[v4,1/1] apps: cam: Add support for PPM output format
diff mbox series

Message ID 20240322195032.1803017-2-mzamazal@redhat.com
State Accepted
Headers show
Series
  • cam: Add support for PPM output format
Related show

Commit Message

Milan Zamazal March 22, 2024, 7:50 p.m. UTC
When file output is requested from cam app, it simply dumps the processed data
and it must be converted to a readable image format manually.  Let's add support
for PPM output file format to make files produced by cam directly readable by
image display and processing software.

For now, only BGR888 output format, which is the simplest one to use, is
supported but nothing prevents adding support for other output formats if
needed.  Nevertheless, they would typically need byte reordering or other
conversions for PPM file format.  It may be better to find a way to dump the
image data in other output formats directly using some of the already existing
file formats or raw file format converters.

Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
---
 src/apps/cam/file_sink.cpp     | 11 +++++++
 src/apps/cam/main.cpp          |  2 ++
 src/apps/common/meson.build    |  1 +
 src/apps/common/ppm_writer.cpp | 53 ++++++++++++++++++++++++++++++++++
 src/apps/common/ppm_writer.h   | 20 +++++++++++++
 5 files changed, 87 insertions(+)
 create mode 100644 src/apps/common/ppm_writer.cpp
 create mode 100644 src/apps/common/ppm_writer.h

Comments

Laurent Pinchart March 28, 2024, 1:06 a.m. UTC | #1
Hi Milan,

Thank you for the patch.

