FFmpeg/libavcodec/h264.h
Mark Thompson d05444d2c6 h264: Add stream constraint values to the common header
With comments describing the derivation of each value.

(cherry picked from commit aaf4414650)
2017-10-17 20:56:29 +01:00

93 lines
3.2 KiB
C

/*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* H.264 common definitions
*/
#ifndef AVCODEC_H264_H
#define AVCODEC_H264_H
#define QP_MAX_NUM (51 + 6*6) // The maximum supported qp
/* NAL unit types */
enum {
H264_NAL_SLICE = 1,
H264_NAL_DPA = 2,
H264_NAL_DPB = 3,
H264_NAL_DPC = 4,
H264_NAL_IDR_SLICE = 5,
H264_NAL_SEI = 6,
H264_NAL_SPS = 7,
H264_NAL_PPS = 8,
H264_NAL_AUD = 9,
H264_NAL_END_SEQUENCE = 10,
H264_NAL_END_STREAM = 11,
H264_NAL_FILLER_DATA = 12,
H264_NAL_SPS_EXT = 13,
H264_NAL_AUXILIARY_SLICE = 19,
};
enum {
// 7.4.2.1.1: seq_parameter_set_id is in [0, 31].
H264_MAX_SPS_COUNT = 32,
// 7.4.2.2: pic_parameter_set_id is in [0, 255].
H264_MAX_PPS_COUNT = 256,
// A.3: MaxDpbFrames is bounded above by 16.
H264_MAX_DPB_FRAMES = 16,
// 7.4.2.1.1: max_num_ref_frames is in [0, MaxDpbFrames], and
// each reference frame can have two fields.
H264_MAX_REFS = 2 * H264_MAX_DPB_FRAMES,
// 7.4.3.1: modification_of_pic_nums_idc is not equal to 3 at most
// num_ref_idx_lN_active_minus1 + 1 times (that is, once for each
// possible reference), then equal to 3 once.
H264_MAX_RPLM_COUNT = H264_MAX_REFS + 1,
// 7.4.3.3: in the worst case, we begin with a full short-term
// reference picture list. Each picture in turn is moved to the
// long-term list (type 3) and then discarded from there (type 2).
// Then, we set the length of the long-term list (type 4), mark
// the current picture as long-term (type 6) and terminate the
// process (type 0).
H264_MAX_MMCO_COUNT = H264_MAX_REFS * 2 + 3,
// A.2.1, A.2.3: profiles supporting FMO constrain
// num_slice_groups_minus1 to be in [0, 7].
H264_MAX_SLICE_GROUPS = 8,
// E.2.2: cpb_cnt_minus1 is in [0, 31].
H264_MAX_CPB_CNT = 32,
// A.3: in table A-1 the highest level allows a MaxFS of 139264.
H264_MAX_MB_PIC_SIZE = 139264,
// A.3.1, A.3.2: PicWidthInMbs and PicHeightInMbs are constrained
// to be not greater than sqrt(MaxFS * 8). Hence height/width are
// bounded above by sqrt(139264 * 8) = 1055.5 macroblocks.
H264_MAX_MB_WIDTH = 1055,
H264_MAX_MB_HEIGHT = 1055,
H264_MAX_WIDTH = H264_MAX_MB_WIDTH * 16,
H264_MAX_HEIGHT = H264_MAX_MB_HEIGHT * 16,
};
#endif /* AVCODEC_H264_H */