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/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Copyright (C) 2019, Google Inc.
*
* stream.cpp - Video stream for a Camera
*/
#include <libcamera/stream.h>
#include <algorithm>
#include <array>
#include <iomanip>
#include <limits.h>
#include <sstream>
#include <libcamera/request.h>
#include <libcamera/base/log.h>
#include <libcamera/base/utils.h>
/**
* \file stream.h
* \brief Video stream for a Camera
*
* A camera device can provide frames in different resolutions and formats
* concurrently from a single image source. The Stream class represents
* one of the multiple concurrent streams.
*
* All streams exposed by a camera device share the same image source and are
* thus not fully independent. Parameters related to the image source, such as
* the exposure time or flash control, are common to all streams. Other
* parameters, such as format or resolution, may be specified per-stream,
* depending on the capabilities of the camera device.
*
* Camera devices expose at least one stream, and may expose additional streams
* based on the device capabilities. This can be used, for instance, to
* implement concurrent viewfinder and video capture, or concurrent viewfinder,
* video capture and still image capture.
*/
namespace libcamera {
LOG_DEFINE_CATEGORY(Stream)
/**
* \class StreamFormats
* \brief Hold information about supported stream formats
*
* The StreamFormats class holds information about the pixel formats and frame
* sizes a stream supports. The class groups size information by the pixel
* format which can produce it.
*
* There are two ways to examine the size information, as a range or as a list
* of discrete sizes. When sizes are viewed as a range it describes the minimum
* and maximum width and height values. The range description can include
* horizontal and vertical steps.
*
* When sizes are viewed as a list of discrete sizes they describe the exact
* dimensions which can be selected and used.
*
* Pipeline handlers can create StreamFormats describing each pixel format using
* either a range or a list of discrete sizes. The StreamFormats class attempts
* to translate between the two different ways to view them. The translations
* are performed as:
*
* - If the StreamFormat is constructed using a list of discrete image sizes
* and a range is requested, it gets created by taking the minimum and
* maximum width/height in the list. The step information is not recreated
* and is set to 0 to indicate the range is generated.
*
* - If the image sizes used to construct a StreamFormat are expressed as a
* range and a list of discrete sizes is requested, one which fits inside
* that range are selected from a list of common sizes. The step information
* is taken into consideration when generating the sizes.
*
* Applications examining sizes as a range with step values of 0 shall be
* aware that the range are generated from a list of discrete sizes and there
* could be a large number of possible Size combinations that may not be
* supported by the Stream.
*
* All sizes retrieved from StreamFormats shall be treated as advisory and no
* size shall be considered to be supported until it has been verified using
* CameraConfiguration::validate().
*
* \todo Review the usage patterns of this class, and cache the computed
* pixelformats(), sizes() and range() if this would improve performances.
*/
StreamFormats::StreamFormats()
{
}
/**
* \brief Construct a StreamFormats object with a map of image formats
* \param[in] formats A map of pixel formats to a sizes description
*/
StreamFormats::StreamFormats(const std::map<PixelFormat, std::vector<SizeRange>> &formats)
: formats_(formats)
{
}
/**
* \brief Retrieve the list of supported pixel formats
* \return The list of supported pixel formats
*/
std::vector<PixelFormat> StreamFormats::pixelformats() const
{
std::vector<PixelFormat> formats;
for (auto const &it : formats_)
formats.push_back(it.first);
return formats;
}
/**
* \brief Retrieve the list of frame sizes supported for \a pixelformat
* \param[in] pixelformat PixelFormat to retrieve sizes for
*
* If the sizes described for \a pixelformat are discrete they are returned
* directly.
*
* If the sizes are described as a range, a list of discrete sizes are computed
* from a list of common resolutions that fit inside the described range. When
* computing the discrete list step values are considered but there are no
* guarantees that all sizes computed are supported.
*
* \return A list of frame sizes or an empty list on error
*/
std::vector<Size> StreamFormats::sizes(const PixelFormat &pixelformat) const
{
/*
* Sizes to try and extract from ranges.
* \todo Verify list of resolutions are good, current list compiled
* from v4l2 documentation and source code as well as lists of
* common frame sizes.
