Source code for picamera.encoders

# vim: set et sw=4 sts=4 fileencoding=utf-8:
#
# Python camera library for the Rasperry-Pi camera module
# Copyright (c) 2013-2015 Dave Jones <dave@waveform.org.uk>
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"""
The encoders module defines encoder classes for use by the camera. Most users
will have no direct need to use these classes directly, but advanced users may
find them useful as base classes for :ref:`custom_encoders`.

.. note::

    All classes in this module are available from the :mod:`picamera` namespace
    without having to import :mod:`picamera.encoders` directly.

The following classes are defined in the module:


PiVideoFrameType
================

.. autoclass:: PiVideoFrameType
    :members:


PiVideoFrame
============

.. autoclass:: PiVideoFrame(index, frame_type, frame_size, video_size, split_size, timestamp)
    :members:


PiEncoder
=========

.. autoclass:: PiEncoder
    :members:
    :private-members:


PiVideoEncoder
==============

.. autoclass:: PiVideoEncoder
    :members:
    :private-members:


PiImageEncoder
==============

.. autoclass:: PiImageEncoder
    :members:
    :private-members:


PiRawMixin
==========

.. autoclass:: PiRawMixin
    :members:
    :private-members:


PiCookedVideoEncoder
====================

.. autoclass:: PiCookedVideoEncoder
    :members:
    :private-members:


PiRawVideoEncoder
=================

.. autoclass:: PiRawVideoEncoder
    :members:
    :private-members:


PiOneImageEncoder
=================

.. autoclass:: PiOneImageEncoder
    :members:
    :private-members:


PiMultiImageEncoder
===================

.. autoclass:: PiMultiImageEncoder
    :members:
    :private-members:


PiRawImageMixin
===============

.. autoclass:: PiRawImageMixin
    :members:
    :private-members:


PiCookedOneImageEncoder
=======================

.. autoclass:: PiCookedOneImageEncoder
    :members:
    :private-members:


PiRawOneImageEncoder
====================

.. autoclass:: PiRawOneImageEncoder
    :members:
    :private-members:


PiCookedMultiImageEncoder
=========================

.. autoclass:: PiCookedMultiImageEncoder
    :members:
    :private-members:


PiRawMultiImageEncoder
======================

.. autoclass:: PiRawMultiImageEncoder
    :members:
    :private-members:

"""

from __future__ import (
    unicode_literals,
    print_function,
    division,
    absolute_import,
    )

# Make Py2's str and range equivalent to Py3's
str = type('')
try:
    range = xrange
except NameError:
    pass

import io
import datetime
import threading
import warnings
import ctypes as ct
from collections import namedtuple

import picamera.mmal as mmal
from picamera.exc import (
    mmal_check,
    PiCameraError,
    PiCameraMMALError,
    PiCameraValueError,
    PiCameraRuntimeError,
    PiCameraDeprecated,
    )