On Fri, Mar 22, 2024 at 08:50:32PM +0100, Milan Zamazal wrote:
> When file output is requested from cam app, it simply dumps the processed data
> and it must be converted to a readable image format manually.  Let's add support
> for PPM output file format to make files produced by cam directly readable by
> image display and processing software.
> 
> For now, only BGR888 output format, which is the simplest one to use, is
> supported but nothing prevents adding support for other output formats if
> needed.  Nevertheless, they would typically need byte reordering or other
> conversions for PPM file format.  It may be better to find a way to dump the
> image data in other output formats directly using some of the already existing
> file formats or raw file format converters.
> 
> Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  src/apps/cam/file_sink.cpp     | 11 +++++++
>  src/apps/cam/main.cpp          |  2 ++
>  src/apps/common/meson.build    |  1 +
>  src/apps/common/ppm_writer.cpp | 53 ++++++++++++++++++++++++++++++++++
>  src/apps/common/ppm_writer.h   | 20 +++++++++++++
>  5 files changed, 87 insertions(+)
>  create mode 100644 src/apps/common/ppm_writer.cpp
>  create mode 100644 src/apps/common/ppm_writer.h
> 
> diff --git a/src/apps/cam/file_sink.cpp b/src/apps/cam/file_sink.cpp
> index dca350c4..906b50e6 100644
> --- a/src/apps/cam/file_sink.cpp
> +++ b/src/apps/cam/file_sink.cpp
> @@ -17,6 +17,7 @@
>  
>  #include "../common/dng_writer.h"
>  #include "../common/image.h"
> +#include "../common/ppm_writer.h"
>  
>  #include "file_sink.h"
>  
> @@ -76,6 +77,7 @@ void FileSink::writeBuffer(const Stream *stream, FrameBuffer *buffer,
>  #ifdef HAVE_TIFF
>  	bool dng = filename.find(".dng", filename.size() - 4) != std::string::npos;
>  #endif /* HAVE_TIFF */
> +	bool ppm = filename.find(".ppm", filename.size() - 4) != std::string::npos;
>  
>  	if (filename.empty() || filename.back() == '/')
>  		filename += "frame-#.bin";
> @@ -102,6 +104,15 @@ void FileSink::writeBuffer(const Stream *stream, FrameBuffer *buffer,
>  		return;
>  	}
>  #endif /* HAVE_TIFF */
> +	if (ppm) {
> +		ret = PPMWriter::write(filename.c_str(), stream->configuration(),
> +				       image->data(0));
> +		if (ret < 0)
> +			std::cerr << "failed to write PPM file `" << filename
> +				  << "'" << std::endl;
> +
> +		return;
> +	}
>  
>  	fd = open(filename.c_str(), O_CREAT | O_WRONLY |
>  		  (pos == std::string::npos ? O_APPEND : O_TRUNC),
> diff --git a/src/apps/cam/main.cpp b/src/apps/cam/main.cpp
> index 179cc376..1aabee01 100644
> --- a/src/apps/cam/main.cpp
> +++ b/src/apps/cam/main.cpp
> @@ -154,6 +154,8 @@ int CamApp::parseOptions(int argc, char *argv[])
>  			 "If the file name ends with '.dng', then the frame will be written to\n"
>  			 "the output file(s) in DNG format.\n"
>  #endif
> +			 "If the file name ends with '.ppm', then the frame will be written to\n"
> +			 "the output file(s) in PPM format.\n"
>  			 "The default file name is 'frame-#.bin'.",
>  			 "file", ArgumentOptional, "filename", false,
>  			 OptCamera);
> diff --git a/src/apps/common/meson.build b/src/apps/common/meson.build
> index 479326cd..5b683390 100644
> --- a/src/apps/common/meson.build
> +++ b/src/apps/common/meson.build
> @@ -3,6 +3,7 @@
>  apps_sources = files([
>      'image.cpp',
>      'options.cpp',
> +    'ppm_writer.cpp',
>      'stream_options.cpp',
>  ])
>  
> diff --git a/src/apps/common/ppm_writer.cpp b/src/apps/common/ppm_writer.cpp
> new file mode 100644
> index 00000000..04a49499
> --- /dev/null
> +++ b/src/apps/common/ppm_writer.cpp
> @@ -0,0 +1,53 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2024 Red Hat, Inc.
> + *
> + * ppm_writer.cpp - PPM writer
> + */
> +
> +#include <fstream>
> +#include <iostream>
> +
> +#include <libcamera/formats.h>
> +#include <libcamera/pixel_format.h>
> +
> +#include "ppm_writer.h"
> +
> +using namespace libcamera;
> +
> +int PPMWriter::write(const char *filename,
> +		     const StreamConfiguration &config,
> +		     const Span<uint8_t> &data)
> +{
> +	if (config.pixelFormat != formats::BGR888) {
> +		std::cerr << "Only BGR888 output pixel format is supported ("
> +			  << config.pixelFormat << " requested)" << std::endl;
> +		return -EINVAL;
> +	}
> +
> +	std::ofstream output(filename, std::ios::binary);
> +	if (!output) {
> +		std::cerr << "Failed to open ppm file: " << filename << std::endl;
> +		return -EINVAL;
> +	}
> +
> +	output << "P6" << std::endl
> +	       << config.size.width << " " << config.size.height << std::endl
> +	       << "255" << std::endl;
> +	if (!output) {
> +		std::cerr << "Failed to write the file header" << std::endl;
> +		return -EINVAL;
> +	}
> +
> +	const unsigned int rowLength = config.size.width * 3;
> +	const char *row = reinterpret_cast<const char *>(data.data());
> +	for (unsigned int y = 0; y < config.size.height; y++, row += config.stride) {
> +		output.write(row, rowLength);
> +		if (!output) {
> +			std::cerr << "Failed to write image data at row " << y << std::endl;
> +			return -EINVAL;
> +		}
> +	}
> +
> +	return 0;
> +}
> diff --git a/src/apps/common/ppm_writer.h b/src/apps/common/ppm_writer.h
> new file mode 100644
> index 00000000..4c38f5ce
> --- /dev/null
> +++ b/src/apps/common/ppm_writer.h
> @@ -0,0 +1,20 @@
> +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> +/*
> + * Copyright (C) 2024, Red Hat, Inc.
> + *
> + * ppm_writer.h - PPM writer
> + */
> +
> +#pragma once
> +
> +#include <libcamera/base/span.h>
> +
> +#include <libcamera/stream.h>
> +
> +class PPMWriter
> +{
> +public:
> +	static int write(const char *filename,
> +			 const libcamera::StreamConfiguration &config,
> +			 const libcamera::Span<uint8_t> &data);
> +};
Laurent Pinchart March 28, 2024, 1:11 a.m. UTC | #2
Actually,

