FFmpeg: libavcodec/bitstream_template.h File Reference

static int BS_FUNC() read_vlc_multi (BSCTX *bc, uint8_t dst[8], const VLC_MULTI_ELEM *const Jtable, const VLCElem *const table, const int bits, const int max_depth, const int symbols_size)

Parse a vlc / vlc_multi code. More...

Macro Definition Documentation

◆ BS_SUFFIX_LOWER

#define BS_SUFFIX_LOWER _be

Definition at line 25 of file bitstream_template.h.

◆ BS_SUFFIX_UPPER

#define BS_SUFFIX_UPPER BE

Definition at line 26 of file bitstream_template.h.

◆ BS_JOIN

#define BS_JOIN ( x,

) x ## y ## z

Definition at line 29 of file bitstream_template.h.

◆ BS_JOIN3

#define BS_JOIN3 ( x,

) BS_JOIN(x, y, z)

Definition at line 30 of file bitstream_template.h.

◆ BS_FUNC

#define BS_FUNC ( x ) BS_JOIN3(bits_, x, BS_SUFFIX_LOWER)

Definition at line 31 of file bitstream_template.h.

◆ BSCTX

#define BSCTX BS_JOIN3(Bitstream, Context, BS_SUFFIX_UPPER)

Definition at line 33 of file bitstream_template.h.

Function Documentation

◆ priv_refill_64()

static int BS_FUNC() priv_refill_64 ( BSCTX * bc )

inlinestatic

Returns

0 on successful refill
a negative number when bitstream end is hit

Always succeeds when UNCHECKED_BITSTREAM_READER is enabled.

Definition at line 50 of file bitstream_template.h.

Referenced by init(), read_63(), read_bit(), and skip().

◆ priv_refill_32()

static int BS_FUNC() priv_refill_32 ( BSCTX * bc )

inlinestatic

Returns

0 on successful refill
a negative number when bitstream end is hit

Always succeeds when UNCHECKED_BITSTREAM_READER is enabled.

Definition at line 75 of file bitstream_template.h.

Referenced by peek_nz(), and read_nz().

◆ init()

static int BS_FUNC() init ( BSCTX * bc,

const uint8_t * buffer,

unsigned int bit_size

)

inlinestatic

Initialize BitstreamContext.

Parameters: buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes larger than the actual read bits because some optimized bitstream readers read 32 or 64 bits at once and could read over the end

bit_size the size of the buffer in bits

Returns: 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.

Definition at line 101 of file bitstream_template.h.

Referenced by init8().

◆ init8()

static int BS_FUNC() init8 ( BSCTX * bc,

const uint8_t * buffer,

unsigned int byte_size

)

inlinestatic

Initialize BitstreamContext.

Parameters: buffer bitstream buffer, must be AV_INPUT_BUFFER_PADDING_SIZE bytes larger than the actual read bits because some optimized bitstream readers read 32 or 64 bits at once and could read over the end

byte_size the size of the buffer in bytes

Returns: 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow

Definition at line 135 of file bitstream_template.h.

◆ tell()

static int BS_FUNC() tell ( const BSCTX * bc )

inlinestatic

Return number of bits already read.

Definition at line 146 of file bitstream_template.h.

Referenced by align(), and quant_band_template().

◆ size()

static int BS_FUNC() size ( const BSCTX * bc )

inlinestatic

Return buffer size in bits.

Definition at line 154 of file bitstream_template.h.

static unsigned int BS_FUNC() read_bit ( BSCTX * bc )

inlinestatic

Return one bit from the buffer.

Definition at line 203 of file bitstream_template.h.

Referenced by decode012(), decode210(), read_64(), and skip_1stop_8data().

◆ read_nz()

static uint32_t BS_FUNC() read_nz ( BSCTX * bc,

unsigned int n

)

inlinestatic

Return n bits from the buffer, n has to be in the 1-32 range.

May be faster than bits_read() when n is not a compile-time constant and is known to be non-zero;

Definition at line 216 of file bitstream_template.h.

Referenced by read(), and read_signed_nz().

◆ read()

static uint32_t BS_FUNC() read ( BSCTX * bc,

unsigned int n

)

inlinestatic

Return n bits from the buffer, n has to be in the 0-32 range.

Examples: ffhash.c.

Definition at line 231 of file bitstream_template.h.