[docs]class PiVideoFrameType(object): """ This class simply defines constants used to represent the type of a frame in :attr:`PiVideoFrame.frame_type`. Effectively it is a namespace for an enum. .. attribute:: frame Indicates a predicted frame (P-frame). This is the most common frame type. .. attribute:: key_frame Indicates an intra-frame (I-frame) also known as a key frame. .. attribute:: sps_header Indicates an inline SPS/PPS header (rather than picture data) which is typically used as a split point. .. attribute:: motion_data Indicates the frame is inline motion vector data, rather than picture data. .. versionadded:: 1.5 """ frame = 0 key_frame = 1 sps_header = 2 motion_data = 3
[docs]class PiVideoFrame(namedtuple('PiVideoFrame', ( 'index', # the frame number, where the first frame is 0 'frame_type', # a constant indicating the frame type (see PiVideoFrameType) 'frame_size', # the size (in bytes) of the frame's data 'video_size', # the size (in bytes) of the video so far 'split_size', # the size (in bytes) of the video since the last split 'timestamp', # the presentation timestamp (PTS) of the frame 'complete', # whether the frame is complete or not ))): """ This class is a namedtuple derivative used to store information about a video frame. It is recommended that you access the information stored by this class by attribute name rather than position (for example: ``frame.index`` rather than ``frame[0]``). .. attribute:: index Returns the zero-based number of the frame. This is a monotonic counter that is simply incremented every time the camera starts outputting a new frame. As a consequence, this attribute cannot be used to detect dropped frames. Nor does it necessarily represent actual frames; it will be incremented for SPS headers and motion data buffers too. .. attribute:: frame_type Returns a constant indicating the kind of data that the frame contains (see :class:`PiVideoFrameType`). Please note that certain frame types contain no image data at all. .. attribute:: frame_size Returns the size in bytes of the current frame. If a frame is written in multiple chunks, this value will increment while :attr:`index` remains static. Query :attr:`complete` to determine whether the frame has been completely output yet. .. attribute:: video_size Returns the size in bytes of the entire video up to the current frame. Note that this is unlikely to match the size of the actual file/stream written so far. This is because a stream may utilize buffering which will cause the actual amount written (e.g. to disk) to lag behind the value reported by this attribute. .. attribute:: split_size Returns the size in bytes of the video recorded since the last call to either :meth:`~picamera.camera.PiCamera.start_recording` or :meth:`~picamera.camera.PiCamera.split_recording`. For the reasons explained above, this may differ from the size of the actual file/stream written so far. .. attribute:: timestamp Returns the presentation timestamp (PTS) of the current frame as reported by the encoder. This is represented by the number of microseconds (millionths of a second) since video recording started. As the frame attribute is only updated when the encoder outputs the end of a frame, this value may lag behind the actual time since :meth:`~picamera.camera.PiCamera.start_recording` was called. .. warning:: Currently, the video encoder occasionally returns "time unknown" values in this field which picamera represents as ``None``. If you are querying this property you will need to check the value is not ``None`` before using it. .. attribute:: complete Returns a bool indicating whether the current frame is complete or not. If the frame is complete then :attr:`frame_size` will not increment any further, and will reset for the next frame. .. versionchanged:: 1.5 Deprecated :attr:`header` and :attr:`keyframe` attributes and added the new :attr:`frame_type` attribute instead. .. versionchanged:: 1.9 Added the :attr:`complete` attribute. """ @property
[docs] def position(self): """ Returns the zero-based position of the frame in the stream containing it. """ return self.split_size - self.frame_size
@property
[docs] def keyframe(self): """ Returns a bool indicating whether the current frame is a keyframe (an intra-frame, or I-frame in MPEG parlance). .. deprecated:: 1.5 Please compare :attr:`frame_type` to :attr:`PiVideoFrameType.key_frame` instead. """ warnings.warn( PiCameraDeprecated( 'PiVideoFrame.keyframe is deprecated; please check ' 'PiVideoFrame.frame_type for equality with ' 'PiVideoFrameType.key_frame instead')) return self.frame_type == PiVideoFrameType.key_frame
@property
[docs] def header(self): """ Contains a bool indicating whether the current frame is actually an SPS/PPS header. Typically it is best to split an H.264 stream so that it starts with an SPS/PPS header. .. deprecated:: 1.5 Please compare :attr:`frame_type` to :attr:`PiVideoFrameType.sps_header` instead. """ warnings.warn( PiCameraDeprecated( 'PiVideoFrame.header is deprecated; please check ' 'PiVideoFrame.frame_type for equality with ' 'PiVideoFrameType.sps_header instead')) return self.frame_type == PiVideoFrameType.sps_header
def _debug_buffer(buf): f = buf[0].flags print(''.join(( 'flags=', 'E' if f & mmal.MMAL_BUFFER_HEADER_FLAG_FRAME_END else '_', 'K' if f & mmal.MMAL_BUFFER_HEADER_FLAG_KEYFRAME else '_', 'C' if f & mmal.MMAL_BUFFER_HEADER_FLAG_CONFIG else '_', 'M' if f & mmal.MMAL_BUFFER_HEADER_FLAG_CODECSIDEINFO else '_', 'X' if f & mmal.MMAL_BUFFER_HEADER_FLAG_EOS else '_', ' ', 'len=%d' % buf[0].length, ))) def _encoder_callback(port, buf): #_debug_buffer(buf) encoder = ct.cast(port[0].userdata, ct.POINTER(ct.py_object))[0] encoder._callback(port, buf) _encoder_callback = mmal.MMAL_PORT_BH_CB_T(_encoder_callback)
