write. |
GF_BitStream* gf_bs_from_file | ( | FILE * | f, |
u32 | mode | ||
) |
Creates a bitstream from a file handle.
f | handle of the file to use. This handle must be created with binary mode. |
mode | operation mode for this bitstream: GF_BITSTREAM_READ for read, GF_BITSTREAM_WRITE for write. |
void gf_bs_del | ( | GF_BitStream * | bs | ) |
Deletes the bitstream object. If the buffer was created by the bitstream, it is deleted if still present.
Sets the write cache size for file-based bitstreams.
bs | the target bitstream |
size | size of the write cache in bytes |
u32 gf_bs_get_output_buffering | ( | GF_BitStream * | bs | ) |
Gets the write cache size for file-based bitstreams.
bs | the target bitstream |
Reads an integer coded on a number of bit.
bs | the target bitstream |
nBits | the number of bits to read |
Reads a large integer coded on a number of bit bigger than 32.
bs | the target bitstream |
nBits | the number of bits to read |
Float gf_bs_read_float | ( | GF_BitStream * | bs | ) |
Reads a float coded as IEEE 32 bit format.
bs | the target bitstream |
Double gf_bs_read_double | ( | GF_BitStream * | bs | ) |
Reads a double coded as IEEE 64 bit format.
bs | the target bitstream |
Reads a data buffer
bs | the target bitstream |
data | the data buffer to be filled |
nbBytes | the amount of bytes to read |
u32 gf_bs_read_u8 | ( | GF_BitStream * | bs | ) |
Reads an integer coded on 8 bits starting at a byte boundary in the bitstream.
bs | the target bitstream |
Reads an integer coded on 8 bits starting at a byte boundary in the bitstream until
the given appears on the bitstream.
bs | the target bitstream |
delimiter | the stop condition |
out | the resulting value |
max_length | the maximum length of the output |
u32 gf_bs_read_u16 | ( | GF_BitStream * | bs | ) |
Reads an integer coded on 16 bits starting at a byte boundary in the bitstream.
bs | the target bitstream |
u32 gf_bs_read_u24 | ( | GF_BitStream * | bs | ) |
Reads an integer coded on 24 bits starting at a byte boundary in the bitstream.
bs | the target bitstream |
u32 gf_bs_read_u32 | ( | GF_BitStream * | bs | ) |
Reads an integer coded on 32 bits starting at a byte boundary in the bitstream.
bs | the target bitstream |
u64 gf_bs_read_u64 | ( | GF_BitStream * | bs | ) |
Reads an integer coded on 64 bits starting at a byte boundary in the bitstream.
bs | the target bitstream |
u32 gf_bs_read_u32_le | ( | GF_BitStream * | bs | ) |
Reads an integer coded on 32 bits in little-endian order.
bs | the target bitstream |
u16 gf_bs_read_u16_le | ( | GF_BitStream * | bs | ) |
Reads an integer coded on 16 bits in little-endian order.
bs | the target bitstream |
u32 gf_bs_read_vluimsbf5 | ( | GF_BitStream * | bs | ) |
Reads an integer coded on a variable number of 4-bits chunks. The number of chunks is given by the number of non-0 bits at the begining.
bs | the target bitstream |
u32 gf_bs_get_bit_offset | ( | GF_BitStream * | bs | ) |
Returns current bit position in the bitstream - only works in memory mode.
bs | the target bitstream |
u32 gf_bs_get_bit_position | ( | GF_BitStream * | bs | ) |
Returns bit position in the current byte of the bitstream - only works in memory mode.
bs | the target bitstream |
Writes an integer on a given number of bits.
bs | the target bitstream |
value | the integer to write |
nBits | number of bits used to code the integer |
Writes an integer on a given number of bits greater than 32.
bs | the target bitstream |
value | the large integer to write |
nBits | number of bits used to code the integer |
void gf_bs_write_float | ( | GF_BitStream * | bs, |
Float | value | ||
) |
Writes a float in IEEE 32 bits format.
bs | the target bitstream |
value | the float to write |
void gf_bs_write_double | ( | GF_BitStream * | bs, |
Double | value | ||
) |
Writes a double in IEEE 64 bits format.
bs | the target bitstream |
value | the double to write |
Writes a data buffer.
bs | the target bitstream |
data | the data to write |
nbBytes | number of data bytes to write |
void gf_bs_write_u8 | ( | GF_BitStream * | bs, |
u32 | value | ||
) |
Writes an integer on 8 bits starting at a byte boundary in the bitstream.
bs | the target bitstream |
value | the char value to write |
void gf_bs_write_u16 | ( | GF_BitStream * | bs, |
u32 | value | ||
) |
Writes an integer on 16 bits starting at a byte boundary in the bitstream.
