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12 Feb 2007

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VideoRenderer Class Reference

This I/O class renders a gray-scale or RGB stream (via a QFrameBuffer) onto a QLabel widget. Don't forget to set the appropriate VideoFrameBuffer! More...

#include <VideoRenderer.hpp>

Inheritance diagram for VideoRenderer:

List of all members.

Public Member Functions
	VideoRenderer (const VideoESInfo *es, UncompressedVideoFrame::ColorSpace colorSpace, int width, int height, bool isLabelResizable=true, bool fixAspectRatio=true, bool allowUpscaleX=false)
	Constructor.
virtual	~VideoRenderer ()
	Destructor.
virtual Frame *	getFrame ()
	Returns NULL, as this class is intended to be an output class only.
void	setOutputDepth (int depth)
void	setDirectBitBlt (bool direct)
void	setVideoFrameBuffer (VideoFrameBuffer *vfb)
virtual int	writeFrame (Frame *frm, ESInfo *out_es=NULL)
	Renders a frame to the destination QLabel widget.
virtual bool	open ()
	Creates internal frame buffers and checks whether the stream to be rendered matches the widget dimensions.
virtual bool	close (bool immediate=false)
	Does nothing but setting the object state to CLOSED.
virtual bool	destroy ()
	Not applicable to this class.
virtual int	getBufferFillLevel () const
	Not applicable to this class.
virtual const char *	getURL () const
	Returns the fixed string VideoRenderer:.
virtual void	setESInfo (ESInfo *es)
	Not implemented.
virtual ESInfo *	getESInfo ()
	Not implemented.
Protected Member Functions
bool	updateDisplayRegion ()
	Update frame_info (except size) and display_region.
Protected Attributes
char	url [MAX_STR_LEN]
const VideoESInfo *	es
	Elementary video stream information.
VideoFrameBuffer *	frameBuffer
	The frame buffer.
UncompressedVideoFrame::ColorSpace	colorSpace
	The color space of the frames to be rendered.
VideoRect	frame_info
	Dimension, storage size (in bytes), and scaling factors of a decoded video frame.
VideoRect	out_label_info
VideoRect	display_region
	apect-ratio adjusted region of qlabel where frames will be displayed.
int	outputDepth
bool	directBitBlt

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Detailed Description

This I/O class renders a gray-scale or RGB stream (via a QFrameBuffer) onto a QLabel widget. Don't forget to set the appropriate VideoFrameBuffer!

It is intended to be used as a DataSink connected to a DataChannel.

Video frames will be (down or up) scaled to fit into the QLabel widget by preserving the aspect ratio given in VideoESInfo.

The expected format of the gray-scale stream is: 1 byte per pixel.

The expected format of the RGB24 stream is: 3 bytes per pixel, in the order RGB (red, green, blue).

The expected format of the RGB32 stream is: 4 bytes per pixel, in the order BGRA (blue, green, red, alpha). This conforms to the PIX_FMT_RGBA32 format defined in ffmpeg/libavcodec/avcodec.h on little endian architectures.

Author:

Mario Taschwer and Michael Kropfberger

Version:

Id

VideoRenderer.hpp,v 1.15 2006/01/26 11:42:00 mkropfbe Exp

Definition at line 78 of file VideoRenderer.hpp.

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Constructor & Destructor Documentation

VideoRenderer::VideoRenderer (  const VideoESInfo *  es, UncompressedVideoFrame::ColorSpace  colorSpace, int  width, int  height, bool  isLabelResizable = true, bool  fixAspectRatio = true, bool  allowUpscaleX = false )

