CMMFDevVideoRecord Class Reference

Destructor.

Returns coding-standard specific initialization output from the encoder. The information can contain, for example, the MPEG-4 VOL header. This method can be called after Initialize() has been called.

Returns coding-standard specific settings output from the encoder. The information can contain, for example, some bitstream headers that can change based on settings modified while encoding is in progress.

Commit all configuration changes since the last CommitL(), Revert() or Initialize(). This only applies to methods that can be called both before AND after DevVideoRecord has been initialized. See the following methods for details.

See also: SetOutputRectL SetPreProcessTypesL SetRotateOptionsL SetScaleOptionsL SetInputCropOptionsL SetOutputCropOptionsL SetOutputPadOptionsL SetColorEnhancementOptionsL SetFrameStabilisationOptionsL SetCustomPreProcessOptionsL SetCodingStandardSpecificOptionsL SetImplementationSpecificEncoderOptionsL

leave

"The method will leave if an error occurs."

Pre-condition

"This method can only be called after the API has been initialized with Initialize()."

Retrieves a custom interface to the specified hardware device.

Finds all available encoders for a given video type with support for certain pre-processing operations. The video type is specified using its MIME type, which may include parameters specifying the supported level, version, and other information. Encoder hardware devices can use wildcards when listing the supported video types in the ECom registration information, so it is possible that all the encoders returned do not support the specified submode, e.g. profile and level, unless aExactMatch is set.

The encoder capabilities can be checked with VideoEncoderInfoLC().

Finds all available pre-processors for a given set of pre-processing operations.

Freezes the input picture. Freezing is similar to a pause, except that timestamps are incremented normally during a freeze. Normal encoding can be continued using ReleaseFreeze().

Reads the frame stabilisation output picture position. This information can be used for positioning the viewfinder. The position returned is the stabilisation result for the most recent input picture.

Gets the current output buffer status. The information includes the number of free output buffers and the total size of free buffers in bytes.

Reads various counters related to processed video pictures. See the definition of TPictureCounters for a description of the counters. The counters are reset when Initialize() or this method is called, and thus they only include pictures processed since the last call.

Returns implementation-specific initialization output from the encoder. This method can be called after Initialize() has been called.

Returns implementation-specific settings output from the encoder. The information can contain, for example, some bitstream headers that can change based on settings modified while encoding is in progress.

Initializes the video devices, and reserves hardware resources. This method is asynchronous, DevVideoRecord will call MMMFDevVideoRecordObserver::MdvroInitializeComplete() after initialization has completed. If direct capture is used, this method also prepares the camera API for capture by calling PrepareVideoCaptureL(). No DevVideoRecord method may be called while initialization is in progress, the initialization process can only be cancelled by destroying the DevVideoRecord object.

After initialization has successfully been completed, video capturing and encoding can be started with Start() with a relatively low delay since the hardware has already been set up.

If Initialize() fails, the DevVideoRecord object must be destroyed, and set up from scratch.

Notifies the system that the end of input data has been reached. No more input data can be written through the API. The encoder and pre-processor can use this signal to ensure that the remaining data gets processed, without waiting for new data. After the remaining data has been processed, the client gets notified by the MdvroStreamEnd() callback.

Retrieves the next output buffer, in coding order. The buffer must be returned using ReturnBuffer() when it is no longer used. The maximum amount of buffers that the caller can keep in its use is controlled by the iMinNumOutputBuffers and iMinTotalOutputBufferSize fields in the TEncoderBufferOptions settings.

Retrieves the number of complexity control levels available for a hardware device. Devices can support processing the same input data with different computational complexity levels. The complexity level can affect, for example, the motion vector search range used in an encoder.

Returns the number of output buffers currently containing valid output data.

Pauses video recording. Recording can be resumed using Resume().

While video is paused, new pictures are not captured, and input pictures written using WritePictureL() are discarded. Timestamps are not incremented - the encoder assumes that the clock source is paused as well, and input picture timestamps are adjusted accordingly. Pause is typically used in video recording applications to pause recording, conversational applications should use Freeze() instead.

Indicates to the encoder the pictures that have been lost. The encoder can react to this by transmitting an intra-picture.

Returns the current recording position. The position is the capture timestamp from the latest input picture, or the capture timestamp for the latest picture captured from the camera when direct capture is used.

Sends a reference picture selection request to the encoder. The request is delivered as a coding-standard specific binary message. Reference picture selection can be used to select a previous correctly transmitted picture to use as a reference in case later pictures have been lost.

Returns a used output buffer back to the encoder. The buffer can no longer be used by the client.

Revert any configuration changes that have not yet been committed using CommitL(). This only applies to methods that can be called both before AND after DevVideoRecord has been initialized. See the following methods for details.

See also: SetOutputRectL SetPreProcessTypesL SetRotateOptionsL SetScaleOptionsL SetInputCropOptionsL SetOutputCropOptionsL SetOutputPadOptionsL SetColorEnhancementOptionsL SetFrameStabilisationOptionsL SetCustomPreProcessOptionsL SetCodingStandardSpecificOptionsL SetImplementationSpecificEncoderOptionsL

Pre-condition

"This method can only be called after the API has been initialized with Initialize()."

Selects the video encoder to be used. This method must be called before any other video encoder related methods are used. The encoder can be changed by calling this method again before the system has been initialized with Initialize().

All video encoder settings are reset to their default values. By default no pre-processing is performed.

Selects the video pre-processor to be used. This method must be called before any other pre-processor related methods are used. The pre-processor to use can be changed by calling this method again before the API has been initialized with Initialize().

All pre-processor settings are reset to their default values. By default no pre-processing is performed.

