[libcamera-devel] [RFC PATCH 1/6] android: Introduce JPEG compression
Jacopo Mondi
jacopo at jmondi.org
Wed Jul 22 10:50:34 CEST 2020
Hi Kieran,
just skimming through.. some nits and questions below...
On Tue, Jul 21, 2020 at 11:01:21PM +0100, Kieran Bingham wrote:
> Provide a compressor interface and implement a JPEG compressor using libjpeg.
>
> Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> ---
> src/android/jpeg/compressor.h | 28 +++
> src/android/jpeg/compressor_jpeg.cpp | 279 +++++++++++++++++++++++++++
> src/android/jpeg/compressor_jpeg.h | 44 +++++
> src/android/meson.build | 1 +
> src/libcamera/meson.build | 2 +
> 5 files changed, 354 insertions(+)
> create mode 100644 src/android/jpeg/compressor.h
> create mode 100644 src/android/jpeg/compressor_jpeg.cpp
> create mode 100644 src/android/jpeg/compressor_jpeg.h
>
> diff --git a/src/android/jpeg/compressor.h b/src/android/jpeg/compressor.h
> new file mode 100644
> index 000000000000..f95e4a4539cb
> --- /dev/null
> +++ b/src/android/jpeg/compressor.h
> @@ -0,0 +1,28 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2020, Google Inc.
> + *
> + * compressor.h - Image compression interface
> + */
Don't we usually have an empty line here ?
> +#ifndef __LIBCAMERA_COMPRESSOR_H__
> +#define __LIBCAMERA_COMPRESSOR_H__
Maybe __LIBCAMERA_ANDROID_COMPRESSOR__ ?
> +
> +#include <libcamera/buffer.h>
> +#include <libcamera/stream.h>
> +
> +struct CompressedImage {
> + unsigned char *data;
> + unsigned long length;
> +};
> +
> +class Compressor
> +{
> +public:
> + virtual ~Compressor() { };
> +
> + virtual int configure(const libcamera::StreamConfiguration &cfg) = 0;
> + virtual int compress(const libcamera::FrameBuffer *source, CompressedImage *image) = 0;
> + virtual void free(CompressedImage *image) = 0;
> +};
Do we expect more compressors ? Why a pure virtual class to define an
interface ?
> +
> +#endif /* __LIBCAMERA_COMPRESSOR_H__ */
> diff --git a/src/android/jpeg/compressor_jpeg.cpp b/src/android/jpeg/compressor_jpeg.cpp
> new file mode 100644
> index 000000000000..78fa5e399d99
> --- /dev/null
> +++ b/src/android/jpeg/compressor_jpeg.cpp
> @@ -0,0 +1,279 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2020, Google Inc.
> + *
> + * compressor_jpeg.cpp - JPEG compression using libjpeg native API
s/native API//
Or is there a value in saying that ?
> + */
> +
> +#include "compressor_jpeg.h"
> +
> +#include <fcntl.h>
> +#include <iomanip>
> +#include <iostream>
> +#include <sstream>
> +#include <string.h>
> +#include <sys/mman.h>
> +#include <unistd.h>
> +#include <vector>
> +
> +#include <libcamera/camera.h>
> +#include <libcamera/formats.h>
> +#include <libcamera/pixel_format.h>
> +
> +#include "libcamera/internal/log.h"
> +
> +using namespace libcamera;
> +
> +LOG_DEFINE_CATEGORY(JPEG)
> +
> +struct PixelFormatPlaneInfo {
> + unsigned int bitsPerPixel;
> + unsigned int hSubSampling;
> + unsigned int vSubSampling;
> +};
> +
> +struct PixelFormatInfo {
> + J_COLOR_SPACE colorSpace;
> + unsigned int numPlanes;
> + bool nvSwap;
> + PixelFormatPlaneInfo planes[3];
> +};
Is there a reason why we can't use the libcamera PixelFormatInfo and
maybe keep an association with the J_COLOR_SPACE field ? The android
layer can use internal headers, right ?
