Windos下的HM播放器，MFC制作 - Fla
Windos下的HM播放器，MFC制作
使用MFC制作播放器时，需要考虑的主要问题有两点：
1、如何让HM解码出一帧图像就停止。
2、如何显示HM解码的图像（YUV420格式）。
第一点，建议大家自己跟踪调试一下HM的解码器，最起码需要在 TAppDecoder 项目的代码级别进行调试，
可以不进入更深的解码过程。这个过程清除之后，应该知道如何得到一帧解码的图像，
HM代码中是在TAppDecoder/TDecTop.cpp 的 TDecTop::xWriteFlush函数中，
所以我们所做的只是大概修改一下其处理流程，然后封装出一个新的接口。
第二点，如何显示YUV420格式的图像
这里我的方法是先转换成一个Bitmap，这里涉及到了YUV到RGB颜色空间的转换。
较为详细的说明可以参加我的CSDN博客：http://blog.csdn.net/luofl1992/article/details/8654317
以下为关键接口的代码：
#include "stdafx.h"
#include "NcMHevcDecoder.h"
Bool g_md5_mismatch; ///< top level flag to signal when there is a decode problem
#define TEST_RECON 0
CNcMHevcDecoder::CNcMHevcDecoder()
: bytestream(bitstreamFile)
, poc(0)
, recon_opened(false)
, width(416)
, height(240)
, bFirstFrame(false)
, last_tId(-2)
{
pcListPic = NULL;
lpDiBits = NULL;
}
CNcMHevcDecoder::~CNcMHevcDecoder()
{
// xFlushOutput( pcListPic );
// delete buffers
m_cTDecTop.deletePicBuffer();
// destroy internal classes
xDestroyDecLib();
TAppDecTop::destroy();
}
bool CNcMHevcDecoder::OpenFile( LPCTSTR lpFilePath, BITMAPINFO &info )
{
TAppDecTop::create();
if( !TAppDecTop::parseCfg( lpFilePath ) )
{
TAppDecTop::destroy();
return false;
}
#if TEST_RECON
m_pchReconFile = "recPlayer.yuv";
#endif
bitstreamFile.open( m_pchBitstreamFile, ifstream::in | ifstream::binary );
if( !bitstreamFile )
return false;
// create & initialize internal classes
xCreateDecLib();
xInitDecLib();
#if 0
m_iPOCLastDisplay = m_iSkipFrame; // set the last displayed POC correctly for skip forward.
#else
m_iPOCLastDisplay = -1;
#endif
UInt tId = DecodeFrames();
if ( pcListPic != NULL && pcListPic->size() )
{
TComPicYuv * pcPicYuv = (*(pcListPic->begin()))->getPicYuvRec();
width = pcPicYuv->getWidth();
height = pcPicYuv->getHeight();
bFirstFrame = true;
}
BITMAPINFOHEADER &header( bmpInfo.bmiHeader );
header.biBitCount = 32;
header.biClrImportant = 0;
header.biClrUsed = 0;
header.biCompression = 0;
// header.biHeight = 0 - is->video_st->codec->height; // 这里要是负数，否则图像是倒着的
// header.biWidth = is->video_st->codec->width;
header.biPlanes = 1;
header.biSize = 40;
header.biSizeImage = 0;
header.biXPelsPerMeter = 0;
header.biYPelsPerMeter = 0;
header.biHeight = -height;
header.biWidth = width;
memset ( bmpInfo.bmiColors, 0, sizeof(bmpInfo.bmiColors));
memcpy( &info, &bmpInfo, sizeof(bmpInfo) );
return true;
}
int CNcMHevcDecoder::DecodeFrames( void )
{
// main decode loop
if ( last_tId != -2 || last_tId == -1 )
return last_tId;
while ( !!bitstreamFile )
{
/* location serves to work around a design fault in the decoder, whereby
* the process of reading a new slice that is the first slice of a new frame
* requires the TDecTop::decode() method to be called again with the same
* nal unit. */
streampos location = bitstreamFile.tellg();
AnnexBStats stats = AnnexBStats();
Bool bPreviousPictureDecoded = false;
vector<uint8_t> nalUnit;
InputNALUnit nalu;
byteStreamNALUnit( bytestream, nalUnit, stats );
// call actual decoding function
Bool bNewPicture = false;
if( nalUnit.empty() )
{
/* this can happen if the following occur:
* - empty input file
* - two back-to-back start_code_prefixes
* - start_code_prefix immediately followed by EOF
*/
fprintf( stderr, "Warning: Attempt to decode an empty NAL unit\n" );
}
else
{
read( nalu, nalUnit );
if( ( m_iMaxTemporalLayer >= 0 && nalu.m_temporalId > m_iMaxTemporalLayer ) || !isNaluWithinTargetDecLayerIdSet( &nalu ) )
{
if( bPreviousPictureDecoded )
{
bNewPicture = true;
bPreviousPictureDecoded = false;
}
else
{
bNewPicture = false;
}
}
else
{
bNewPicture = m_cTDecTop.decode( nalu, m_iSkipFrame, m_iPOCLastDisplay );
if( bNewPicture )
{
bitstreamFile.clear();
/* location points to the current nalunit payload[1] due to the
* need for the annexB parser to read three extra bytes.