[docs]class PiEncoder(object): """ Base implementation of an MMAL encoder for use by PiCamera. The *parent* parameter specifies the :class:`~picamera.camera.PiCamera` instance that has constructed the encoder. The *camera_port* parameter provides the MMAL camera port that the encoder should enable for capture (this will be the still or video port of the camera component). The *input_port* parameter specifies the MMAL port that the encoder should connect to its input. Sometimes this will be the same as the camera port, but if other components are present in the pipeline (e.g. a splitter), it may be different. The *format* parameter specifies the format that the encoder should produce in its output. This is specified as a string and will be one of the following for image encoders: * ``'jpeg'`` * ``'png'`` * ``'gif'`` * ``'bmp'`` * ``'yuv'`` * ``'rgb'`` * ``'rgba'`` * ``'bgr'`` * ``'bgra'`` And one of the following for video encoders: * ``'h264'`` * ``'mjpeg'`` The *resize* parameter is either ``None`` (indicating no resizing should take place), or a ``(width, height)`` tuple specifying the resolution that the output of the encoder should be resized to. Finally, the *options* parameter specifies additional keyword arguments that can be used to configure the encoder (e.g. bitrate for videos, or quality for images). The class has a number of attributes: .. attribute:: camera_port A pointer to the camera output port that needs to be activated and deactivated in order to start/stop capture. This is not necessarily the port that the encoder component's input port is connected to (for example, in the case of video-port based captures, this will be the camera video port behind the splitter). .. attribute:: encoder A pointer to the MMAL encoder component, or None if no encoder component has been created (some encoder classes don't use an actual encoder component, for example :class:`PiRawImageMixin`). .. attribute:: encoder_connection A pointer to the MMAL connection linking the encoder's input port to the camera, splitter, or resizer output port (depending on configuration), if any. .. attribute:: event A :class:`threading.Event` instance used to synchronize operations (like start, stop, and split) between the control thread and the callback thread. .. attribute:: exception If an exception occurs during the encoder callback, this attribute is used to store the exception until it can be re-raised in the control thread. .. attribute:: format The image or video format that the encoder is expected to produce. This is equal to the value of the *format* parameter. .. attribute:: input_port A pointer to the MMAL port that the encoder component's input port should be connected to. .. attribute:: output_port A pointer to the MMAL port of the encoder's output. In the case no encoder component is created, this should be the camera/component output port responsible for producing data. In other words, this attribute **must** be set on initialization. .. attribute:: outputs A mapping of ``key`` to ``(output, opened)`` tuples where ``output`` is a file-like object, and ``opened`` is a bool indicating whether or not we opened the output object (and thus whether we are responsible for eventually closing it). .. attribute:: outputs_lock A :func:`threading.Lock` instance used to protect access to :attr:`outputs`. .. attribute:: parent The :class:`~picamera.camera.PiCamera` instance that created this PiEncoder instance. .. attribute:: pool A pointer to a pool of MMAL buffers. .. attribute:: resizer A pointer to the MMAL resizer component, or None if no resizer component has been created. .. attribute:: resizer_connection A pointer to the MMAL connection linking the resizer's input port to the camera or splitter's output port, if any. """ encoder_type = None def __init__( self, parent, camera_port, input_port, format, resize, **options): self.parent = parent self.format = format self.encoder = None self.resizer = None self.encoder_connection = None self.resizer_connection = None self.camera_port = camera_port self.input_port = input_port self.output_port = None self.pool = None self.started_capture = False self.outputs_lock = threading.Lock() # protects access to self.outputs self.outputs = {} self.exception = None self.event = threading.Event() self.stopped = True try: if parent.closed: raise PiCameraRuntimeError("Camera is closed") if resize: self._create_resizer(*resize) self._create_encoder(**options) self._create_pool() self._create_connections() except: self.close() raise
[docs] def _create_resizer(self, width, height): """ Creates and configures an MMAL resizer component. This is called when the initializer's *resize* parameter is something other than ``None``. The *width* and *height* parameters are passed to the constructed resizer. Note that this method only constructs the resizer - it does not connect it to the encoder. The method sets the :attr:`resizer` attribute to the constructed resizer component. """ self.resizer = ct.POINTER(mmal.MMAL_COMPONENT_T)() mmal_check( mmal.mmal_component_create( mmal.MMAL_COMPONENT_DEFAULT_RESIZER, self.resizer), prefix="Failed to create resizer component") if not self.resizer[0].input_num: raise PiCameraError("No input ports on resizer component") if not self.resizer[0].output_num: raise PiCameraError("No output ports on resizer component") # Copy the original input port's format to the resizer's input, # then the resizer's input format to the output, and configure it mmal.mmal_format_copy( self.resizer[0].input[0][0].format, self.input_port[0].format) mmal_check( mmal.mmal_port_format_commit(self.resizer[0].input[0]), prefix="Failed to set resizer input port format") mmal.mmal_format_copy( self.resizer[0].output[0][0].format, self.resizer[0].input[0][0].format) fmt = self.resizer[0].output[0][0].format fmt[0].es[0].video.width = mmal.VCOS_ALIGN_UP(width, 32) fmt[0].es[0].video.height = mmal.VCOS_ALIGN_UP(height, 16) fmt[0].es[0].video.crop.x = 0 fmt[0].es[0].video.crop.y = 0 fmt[0].es[0].video.crop.width = width fmt[0].es[0].video.crop.height = height mmal_check( mmal.mmal_port_format_commit(self.resizer[0].output[0]), prefix="Failed to set resizer output port format")
[docs] def _create_encoder(self): """ Creates and configures the MMAL encoder component. This method only constructs the encoder; it does not connect it to the input port. The method sets the :attr:`encoder` attribute to the constructed encoder component, and the :attr:`output_port` attribute to the encoder's output port (or the previously constructed resizer's output port if one has been requested). Descendent classes extend this method to finalize encoder configuration. .. note:: It should be noted that this method is called with the initializer's ``option`` keyword arguments. This base implementation expects no additional arguments, but descendent classes extend the parameter list to include options relevant to them. """ assert not self.encoder self.encoder = ct.POINTER(mmal.MMAL_COMPONENT_T)() mmal_check( mmal.mmal_component_create(self.encoder_type, self.encoder), prefix="Failed to create encoder component") if not self.encoder[0].input_num: raise PiCameraError("No input ports on encoder component") if not self.encoder[0].output_num: raise PiCameraError("No output ports on encoder component") # Ensure output format is the same as the input self.output_port = self.encoder[0].output[0] if self.resizer: mmal.mmal_format_copy( self.encoder[0].input[0][0].format, self.resizer[0].output[0][0].format) else: mmal.mmal_format_copy( self.encoder[0].input[0][0].format, self.input_port[0].format) mmal_check( mmal.mmal_port_format_commit(self.encoder[0].input[0]), prefix="Failed to set encoder input port format") mmal.mmal_format_copy( self.output_port[0].format, self.encoder[0].input[0][0].format) # Set buffer size and number to appropriate values if self.format == 'mjpeg': # There is a bug in the MJPEG encoder that causes a deadlock if the # FIFO is full on shutdown. Increasing the encoder buffer size # makes this less likely to happen. See # https://github.com/raspberrypi/userland/issues/208 self.output_port[0].buffer_size = max(512 * 1024, self.output_port[0].buffer_size_recommended) else: self.output_port[0].buffer_size = self.output_port[0].buffer_size_recommended self.output_port[0].buffer_num = self.output_port[0].buffer_num_recommended # NOTE: We deliberately don't commit the output port format here as # this is a base class and the output configuration is incomplete at # this point. Descendents are expected to finish configuring the # encoder and then commit the port format themselves
[docs] def _create_pool(self): """ Allocates a pool of MMAL buffers for the encoder. This method is expected to construct an MMAL pool of buffers for the :attr:`output_port`, and store the result in the :attr:`pool` attribute. """ assert not self.pool self.pool = mmal.mmal_port_pool_create( self.output_port, self.output_port[0].buffer_num, self.output_port[0].buffer_size) if not self.pool: raise PiCameraError( "Failed to create buffer header pool for encoder component")
[docs] def _create_connections(self): """ Creates all connections between MMAL components. This method is called to connect the encoder and the optional resizer to the input port provided by the camera. It sets the :attr:`encoder_connection` and :attr:`resizer_connection` attributes as required. """ assert not self.encoder_connection if self.resizer: self.resizer_connection = self.parent._connect_ports( self.input_port, self.resizer[0].input[0]) self.encoder_connection = self.parent._connect_ports( self.resizer[0].output[0], self.encoder[0].input[0]) else: self.encoder_connection = self.parent._connect_ports( self.input_port, self.encoder[0].input[0])
[docs] def _callback(self, port, buf): """ The encoder's main callback function. When the encoder is active, this method is periodically called in a background thread. The *port* parameter specifies the MMAL port providing the output (typically this is the encoder's output port, but in the case of unencoded captures may simply be a camera port), while the *buf* parameter is an MMAL buffer header pointer which can be used to obtain the data to write, along with meta-data about the current frame. This method *must* release the MMAL buffer header before returning (failure to do so will cause a lockup), and should recycle buffers if expecting further data (the :meth:`_callback_recycle` method can be called to perform the latter duty). Finally, this method must set :attr:`event` when the encoder has finished (and should set :attr:`exception` if an exception occurred during encoding). Developers wishing to write a custom encoder class may find it simpler to override the :meth:`_callback_write` method, rather than deal with these complexities. """ if self.stopped: mmal.mmal_buffer_header_release(buf) else: stop = False try: try: mmal_check( mmal.mmal_buffer_header_mem_lock(buf), prefix="Unable to lock buffer header memory") try: stop = self._callback_write(buf) finally: mmal.mmal_buffer_header_mem_unlock(buf) finally: mmal.mmal_buffer_header_release(buf) self._callback_recycle(port, buf) except Exception as e: stop = True self.exception = e if stop: self.stopped = True self.event.set()
[docs] def _callback_write(self, buf, key=PiVideoFrameType.frame): """ Writes output on behalf of the encoder callback function. This method is called by :meth:`_callback` to handle writing to an object in :attr:`outputs` identified by *key*. The *buf* parameter is an MMAL buffer header pointer which can be used to obtain the length of data available (``buf[0].length``), a pointer to the data (``buf[0].data``) which should typically be used with :func:`ctypes.string_at`, and meta-data about the contents of the buffer (``buf[0].flags``). The method is expected to return a boolean to indicate whether output is complete (``True``) or whether more data is expected (``False``). The default implementation simply writes the contents of the buffer to the output identified by *key*, and returns ``True`` if the buffer flags indicate end of stream. Image encoders will typically override the return value to indicate ``True`` on end of frame (as they only wish to output a single image). Video encoders will typically override this method to determine where key-frames and SPS headers occur. """ if buf[0].length: with self.outputs_lock: try: written = self.outputs[key][0].write( ct.string_at(buf[0].data, buf[0].length)) except KeyError: pass else: # Ignore None return value; most Python 2 streams have # no return value for write() if (written is not None) and (written != buf[0].length): raise PiCameraError( "Unable to write buffer to output %s" % key) return bool(buf[0].flags & mmal.MMAL_BUFFER_HEADER_FLAG_EOS)
[docs] def _callback_recycle(self, port, buf): """ Recycles the buffer on behalf of the encoder callback function. This method is called by :meth:`_callback` when there is a buffer to recycle (because further output is expected). It is unlikely descendent classes will have a need to override this method, but if they override the :meth:`_callback` method they may wish to call it. """ new_buf = mmal.mmal_queue_get(self.pool[0].queue) if not new_buf: raise PiCameraError( "Unable to get a buffer to return to the encoder port") mmal_check( mmal.mmal_port_send_buffer(port, new_buf), prefix="Unable to return a buffer to the encoder port")
[docs] def _open_output(self, output, key=PiVideoFrameType.frame): """ Opens *output* and associates it with *key* in :attr:`outputs`. If *output* is a string, this method opens it as a filename and keeps track of the fact that the encoder was the one to open it (which implies that :meth:`_close_output` should eventually close it). Otherwise, *output* is assumed to be a file-like object and is used verbatim. The opened output is added to the :attr:`outputs` dictionary with the specified *key*. """ with self.outputs_lock: opened = isinstance(output, (bytes, str)) if opened: # Open files in binary mode with a decent buffer size output = io.open(output, 'wb', buffering=65536) self.outputs[key] = (output, opened)