*/
static const std::array<Size, 53> rangeDiscreteSizes = {
Size(160, 120),
Size(240, 160),
Size(320, 240),
Size(400, 240),
Size(480, 320),
Size(640, 360),
Size(640, 480),
Size(720, 480),
Size(720, 576),
Size(768, 480),
Size(800, 600),
Size(854, 480),
Size(960, 540),
Size(960, 640),
Size(1024, 576),
Size(1024, 600),
Size(1024, 768),
Size(1152, 864),
Size(1280, 1024),
Size(1280, 1080),
Size(1280, 720),
Size(1280, 800),
Size(1360, 768),
Size(1366, 768),
Size(1400, 1050),
Size(1440, 900),
Size(1536, 864),
Size(1600, 1200),
Size(1600, 900),
Size(1680, 1050),
Size(1920, 1080),
Size(1920, 1200),
Size(2048, 1080),
Size(2048, 1152),
Size(2048, 1536),
Size(2160, 1080),
Size(2560, 1080),
Size(2560, 1440),
Size(2560, 1600),
Size(2560, 2048),
Size(2960, 1440),
Size(3200, 1800),
Size(3200, 2048),
Size(3200, 2400),
Size(3440, 1440),
Size(3840, 1080),
Size(3840, 1600),
Size(3840, 2160),
Size(3840, 2400),
Size(4096, 2160),
Size(5120, 2160),
Size(5120, 2880),
Size(7680, 4320),
};
std::vector<Size> sizes;
/* Make sure pixel format exists. */
auto const &it = formats_.find(pixelformat);
if (it == formats_.end())
return {};
/* Try creating a list of discrete sizes. */
const std::vector<SizeRange> &ranges = it->second;
bool discrete = true;
for (const SizeRange &range : ranges) {
if (range.min != range.max) {
discrete = false;
break;
}
sizes.emplace_back(range.min);
}
/* If discrete not possible generate from range. */
if (!discrete) {
if (ranges.size() != 1) {
LOG(Stream, Error) << "Range format is ambiguous";
return {};
}
const SizeRange &limit = ranges.front();
sizes.clear();
for (const Size &size : rangeDiscreteSizes)
if (limit.contains(size))
sizes.push_back(size);
}
std::sort(sizes.begin(), sizes.end());
return sizes;
}
/**
* \brief Retrieve the range of minimum and maximum sizes
* \param[in] pixelformat PixelFormat to retrieve range for
*
* If the size described for \a pixelformat is a range, that range is returned
* directly. If the sizes described are a list of discrete sizes, a range is
* created from the minimum and maximum sizes in the list. The step values of
* the range are set to 0 to indicate that the range is generated and that not
* all image sizes contained in the range might be supported.
*
* \return A range of valid image sizes or an empty range on error
*/
SizeRange StreamFormats::range(const PixelFormat &pixelformat) const
{
auto const it = formats_.find(pixelformat);
if (it == formats_.end())
return {};
const std::vector<SizeRange> &ranges = it->second;
if (ranges.size() == 1)
return ranges[0];
LOG(Stream, Debug) << "Building range from discrete sizes";
SizeRange range({ UINT_MAX, UINT_MAX }, { 0, 0 });
for (const SizeRange &limit : ranges) {
if (limit.min < range.min)
range.min = limit.min;
if (limit.max > range.max)
range.max = limit.max;
}
range.hStep = 0;
range.vStep = 0;
return range;
}
/**
* \struct StreamConfiguration
* \brief Configuration parameters for a stream
*
* The StreamConfiguration structure models all information which can be
* configured for a single video stream.
*/
/**
* \todo This method is deprecated and should be removed once all pipeline
* handlers provide StreamFormats.