Constructor. If the parameters are invalid, the open() method will fail. Parameters: es  elementary stream information about the video stream to be rendered. colorSpace  the color space of the video stream to be rendered; must be one of: MP4Decoder::ColorSpaceGRAY8, MP4Decoder::ColorSpaceRGB24, MP4Decoder::ColorSpaceRGB32. width  the width of the output label/window height  the height of the output label/window isLabelResizable  if true, the given width/height is assumed to be flexible, so it will be tried to keep the original video size (plus adhering #fixAspectRatio) setting this to true, width&height may be zero, only the video is used to determine the resolution fixAspectRatio  if true, video frames may be resized according to their ESInfo aspectRatio, which means upscaling in the y-dimension allowUpscaleX  if true, video frames may be upscaled in x-dimension to fit the label, which may result in significant quality loss, since a very simple upscaling algorithm is used (assumes isLabelResizable==false). Definition at line 49 of file VideoRenderer.cpp. References UncompressedVideoFrame::ColorSpace, es, frame_info, and frameBuffer. : IO() { strcpy(this->url,"VideoRenderer"); this->es = _es; this->colorSpace = colorSpace; this->outputDepth = 24; //default value assumes modern display this->directBitBlt = false; frameBuffer = NULL; dprintf_full("VideoRenderer Construct (colorSpace %s, depth %i bit, resolution %ix%i, allowUpscaleX: %s)\n", colorSpace==UncompressedVideoFrame::ColorSpaceGRAY8?"RGB8gray": colorSpace==UncompressedVideoFrame::ColorSpaceRGB24?"RGB24": colorSpace==UncompressedVideoFrame::ColorSpaceRGB32?"RGB32": colorSpace==UncompressedVideoFrame::ColorSpaceRGB565?"RGB565": colorSpace==UncompressedVideoFrame::ColorSpaceI420?"I420": colorSpace==UncompressedVideoFrame::ColorSpaceYV12?"YV12": "UNKNOWN", UncompressedVideoFrame::mapColorSpaceToBitDepth(colorSpace), width, height, allowUpscaleX?"yes":"no"); frame_info.width = 0; frame_info.height = 0; frame_info.size = 0; frame_info.scaleX = INT2FIXED(1); frame_info.scaleY = INT2FIXED(1); frame_info.fixAspectRatio = fixAspectRatio; frame_info.allowUpscaleX = allowUpscaleX; out_label_info.isLabelResizable = isLabelResizable; out_label_info.left=0; out_label_info.top=0; if (isLabelResizable) { //get first hint from ES, aspectRatio may be calc'd later out_label_info.width=es->getWidth(); out_label_info.height=es->getHeight(); } else { out_label_info.width=width; out_label_info.height=height; } state = CLOSED; }

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Member Function Documentation

virtual bool VideoRenderer::close (  bool  immediate = false  )  [inline, virtual]

Does nothing but setting the object state to CLOSED. Parameters: immediate  ignored. Returns: true See also: IO::close(bool) Implements IO. Definition at line 169 of file VideoRenderer.hpp. { state=CLOSED; return true; };

virtual bool VideoRenderer::destroy (   )  [inline, virtual]

Not applicable to this class. Returns: true See also: IO::destroy() Implements IO. Definition at line 178 of file VideoRenderer.hpp. { return true; };

virtual int VideoRenderer::getBufferFillLevel (   )  const [inline, virtual]

Not applicable to this class. Returns: 50 See also: IO::getBufferFillLevel() Implements IO. Definition at line 186 of file VideoRenderer.hpp. { return 50; };

virtual ESInfo* VideoRenderer::getESInfo (   )  [inline, virtual]

Not implemented. Returns: NULL Implements IO. Definition at line 201 of file VideoRenderer.hpp. { return NULL;};

bool VideoRenderer::open (   )  [virtual]

Creates internal frame buffers and checks whether the stream to be rendered matches the widget dimensions. Returns: true on success, false on error. See also: IO::open() Implements IO. Reimplemented in QLabelRenderer, SDLRenderer, and X11Renderer. Definition at line 214 of file VideoRenderer.cpp. Referenced by Visualizer::adapt(). { /* implement in subclass! */ return true; }

bool VideoRenderer::updateDisplayRegion (   )  [protected]