On Thu, Mar 28, 2024 at 03:06:23AM +0200, Laurent Pinchart wrote:
> On Fri, Mar 22, 2024 at 08:50:32PM +0100, Milan Zamazal wrote:
> > When file output is requested from cam app, it simply dumps the processed data
> > and it must be converted to a readable image format manually.  Let's add support
> > for PPM output file format to make files produced by cam directly readable by
> > image display and processing software.
> > 
> > For now, only BGR888 output format, which is the simplest one to use, is
> > supported but nothing prevents adding support for other output formats if
> > needed.  Nevertheless, they would typically need byte reordering or other
> > conversions for PPM file format.  It may be better to find a way to dump the
> > image data in other output formats directly using some of the already existing
> > file formats or raw file format converters.
> > 
> > Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
> > Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
> 
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> 
> > ---
> >  src/apps/cam/file_sink.cpp     | 11 +++++++
> >  src/apps/cam/main.cpp          |  2 ++
> >  src/apps/common/meson.build    |  1 +
> >  src/apps/common/ppm_writer.cpp | 53 ++++++++++++++++++++++++++++++++++
> >  src/apps/common/ppm_writer.h   | 20 +++++++++++++
> >  5 files changed, 87 insertions(+)
> >  create mode 100644 src/apps/common/ppm_writer.cpp
> >  create mode 100644 src/apps/common/ppm_writer.h
> > 
> > diff --git a/src/apps/cam/file_sink.cpp b/src/apps/cam/file_sink.cpp
> > index dca350c4..906b50e6 100644
> > --- a/src/apps/cam/file_sink.cpp
> > +++ b/src/apps/cam/file_sink.cpp
> > @@ -17,6 +17,7 @@
> >  
> >  #include "../common/dng_writer.h"
> >  #include "../common/image.h"
> > +#include "../common/ppm_writer.h"
> >  
> >  #include "file_sink.h"
> >  
> > @@ -76,6 +77,7 @@ void FileSink::writeBuffer(const Stream *stream, FrameBuffer *buffer,
> >  #ifdef HAVE_TIFF
> >  	bool dng = filename.find(".dng", filename.size() - 4) != std::string::npos;
> >  #endif /* HAVE_TIFF */
> > +	bool ppm = filename.find(".ppm", filename.size() - 4) != std::string::npos;
> >  
> >  	if (filename.empty() || filename.back() == '/')
> >  		filename += "frame-#.bin";
> > @@ -102,6 +104,15 @@ void FileSink::writeBuffer(const Stream *stream, FrameBuffer *buffer,
> >  		return;
> >  	}
> >  #endif /* HAVE_TIFF */
> > +	if (ppm) {
> > +		ret = PPMWriter::write(filename.c_str(), stream->configuration(),
> > +				       image->data(0));
> > +		if (ret < 0)
> > +			std::cerr << "failed to write PPM file `" << filename
> > +				  << "'" << std::endl;
> > +
> > +		return;
> > +	}
> >  
> >  	fd = open(filename.c_str(), O_CREAT | O_WRONLY |
> >  		  (pos == std::string::npos ? O_APPEND : O_TRUNC),
> > diff --git a/src/apps/cam/main.cpp b/src/apps/cam/main.cpp
> > index 179cc376..1aabee01 100644
> > --- a/src/apps/cam/main.cpp
> > +++ b/src/apps/cam/main.cpp
> > @@ -154,6 +154,8 @@ int CamApp::parseOptions(int argc, char *argv[])
> >  			 "If the file name ends with '.dng', then the frame will be written to\n"
> >  			 "the output file(s) in DNG format.\n"
> >  #endif
> > +			 "If the file name ends with '.ppm', then the frame will be written to\n"
> > +			 "the output file(s) in PPM format.\n"
> >  			 "The default file name is 'frame-#.bin'.",
> >  			 "file", ArgumentOptional, "filename", false,
> >  			 OptCamera);
> > diff --git a/src/apps/common/meson.build b/src/apps/common/meson.build
> > index 479326cd..5b683390 100644
> > --- a/src/apps/common/meson.build
> > +++ b/src/apps/common/meson.build
> > @@ -3,6 +3,7 @@
> >  apps_sources = files([
> >      'image.cpp',
> >      'options.cpp',
> > +    'ppm_writer.cpp',
> >      'stream_options.cpp',
> >  ])
> >  
> > diff --git a/src/apps/common/ppm_writer.cpp b/src/apps/common/ppm_writer.cpp
> > new file mode 100644
> > index 00000000..04a49499
> > --- /dev/null
> > +++ b/src/apps/common/ppm_writer.cpp
> > @@ -0,0 +1,53 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2024 Red Hat, Inc.
> > + *
> > + * ppm_writer.cpp - PPM writer
> > + */
> > +
> > +#include <fstream>
> > +#include <iostream>
> > +
> > +#include <libcamera/formats.h>
> > +#include <libcamera/pixel_format.h>
> > +
> > +#include "ppm_writer.h"