[docs] def _close_output(self, key=PiVideoFrameType.frame): """ Closes the output associated with *key* in :attr:`outputs`. Closes the output object associated with the specified *key*, and removes it from the :attr:`outputs` dictionary (if we didn't open the object then we attempt to flush it instead). """ with self.outputs_lock: try: (output, opened) = self.outputs.pop(key) except KeyError: pass else: if opened: output.close() else: try: output.flush() except AttributeError: pass
@property
[docs] def active(self): """ Returns ``True`` if the MMAL encoder exists and is enabled. """ return bool(self.encoder and self.output_port[0].is_enabled)
[docs] def start(self, output): """ Starts the encoder object writing to the specified output. This method is called by the camera to start the encoder capturing data from the camera to the specified output. The *output* parameter is either a filename, or a file-like object (for image and video encoders), or an iterable of filenames or file-like objects (for multi-image encoders). """ self.event.clear() self.stopped = False self.exception = None self._open_output(output) self.output_port[0].userdata = ct.cast( ct.pointer(ct.py_object(self)), ct.c_void_p) with self.parent._encoders_lock: mmal_check( mmal.mmal_port_enable(self.output_port, _encoder_callback), prefix="Failed to enable encoder output port") for q in range(mmal.mmal_queue_length(self.pool[0].queue)): buf = mmal.mmal_queue_get(self.pool[0].queue) if not buf: raise PiCameraRuntimeError( "Unable to get a required buffer from pool queue") mmal_check( mmal.mmal_port_send_buffer(self.output_port, buf), prefix="Unable to send a buffer to encoder output port") self.parent._start_capture(self.camera_port)
[docs] def wait(self, timeout=None): """ Waits for the encoder to finish (successfully or otherwise). This method is called by the owning camera object to block execution until the encoder has completed its task. If the *timeout* parameter is None, the method will block indefinitely. Otherwise, the *timeout* parameter specifies the (potentially fractional) number of seconds to block for. If the encoder finishes successfully within the timeout, the method returns ``True``. Otherwise, it returns ``False``. """ result = self.event.wait(timeout) if result: self.stop() # Check whether the callback set an exception if self.exception: raise self.exception return result
[docs] def stop(self): """ Stops the encoder, regardless of whether it's finished. This method is called by the camera to terminate the execution of the encoder. Typically, this is used with video to stop the recording, but can potentially be called in the middle of image capture to terminate the capture. """ # The check below is not a race condition; we ignore the EINVAL error # in the case the port turns out to be disabled when we disable below. # The check exists purely to prevent stderr getting spammed by our # continued attempts to disable an already disabled port with self.parent._encoders_lock: if self.active: self.parent._stop_capture(self.camera_port) try: mmal_check( mmal.mmal_port_disable(self.output_port), prefix="Failed to disable encoder output port") except PiCameraMMALError as e: if e.status != mmal.MMAL_EINVAL: raise self.stopped = True self.event.set() self._close_output()
[docs] def close(self): """ Finalizes the encoder and deallocates all structures. This method is called by the camera prior to destroying the encoder (or more precisely, letting it go out of scope to permit the garbage collector to destroy it at some future time). The method destroys all components that the various create methods constructed and resets their attributes. """ self.stop() if self.encoder_connection: mmal.mmal_connection_destroy(self.encoder_connection) self.encoder_connection = None if self.pool: mmal.mmal_port_pool_destroy(self.output_port, self.pool) self.pool = None if self.resizer_connection: mmal.mmal_connection_destroy(self.resizer_connection) if self.encoder: mmal.mmal_component_destroy(self.encoder) self.encoder = None if self.resizer: mmal.mmal_component_destroy(self.resizer) self.resizer = None self.output_port = None
[docs]class PiRawMixin(PiEncoder): """ Mixin class for "raw" (unencoded) output. This mixin class overrides the initializer of :class:`PiEncoder`, along with :meth:`_create_resizer` and :meth:`_create_encoder` to configure the pipeline for unencoded output. Specifically, it disables the construction of an encoder, and sets the output port to the input port passed to the initializer, unless resizing is required (either for actual resizing, or for format conversion) in which case the resizer's output is used. """ RAW_ENCODINGS = { # name mmal-encoding bytes-per-pixel 'yuv': (mmal.MMAL_ENCODING_I420, 1.5), 'rgb': (mmal.MMAL_ENCODING_RGBA, 3), 'rgba': (mmal.MMAL_ENCODING_RGBA, 4), 'bgr': (mmal.MMAL_ENCODING_BGRA, 3), 'bgra': (mmal.MMAL_ENCODING_BGRA, 4), } def __init__( self, parent, camera_port, input_port, format, resize, **options): # If a resize hasn't been requested, check the input_port format. If # it requires conversion, force the use of a resizer to perform the # conversion if not resize: if parent.RAW_FORMATS[format] != input_port[0].format[0].encoding.value: resize = parent.resolution # Workaround: If a non-alpha format is requested when a resizer is # required, we use the alpha-inclusive format and set a flag to get the # callback to strip the alpha bytes (for some reason the resizer won't # work with non-alpha output formats - firmware bug?) if resize: width, height = resize self._strip_alpha = format in ('rgb', 'bgr') else: width, height = parent.resolution self._strip_alpha = False width = mmal.VCOS_ALIGN_UP(width, 32) height = mmal.VCOS_ALIGN_UP(height, 16) # Workaround (#83): when the resizer is used the width and height must # be aligned (both the actual and crop values) to avoid an error when # the output port format is set if resize: resize = (width, height) # Workaround: Calculate the expected image size, to be used by the # callback to decide when a frame ends. This is to work around a # firmware bug that causes the raw image to be returned twice when the # maximum camera resolution is requested self._frame_size = int(width * height * self.RAW_ENCODINGS[format][1]) super(PiRawMixin, self).__init__( parent, camera_port, input_port, format, resize, **options)