bs | the target bitstream |
value | the short value to write |
void gf_bs_write_u24 | ( | GF_BitStream * | bs, |
u32 | value | ||
) |
Writes an integer on 24 bits starting at a byte boundary in the bitstream.
bs | the target bitstream |
value | the integer value to write |
void gf_bs_write_u32 | ( | GF_BitStream * | bs, |
u32 | value | ||
) |
Writes an integer on 32 bits starting at a byte boundary in the bitstream.
bs | the target bitstream |
value | the integer value to write |
void gf_bs_write_u64 | ( | GF_BitStream * | bs, |
u64 | value | ||
) |
Writes an integer on 64 bits starting at a byte boundary in the bitstream.
bs | the target bitstream |
value | the large integer value to write |
void gf_bs_write_u32_le | ( | GF_BitStream * | bs, |
u32 | value | ||
) |
Writes an integer on 32 bits in little-endian order.
bs | the target bitstream |
value | the integer value to write |
void gf_bs_write_u16_le | ( | GF_BitStream * | bs, |
u32 | value | ||
) |
Writes an integer on 16 bits in little-endian order.
bs | the target bitstream |
value | the short value to write |
Writes a give byte multiple times.
bs | the target bitstream |
byte | the byte value to write |
count | the number of times the byte should be written |
void gf_bs_set_eos_callback | ( | GF_BitStream * | bs, |
void(*)(void *par) | EndOfStream, | ||
void * | par | ||
) |
Assigns a notification callback function for end of stream signaling in read mode
bs | the target bitstream |
EndOfStream | the notification function to use |
par | opaque user data passed to the bitstream |
u8 gf_bs_align | ( | GF_BitStream * | bs | ) |
Aligns bitstream to next byte boundary. In write mode, this will write 0 bit values until alignment.
bs | the target bitstream |
u64 gf_bs_available | ( | GF_BitStream * | bs | ) |
Returns the number of bytes still available in the bitstream in read mode.
bs | the target bitstream |
void gf_bs_get_content | ( | GF_BitStream * | bs, |
char ** | output, | ||
u32 * | outSize | ||
) |
Fetches the internal bitstream buffer in write mode. If a buffer was given at the bitstream construction, or if the bitstream is in read mode, this does nothing.
bs | the target bitstream |
output | address of a memory block to be allocated for bitstream data. |
outSize | set to the size of the allocated memory block. |
void gf_bs_skip_bytes | ( | GF_BitStream * | bs, |
u64 | nbBytes | ||
) |
Skips bytes in the bitstream. In Write mode, this will write the 0 integer value for memory-based bitstreams or seek the stream
for file-based bitstream.
bs | the target bitstream |
nbBytes | the number of bytes to skip |
Seeks the bitstream to a given offset after the begining of the stream. This will perform alignment of the bitstream in all modes.
bs | the target bitstream |
offset | buffer/file offset to seek to |
void gf_bs_truncate | ( | GF_BitStream * | bs | ) |
Truncates the bitstream at the current position
bs | the target bitstream |
Peeks a given number of bits (read without moving the position indicator) for read modes only.
bs | the target bitstream |
numBits | the number of bits to peek |
byte_offset | if set, bitstream is aligned and moved from byte_offset before peeking (byte-aligned picking) otherwise, bitstream is not aligned and bits are peeked from current state |
u8 gf_bs_bits_available | ( | GF_BitStream * | bs | ) |
Queries the number of bits available in read mode.
bs | the target bitstream |
u64 gf_bs_get_position | ( | GF_BitStream * | bs | ) |
Returns the reading/writting position in the buffer/file.
bs | the target bitstream |
u64 gf_bs_get_size | ( | GF_BitStream * | bs | ) |
Returns the size of the associated buffer/file.
bs | the target bitstream |
u64 gf_bs_get_refreshed_size | ( | GF_BitStream * | bs | ) |
Returns the size of a file-based bitstream and force a seek to end of file. This is used in case the file handle describes a file being constructed on disk while being read?
bs | the target bitstream |
GF_Err gf_bs_transfer | ( | GF_BitStream * | dst, |
GF_BitStream * | src | ||
) |
Returns the size of the associated buffer/file.
dst | the target bitstream |
src | the source bitstream. This bitstream is empty after calling teh function |
void gf_bs_flush | ( | GF_BitStream * | bs | ) |
Flushes bitstream contet to disk
bs | the target bitstream |
void gf_bs_reassign | ( | GF_BitStream * | bs, |
FILE * | stream | ||
) |
Reassigns FILE object for stream-based bitstreams. Automatically sets the stream position to the bitstream position
bs | the target bitstream |
stream | the new stream to assign |