> +
> +namespace {
> +
> +static const std::map<PixelFormat, struct PixelFormatInfo> pixelInfo{
> + { formats::R8, { JCS_GRAYSCALE, 1, false, { { 8, 1, 1 }, { 0, 0, 0 }, { 0, 0, 0 } } } },
> +
> + /* RGB formats. */
> + { formats::RGB888, { JCS_EXT_BGR, 1, false, { { 24, 1, 1 }, { 0, 0, 0 }, { 0, 0, 0 } } } },
> + { formats::BGR888, { JCS_EXT_RGB, 1, false, { { 24, 1, 1 }, { 0, 0, 0 }, { 0, 0, 0 } } } },
> +
> + /* YUV packed formats. */
> + { formats::UYVY, { JCS_YCbCr, 1, false, { { 16, 1, 1 }, { 0, 0, 0 }, { 0, 0, 0 } } } },
> + { formats::VYUY, { JCS_YCbCr, 1, false, { { 16, 1, 1 }, { 0, 0, 0 }, { 0, 0, 0 } } } },
> + { formats::YUYV, { JCS_YCbCr, 1, false, { { 16, 1, 1 }, { 0, 0, 0 }, { 0, 0, 0 } } } },
> + { formats::YVYU, { JCS_YCbCr, 1, false, { { 16, 1, 1 }, { 0, 0, 0 }, { 0, 0, 0 } } } },
> +
> + /* YUY planar formats. */
> + { formats::NV12, { JCS_YCbCr, 2, false, { { 8, 1, 1 }, { 16, 2, 2 }, { 0, 0, 0 } } } },
> + { formats::NV21, { JCS_YCbCr, 2, true, { { 8, 1, 1 }, { 16, 2, 2 }, { 0, 0, 0 } } } },
> + { formats::NV16, { JCS_YCbCr, 2, false, { { 8, 1, 1 }, { 16, 2, 1 }, { 0, 0, 0 } } } },
> + { formats::NV61, { JCS_YCbCr, 2, true, { { 8, 1, 1 }, { 16, 2, 1 }, { 0, 0, 0 } } } },
> + { formats::NV24, { JCS_YCbCr, 2, false, { { 8, 1, 1 }, { 16, 1, 1 }, { 0, 0, 0 } } } },
> + { formats::NV42, { JCS_YCbCr, 2, true, { { 8, 1, 1 }, { 16, 1, 1 }, { 0, 0, 0 } } } },
> +};
Could this become
struct JPEGPixelFormatInfo
{
J_COLOR_SPACE colorSpace;
PixelFormatInfo pixelFormatInfo;
};
std::map<PixelFormat, JPEGPixelFormatInfo> pixelInfo{
{ formats::RGB888, { JCS_EXT_BGR, PixelFormatInfo::info(formats::RGB888 },
..
};
> +
> +}
> +
> +const struct PixelFormatInfo &findPixelInfo(const PixelFormat &format)
> +{
> + static const struct PixelFormatInfo invalidPixelFormat {
> + JCS_UNKNOWN, 0, false, {}
> + };
> +
> + const auto iter = pixelInfo.find(format);
> + if (iter == pixelInfo.end()) {
> + LOG(JPEG, Error) << "Unsupported pixel format for JPEG compressor: "
> + << format.toString();
> + return invalidPixelFormat;
> + }
> +
> + return iter->second;
> +}
> +
> +CompressorJPEG::CompressorJPEG()
> + : quality_(95)
> +{
> + /* \todo: Expand error handling coverage. */
> + compress_.err = jpeg_std_error(&jerr_);
> +
> + jpeg_create_compress(&compress_);
> +}
> +
> +CompressorJPEG::~CompressorJPEG()
> +{
> + jpeg_destroy_compress(&compress_);
> +}
> +
> +int CompressorJPEG::configure(const StreamConfiguration &cfg)
> +{
> + {
> + LOG(JPEG, Warning) << "Configuring pixelformat as : "
> + << cfg.pixelFormat.toString();
> + LOG(JPEG, Warning) << " : " << cfg.toString();
> +
> + std::vector<PixelFormat> formats = cfg.formats().pixelformats();
> + LOG(JPEG, Warning) << "StreamConfiguration supports " << formats.size() << " formats:";
> + for (const PixelFormat &format : formats)
> + LOG(JPEG, Warning) << " - " << format.toString();
> + }
> +
> + const struct PixelFormatInfo info = findPixelInfo(cfg.pixelFormat);
> + if (info.colorSpace == JCS_UNKNOWN)
> + return -ENOTSUP;
> +
> + /*
> + * Todo: The stride given by the stream configuration has caused issues.
> + * Validate it and also handle per-plane strides.
On which platform ? IPU3 ? Is there an error on how the stride is
reported ?