*/
StreamConfiguration::StreamConfiguration()
: pixelFormat(0), stride(0), frameSize(0), bufferCount(0),
stream_(nullptr)
{
}
/**
* \brief Construct a configuration with stream formats
*/
StreamConfiguration::StreamConfiguration(const StreamFormats &formats)
: pixelFormat(0), stride(0), frameSize(0), bufferCount(0),
stream_(nullptr), formats_(formats)
{
}
/**
* \var StreamConfiguration::size
* \brief Stream size in pixels
*/
/**
* \var StreamConfiguration::pixelFormat
* \brief Stream pixel format
*/
/**
* \var StreamConfiguration::stride
* \brief Image stride for the stream, in bytes
*
* The stride value reports the number of bytes between the beginning of
* successive lines in an image buffer for this stream. The value is
* valid after successfully validating the configuration with a call to
* CameraConfiguration::validate().
*/
/**
* \var StreamConfiguration::frameSize
* \brief Frame size for the stream, in bytes
*
* The frameSize value reports the number of bytes necessary to contain one
* frame of an image buffer for this stream. This total includes the bytes
* required for all image planes. The value is valid after successfully
* validating the configuration with a call to CameraConfiguration::validate().
*/
/**
* \var StreamConfiguration::bufferCount
* \brief Requested number of buffers to allocate for the stream
*/
/**
* \fn StreamConfiguration::stream()
* \brief Retrieve the stream associated with the configuration
*
* When a camera is configured with Camera::configure() Stream instances are
* associated with each stream configuration entry. This method retrieves the
* associated Stream, which remains valid until the next call to
* Camera::configure() or Camera::release().
*
* \return The stream associated with the configuration
*/
/**
* \fn StreamConfiguration::setStream()
* \brief Associate a stream with a configuration
*
* This method is meant for the PipelineHandler::configure() method and shall
* not be called by applications.
*
* \param[in] stream The stream
*/
/**
* \fn StreamConfiguration::formats()
* \brief Retrieve advisory stream format information
*
* This method retrieves information about the pixel formats and sizes supported
* by the stream configuration. The sizes are advisory and not all of them are
* guaranteed to be supported by the stream. Users shall always inspect the size
* in the stream configuration after calling CameraConfiguration::validate().
*
* \return Stream formats information
*/
/**
* \brief Assemble and return a string describing the configuration
*
* \return A string describing the StreamConfiguration
*/
std::string StreamConfiguration::toString() const
{
return size.toString() + "-" + pixelFormat.toString();
}
/**
* \enum StreamRole
* \brief Identify the role a stream is intended to play
*
* The StreamRole describes how an application intends to use a stream. Roles
* are specified by applications and passed to cameras, that then select the
* most appropriate streams and their default configurations.
*
* \var Raw
* The stream is intended to capture raw frames from the sensor.
* \var StillCapture
* The stream is intended to capture high-resolution, high-quality still images
* with low frame rate. The captured frames may be exposed with flash.
* \var VideoRecording
* The stream is intended to capture video for the purpose of recording or
* streaming. The video stream may produce a high frame rate and may be
* enhanced with video stabilization.
* \var Viewfinder
* The stream is intended to capture video for the purpose of display on the
* local screen. Trade-offs between quality and usage of system resources are
* acceptable.
*/
/**
* \typedef StreamRoles
* \brief A vector of StreamRole
*/
/**
* \class Stream
* \brief Video stream for a camera
*
* The Stream class models all static information which are associated with a
* single video stream. Streams are exposed by the Camera object they belong to.
*
* Cameras may supply more than one stream from the same video source. In such
* cases an application can inspect all available streams and select the ones
* that best fit its use case.
*
* \todo Add capabilities to the stream API. Without this the Stream class only
* serves to reveal how many streams of unknown capabilities a camera supports.
* This in itself is productive as it allows applications to configure and
* capture from one or more streams even if they won't be able to select the
* optimal stream for the task.
*/
/**
* \brief Construct a stream with default parameters
*/
Stream::Stream()
{
}
/**
* \fn Stream::configuration()
* \brief Retrieve the active configuration of the stream
* \return The active configuration of the stream
*/
/**
* \var Stream::configuration_
* \brief The stream configuration
*
* The configuration for the stream is set by any successful call to
* Camera::configure() that includes the stream, and remains valid until the
* next call to Camera::configure() regardless of if it includes the stream.
*/
} /* namespace libcamera */
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