Update frame_info (except size) and display_region. This function is not thread-safe, and is internally called by the open() method. Reimplemented in QLabelRenderer, SDLRenderer, and X11Renderer. Definition at line 111 of file VideoRenderer.cpp. References display_region, es, and frame_info. Referenced by X11Renderer::updateDisplayRegion(), SDLRenderer::updateDisplayRegion(), and QLabelRenderer::updateDisplayRegion(). { int width, height; double scalex, scaley; double aspect; if (!es || !es->isVisualStream()) { dprintf_err("VideoRenderer::updateDisplayRegion(): invalid member: es = %p\n", es); return false; } /* update frame_info */ frame_info.width = (int) es->getWidth(); frame_info.height = (int) es->getHeight(); /* compute frame display region with correct aspect ratio */ display_region.top = 0; display_region.left = 0; display_region.width = frame_info.width; display_region.height = frame_info.height; aspect = (double) frame_info.width / (double) frame_info.height; if (es->getAspectRatio() > 0.0 && es->getAspectRatio() < 10.0) aspect = es->getAspectRatio(); width=display_region.width; height = (int) ((double) display_region.width / aspect); if (height < display_region.height) { //always scale up, not down! height= display_region.height; width = (int) ((double) display_region.height * aspect); } // adjust to even value height += height % 2; if (height == 242 || height == 642) //quick hack, but works height -= 2; display_region.height = height; display_region.width = width; dprintf_full("VideoRenderer::updateDisplayRegion() aspect-correct frame size (%d x %d)\n" " aspect ratio = %5.3f (using: %5.3f)\n", display_region.width, display_region.height, es->getAspectRatio(), aspect); /* if label/widget is resizeable, adjust out_label_info to display_region */ if (out_label_info.isLabelResizable) { out_label_info.width = display_region.width; out_label_info.height = display_region.height; scalex = scaley = 1.0; } else { /* otherwise, fit display_region into label */ width = out_label_info.width; height = out_label_info.height; if (display_region.width < width && !frame_info.allowUpscaleX) { width = display_region.width; } scalex = (double) width / (double) display_region.width; scaley = (double) height / (double) display_region.height; if ((scalex >= scaley && scaley >= 1.0) || (scaley <= scalex && scaley < 1.0)) { /* scale to height */ if (height == display_region.height) width = display_region.width; else width = (int) (display_region.width * scaley); } else if ((scaley >= scalex && scalex >= 1.0) || (scalex <= scaley && scalex < 1.0)) { /* scale to width */ if (width == display_region.width) height = display_region.height; else height = (int) (display_region.height * scalex); } // adjust width and height to even values width += width % 2; height += height % 2; display_region.width = width; display_region.height = height; } dprintf_full("VideoRenderer::updateDisplayRegion() set display_region to (%d x %d)\n" " scalex = %5.3f, scaley = %5.3f, label/widget (%d x %d)\n", display_region.width, display_region.height, scalex, scaley, out_label_info.width, out_label_info.height); if (display_region.width > out_label_info.width || display_region.height > out_label_info.height || display_region.width <= 0 || display_region.height <= 0) { dprintf_err("VideoRenderer::updateDisplayRegion(): invalid size:\n" " video (%d x %d), qlabel (%d x %d)\n", display_region.width, display_region.height, out_label_info.width, out_label_info.height); return false; } /* center displayed region within label/widget */ display_region.left += (out_label_info.width - display_region.width) / 2; display_region.top += (out_label_info.height - display_region.height) / 2; /* update frame_info.scale{X,Y} */ frame_info.scaleX = DIV_FIXED(frame_info.width, display_region.width); frame_info.scaleY = DIV_FIXED(frame_info.height, display_region.height); display_region.right = display_region.left + display_region.width; display_region.bottom = display_region.top + display_region.height; return true; }

int VideoRenderer::writeFrame (  Frame *  frm, ESInfo *  out_es = NULL )  [virtual]