[docs] def _create_resizer(self, width, height): """ Overridden to configure the resizer's output with the required encoding. """ super(PiRawMixin, self)._create_resizer(width, height) encoding = self.RAW_ENCODINGS[self.format][0] port = self.resizer[0].output[0] port[0].format[0].encoding = encoding port[0].format[0].encoding_variant = encoding mmal_check( mmal.mmal_port_format_commit(port), prefix="Failed to set resizer output port format")
[docs] def _create_encoder(self): """ Overridden to skip creating an encoder. Instead, this class simply uses the resizer's port as the output port (if a resizer has been configured) or the specified input port otherwise. """ if self.resizer: self.output_port = self.resizer[0].output[0] else: self.output_port = self.input_port
[docs] def _create_connections(self): """ Overridden to skip creating an encoder connection; only a resizer connection is required (if one has been configured). """ if self.resizer: self.resizer_connection = self.parent._connect_ports( self.input_port, self.resizer[0].input[0])
@property def active(self): return bool(self.output_port[0].is_enabled)
[docs] def _callback_write(self, buf, key=PiVideoFrameType.frame): """ Overridden to strip alpha bytes when required. """ if self._strip_alpha: s = ct.string_at(buf[0].data, buf[0].length) s = bytearray(s) del s[3::4] # All this messing around with buffers is to work around some issue # with MMAL or ctypes (I'm not sure which is at fault). Anyway, the # upshot is that if you fiddle with buf[0].data in any way # whatsoever (even if you make every attempt to restore its value # afterward), mmal_port_disable locks up when we call it in stop() new_buf = mmal.MMAL_BUFFER_HEADER_T.from_buffer_copy(buf[0]) new_buf.length = len(s) new_buf.data = ct.pointer(ct.c_uint8.from_buffer(s)) return super(PiRawMixin, self)._callback_write(ct.pointer(new_buf), key) else: return super(PiRawMixin, self)._callback_write(buf, key)
[docs]class PiVideoEncoder(PiEncoder): """ Encoder for video recording. This derivative of :class:`PiEncoder` configures itself for H.264 or MJPEG encoding. It also introduces a :meth:`split` method which is used by :meth:`~picamera.camera.PiCamera.split_recording` and :meth:`~picamera.camera.PiCamera.record_sequence` to redirect future output to a new filename or object. Finally, it also extends :meth:`PiEncoder.start` and :meth:`PiEncoder._callback_write` to track video frame meta-data, and to permit recording motion data to a separate output object. """ encoder_type = mmal.MMAL_COMPONENT_DEFAULT_VIDEO_ENCODER def __init__( self, parent, camera_port, input_port, format, resize, **options): super(PiVideoEncoder, self).__init__( parent, camera_port, input_port, format, resize, **options) self._next_output = [] self.frame = None
[docs] def _create_encoder( self, bitrate=17000000, intra_period=None, profile='high', quantization=0, quality=0, inline_headers=True, sei=False, motion_output=None, intra_refresh=None): """ Extends the base :meth:`~PiEncoder._create_encoder` implementation to configure the video encoder for H.264 or MJPEG output. """ super(PiVideoEncoder, self)._create_encoder() # XXX Remove quantization in 2.0 quality = quality or quantization try: self.output_port[0].format[0].encoding = { 'h264': mmal.MMAL_ENCODING_H264, 'mjpeg': mmal.MMAL_ENCODING_MJPEG, }[self.format] except KeyError: raise PiCameraValueError('Unrecognized format %s' % self.format) if not (0 <= bitrate <= 25000000): raise PiCameraValueError('bitrate must be between 0 and 25Mbps') self.output_port[0].format[0].bitrate = bitrate self.output_port[0].format[0].es[0].video.frame_rate.num = 0 self.output_port[0].format[0].es[0].video.frame_rate.den = 1 mmal_check( mmal.mmal_port_format_commit(self.output_port), prefix="Unable to set format on encoder output port") if self.format == 'h264': mp = mmal.MMAL_PARAMETER_VIDEO_PROFILE_T( mmal.MMAL_PARAMETER_HEADER_T( mmal.MMAL_PARAMETER_PROFILE, ct.sizeof(mmal.MMAL_PARAMETER_VIDEO_PROFILE_T), ), ) try: mp.profile[0].profile = { 'baseline': mmal.MMAL_VIDEO_PROFILE_H264_BASELINE, 'main': mmal.MMAL_VIDEO_PROFILE_H264_MAIN, 'high': mmal.MMAL_VIDEO_PROFILE_H264_HIGH, 'constrained': mmal.MMAL_VIDEO_PROFILE_H264_CONSTRAINED_BASELINE, }[profile] except KeyError: raise PiCameraValueError("Invalid H.264 profile %s" % profile) mp.profile[0].level = mmal.MMAL_VIDEO_LEVEL_H264_4 mmal_check( mmal.mmal_port_parameter_set(self.output_port, mp.hdr), prefix="Unable to set encoder H.264 profile") if inline_headers: mmal_check( mmal.mmal_port_parameter_set_boolean( self.output_port, mmal.MMAL_PARAMETER_VIDEO_ENCODE_INLINE_HEADER, mmal.MMAL_TRUE), prefix="Unable to set inline_headers") if sei: mmal_check( mmal.mmal_port_parameter_set_boolean( self.output_port, mmal.MMAL_PARAMETER_VIDEO_ENCODE_SEI_ENABLE, mmal.MMAL_TRUE), prefix="Unable to set SEI") if motion_output: mmal_check( mmal.mmal_port_parameter_set_boolean( self.output_port, mmal.MMAL_PARAMETER_VIDEO_ENCODE_INLINE_VECTORS, mmal.MMAL_TRUE), prefix="Unable to set inline motion vectors") # We need the intra-period to calculate the SPS header timeout in # the split method below. If one is not set explicitly, query the # encoder's default if intra_period is not None: mp = mmal.MMAL_PARAMETER_UINT32_T( mmal.MMAL_PARAMETER_HEADER_T( mmal.MMAL_PARAMETER_INTRAPERIOD, ct.sizeof(mmal.MMAL_PARAMETER_UINT32_T), ), intra_period ) mmal_check( mmal.mmal_port_parameter_set(self.output_port, mp.hdr), prefix="Unable to set encoder intra_period") self._intra_period = intra_period else: mp = mmal.MMAL_PARAMETER_UINT32_T( mmal.MMAL_PARAMETER_HEADER_T( mmal.MMAL_PARAMETER_INTRAPERIOD, ct.sizeof(mmal.MMAL_PARAMETER_UINT32_T), )) mmal_check( mmal.mmal_port_parameter_get(self.output_port, mp.hdr), prefix="Unable to get encoder intra_period") self._intra_period = mp.value if intra_refresh is not None: # Get the intra-refresh structure first as there are several # other fields in it which we don't wish to overwrite mp = mmal.MMAL_PARAMETER_VIDEO_INTRA_REFRESH_T( mmal.MMAL_PARAMETER_HEADER_T( mmal.MMAL_PARAMETER_VIDEO_INTRA_REFRESH, ct.sizeof(mmal.MMAL_PARAMETER_VIDEO_INTRA_REFRESH_T), )) # Deliberately avoid checking whether this call succeeds mmal.mmal_port_parameter_get(self.output_port, mp.hdr) try: mp.refresh_mode = { 'cyclic': mmal.MMAL_VIDEO_INTRA_REFRESH_CYCLIC, 'adaptive': mmal.MMAL_VIDEO_INTRA_REFRESH_ADAPTIVE, 'both': mmal.MMAL_VIDEO_INTRA_REFRESH_BOTH, 'cyclicrows': mmal.MMAL_VIDEO_INTRA_REFRESH_CYCLIC_MROWS, }[intra_refresh] except KeyError: raise PiCameraValueError( "Invalid intra_refresh %s" % intra_refresh) mmal_check( mmal.mmal_port_parameter_set(self.output_port, mp.hdr), prefix="Unable to set encoder intra_refresh") elif self.format == 'mjpeg': # MJPEG