标签：java StartBit H264 SPS nLen int flag Ue buf
数据需要去掉头，SPS测试数据 byte[] buffer = new byte[]{103, 66, -64, 12, -38, 5, 7, -56, 7, -124, 2} 得到结果宽320高240.
public class H264SpsParser {
private final static String TAG = H264SpsParser.class.getCanonicalName();
private final static int NAL_HEADER = 0;
private static int nStartBit = 0;
private static int Ue(byte[] pBuff, int nLen) {
int nZeroNum = 0;
while (nStartBit < nLen * 8) {
if ((pBuff[nStartBit / 8] & (0x80 >> (nStartBit % 8))) != 0) {
break;
}
nZeroNum++;
nStartBit++;
}
nStartBit++;
int dwRet = 0;
for (int i = 0; i < nZeroNum; i++) {
dwRet <<= 1;
if ((pBuff[nStartBit / 8] & (0x80 >> (nStartBit % 8))) != 0) {
dwRet += 1;
}
nStartBit++;
}
return (1 << nZeroNum) - 1 + dwRet;
}
private static int Se(byte[] pBuff, int nLen) {
int UeVal = Ue(pBuff, nLen);
double k = UeVal;
int nValue = (int) Math.ceil(k / 2);
if (UeVal % 2 == 0) {
nValue = -nValue;
}
return nValue;
}
private static int u(int BitCount, byte[] buf) {
int dwRet = 0;
for (int i = 0; i < BitCount; i++) {
dwRet <<= 1;
if ((buf[nStartBit / 8] & (0x80 >> (nStartBit % 8))) != 0) {
dwRet += 1;
}
nStartBit++;
}
return dwRet;
}
private static boolean h264_decode_seq_parameter_set(byte[] buf, int nLen, int[] size) {
nStartBit = 0;
int forbidden_zero_bit = u(1, buf);
int nal_ref_idc = u(2, buf);
int nal_unit_type = u(5, buf);
if (nal_unit_type == 7) {
int profile_idc = u(8, buf);
int constraint_set0_flag = u(1, buf);//(buf[1] & 0x80)>>7;
int constraint_set1_flag = u(1, buf);//(buf[1] & 0x40)>>6;
int constraint_set2_flag = u(1, buf);//(buf[1] & 0x20)>>5;
int constraint_set3_flag = u(1, buf);//(buf[1] & 0x10)>>4;
int reserved_zero_4bits = u(4, buf);
int level_idc = u(8, buf);
int seq_parameter_set_id = Ue(buf, nLen);
if (profile_idc == 100 || profile_idc == 110 ||
profile_idc == 122 || profile_idc == 144) {
int chroma_format_idc = Ue(buf, nLen);
if (chroma_format_idc == 3) {
int residual_colour_transform_flag = u(1, buf);
}
int bit_depth_luma_minus8 = Ue(buf, nLen);
int bit_depth_chroma_minus8 = Ue(buf, nLen);
int qpprime_y_zero_transform_bypass_flag = u(1, buf);
int seq_scaling_matrix_present_flag = u(1, buf);
int[] seq_scaling_list_present_flag = new int[8];
if (seq_scaling_matrix_present_flag != 0) {
for (int i = 0; i < 8; i++) {
seq_scaling_list_present_flag[i] = u(1, buf);
}
}
}
int log2_max_frame_num_minus4 = Ue(buf, nLen);
int pic_order_cnt_type = Ue(buf, nLen);
if (pic_order_cnt_type == 0) {
int log2_max_pic_order_cnt_lsb_minus4 = Ue(buf, nLen);
} else if (pic_order_cnt_type == 1) {
int delta_pic_order_always_zero_flag = u(1, buf);
int offset_for_non_ref_pic = Se(buf, nLen);
int offset_for_top_to_bottom_field = Se(buf, nLen);
int num_ref_frames_in_pic_order_cnt_cycle = Ue(buf, nLen);
int[] offset_for_ref_frame = new int[num_ref_frames_in_pic_order_cnt_cycle];