checkstyle.py told me that this should go to the top. I'll fix when
applying.

> > +
> > +using namespace libcamera;
> > +
> > +int PPMWriter::write(const char *filename,
> > +		     const StreamConfiguration &config,
> > +		     const Span<uint8_t> &data)
> > +{
> > +	if (config.pixelFormat != formats::BGR888) {
> > +		std::cerr << "Only BGR888 output pixel format is supported ("
> > +			  << config.pixelFormat << " requested)" << std::endl;
> > +		return -EINVAL;
> > +	}
> > +
> > +	std::ofstream output(filename, std::ios::binary);
> > +	if (!output) {
> > +		std::cerr << "Failed to open ppm file: " << filename << std::endl;
> > +		return -EINVAL;
> > +	}
> > +
> > +	output << "P6" << std::endl
> > +	       << config.size.width << " " << config.size.height << std::endl
> > +	       << "255" << std::endl;
> > +	if (!output) {
> > +		std::cerr << "Failed to write the file header" << std::endl;
> > +		return -EINVAL;
> > +	}
> > +
> > +	const unsigned int rowLength = config.size.width * 3;
> > +	const char *row = reinterpret_cast<const char *>(data.data());
> > +	for (unsigned int y = 0; y < config.size.height; y++, row += config.stride) {
> > +		output.write(row, rowLength);
> > +		if (!output) {
> > +			std::cerr << "Failed to write image data at row " << y << std::endl;
> > +			return -EINVAL;
> > +		}
> > +	}
> > +
> > +	return 0;
> > +}
> > diff --git a/src/apps/common/ppm_writer.h b/src/apps/common/ppm_writer.h
> > new file mode 100644
> > index 00000000..4c38f5ce
> > --- /dev/null
> > +++ b/src/apps/common/ppm_writer.h
> > @@ -0,0 +1,20 @@
> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
> > +/*
> > + * Copyright (C) 2024, Red Hat, Inc.
> > + *
> > + * ppm_writer.h - PPM writer
> > + */
> > +
> > +#pragma once
> > +
> > +#include <libcamera/base/span.h>
> > +
> > +#include <libcamera/stream.h>
> > +
> > +class PPMWriter
> > +{
> > +public:
> > +	static int write(const char *filename,
> > +			 const libcamera::StreamConfiguration &config,
> > +			 const libcamera::Span<uint8_t> &data);
> > +};
Milan Zamazal March 28, 2024, 8:12 a.m. UTC | #3
Laurent Pinchart <laurent.pinchart@ideasonboard.com> writes:

> Actually,
>
> On Thu, Mar 28, 2024 at 03:06:23AM +0200, Laurent Pinchart wrote:
>> On Fri, Mar 22, 2024 at 08:50:32PM +0100, Milan Zamazal wrote:
>> > When file output is requested from cam app, it simply dumps the processed data
>> > and it must be converted to a readable image format manually.  Let's add support
>> > for PPM output file format to make files produced by cam directly readable by
>> > image display and processing software.
>> > 
>> > For now, only BGR888 output format, which is the simplest one to use, is
>> > supported but nothing prevents adding support for other output formats if
>> > needed.  Nevertheless, they would typically need byte reordering or other
>> > conversions for PPM file format.  It may be better to find a way to dump the
>> > image data in other output formats directly using some of the already existing
>> > file formats or raw file format converters.
>> > 
>> > Signed-off-by: Milan Zamazal <mzamazal@redhat.com>
>> > Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
>> 
>> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
>> 
>> > ---
>> >  src/apps/cam/file_sink.cpp     | 11 +++++++
>> >  src/apps/cam/main.cpp          |  2 ++
>> >  src/apps/common/meson.build    |  1 +
>> >  src/apps/common/ppm_writer.cpp | 53 ++++++++++++++++++++++++++++++++++
>> >  src/apps/common/ppm_writer.h   | 20 +++++++++++++
>> >  5 files changed, 87 insertions(+)
>> >  create mode 100644 src/apps/common/ppm_writer.cpp
>> >  create mode 100644 src/apps/common/ppm_writer.h
>> > 
>> > diff --git a/src/apps/cam/file_sink.cpp b/src/apps/cam/file_sink.cpp
>> > index dca350c4..906b50e6 100644
>> > --- a/src/apps/cam/file_sink.cpp
>> > +++ b/src/apps/cam/file_sink.cpp
>> > @@ -17,6 +17,7 @@
>> >  
>> >  #include "../common/dng_writer.h"
>> >  #include "../common/image.h"
>> > +#include "../common/ppm_writer.h"
>> >  
>> >  #include "file_sink.h"
>> >  
>> > @@ -76,6 +77,7 @@ void FileSink::writeBuffer(const Stream *stream, FrameBuffer *buffer,
>> >  #ifdef HAVE_TIFF
>> >  	bool dng = filename.find(".dng", filename.size() - 4) != std::string::npos;
>> >  #endif /* HAVE_TIFF */
>> > +	bool ppm = filename.find(".ppm", filename.size() - 4) != std::string::npos;
>> >  
>> >  	if (filename.empty() || filename.back() == '/')
>> >  		filename += "frame-#.bin";
>> > @@ -102,6 +104,15 @@ void FileSink::writeBuffer(const Stream *stream, FrameBuffer *buffer,
>> >  		return;
>> >  	}
>> >  #endif /* HAVE_TIFF */
>> > +	if (ppm) {
>> > +		ret = PPMWriter::write(filename.c_str(), stream->configuration(),
>> > +				       image->data(0));
>> > +		if (ret < 0)
>> > +			std::cerr << "failed to write PPM file `" << filename
>> > +				  << "'" << std::endl;
>> > +
>> > +		return;
>> > +	}
>> >  
>> >  	fd = open(filename.c_str(), O_CREAT | O_WRONLY |
>> >  		  (pos == std::string::npos ? O_APPEND : O_TRUNC),
>> > diff --git a/src/apps/cam/main.cpp b/src/apps/cam/main.cpp
>> > index 179cc376..1aabee01 100644
>> > --- a/src/apps/cam/main.cpp
>> > +++ b/src/apps/cam/main.cpp
>> > @@ -154,6 +154,8 @@ int CamApp::parseOptions(int argc, char *argv[])
>> >  			 "If the file name ends with '.dng', then the frame will be written to\n"
>> >  			 "the output file(s) in DNG format.\n"
>> >  #endif
>> > +			 "If the file name ends with '.ppm', then the frame will be written to\n"
>> > +			 "the output file(s) in PPM format.\n"
>> >  			 "The default file name is 'frame-#.bin'.",
>> >  			 "file", ArgumentOptional, "filename", false,
>> >  			 OptCamera);
>> > diff --git a/src/apps/common/meson.build b/src/apps/common/meson.build
>> > index 479326cd..5b683390 100644
>> > --- a/src/apps/common/meson.build
>> > +++ b/src/apps/common/meson.build
>> > @@ -3,6 +3,7 @@
>> >  apps_sources = files([
>> >      'image.cpp',
>> >      'options.cpp',
>> > +    'ppm_writer.cpp',
>> >      'stream_options.cpp',
>> >  ])
>> >  
>> > diff --git a/src/apps/common/ppm_writer.cpp b/src/apps/common/ppm_writer.cpp
>> > new file mode 100644
>> > index 00000000..04a49499
>> > --- /dev/null
>> > +++ b/src/apps/common/ppm_writer.cpp
>> > @@ -0,0 +1,53 @@
>> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
>> > +/*
>> > + * Copyright (C) 2024 Red Hat, Inc.
>> > + *
>> > + * ppm_writer.cpp - PPM writer
>> > + */
>> > +
>> > +#include <fstream>
>> > +#include <iostream>
>> > +
>> > +#include <libcamera/formats.h>
>> > +#include <libcamera/pixel_format.h>
>> > +
>> > +#include "ppm_writer.h"
>
> checkstyle.py told me that this should go to the top. I'll fix when
> applying.