* [1] except for the first NAL unit in the file
* (but bNewPicture doesn't happen then) */
bitstreamFile.seekg( location - streamoff( 3 ) );
bytestream.reset();
}
bPreviousPictureDecoded = true;
}
}
if( bNewPicture || !bitstreamFile )
{
// 执行环路滤波
m_cTDecTop.executeLoopFilters( poc, pcListPic );
}
if( pcListPic )
{
if( m_pchReconFile && !recon_opened )
{
if( !m_outputBitDepthY )
{
m_outputBitDepthY = g_bitDepthY;
}
if( !m_outputBitDepthC )
{
m_outputBitDepthC = g_bitDepthC;
}
m_cTVideoIOYuvReconFile.open( m_pchReconFile, true, m_outputBitDepthY, m_outputBitDepthC, g_bitDepthY, g_bitDepthC ); // write mode
recon_opened = true;
}
if( bNewPicture )
{
/* if ( nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_IDR
|| nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_IDR_N_LP
|| nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_BLA_N_LP
|| nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_BLANT
|| nalu.m_nalUnitType == NAL_UNIT_CODED_SLICE_BLA )
xFlushOutput( pcListPic );*/
// write reconstruction to file
#if TEST_RECON
xWriteOutput( pcListPic, nalu.m_temporalId ); // 这里修改成传递出去一个新的图像帧用于界面显示
#else
return last_tId = nalu.m_temporalId;
#endif
}
}
}
return -1;
}
inline byte clip(const Int x)
{
return x > 255 ? 255 : ( x < 0 ? 0 : x );
}
// 是否采用快速 YUV 到 RGB 转换算法（四个点同时计算）
#define USE_FAST_YUV_2_RGB 0
#if USE_FAST_YUV_2_RGB
// pcPicYuv := pcPic->getPicYuvRec()
// pRGB := RGB颜色的起始地址
static void NcDecoderYUV2RGB(TComPicYuv *pcPicYuv, byte *pRGB, int width, int height)
{
if ( NULL == pRGB )
return;
Pel *y = pcPicYuv->getLumaAddr(), // 重建图像的 Y 颜色开始地址
*u = pcPicYuv->getCbAddr(), // 重建图像的 Cb 颜色开始地址
*v = pcPicYuv->getCrAddr(); // 重建图像的 Cr 颜色开始地址
UInt dRGB = width << 2; // bmp 一行的某个像素的下一行同样位置的像素值偏移
UInt dY = pcPicYuv->getStride(); // YUV 一行的一个y值对应下一行的同样位置的位置增量
const Int dY2 = dY + 1, dRGB2 = dRGB + 4;
UInt d2Y = 2 *dY - width; // YUV Y像素偏移值的修正
UInt dUV = pcPicYuv->getCStride() - width / 2; // YUV UV像素偏移值的修正
Int dB = 0, dG = 0, dR = 0, i = 0, j = 0;
Int Cb = 0, Cr = 0;
height = height >> 1 ; width = width >> 1 ; // 行数和列数均减半
for ( j = 0; j < height; j++ )
{
for ( i = 0; i < width; i++ )
{
// ARGB_8888: 四个像素值依次为 BGRA (已经验证，同时A值应为255表示不透明)
// a fast mode using shifting.