for (int i = 0; i < num_ref_frames_in_pic_order_cnt_cycle; i++) {
offset_for_ref_frame[i] = Se(buf, nLen);
}
}
int num_ref_frames = Ue(buf, nLen);
int gaps_in_frame_num_value_allowed_flag = u(1, buf);
int pic_width_in_mbs_minus1 = Ue(buf, nLen);
int pic_height_in_map_units_minus1 = Ue(buf, nLen);
size[0] = (pic_width_in_mbs_minus1 + 1) * 16;
size[1] = (pic_height_in_map_units_minus1 + 1) * 16;
/*
int frame_mbs_only_flag=u(1,buf,StartBit);
if(!frame_mbs_only_flag)
int mb_adaptive_frame_field_flag=u(1,buf,StartBit);
int direct_8x8_inference_flag=u(1,buf,StartBit);
int frame_cropping_flag=u(1,buf,StartBit);
if(frame_cropping_flag)
{
int frame_crop_left_offset=Ue(buf,nLen,StartBit);
int frame_crop_right_offset=Ue(buf,nLen,StartBit);
int frame_crop_top_offset=Ue(buf,nLen,StartBit);
int frame_crop_bottom_offset=Ue(buf,nLen,StartBit);
}
int vui_parameter_present_flag=u(1,buf,StartBit);
if(vui_parameter_present_flag)
{
int aspect_ratio_info_present_flag=u(1,buf,StartBit);
if(aspect_ratio_info_present_flag)
{
int aspect_ratio_idc=u(8,buf,StartBit);
if(aspect_ratio_idc==255)
{
int sar_width=u(16,buf,StartBit);
int sar_height=u(16,buf,StartBit);
}
}
int overscan_info_present_flag=u(1,buf,StartBit);
if(overscan_info_present_flag)
int overscan_appropriate_flagu=u(1,buf,StartBit);
int video_signal_type_present_flag=u(1,buf,StartBit);
if(video_signal_type_present_flag)
{
int video_format=u(3,buf,StartBit);
int video_full_range_flag=u(1,buf,StartBit);
int colour_description_present_flag=u(1,buf,StartBit);
if(colour_description_present_flag)
{
int colour_primaries=u(8,buf,StartBit);
int transfer_characteristics=u(8,buf,StartBit);
int matrix_coefficients=u(8,buf,StartBit);
}
}
int chroma_loc_info_present_flag=u(1,buf,StartBit);
if(chroma_loc_info_present_flag)
{
int chroma_sample_loc_type_top_field=Ue(buf,nLen,StartBit);
int chroma_sample_loc_type_bottom_field=Ue(buf,nLen,StartBit);
}
int timing_info_present_flag=u(1,buf,StartBit);
if(timing_info_present_flag)
{
int num_units_in_tick=u(32,buf,StartBit);
int time_scale=u(32,buf,StartBit);
fps=time_scale/num_units_in_tick;
int fixed_frame_rate_flag=u(1,buf,StartBit);
if(fixed_frame_rate_flag)
{
fps=fps/2;
}
}
}
*/
return true;
}
return false;
}
public static int[] getSizeFromSps(byte[] data) {
// for (int i=0; i<data.length-4; i++)
// {
if (data[i]==0 && data[i+1]==0 && data[i+2]==0 && data[i+3]==1 && data[i+4]==0x67)
{
int[] size = new int[2];
h264_decode_seq_parameter_set(data, data.length, size);
Log.d(TAG, "Sps=("+size[0]+", "+size[1]+")");
return size;
}
// }
int[] size = new int[2];
h264_decode_seq_parameter_set(data, data.length, size);
Log.e(TAG, "Sps=(" + size[0] + ", " + size[1] + ")");
return size;
}
}
标签：java,StartBit,H264,SPS,nLen,int,flag,Ue,buf 来源： https://blog.csdn.net/xiaopangcame/article/details/114239161
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