Referenced by audio_read_packet(), av_file_map(), cache_read(), check(), ebml_read_num(), ff_amf_read_number(), ff_get_cpu_flags_ppc(), ff_iamf_read_packet(), file_read(), flv_set_video_codec(), ftp_read(), get_strl(), headphone_convolute(), jpegxl_anim_read_header(), lag_decode_arith_plane(), main(), mlp_read_header(), mxf_parse_klv(), read_key(), read_line_to_bprint_escaped(), read_string_to_bprint(), retry_transfer_wrapper(), rtmp_packet_read_one_chunk(), skip_icc_profile(), smush_read_header(), sofalizer_convolute(), str_read_packet(), and tls_read_cb().

◆ read_63()

static uint64_t BS_FUNC() read_63 ( BSCTX * bc,

unsigned int n

)

inlinestatic

Return n bits from the buffer, n has to be in the 0-63 range.

Definition at line 244 of file bitstream_template.h.

static int BS_FUNC() peek_signed ( BSCTX * bc,

unsigned int n

)

inlinestatic

Return n bits from the buffer as a signed integer, do not change the buffer state.

n has to be in the 0-32 range.

Definition at line 362 of file bitstream_template.h.

◆ skip()

static void BS_FUNC() skip ( BSCTX * bc,

unsigned int n

)

inlinestatic

Skip n bits in the buffer.

Definition at line 375 of file bitstream_template.h.

Referenced by aax_read_packet(), ac3_decode_frame(), align(), append_flv_data(), asf_read_multiple_payload(), av_read_image_line2(), av_write_image_line2(), avui_decode_frame(), avui_encode_frame(), cbs_h264_discarded_nal_unit(), cbs_h265_discarded_nal_unit(), cdtoons_render_sprite(), clv_decode_frame(), conv_down(), convert_coeffs(), convert_frame(), convert_frame_partial(), cpia_decode_frame(), cri_decode_frame(), decode_555(), decode_block(), decode_dct(), decode_frame(), decode_header_trees(), decode_inter_block(), decode_inter_blocks(), decode_inter_plane(), decode_intra_block(), decode_intra_blocks(), decode_intra_plane(), decode_long_vertical_delta2(), decode_mad1(), decode_motion_vectors(), decode_mvdv(), decode_rle(), decode_scale_factors(), decode_tdlt(), decompress_5(), decompress_68(), draw(), dshow_cycle_devices(), dtshd_read_header(), dwa_uncompress(), dwt_plane(), dxv_decompress_yo(), encode_slices(), end_ebml_master_crc32(), escape124_decode_frame(), escape130_decode_frame(), ff_cbs_discard_units(), ff_configure_buffers_for_index(), ff_dovi_configure_ext(), ff_h264_decode_mb_cabac(), ff_hevc_hls_filter(), ff_htmlmarkup_to_ass(), ff_iamf_parse_obu_header(), ff_libwebp_get_frame(), ff_mjpeg_decode_frame_from_buf(), ff_mjpeg_find_marker(), ff_rm_read_mdpr_codecdata(), ff_tx_decompose_length(), ff_vk_filter_init_context(), fic_decode_frame(), filter_channel(), filter_start(), find_frame_end(), finished_reading_packet(), flush(), flv_data_packet(), flv_read_packet(), forward(), frame_data_apply(), g722_decode_frame(), gif_read_header(), gxf_packet(), handle_notify(), ipvideo_decode_format_10_opcodes(), is_animated_webp_packet(), load_enabled_qfs(), main(), min_cb_nz_tl_init(), mp_decode_layer3(), mpc7_decode_frame(), mpegps_read_packet(), mpegps_read_pes_header(), mpegts_push_data(), mss4_decode_dct(), mxf_read_packet(), nut_read_packet(), old_codec47(), opus_packet(), output_chunk_list(), pnm_parse(), qpeg_decode_inter(), qtrle_decode_1bpp(), r3d_read_packet(), read_code(), read_header(), read_kuki_chunk(), read_packet(), rm_read_index(), rm_sync(), rtmp_write(), rtp_asf_fix_header(), seek(), sga_read_header(), skip_1stop_8data(), swf_read_packet(), tm2_read_stream(), ulti_decode_frame(), vc1_decode_ac_coeff(), vc1_decode_i_block(), vc1_decode_i_block_adv(), vc1_decode_intra_block(), vc1_decode_p_block(), vc1_unescape_buffer_neon(), vorbis_packet(), vpk_read_packet(), and webvtt_event_to_ass().

◆ seek()

static void BS_FUNC() seek ( BSCTX * bc,

unsigned pos

)

inlinestatic

Seek to the given bit position.

Definition at line 399 of file bitstream_template.h.

Referenced by avio_alloc_context(), ffio_init_context(), id3v2_parse(), and main().

◆ align()

static const uint8_t* BS_FUNC() align ( BSCTX * bc )

inlinestatic

Skip bits to a byte boundary.