Cb = *u - 128;
Cr = *v - 128;
dB = Cb + (Cb>>1) + (Cb>>2) + (Cb>>6);
dG = - ((Cb>>2) + (Cb>>4) + (Cb>>5) ) - ((Cr>>1) + (Cr>>3) + (Cr>>4) + (Cr>>5));
dR = Cr + (Cr>>2) + (Cr>>3) + (Cr>>5);
#if 0
*( pRGB) = clip(*y + dB); // B
*(pRGB+ 4 ) = clip(*(y+1) + dB);
*(pRGB+dRGB) = clip(*(y+dY) + dB);
*(pRGB+dRGB2) = clip(*(y+dY2) + dB);
*(++pRGB) = clip(*y + dG); // G
*(pRGB+ 4 ) = clip(*(y+1) + dG);
*(pRGB+dRGB) = clip(*(y+dY) + dG);
*(pRGB+dRGB2) = clip(*(y+dY2) + dG);
*(++pRGB) = clip(*y + dR); // R
*(pRGB+ 4 ) = clip(*(y+1) + dR);
*(pRGB+dRGB) = clip(*(y+dY) + dR);
*(pRGB+dRGB2) = clip(*(y+dY2) + dR);
#else
Pel y0 = *y, y1 = *(y+1);
Pel y2 = *(y+dY), y3 = *(y+dY2);
*( pRGB) = clip(y0 + dB); // B
*(pRGB+ 4 ) = clip(y1 + dB);
*(pRGB+dRGB) = clip(y2 + dB);
*(pRGB+dRGB2) = clip(y3 + dB);
*(++pRGB) = clip(y0 + dG); // G
*(pRGB+ 4 ) = clip(y1 + dG);
*(pRGB+dRGB) = clip(y2 + dG);
*(pRGB+dRGB2) = clip(y3 + dG);
*(++pRGB) = clip(y0 + dR); // R
*(pRGB+ 4 ) = clip(y1 + dR);
*(pRGB+dRGB) = clip(y2 + dR);
*(pRGB+dRGB2) = clip(y3 + dR);
#endif
pRGB += 6; // 总计两个RGBA像素，指针需要移动 8 个字节，补齐
// 初始化中已经对 A 赋值，故此处不再处理 2013-3-24
y+=2;
u++; v++; // 横向两个点才变化一次，因为其表示了 2 * 2个点的像素值
} // for loop (i < width)
pRGB += dRGB; // 跳过一行，因为上面是两行两行的处理，每次处理了 4 个点
y += d2Y; // y 像素值的偏移位置修正(两行)
u += dUV; // u 像素值偏移的修正
v += dUV; // v 像素值偏移的修正
} // for loop (j < height)
}
#else
static void NcDecoderYUV2RGB(TComPicYuv *pcPicYuv, byte *pRGB, int width, int height)
{
if ( NULL == pRGB )
return;
Pel *y = pcPicYuv->getLumaAddr(), // 重建图像的 Y 颜色开始地址
*u = pcPicYuv->getCbAddr(), // 重建图像的 Cb 颜色开始地址
*v = pcPicYuv->getCrAddr(); // 重建图像的 Cr 颜色开始地址
// byte *pRGB = (byte *)lpDiBits; // bmp 的颜色开始
// UInt *p = lpDiBits;
UInt dy = pcPicYuv->getStride(); // 一行的一个y值对应下一行的同样位置的位置增量
UInt dUV = (pcPicYuv->getCStride() - width / 2); // 像素值偏移的修正
for ( int j = 0; j < height; j++ )
{
for ( int i = 0; i < width; i+=2 )
{
// ARGB_8888: 四个像素值依次为 BGRA (已经验证，同时A值应为255表示不透明)
#if 1
int dB = 1.772 * ( *u - 128 );
int dG = -0.34413*(*u-128) - 0.71414*(*v-128);
int dR = 1.402*(*v-128);
*pRGB++ = clip(*y + 1.772 * ( *u - 128 )); // B
*pRGB++ = clip(*y -0.34413*(*u-128) - 0.71414*(*v-128)); // G
*pRGB++ = clip(*y + 8 + 1.402*(*v-128)); // R
*pRGB++; // = 255; // A
y++;
*pRGB++ = clip(*y + 1.772 * ( *u - 128 )); // B
*pRGB++ = clip(*y -0.34413*(*u-128) - 0.71414*(*v-128)); // G
*pRGB++ = clip(*y + 8 + 1.402*(*v-128)); // R
*pRGB++; // = 255; // A
#else
// 以下：用于测试各个位表示什么颜色 2013-3-14 已经验证按指针从低到高访问时依次为 BGRA
*pRGB++ = 255; *pRGB++ = 0; *pRGB++ = 0; *pRGB++ = 128; y++;
*pRGB++ = 255; *pRGB++ = 0; *pRGB++ = 0; *pRGB++ = 128;
/* // 用32位来处理，效率反而降低了
*p++ = ((UInt( *y + 1.772 * *u - 0xE2) & 0xff) << 0) // B
| ((UInt( *y - 0.34413 * *u - 0.71414 * *v + 0x87) & 0xff) << 8) // G
| ((UInt( *y + 1.402 * *v - 0xAB) & 0xff) << 16 ) // R
| 0xff000000;
y++;
*p++ = ((UInt( *y + 1.772 * *u - 0xE2) & 0xff) << 0) // B
| ((UInt( *y - 0.34413 * *u - 0.71414 * *v + 0x87) & 0xff) << 8) // G