Thanks!  (And sorry for this omission.)

>> > +
>> > +using namespace libcamera;
>> > +
>> > +int PPMWriter::write(const char *filename,
>> > +		     const StreamConfiguration &config,
>> > +		     const Span<uint8_t> &data)
>> > +{
>> > +	if (config.pixelFormat != formats::BGR888) {
>> > +		std::cerr << "Only BGR888 output pixel format is supported ("
>> > +			  << config.pixelFormat << " requested)" << std::endl;
>> > +		return -EINVAL;
>> > +	}
>> > +
>> > +	std::ofstream output(filename, std::ios::binary);
>> > +	if (!output) {
>> > +		std::cerr << "Failed to open ppm file: " << filename << std::endl;
>> > +		return -EINVAL;
>> > +	}
>> > +
>> > +	output << "P6" << std::endl
>> > +	       << config.size.width << " " << config.size.height << std::endl
>> > +	       << "255" << std::endl;
>> > +	if (!output) {
>> > +		std::cerr << "Failed to write the file header" << std::endl;
>> > +		return -EINVAL;
>> > +	}
>> > +
>> > +	const unsigned int rowLength = config.size.width * 3;
>> > +	const char *row = reinterpret_cast<const char *>(data.data());
>> > +	for (unsigned int y = 0; y < config.size.height; y++, row += config.stride) {
>> > +		output.write(row, rowLength);
>> > +		if (!output) {
>> > +			std::cerr << "Failed to write image data at row " << y << std::endl;
>> > +			return -EINVAL;
>> > +		}
>> > +	}
>> > +
>> > +	return 0;
>> > +}
>> > diff --git a/src/apps/common/ppm_writer.h b/src/apps/common/ppm_writer.h
>> > new file mode 100644
>> > index 00000000..4c38f5ce
>> > --- /dev/null
>> > +++ b/src/apps/common/ppm_writer.h
>> > @@ -0,0 +1,20 @@
>> > +/* SPDX-License-Identifier: LGPL-2.1-or-later */
>> > +/*
>> > + * Copyright (C) 2024, Red Hat, Inc.
>> > + *
>> > + * ppm_writer.h - PPM writer
>> > + */
>> > +
>> > +#pragma once
>> > +
>> > +#include <libcamera/base/span.h>
>> > +
>> > +#include <libcamera/stream.h>
>> > +
>> > +class PPMWriter
>> > +{
>> > +public:
>> > +	static int write(const char *filename,
>> > +			 const libcamera::StreamConfiguration &config,
>> > +			 const libcamera::Span<uint8_t> &data);
>> > +};

Patch
diff mbox series

diff --git a/src/apps/cam/file_sink.cpp b/src/apps/cam/file_sink.cpp
index dca350c4..906b50e6 100644
--- a/src/apps/cam/file_sink.cpp
+++ b/src/apps/cam/file_sink.cpp
@@ -17,6 +17,7 @@ 
 
 #include "../common/dng_writer.h"
 #include "../common/image.h"
+#include "../common/ppm_writer.h"
 
 #include "file_sink.h"
 