> + */
> + stride_ = cfg.stride;
> + stride_ = cfg.size.width * info.planes[0].bitsPerPixel / 8;
> + /* Saw some errors with strides, so this is a debug/develop check */
> + if (cfg.stride != stride_)
> + LOG(JPEG, Error) << "*** StreamConfigure provided stride of "
> + << cfg.stride << " rather than " << stride_;
> +
> + compress_.image_width = cfg.size.width;
> + compress_.image_height = cfg.size.height;
> + compress_.in_color_space = info.colorSpace;
> +
> + compress_.input_components = info.colorSpace == JCS_GRAYSCALE ? 1 : 3;
> +
> + jpeg_set_defaults(&compress_);
> + jpeg_set_quality(&compress_, quality_, TRUE);
> +
> + nv_ = info.numPlanes == 2;
> + nvSwap_ = info.nvSwap;
> +
> + /* Use the 'last' plane for subsampling of component info. */
> + unsigned int p = info.numPlanes - 1;
> + horzSubSample_ = info.planes[p].hSubSampling;
> + vertSubSample_ = info.planes[p].vSubSampling;
> +
You could infer the sub-sampling from libcamera PixelFormatInfo I
guess
> + return 0;
> +}
> +
> +void CompressorJPEG::compressRGB(const libcamera::MappedFrameBuffer *frame)
> +{
> + unsigned char *src = static_cast<unsigned char *>(frame->maps()[0].address);
> +
> + JSAMPROW row_pointer[1];
> +
> + while (compress_.next_scanline < compress_.image_height) {
> + row_pointer[0] = &src[compress_.next_scanline * stride_];
> + jpeg_write_scanlines(&compress_, row_pointer, 1);
> + }
> +}
> +
> +/*
> + * A very dull implementation to compress YUYV.
> + * To be converted to a generic algorithm akin to NV12.
> + * If it can be shared with NV12 great, but we might be able to further
> + * optimisze the NV layouts by only depacking the CrCb pixels.
> + */
> +void CompressorJPEG::compressYUV(const libcamera::MappedFrameBuffer *frame)
> +{
> + std::vector<uint8_t> tmprowbuf(compress_.image_width * 3);
> + unsigned char *input = static_cast<unsigned char *>(frame->maps()[0].address);
> +
> + JSAMPROW row_pointer[1];
> + row_pointer[0] = &tmprowbuf[0];
> + while (compress_.next_scanline < compress_.image_height) {
> + unsigned i, j;
> + unsigned offset = compress_.next_scanline * compress_.image_width * 2; //offset to the correct row
> + for (i = 0, j = 0; i < compress_.image_width * 2; i += 4, j += 6) { //input strides by 4 bytes, output strides by 6 (2 pixels)
> + tmprowbuf[j + 0] = input[offset + i + 0]; // Y (unique to this pixel)
> + tmprowbuf[j + 1] = input[offset + i + 1]; // U (shared between pixels)
> + tmprowbuf[j + 2] = input[offset + i + 3]; // V (shared between pixels)
> + tmprowbuf[j + 3] = input[offset + i + 2]; // Y (unique to this pixel)
> + tmprowbuf[j + 4] = input[offset + i + 1]; // U (shared between pixels)
> + tmprowbuf[j + 5] = input[offset + i + 3]; // V (shared between pixels)
> + }
> + jpeg_write_scanlines(&compress_, row_pointer, 1);
> + }
> +}
> +
> +/*
> + * Really inefficient NV unpacking to YUV888 for JPEG compress.
> + * This /could/ be improved (drastically I hope) ;-)
> + */
> +void CompressorJPEG::compressNV(const libcamera::MappedFrameBuffer *frame)
> +{
> + std::vector<uint8_t> tmprowbuf(compress_.image_width * 3);
> +
> + /*
> + * Todo: Use the raw api, and only unpack the cb/cr samples to new line buffers.
If you want this and other todo items recorded: \todo
> + * If possible, see if we can set appropriate pixel strides too to save even that copy.
> + *
> + * Possible hints at:
> + * https://sourceforge.net/p/libjpeg/mailman/message/30815123/
> + */
> + unsigned int c_stride = compress_.image_width * (2 / horzSubSample_);
> + unsigned int c_inc = horzSubSample_ == 1 ? 2 : 0;
> + unsigned int cb_pos = nvSwap_ ? 1 : 0;
> + unsigned int cr_pos = nvSwap_ ? 0 : 1;
> +
> + const unsigned char *src = static_cast<unsigned char *>(frame->maps()[0].address);
> + const unsigned char *src_c = src + compress_.image_width * compress_.image_height; // * stride[0] surely
> +
> + JSAMPROW row_pointer[1];
> + row_pointer[0] = &tmprowbuf[0];
> +
> + for (unsigned int y = 0; y < compress_.image_height; y++) {
> + unsigned char *dst = &tmprowbuf[0];
> +
> + const unsigned char *src_y = src + y * compress_.image_width;
> + const unsigned char *src_cb = src_c + (y / vertSubSample_) *
> + c_stride + cb_pos;
> + const unsigned char *src_cr = src_c + (y / vertSubSample_) *
> + c_stride + cr_pos;