doesn't have an intra_period setting as such, but as every # frame is a full-frame, the intra_period is effectively 1 self._intra_period = 1 if quality: mp = mmal.MMAL_PARAMETER_UINT32_T( mmal.MMAL_PARAMETER_HEADER_T( mmal.MMAL_PARAMETER_VIDEO_ENCODE_INITIAL_QUANT, ct.sizeof(mmal.MMAL_PARAMETER_UINT32_T), ), quality ) mmal_check( mmal.mmal_port_parameter_set(self.output_port, mp.hdr), prefix="Unable to set initial quality") mp = mmal.MMAL_PARAMETER_UINT32_T( mmal.MMAL_PARAMETER_HEADER_T( mmal.MMAL_PARAMETER_VIDEO_ENCODE_MIN_QUANT, ct.sizeof(mmal.MMAL_PARAMETER_UINT32_T), ), quality, ) mmal_check( mmal.mmal_port_parameter_set(self.output_port, mp.hdr), prefix="Unable to set minimum quality") mp = mmal.MMAL_PARAMETER_UINT32_T( mmal.MMAL_PARAMETER_HEADER_T( mmal.MMAL_PARAMETER_VIDEO_ENCODE_MAX_QUANT, ct.sizeof(mmal.MMAL_PARAMETER_UINT32_T), ), quality, ) mmal_check( mmal.mmal_port_parameter_set(self.output_port, mp.hdr), prefix="Unable to set maximum quality") mmal_check( mmal.mmal_port_parameter_set_boolean( self.encoder[0].input[0], mmal.MMAL_PARAMETER_VIDEO_IMMUTABLE_INPUT, 1), prefix="Unable to set immutable flag on encoder input port") mmal_check( mmal.mmal_component_enable(self.encoder), prefix="Unable to enable video encoder component")
[docs] def start(self, output, motion_output=None): """ Extended to initialize video frame meta-data tracking. """ self.frame = PiVideoFrame( index=0, frame_type=None, frame_size=0, video_size=0, split_size=0, timestamp=0, complete=False, ) if motion_output is not None: self._open_output(motion_output, PiVideoFrameType.motion_data) super(PiVideoEncoder, self).start(output)
def stop(self): super(PiVideoEncoder, self).stop() self._close_output(PiVideoFrameType.motion_data)
[docs] def split(self, output, motion_output=None): """ Called to switch the encoder's output. This method is called by :meth:`~picamera.camera.PiCamera.split_recording` and :meth:`~picamera.camera.PiCamera.record_sequence` to switch the encoder's :attr:`output` object to the *output* parameter (which can be a filename or a file-like object, as with :meth:`start`). """ with self.outputs_lock: outputs = {} if output is not None: outputs[PiVideoFrameType.frame] = output if motion_output is not None: outputs[PiVideoFrameType.motion_data] = motion_output self._next_output.append(outputs) # intra_period / framerate gives the time between I-frames (which # should also coincide with SPS headers). We multiply by three to # ensure the timeout is deliberately excessive, and clamp the minimum # timeout to 1 second (otherwise unencoded formats tend to fail # presumably due to I/O capacity) timeout = max(1.0, float(self._intra_period / self.parent.framerate) * 3.0) if not self.event.wait(timeout): raise PiCameraRuntimeError( 'Timed out waiting for a split point') self.event.clear()
[docs] def _callback_write(self, buf, key=PiVideoFrameType.frame): """ Extended to implement video frame meta-data tracking, and to handle splitting video recording to the next output when :meth:`split` is called. """ self.frame = PiVideoFrame( index= self.frame.index + 1 if self.frame.complete else self.frame.index, frame_type= PiVideoFrameType.key_frame if buf[0].flags & mmal.MMAL_BUFFER_HEADER_FLAG_KEYFRAME else PiVideoFrameType.sps_header if buf[0].flags & mmal.MMAL_BUFFER_HEADER_FLAG_CONFIG else PiVideoFrameType.motion_data if buf[0].flags & mmal.MMAL_BUFFER_HEADER_FLAG_CODECSIDEINFO else PiVideoFrameType.frame, frame_size= buf[0].length if self.frame.complete else self.frame.frame_size + buf[0].length, video_size= self.frame.video_size if buf[0].flags & mmal.MMAL_BUFFER_HEADER_FLAG_CODECSIDEINFO else self.frame.video_size + buf[0].length, split_size= self.frame.split_size if buf[0].flags & mmal.MMAL_BUFFER_HEADER_FLAG_CODECSIDEINFO else self.frame.split_size + buf[0].length, timestamp= None if buf[0].pts in (0, mmal.MMAL_TIME_UNKNOWN) else buf[0].pts, complete= bool(buf[0].flags & mmal.MMAL_BUFFER_HEADER_FLAG_FRAME_END), ) if self.format != 'h264' or (buf[0].flags & mmal.MMAL_BUFFER_HEADER_FLAG_CONFIG): with self.outputs_lock: try: new_outputs = self._next_output.pop(0) except IndexError: new_outputs = None if new_outputs: for new_key, new_output in new_outputs.items(): self._close_output(new_key) self._open_output(new_output, new_key) if new_key == PiVideoFrameType.frame: self.frame = PiVideoFrame( index=self.frame.index, frame_type=self.frame.frame_type, frame_size=self.frame.frame_size, video_size=self.frame.video_size, split_size=0, timestamp=self.frame.timestamp, complete=self.frame.complete, ) self.event.set() if buf[0].flags & mmal.MMAL_BUFFER_HEADER_FLAG_CODECSIDEINFO: key = PiVideoFrameType.motion_data return super(PiVideoEncoder, self)._callback_write(buf, key)
[docs]class PiCookedVideoEncoder(PiVideoEncoder): """ Video encoder for encoded recordings. This class is a derivative of :class:`PiVideoEncoder` and only exists to provide naming symmetry with the image encoder classes. """
[docs]class PiRawVideoEncoder(PiRawMixin, PiVideoEncoder): """ Video encoder for unencoded recordings. This class is a derivative of :class:`PiVideoEncoder` and the :class:`PiRawMixin` class intended for use with :meth:`~picamera.camera.PiCamera.start_recording` when it is called with an unencoded format. .. warning:: This class creates an inheritance diamond. Take care to determine the MRO of super-class calls. """ def _create_encoder(self): super(PiRawVideoEncoder, self)._create_encoder() # Raw formats don't have an intra_period setting as such, but as every # frame is a full-frame, the intra_period is effectively 1 self._intra_period = 1
[docs]class PiImageEncoder(PiEncoder): """ Encoder for image capture. This derivative of :class:`PiEncoder` extends the :meth:`_create_encoder` method to configure the encoder for a variety of encoded image outputs (JPEG, PNG, etc.). """ encoder_type = mmal.MMAL_COMPONENT_DEFAULT_IMAGE_ENCODER