@@ -76,6 +77,7 @@  void FileSink::writeBuffer(const Stream *stream, FrameBuffer *buffer,
 #ifdef HAVE_TIFF
 	bool dng = filename.find(".dng", filename.size() - 4) != std::string::npos;
 #endif /* HAVE_TIFF */
+	bool ppm = filename.find(".ppm", filename.size() - 4) != std::string::npos;
 
 	if (filename.empty() || filename.back() == '/')
 		filename += "frame-#.bin";
@@ -102,6 +104,15 @@  void FileSink::writeBuffer(const Stream *stream, FrameBuffer *buffer,
 		return;
 	}
 #endif /* HAVE_TIFF */
+	if (ppm) {
+		ret = PPMWriter::write(filename.c_str(), stream->configuration(),
+				       image->data(0));
+		if (ret < 0)
+			std::cerr << "failed to write PPM file `" << filename
+				  << "'" << std::endl;
+
+		return;
+	}
 
 	fd = open(filename.c_str(), O_CREAT | O_WRONLY |
 		  (pos == std::string::npos ? O_APPEND : O_TRUNC),
diff --git a/src/apps/cam/main.cpp b/src/apps/cam/main.cpp
index 179cc376..1aabee01 100644
--- a/src/apps/cam/main.cpp
+++ b/src/apps/cam/main.cpp
@@ -154,6 +154,8 @@  int CamApp::parseOptions(int argc, char *argv[])
 			 "If the file name ends with '.dng', then the frame will be written to\n"
 			 "the output file(s) in DNG format.\n"
 #endif
+			 "If the file name ends with '.ppm', then the frame will be written to\n"
+			 "the output file(s) in PPM format.\n"
 			 "The default file name is 'frame-#.bin'.",
 			 "file", ArgumentOptional, "filename", false,
 			 OptCamera);
diff --git a/src/apps/common/meson.build b/src/apps/common/meson.build
index 479326cd..5b683390 100644
--- a/src/apps/common/meson.build
+++ b/src/apps/common/meson.build
@@ -3,6 +3,7 @@ 
 apps_sources = files([
     'image.cpp',
     'options.cpp',
+    'ppm_writer.cpp',
     'stream_options.cpp',
 ])
 
diff --git a/src/apps/common/ppm_writer.cpp b/src/apps/common/ppm_writer.cpp
new file mode 100644
index 00000000..04a49499
--- /dev/null
+++ b/src/apps/common/ppm_writer.cpp
@@ -0,0 +1,53 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024 Red Hat, Inc.
+ *
+ * ppm_writer.cpp - PPM writer
+ */
+
+#include <fstream>
+#include <iostream>
+
+#include <libcamera/formats.h>
+#include <libcamera/pixel_format.h>
+
+#include "ppm_writer.h"
+
+using namespace libcamera;
+
+int PPMWriter::write(const char *filename,
+		     const StreamConfiguration &config,
+		     const Span<uint8_t> &data)
+{
+	if (config.pixelFormat != formats::BGR888) {
+		std::cerr << "Only BGR888 output pixel format is supported ("
+			  << config.pixelFormat << " requested)" << std::endl;
+		return -EINVAL;
+	}
+
+	std::ofstream output(filename, std::ios::binary);
+	if (!output) {
+		std::cerr << "Failed to open ppm file: " << filename << std::endl;
+		return -EINVAL;
+	}
+
+	output << "P6" << std::endl
+	       << config.size.width << " " << config.size.height << std::endl
+	       << "255" << std::endl;
+	if (!output) {
+		std::cerr << "Failed to write the file header" << std::endl;
+		return -EINVAL;
+	}
+
+	const unsigned int rowLength = config.size.width * 3;
+	const char *row = reinterpret_cast<const char *>(data.data());
+	for (unsigned int y = 0; y < config.size.height; y++, row += config.stride) {
+		output.write(row, rowLength);
+		if (!output) {
+			std::cerr << "Failed to write image data at row " << y << std::endl;
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
diff --git a/src/apps/common/ppm_writer.h b/src/apps/common/ppm_writer.h
new file mode 100644
index 00000000..4c38f5ce
--- /dev/null
+++ b/src/apps/common/ppm_writer.h
@@ -0,0 +1,20 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Red Hat, Inc.
+ *
+ * ppm_writer.h - PPM writer
+ */
+
+#pragma once
+
+#include <libcamera/base/span.h>
+
+#include <libcamera/stream.h>
+
+class PPMWriter
+{
+public:
+	static int write(const char *filename,
+			 const libcamera::StreamConfiguration &config,
+			 const libcamera::Span<uint8_t> &data);
+};