> +
> + for (unsigned int x = 0; x < compress_.image_width; x += 2) {
> + dst[0] = *src_y;
> + dst[1] = *src_cb;
> + dst[2] = *src_cr;
> + src_y++;
> + src_cb += c_inc;
> + src_cr += c_inc;
> + dst += 3;
> +
> + dst[0] = *src_y;
> + dst[1] = *src_cb;
> + dst[2] = *src_cr;
> + src_y++;
> + src_cb += 2;
> + src_cr += 2;
> + dst += 3;
> + }
> +
> + jpeg_write_scanlines(&compress_, row_pointer, 1);
> + }
> +}
> +
> +int CompressorJPEG::compress(const FrameBuffer *source, CompressedImage *jpeg)
> +{
> + MappedFrameBuffer frame(source, PROT_READ);
> + if (!frame.isValid()) {
> + LOG(JPEG, Error) << "Failed to map FrameBuffer : "
> + << strerror(frame.error());
> + return -frame.error();
> + }
> +
> + jpeg_mem_dest(&compress_, &jpeg->data, &jpeg->length);
> +
> + jpeg_start_compress(&compress_, TRUE);
> +
> + LOG(JPEG, Debug) << "JPEG Compress Starting";
> + LOG(JPEG, Debug) << "Width: " << compress_.image_width
> + << " height: " << compress_.image_height
> + << " stride: " << stride_;
> +
> + if (nv_)
> + compressNV(&frame);
> + else if (compress_.in_color_space == JCS_YCbCr)
> + compressYUV(&frame);
> + else
> + compressRGB(&frame);
If you have your map of PixelFormat to a custom class you can there
store a pointer to the conversion function associated to each format and
avoid the switch here
> +
> + LOG(JPEG, Debug) << "JPEG Compress Completed";
> +
> + jpeg_finish_compress(&compress_);
> +
> + return 0;
> +}
> +
> +void CompressorJPEG::free(CompressedImage *jpeg)
> +{
> + ::free(jpeg->data);
> + jpeg->data = nullptr;
> +}
> diff --git a/src/android/jpeg/compressor_jpeg.h b/src/android/jpeg/compressor_jpeg.h
> new file mode 100644
> index 000000000000..11009481a2fe
> --- /dev/null
> +++ b/src/android/jpeg/compressor_jpeg.h
> @@ -0,0 +1,44 @@
> +/* SPDX-License-Identifier: GPL-2.0-or-later */
> +/*
> + * Copyright (C) 2020, Google Inc.
> + *
> + * compressor_jpeg.h - JPEG compression using libjpeg
> + */
> +#ifndef __COMPRESSOR_JPEG_H__
> +#define __COMPRESSOR_JPEG_H__
Same as above, I think ANDROID_ should be part of the inclusion guard
> +
> +#include "compressor.h"
> +
> +#include <libcamera/buffer.h>
> +#include <libcamera/stream.h>
> +
> +#include <jpeglib.h>
> +
> +class CompressorJPEG : public Compressor
> +{
> +public:
> + CompressorJPEG();
> + ~CompressorJPEG();
> +
> + int configure(const libcamera::StreamConfiguration &cfg);
> + int compress(const libcamera::FrameBuffer *source, CompressedImage *jpeg);
> + void free(CompressedImage *jpeg);
> +
> +private:
> + void compressRGB(const libcamera::MappedFrameBuffer *frame);
> + void compressYUV(const libcamera::MappedFrameBuffer *frame);
> + void compressNV(const libcamera::MappedFrameBuffer *frame);
> +
> + struct jpeg_compress_struct compress_;
> + struct jpeg_error_mgr jerr_;
> +
> + unsigned int quality_;
> + unsigned int stride_;
> +
> + bool nv_;
> + bool nvSwap_;
> + unsigned int horzSubSample_;
> + unsigned int vertSubSample_;
These information should be decoupled from the compressor class, as
they belong to the format the is being compressed, not to the
compressor instance. What do you think ? Are compressors throw away
objects created to run once on a format and thrown away ?
> +};
> +
> +#endif /* __COMPRESSOR_JPEG_H__ */
> diff --git a/src/android/meson.build b/src/android/meson.build
> index 822cad621f01..51dcd99ee62f 100644
> --- a/src/android/meson.build
> +++ b/src/android/meson.build
> @@ -6,6 +6,7 @@ android_hal_sources = files([
> 'camera_device.cpp',
> 'camera_metadata.cpp',
> 'camera_ops.cpp',
> + 'jpeg/compressor_jpeg.cpp',
> ])
>
> android_camera_metadata_sources = files([
> diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
> index 3aad4386ffc2..d78e2c1f6eb8 100644
> --- a/src/libcamera/meson.build
> +++ b/src/libcamera/meson.build
> @@ -124,6 +124,8 @@ if get_option('android')
> libcamera_sources += android_hal_sources
> includes += android_includes
> libcamera_link_with += android_camera_metadata
> +
> + libcamera_deps += dependency('libjpeg')
Shouldn't this be a dependency introduced by compiling the android HAL
in ?
Thanks
j
> endif
>
> # We add '/' to the build_rpath as a 'safe' path to act as a boolean flag.
> --
> 2.25.1
>
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