| ((UInt( *y + 1.402 * *v - 0xAB) & 0xff) << 16 ) // R
| 0xff000000;
*/ // *p++ = 0xff0000ff; y++; *p++ = 0xff0000ff;
#endif
y++;
u++; v++; // 横向两个点才变化一次，因为其表示了 2 * 2个点的像素值
}
y += ( pcPicYuv->getStride() - width); // 像素值的偏移位置修正
if ( j % 2 == 0 )
{
u -= width / 2; v -= width / 2; // 偶数行不变
}
else
{
// 奇数行（从0开始编号）才变化，也就是到下一个偶数像素点时改变了
u += dUV; // 像素值偏移的修正
v += dUV; // 像素值偏移的修正
}
} // for loop (j < height2)
}
#endif
LPVOID CNcMHevcDecoder::GetNextFrame(void)
{
UInt tId = DecodeFrames();
last_tId = -2;
TComList<TComPic*>::iterator iterPic = pcListPic->begin();
Int not_displayed = 0;
while (iterPic != pcListPic->end())
{
TComPic* pcPic = *(iterPic);
if(pcPic->getOutputMark() && pcPic->getPOC() > m_iPOCLastDisplay)
not_displayed++;
iterPic++;
}
if ( 0 == not_displayed )
{
while ( -1 != tId && 0 == not_displayed )
{
tId = DecodeFrames();
iterPic = pcListPic->begin();
while ( not_displayed == 0 && iterPic != pcListPic->end())
{
TComPic* pcPic = *(iterPic);
if(pcPic->getOutputMark() && pcPic->getPOC() > m_iPOCLastDisplay)
not_displayed++;
iterPic++;
}
}
if ( 0 == not_displayed )
return NULL;
}
while ( 1 )
{
iterPic = pcListPic->begin();
while (iterPic != pcListPic->end()) // if -> while 2013-3-28
{
TComPic* pcPic = *(iterPic);
if ( /*pcPic->getOutputMark() &&*/ (not_displayed > pcPic->getNumReorderPics(tId) && pcPic->getPOC() > m_iPOCLastDisplay))
{
// write to file
not_displayed--;
if ( NULL == lpDiBits )
{
width = pcPic->getPicYuvRec()->getWidth();
height = pcPic->getPicYuvRec()->getHeight();
lpDiBits = new char[width * height * 4]; // 一般来说视频的图像宽度为 4 的倍数，所以不用管对齐了
memset( lpDiBits, 0xffffffff, width * height * 4 );
}
assert( lpDiBits != NULL );
NcDecoderYUV2RGB( pcPic->getPicYuvRec(), (byte *)lpDiBits, width, height);
/*
if ( m_pchReconFile )
{
CroppingWindow &crop = pcPic->getCroppingWindow();
m_cTVideoIOYuvReconFile.write( pcPic->getPicYuvRec(), crop.getPicCropLeftOffset(), crop.getPicCropRightOffset(), crop.getPicCropTopOffset(), crop.getPicCropBottomOffset() );
}
// update POC of display order
*/
m_iPOCLastDisplay = pcPic->getPOC();
// erase non-referenced picture in the reference picture list after display
pcPic->setOutputMark(false);
return lpDiBits;
}
if ( !pcPic->getSlice(0)->isReferenced() && pcPic->getOutputMark() == false /*&& pcPic->getReconMark() == true*/ )
{
#if !!DYN_REF_FREE
pcPic->setReconMark(false);
// mark it should be extended later
pcPic->getPicYuvRec()->setBorderExtension( false );
#else
pcPic->destroy();
pcListPic->erase( iterPic );
// iterPic = pcListPic->begin(); // to the beginning, non-efficient way, have to be revised!
#endif
iterPic = pcListPic->begin();
}
else
iterPic++;
}
tId = DecodeFrames();
last_tId = -2;
} // 2013-3-28
return ((tId != -1) ? lpDiBits : NULL);
}
/*
UINT CNcMHevcDecoder::ThreadDecode( LPVOID lpVoid )
{
CNcMHevcDecoder *pDecoder = ( CNcMHevcDecoder * )lpVoid;
pDecoder->DecodeFrames();
return 0;
}
*/
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