Definition at line 411 of file bitstream_template.h.

Referenced by ads_read_header(), av_frame_get_buffer(), av_image_alloc(), av_image_copy_to_buffer(), av_image_fill_arrays(), av_image_get_buffer_size(), av_samples_alloc(), av_samples_alloc_array_and_samples(), av_samples_fill_arrays(), av_samples_get_buffer_size(), avcodec_align_dimensions(), avcodec_fill_audio_frame(), check_for_slice(), check_idct(), dcstr_read_header(), decode_0(), decode_block(), decode_frame(), ff_create_memory_sample(), ff_default_get_audio_buffer(), ff_default_get_video_buffer2(), ff_frame_pool_audio_init(), ff_frame_pool_get_audio_config(), ff_frame_pool_get_video_config(), ff_frame_pool_video_init(), ff_mjpeg_escape_FF(), genh_read_header(), get_audio_buffer(), get_video_buffer(), main(), read_vblock(), run_single_test(), save_bits(), svag_read_header(), sws_receive_slice(), and v210_stride().

◆ read_xbits()

static int BS_FUNC() read_xbits ( BSCTX * bc,

unsigned int n

)

inlinestatic

Read MPEG-1 dc-style VLC (sign bit + mantissa with no MSB).

If MSB not set it is negative.

Parameters: n length in bits

Definition at line 424 of file bitstream_template.h.

◆ decode012()

static int BS_FUNC() decode012 ( BSCTX * bc )

inlinestatic

Return decoded truncated unary code for the values 0, 1, 2.

Definition at line 436 of file bitstream_template.h.

Referenced by decode_frame_header(), ff_msmpeg4_decode_picture_header(), ff_vc1_parse_frame_header(), ff_vc1_parse_frame_header_adv(), ff_wmv2_decode_secondary_picture_header(), msmpeg4v34_decode_mb(), mss4_decode_frame(), vc1_decode_b_mb(), vc1_decode_b_mb_intfi(), vc1_decode_b_mb_intfr(), vc1_decode_p_block(), wmv2_decode_inter_block(), and wmv2_decode_mb().

◆ decode210()

static int BS_FUNC() decode210 ( BSCTX * bc )

inlinestatic

Return decoded truncated unary code for the values 2, 1, 0.

Definition at line 447 of file bitstream_template.h.

Referenced by decode_mb(), ff_vc1_parse_frame_header_adv(), and vc1_decode_ac_coeff().

◆ apply_sign()

static int BS_FUNC() apply_sign ( BSCTX * bc,

int val

)

inlinestatic

Definition at line 456 of file bitstream_template.h.

◆ skip_1stop_8data()

static int BS_FUNC() skip_1stop_8data ( BSCTX * s )

inlinestatic

Definition at line 462 of file bitstream_template.h.

◆ priv_set_idx()

static int BS_FUNC() priv_set_idx ( BSCTX * bc,

int code,

int * n,

int * nb_bits,

const VLCElem * table

)

inlinestatic

Return the LUT element for the given bitstream configuration.

Definition at line 479 of file bitstream_template.h.

Referenced by read_vlc(), and read_vlc_multi().

◆ read_vlc()

static int BS_FUNC() read_vlc ( BSCTX * bc,

const VLCElem * table,

int bits,

int max_depth

)

inlinestatic

Parse a vlc code.

Parameters: bits is the number of bits which will be read at once, must be identical to nb_bits in vlc_init()

max_depth is the number of times bits bits must be read to completely read the longest vlc code = (max_vlc_length + bits - 1) / bits If the vlc code is invalid and max_depth=1, then no bits will be removed. If the vlc code is invalid and max_depth>1, then the number of bits removed is undefined.

Definition at line 502 of file bitstream_template.h.

◆ read_vlc_multi()

static int BS_FUNC() read_vlc_multi ( BSCTX * bc,

uint8_t dst[8],

const VLC_MULTI_ELEM *const Jtable,

const VLCElem *const table,

const int bits,

const int max_depth,

const int symbols_size

)

inlinestatic

Parse a vlc / vlc_multi code.

Parameters: bits is the number of bits which will be read at once, must be identical to nb_bits in vlc_init()

max_depth is the number of times bits bits must be read to completely read the longest vlc code = (max_vlc_length + bits - 1) / bits

dst the parsed symbol(s) will be stored here. Up to 8 bytes are written

Returns: number of symbols parsed If the vlc code is invalid and max_depth=1, then no bits will be removed. If the vlc code is invalid and max_depth>1, then the number of bits removed is undefined.

Definition at line 536 of file bitstream_template.h.

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