Renders a frame to the destination QLabel widget. Returns: 1 on success, 0 on error. Implements IO. Reimplemented in QLabelRenderer, SDLRenderer, and X11Renderer. Definition at line 220 of file VideoRenderer.cpp. References colorSpace, frame_info, frameBuffer, Frame::getAU(), VideoFrameBuffer::lock(), VideoFrameBuffer::postPaintEvent(), and VideoFrameBuffer::unlock(). Referenced by Visualizer::adapt(), X11Renderer::writeFrame(), SDLRenderer::writeFrame(), and QLabelRenderer::writeFrame(). { struct AU *au; register int x, x0, y, y0; register u8 *pix, *pixline; register u32 yframe; register u32 one = INT2FIXED(1); if (!frm || !frm->getAU()) { dprintf_err("VideoRenderer::writeFrame(): invalid parameter: frm = %p, au = %p\n", frm, frm ? (void *) frm->getAU() : NULL); state = STREAMERR; return 0; } if (state != OPEN) return 1; framesSeen++; /* we don't set currentFrameNumber, as we have no way to determine it! */ au = frm->getAU(); if (au->size != (u32) frame_info.size) { dprintf_err("VideoRenderer::writeFrame(): frame size mismatch: expected %d bytes, " "got %u bytes\n", frame_info.size, au->size); state = STREAMERR; return 0; } /* convert frame to frameBuffer, * scaling the frame according to frame_info.scaleX and frame_info.scaleY */ frameBuffer->lock(); switch (colorSpace) { case UncompressedVideoFrame::ColorSpaceGRAY8: CHOOSE_SCALE_FRAME(1, *pix) break; case UncompressedVideoFrame::ColorSpaceRGB24: if (outputDepth >= 24) { //note: it is BGR! CHOOSE_SCALE_FRAME(3, (pix[0] << 16) | (pix[1] << 8) | pix[2]) } else { CHOOSE_SCALE_FRAME(3, ((pix[0] >> 3) << 11) + ((pix[1] >> 2) << 5) + (pix[2] >> 3)) // CHOOSE_SCALE_FRAME(3, ((pix[2] >> 11) << 11) + ((pix[1] >> 10) << 5) + (pix[0] >> 11)) } break; case UncompressedVideoFrame::ColorSpaceRGB32: /* Qt expected input format: BGRA */ // CHOOSE_SCALE_FRAME(4, qRgba(pix[2], pix[1], pix[0], pix[3])) /* SDL expected input format: ARGB */ // CHOOSE_SCALE_FRAME(4, (pix[3] << 24) | (pix[2] << 16) | (pix[1] << 8) | pix[0]) /* X11 expected input format: ARGB */ //note: it is RGB! if (outputDepth >= 24) CHOOSE_SCALE_FRAME(4, (pix[3] << 24) | (pix[2] << 16) | (pix[1] << 8) | pix[0]) else CHOOSE_SCALE_FRAME(4, ((pix[2] >> 3) << 11) + ((pix[1] >> 2) << 5) + (pix[0] >> 3)) break; case UncompressedVideoFrame::ColorSpaceRGB565: /* How Do I Convert RGB5XX into a 16-bit number? * #define RGB565(r, g, b) ((r >> 3) << 11)| ((g >> 2) << 5)| ((b >> 3) << 0) * #define RGB555(r, g, b) ((r >> 3) << 10)| ((g >> 3) << 5)| ((b >> 3) << 0) */ if (outputDepth >= 24) { //FIXME: the RGB green-part is fucked up, and I don't find the problem :( //scale up from 16 to 24 bit // CHOOSE_SCALE_FRAME(2, ((pix[0] << 3) <<0) | (pix[0] >>5 | pix[1] >>5 <<3)<<8 | ((pix[1] << 3)>>3)<<16 ) CHOOSE_SCALE_FRAME(2, ((pix[0] << 3)) /*blue*/ | ((pix[1] << 3)>>3<<16) /*red*/ | pix[0] >>5<<10 | pix[1] >>5 <<13 /*green*/ ) } else { CHOOSE_SCALE_FRAME(2, (pix[1]<<8) | pix[0]) } break; default: /* make compiler happy */ break; } frameBuffer->unlock(); dprintf_full("VideoRenderer::writeFrame() posting paint event to frame buffer\n"); frameBuffer->postPaintEvent(); #ifdef _POSIX_PRIORITY_SCHEDULING sched_yield(); //this is necessary to give parallel getFrames a chance #endif return 1; }

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Member Data Documentation

VideoRect VideoRenderer::display_region [protected]

apect-ratio adjusted region of qlabel where frames will be displayed. Frame dimensions may be smaller than display_region and out_label_info dimensions. Definition at line 247 of file VideoRenderer.hpp. Referenced by updateDisplayRegion().

VideoRect VideoRenderer::frame_info [protected]

Dimension, storage size (in bytes), and scaling factors of a decoded video frame. The scaling factors are defined as sx = frame_info.width / display_region.width sy = frame_info.height / display_region.height We use fixed point arithmetic with FIXED_DIGITS binary precision, so scaleX = (int) (sx * 2^FIXED_DIGITS) The product x * sx for an integer x is then computed as the scaled integer product (x * scaleX) >> FIXED_DIGITS which should be considerably faster than floating point multiplication. Definition at line 240 of file VideoRenderer.hpp. Referenced by updateDisplayRegion(), VideoRenderer(), and writeFrame().

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The documentation for this class was generated from the following files:

• VideoRenderer.hpp
• VideoRenderer.cpp

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