grab.cpp File Reference

Grabing classes. More...

#include <libavutil/imgutils.h>
#include <libswscale/swscale.h>
#include <sys/mman.h>
#include <drm_fourcc.h>
#include "drmbuffer.h"
#include "grab.h"
#include "logger.h"
#include "videorender.h"

Go to the source code of this file.

Macros
#define	OPAQUE   0xff
#define	TRANSPARENT   0x00
#define	UNMULTIPLY(color, alpha)   ((0xff * color) / alpha)
#define	BLEND(back, front, alpha)   ((front * alpha) + (back * (255 - alpha))) / 255

Functions
enum AVPixelFormat	DrmFormatToAVFormat (cDrmBuffer *buf)
	Convert a DRM format to a ffmpeg AV format.
static uint8_t *	BufToRgb (cDrmBuffer *buf, int *size, int dstW, int dstH, enum AVPixelFormat dstPixFmt)
	Convert a DRM buffer to rgb format image.
static uint8_t *	ScaleRgb24 (uint8_t *src, int *size, int srcW, int srcH, int dstW, int dstH)
	Scale an image.
static void	AlphaBlend (uint8_t *result, uint8_t *front, uint8_t *back, const unsigned int width, const unsigned int height)
	Blend two images.
static int	BlitVideo (uint8_t *dst, uint8_t *src, int dstW, int dstH, int dstX, int dstY, int srcW, int srcH)
	Blit the video on black background.
uint8_t *	CreateJpeg (uint8_t *image, int *size, int quality, int width, int height)
	Call rgb to jpeg for C Plugin.

Detailed Description

Grabing classes.

This file defines cGrabBuffer and cSoftHdGrab, which are used to handle grab requests.

Copyright

(c) 2025 by Andreas Baierl. All Rights Reserved.

License

AGPLv3

This program is free software: you can redistribute it and/or modify it under the terms of the GNU Affero General Public License as published by the Free Software Foundation, either version 3 of the License.

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 Affero General Public License for more details.

Definition in file grab.cpp.

Macro Definition Documentation

BLEND

#define BLEND	(		back,
			front,
			alpha
	)		((front * alpha) + (back * (255 - alpha))) / 255

Definition at line 43 of file grab.cpp.

OPAQUE

#define OPAQUE   0xff

Definition at line 40 of file grab.cpp.

TRANSPARENT

#define TRANSPARENT   0x00

Definition at line 41 of file grab.cpp.

UNMULTIPLY

#define UNMULTIPLY	(		color,
			alpha
	)		((0xff * color) / alpha)

Definition at line 42 of file grab.cpp.

Function Documentation

AlphaBlend()

static void AlphaBlend ( uint8_t *  result, uint8_t *  front, uint8_t *  back, const unsigned int  width, const unsigned int  height  )

static

Blend two images.

Both, front and back image data have to be same size front is the OSD (ARGB) back is the video (RGB) result is RGB

Parameters

[out]	result	pointer to the resulting image data
[in]	front	pointer to the upper image data
[in]	back	pointer to the lower image data
[in]	width	image width
[in]	height	image height

Definition at line 207 of file grab.cpp.

References BLEND, OPAQUE, TRANSPARENT, and UNMULTIPLY.

Referenced by cSoftHdGrab::ProcessGrab().

BlitVideo()

static int BlitVideo ( uint8_t *  dst, uint8_t *  src, int  dstW, int  dstH, int  dstX, int  dstY, int  srcW, int  srcH  )

static

Blit the video on black background.

Parameters

[in]	dst	pointer to the destination video
[in]	src	pointer to the source video
[in]	dstW	destination width of the image
[in]	dstH	destination height of the image
[in]	dstX	x offset of the (already scaled) video on the image
[in]	dstY	y offset of the (already scaled) video on the image
[in]	srcW	source video width
[in]	srcH	source video height

Returns

0 on success, -1 on error

Definition at line 268 of file grab.cpp.

References L_GRAB, and LOGDEBUG2.

Referenced by cSoftHdGrab::ProcessGrab().

BufToRgb()

static uint8_t * BufToRgb ( cDrmBuffer *  buf, int *  size, int  dstW, int  dstH, enum AVPixelFormat  dstPixFmt  )

static

Convert a DRM buffer to rgb format image.

Conversion is done with ffmpegs swscale

Parameters

[in]	buf	pointer to the source drm buffer struct
[out]	size	size of the return data
[in]	dstW	width of the returned image
[in]	dstH	height of the returned image
[in]	dstPixFmt	pixel format of the returned image

Returns

a pointer to the image data

Definition at line 78 of file grab.cpp.

References DrmFormatToAVFormat(), cDrmBuffer::Height(), L_GRAB, LOGDEBUG2, LOGERROR, cDrmBuffer::NumPlanes(), cDrmBuffer::Offset(), cDrmBuffer::Pitch(), cDrmBuffer::Plane(), cDrmBuffer::Size(), and cDrmBuffer::Width().

Referenced by cSoftHdGrab::GetGrab().

CreateJpeg()

uint8_t * CreateJpeg	(	uint8_t *	image,
		int *	size,
		int	quality,
		int	width,
		int	height
	)

Call rgb to jpeg for C Plugin.

Definition at line 431 of file grab.cpp.

Referenced by cSoftHdGrab::ProcessGrab().

DrmFormatToAVFormat()

enum AVPixelFormat DrmFormatToAVFormat

(

cDrmBuffer *

buf

)

Convert a DRM format to a ffmpeg AV format.

Definition at line 48 of file grab.cpp.

References cDrmBuffer::PixFmt().

Referenced by BufToRgb().

ScaleRgb24()

static uint8_t * ScaleRgb24 ( uint8_t *  src, int *  size, int  srcW, int  srcH, int  dstW, int  dstH  )

static

Scale an image.

Conversion is done with ffmpegs swscale

Parameters

[in]	src	pointer to the source data
[out]	size	size of the return data
[in]	srcW	source width
[in]	srcH	source height
[in]	dstW	width of the returned image
[in]	dstH	height of the returned image

Returns

a pointer to the converted image data

Definition at line 156 of file grab.cpp.

References L_GRAB, LOGDEBUG2, and LOGERROR.

Referenced by cSoftHdGrab::ProcessGrab().