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/*
* Copyright (C) 2010-2015 Hendrik Leppkes
* http://www.1f0.de
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "stdafx.h"
#include "H264SequenceParser.h"
#include "ByteParser.h"
#include "H264Nalu.h"
CH264SequenceParser::CH264SequenceParser(void)
{
ZeroMemory(&sps, sizeof(sps));
ZeroMemory(&pps, sizeof(pps));
}
CH264SequenceParser::~CH264SequenceParser(void)
{
}
HRESULT CH264SequenceParser::ParseNALs(const BYTE *buffer, size_t buflen, int nal_size)
{
CH264Nalu nalu;
nalu.SetBuffer(buffer, buflen, nal_size);
while (nalu.ReadNext()) {
const BYTE *data = nalu.GetDataBuffer() + 1;
const size_t len = nalu.GetDataLength() - 1;
if (nalu.GetType() == NALU_TYPE_SPS) {
ParseSPS(data, len);
break;
}
}
return S_OK;
}
static void SPSDecodeScalingList(CByteParser &parser, int size) {
int i, last = 8, next = 8;
int matrix = parser.BitRead(1);
if (matrix) {
for (i = 0; i < size; i++) {
if(next)
next = (last + parser.SExpGolombRead()) & 0xff;
if(!i && !next){ /* matrix not written */
break;
}
last = next ? next : last;
}
}
}
HRESULT CH264SequenceParser::ParseSPS(const BYTE *buffer, size_t buflen)
{
CByteParser parser(buffer, buflen);
int i;
ZeroMemory(&sps, sizeof(sps));
// Defaults
sps.valid = 1;
sps.primaries = AVCOL_PRI_UNSPECIFIED;
sps.trc = AVCOL_TRC_UNSPECIFIED;
sps.colorspace = AVCOL_SPC_UNSPECIFIED;
sps.full_range = -1;
// Parse
sps.profile = parser.BitRead(8);
parser.BitRead(4); // constraint flags
parser.BitRead(4); // reserved
sps.level = parser.BitRead(8);
parser.UExpGolombRead(); // sps id
if(sps.profile == 100 || sps.profile == 110 || sps.profile == 122 ||
sps.profile == 244 || sps.profile == 44 || sps.profile == 83 ||
sps.profile == 86 || sps.profile == 118 || sps.profile == 128 ||
sps.profile == 144) {
sps.chroma = (int)parser.UExpGolombRead();
if (sps.chroma == 3)
parser.BitRead(1);
sps.luma_bitdepth = (int)parser.UExpGolombRead() + 8;
sps.chroma_bitdepth = (int)parser.UExpGolombRead() + 8;
parser.BitRead(1); // transform_bypass
// decode scaling matrices
int scaling = parser.BitRead(1);
if (scaling) {
// Decode scaling lists
SPSDecodeScalingList(parser, 16); // Intra, Y
SPSDecodeScalingList(parser, 16); // Intra, Cr
SPSDecodeScalingList(parser, 16); // Intra, Cb
SPSDecodeScalingList(parser, 16); // Inter, Y
SPSDecodeScalingList(parser, 16); // Inter, Cr
SPSDecodeScalingList(parser, 16); // Inter, Cb
SPSDecodeScalingList(parser, 64); // Intra, Y
SPSDecodeScalingList(parser, 64); // Inter, Y
if (sps.chroma == 3) {
SPSDecodeScalingList(parser, 64); // Intra, Cr
SPSDecodeScalingList(parser, 64); // Inter, Cr
SPSDecodeScalingList(parser, 64); // Intra, Cb
SPSDecodeScalingList(parser, 64); // Inter, Cb
}
}
} else {
sps.chroma = 1;
sps.luma_bitdepth = 8;
sps.chroma_bitdepth = 8;
}
parser.UExpGolombRead(); // log2_max_frame_num
int poc_type = (int)parser.UExpGolombRead(); // poc_type
if (poc_type == 0)
parser.UExpGolombRead(); // log2_max_poc_lsb
else if (poc_type == 1) {
parser.BitRead(1); // delta_pic_order_always_zero_flag
parser.SExpGolombRead(); // offset_for_non_ref_pic
parser.SExpGolombRead(); // offset_for_top_to_bottom_field
int cyclen = (int)parser.UExpGolombRead(); // poc_cycle_length
for (i = 0; i < cyclen; i++)
parser.SExpGolombRead(); // offset_for_ref_frame[i]
}
sps.ref_frames = parser.UExpGolombRead(); // ref_frame_count
parser.BitRead(1); // gaps_in_frame_num_allowed_flag
parser.UExpGolombRead(); // mb_width
parser.UExpGolombRead(); // mb_height
sps.interlaced = !parser.BitRead(1); // frame_mbs_only_flag
if (sps.interlaced)
parser.BitRead(1); // mb_aff
parser.BitRead(1); // direct_8x8_inference_flag
int crop = parser.BitRead(1); // crop
if (crop) {
parser.UExpGolombRead(); // crop_left
parser.UExpGolombRead(); // crop_right
parser.UExpGolombRead(); // crop_top
parser.UExpGolombRead(); // crop_bottom
}
int vui_present = parser.BitRead(1); // vui_parameters_present_flag
if (vui_present) {
sps.ar_present = parser.BitRead(1); // aspect_ratio_info_present_flag
if (sps.ar_present) {
int ar_idc = parser.BitRead(8); // aspect_ratio_idc
if (ar_idc == 255) {
parser.BitRead(16); // sar.num
parser.BitRead(16); // sar.den
}
}
int overscan = parser.BitRead(1); // overscan_info_present_flag
if (overscan)
parser.BitRead(1); // overscan_appropriate_flag
int vid_sig_type = parser.BitRead(1); // video_signal_type_present_flag
if (vid_sig_type) {
parser.BitRead(3); // video_format
sps.full_range = parser.BitRead(1); // video_full_range_flag
int colorinfo = parser.BitRead(1); // colour_description_present_flag
if (colorinfo) {
sps.primaries = parser.BitRead(8);
sps.trc = parser.BitRead(8);
sps.colorspace = parser.BitRead(8);
}
}
}
return S_OK;
}
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