[docs] def _create_encoder(self, quality=85, thumbnail=(64, 48, 35), bayer=False): """ Extends the base :meth:`~PiEncoder._create_encoder` implementation to configure the image encoder for JPEG, PNG, etc. """ super(PiImageEncoder, self)._create_encoder() try: self.output_port[0].format[0].encoding = { 'jpeg': mmal.MMAL_ENCODING_JPEG, 'png': mmal.MMAL_ENCODING_PNG, 'gif': mmal.MMAL_ENCODING_GIF, 'bmp': mmal.MMAL_ENCODING_BMP, }[self.format] except KeyError: raise PiCameraValueError("Unrecognized format %s" % self.format) mmal_check( mmal.mmal_port_format_commit(self.output_port), prefix="Unable to set format on encoder output port") if self.format == 'jpeg': mmal_check( mmal.mmal_port_parameter_set_uint32( self.output_port, mmal.MMAL_PARAMETER_JPEG_Q_FACTOR, quality), prefix="Failed to set JPEG quality") mmal_check( mmal.mmal_port_parameter_set_boolean( self.camera_port, mmal.MMAL_PARAMETER_ENABLE_RAW_CAPTURE, int(bool(bayer))), prefix="Failed to set raw capture") if thumbnail is None: mp = mmal.MMAL_PARAMETER_THUMBNAIL_CONFIG_T( mmal.MMAL_PARAMETER_HEADER_T( mmal.MMAL_PARAMETER_THUMBNAIL_CONFIGURATION, ct.sizeof(mmal.MMAL_PARAMETER_THUMBNAIL_CONFIG_T) ), 0, 0, 0, 0) else: mp = mmal.MMAL_PARAMETER_THUMBNAIL_CONFIG_T( mmal.MMAL_PARAMETER_HEADER_T( mmal.MMAL_PARAMETER_THUMBNAIL_CONFIGURATION, ct.sizeof(mmal.MMAL_PARAMETER_THUMBNAIL_CONFIG_T) ), 1, *thumbnail) mmal_check( mmal.mmal_port_parameter_set(self.encoder[0].control, mp.hdr), prefix="Failed to set thumbnail configuration") mmal_check( mmal.mmal_component_enable(self.encoder), prefix="Unable to enable encoder component")
[docs]class PiOneImageEncoder(PiImageEncoder): """ Encoder for single image capture. This class simply extends :meth:`~PiEncoder._callback_write` to terminate capture at frame end (i.e. after a single frame has been received). """ def _callback_write(self, buf, key=PiVideoFrameType.frame): return ( super(PiOneImageEncoder, self)._callback_write(buf, key) ) or bool( buf[0].flags & ( mmal.MMAL_BUFFER_HEADER_FLAG_FRAME_END | mmal.MMAL_BUFFER_HEADER_FLAG_TRANSMISSION_FAILED) )
[docs]class PiMultiImageEncoder(PiImageEncoder): """ Encoder for multiple image capture. This class extends :class:`PiImageEncoder` to handle an iterable of outputs instead of a single output. The :meth:`~PiEncoder._callback_write` method is extended to terminate capture when the iterable is exhausted, while :meth:`PiEncoder._open_output` is overridden to begin iteration and rely on the new :meth:`_next_output` method to advance output to the next item in the iterable. """ def _open_output(self, outputs, key=PiVideoFrameType.frame): self._output_iter = iter(outputs) self._next_output(key)
[docs] def _next_output(self, key=PiVideoFrameType.frame): """ This method moves output to the next item from the iterable passed to :meth:`~PiEncoder.start`. """ self._close_output(key) super(PiMultiImageEncoder, self)._open_output(next(self._output_iter), key)
def _callback_write(self, buf, key=PiVideoFrameType.frame): try: if ( super(PiMultiImageEncoder, self)._callback_write(buf, key) ) or bool( buf[0].flags & ( mmal.MMAL_BUFFER_HEADER_FLAG_FRAME_END | mmal.MMAL_BUFFER_HEADER_FLAG_TRANSMISSION_FAILED) ): self._next_output(key) return False except StopIteration: return True
[docs]class PiCookedOneImageEncoder(PiOneImageEncoder): """ Encoder for "cooked" (encoded) single image output. This encoder extends :class:`PiOneImageEncoder` to include Exif tags in the output. """ exif_encoding = 'ascii' def _add_exif_tag(self, tag, value): # Format the tag and value into an appropriate bytes string, encoded # with the Exif encoding (ASCII) if isinstance(tag, str): tag = tag.encode(self.exif_encoding) if isinstance(value, str): value = value.encode(self.exif_encoding) elif isinstance(value, datetime.datetime): value = value.strftime('%Y:%m:%d %H:%M:%S').encode(self.exif_encoding) # MMAL_PARAMETER_EXIF_T is a variable sized structure, hence all the # mucking about with string buffers here... buf = ct.create_string_buffer( ct.sizeof(mmal.MMAL_PARAMETER_EXIF_T) + len(tag) + len(value) + 1) mp = ct.cast(buf, ct.POINTER(mmal.MMAL_PARAMETER_EXIF_T)) mp[0].hdr.id = mmal.MMAL_PARAMETER_EXIF mp[0].hdr.size = len(buf) if (b'=' in tag or b'\x00' in value): data = tag + value mp[0].keylen = len(tag) mp[0].value_offset = len(tag) mp[0].valuelen = len(value) else: data = tag + b'=' + value ct.memmove(mp[0].data, data, len(data)) mmal_check( mmal.mmal_port_parameter_set(self.output_port, mp[0].hdr), prefix="Failed to set Exif tag %s" % tag) def start(self, output): timestamp = datetime.datetime.now() timestamp_tags = ( 'EXIF.DateTimeDigitized', 'EXIF.DateTimeOriginal', 'IFD0.DateTime') # Timestamp tags are always included with the value calculated # above, but the user may choose to override the value in the # exif_tags mapping for tag in timestamp_tags: self._add_exif_tag(tag, self.parent.exif_tags.get(tag, timestamp)) # All other tags are just copied in verbatim for tag, value in self.parent.exif_tags.items(): if not tag in timestamp_tags: self._add_exif_tag(tag, value) super(PiCookedOneImageEncoder, self).start(output)
[docs]class PiCookedMultiImageEncoder(PiMultiImageEncoder): """ Encoder for "cooked" (encoded) multiple image output. This encoder descends from :class:`PiMultiImageEncoder` but includes no new functionality as video-port based encodes (which is all this class is used for) don't support Exif tag output. """ pass
[docs]class PiRawImageMixin(PiRawMixin, PiImageEncoder): """ Mixin class for "raw" (unencoded) image capture. The :meth:`_callback_write` method is overridden to manually calculate when to terminate output. """ def __init__( self, parent, camera_port, input_port, format, resize, **options): super(PiRawImageMixin, self).__init__( parent, camera_port, input_port, format, resize, **options) self._image_size = 0
[docs] def _callback_write(self, buf, key=PiVideoFrameType.frame): """ Overridden to manually calculate when to terminate capture (see comments in :meth:`__init__`). """ if self._image_size > 0: super(PiRawImageMixin, self)._callback_write(buf, key) self._image_size -= buf[0].length return self._image_size <= 0
def start(self, output): self._image_size = self._frame_size super(PiRawImageMixin, self).start(output)
[docs]class PiRawOneImageEncoder(PiOneImageEncoder, PiRawImageMixin): """ Single image encoder for unencoded capture. This class is a derivative of :class:`PiOneImageEncoder` and the :class:`PiRawImageMixin` class intended for use with :meth:`~picamera.camera.PiCamera.capture` (et al) when it is called with an unencoded image format. .. warning:: This class creates an inheritance diamond. Take care to determine the MRO of super-class calls. """ pass
[docs]class PiRawMultiImageEncoder(PiMultiImageEncoder, PiRawImageMixin): """ Multiple image encoder for unencoded capture. This class is a derivative of :class:`PiMultiImageEncoder` and the :class:`PiRawImageMixin` class intended for use with :meth:`~picamera.camera.PiCamera.capture_sequence` when it is called with an unencoded image format. .. warning:: This class creates an inheritance diamond. Take care to determine the MRO of super-class calls. """ def _next_output(self, key=PiVideoFrameType.frame): super(PiRawMultiImageEncoder, self)._next_output(key) self._image_size = self._frame_size