buf2rgb.cpp File Reference

Some helper functions to convert and blit buffers. More...

#include <libavutil/imgutils.h>
#include <libswscale/swscale.h>
#include <sys/mman.h>
#include <drm_fourcc.h>
#include "buf2rgb.h"
#include "logger.h"
#include "drmbuffer.h"

Include dependency graph for buf2rgb.cpp:

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. More...
uint8_t *	BufToRgb (cDrmBuffer *buf, int *size, int dstW, int dstH, enum AVPixelFormat dstPixFmt)
	Convert a DRM buffer to rgb format image. More...
uint8_t *	ScaleRgb24 (uint8_t *src, int *size, int srcW, int srcH, int dstW, int dstH)
	Scale an image. More...
void	AlphaBlend (uint8_t *result, uint8_t *front, uint8_t *back, const unsigned int width, const unsigned int height)
	Blend two images. More...
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. More...
void	PrintStreamData (const uint8_t *data, int size)
	Print raw stream data. More...

Detailed Description

Some helper functions to convert and blit buffers.

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 buf2rgb.cpp.

Macro Definition Documentation

BLEND

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

Definition at line 35 of file buf2rgb.cpp.

OPAQUE

#define OPAQUE   0xff

Definition at line 32 of file buf2rgb.cpp.

TRANSPARENT

#define TRANSPARENT   0x00

Definition at line 33 of file buf2rgb.cpp.

UNMULTIPLY

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

Definition at line 34 of file buf2rgb.cpp.

Function Documentation

AlphaBlend()

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

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 203 of file buf2rgb.cpp.

References BLEND, OPAQUE, TRANSPARENT, and UNMULTIPLY.

Referenced by cSoftHdDevice::GrabImage().

BlitVideo()

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.

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 264 of file buf2rgb.cpp.

References L_GRAB, and LOGDEBUG2.

Referenced by cSoftHdDevice::GrabImage().

BufToRgb()

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

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 74 of file buf2rgb.cpp.

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

Referenced by cVideoRender::ConvertOsdBufToRgb(), cVideoRender::ConvertPipBufToRgb(), and cVideoRender::ConvertVideoBufToRgb().

DrmFormatToAVFormat()

enum AVPixelFormat DrmFormatToAVFormat

(

cDrmBuffer *

buf

)

Convert a DRM format to a ffmpeg AV format.

Definition at line 44 of file buf2rgb.cpp.

References cDrmBuffer::PixFmt().

Referenced by BufToRgb().

PrintStreamData()

void PrintStreamData	(	const uint8_t *	data,
		int	size
	)

Print raw stream data.

Parameters

data	pointer to stream data
size	data size

Definition at line 288 of file buf2rgb.cpp.

References LOGDEBUG.

ScaleRgb24()

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

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 152 of file buf2rgb.cpp.

References L_GRAB, LOGDEBUG2, and LOGERROR.

Referenced by cSoftHdDevice::GrabImage().