Requests the encoder to sends supplemental information in the bitstream. The information data format is coding-standard dependent. Only one supplemental information send request can be active at a time. This variant encodes the information to the next possible picture.

Requests the encoder to send supplemental information in the bitstream. The information data format is coding-standard dependent. Only one supplemental information send request can be active at a time. This variant encodes the information to the picture whose presentation timestamp is equal to or greater than and closest to the value of aTimestamp.

Sets encoder buffering options.

Sets the expected or prevailing channel conditions for an unequal error protection level, in terms of expected bit error rate. The video encoder can use this information to optimize the generated bitstream.

Sets the expected or prevailing channel conditions for an unequal error protection level, in terms of expected packet loss rate. The video encoder can use this information to optimize the generated bitstream.

Sets the clock source to use for video timing. When video recording is synchronized with audio, the clock source is implemented by the audio playback subsystem, otherwise the clock source should get the time from the system clock. This method can be called after all hardware devices have been selected, but before calling Initialize().

If no clock source is set, video recording will not be synchronized, but will proceed as fast as possible, depending on input data and output buffer availability. If direct capturing is used without a clock source, the timestamps in the output data may not be valid. All encoders must support synchronization with an external clock source, as well as unsynchronized non-realtime operation.

Sets coding-standard specific encoder options.

Sets color enhancement pre-processing options.

Sets the complexity level to use for video processing in a hardware device. The level can be changed at any time.

Sets custom implementation-specific pre-processing options.

Sets up an unequal error protection level. If unequal error protection is not used, this method can be used to control settings for the whole encoded bitstream.

Sets the number of unequal error protection levels. By default unequal error protection is not used.

Sets whether bit errors or packets losses can be expected in the video transmission channel. The video encoder can use this information to optimize the bitstream.

Sets frame stabilisation options.

Frame stabilisation is performed as the first pre-processing operation in the hardware device. The stabilisation process gets the complete hardware device input picture as its input, and it produces a smaller stabilised output picture. The rest of the processing in the hardware device is done using the stabilisation output picture.

Sets the reference picture options to be used for all scalability layers. The settings can be overridden for an individual scalability layer by using SetLayerReferenceOptions().

Sets implementation-specific encoder options.

Sets in-layer scalability options for a layer. In-layer bit-rate scalability refers to techniques where a specific part of a single-layer coded stream can be decoded correctly without decoding the leftover part. For example, B-pictures can be used for this. By default in-layer scalability is not used.

Sets pre-processing options for input cropping. Input cropping is typically used for digital zooming.

Sets the input format for a hardware device. If both a pre-processor and an encoder are used, the pre-processor output format and the encoder input format must be the same. The input format for the first device in the system is the input format for video input data.

The method has to be called for both direct capture as well as memory buffer input. The camera API must be initialized by the device using it for capture, since there is no way to query the current format from the camera API.

Sets the period for layer promotions points for a scalability layer. A layer promotion point is a picture where it is possible to start encoding this enhancement layer if only the lower layers were encoded earlier.

Sets the reference picture options to be used for a single scalability layer. These settings override those set with SetGlobalReferenceOptions().

Sets the minimum frequency (in time) for instantaneous random access points in the bitstream. An instantaneous random access point is such where the encoder can achieve a full output picture immediately by encoding data starting from the random access point. The random access point frequency may be higher than signalled, if the sequence contains scene cuts which typically cause a coding of a random access point.

Sets the number of bit-rate scalability layers to use. Set to 1 to disable layered scalability.

Bit-rate scalability refers to the ability of a coded stream to be decoded at different bit-rates. Scalable video is typically ordered into hierarchical layers of data. A base layer contains an individual representation of a video stream and enhancement layers contain refinement data in addition to the base layer. The quality of the encoded video stream progressively improves as enhancement layers are added to the base layer.

Sets pre-processing options for output cropping. Output cropping is performed after other pre-processing operations but before output padding. Output cropping and padding can be used in combination to prepare the picture size to suit the encoder, typically video encoders only support picture sizes that are multiples of 16 pixels.

Sets the output format for a hardware device to a compressed video format. Only applicable for encoder devices. The picture size depends on the input data format and possible scaling performed.

Sets the output format for a hardware device to an uncompressed video format. Only applicable for pre-processor devices. The picture size depends on the input data format and possible scaling performed.

Sets pre-processing options for output padding. Output padding is performed as the last pre-processing operation, and typically used to prepare the picture size to suit the encoder. The image is padded with black pixels.

Sets the encoder output rectangle for encoded video output. This rectangle specifies the part of the input and output pictures which is displayed after encoding. Many video codecs process data in 16x16 pixel units but enable specifying and coding the decoder output rectangle for image sizes that are not multiple of 16 pixels (e.g 160x120).

Sets the pre-processing types to be used in a hardware device. [1 #191] If separate encoder and pre-processor devices are used, both can be configured to perform different pre-processing operations.

Pre-processing operations are carried out in the following order:

1. Frame stabilisation 2. Input cropping 3. Mirroring 4. Rotating 5. Scaling 6. Output cropping 7. Output padding

Color space conversion and color enhancement can be performed at any point in the pre-processing flow.

Sets the bit-rate control options for a layer. If layered bit-rate scalability is not used, the options are set for the whole bitstream.

Sets pre-processing options for RGB to YUV color space conversion. By default, input RGB data is assumed to use the full value range ([0 255]), and the output YUV format is the hardware device output format, so typically calling this method is not necessary.

Sets pre-processing options for rotation.

Sets the scalability type for a bit-rate scalability layer.

Sets pre-processing options for scaling.

Sets the target size of each coded video segment. The segment target size can be specified in terms of number of bytes per segment, number of macroblocks per segment, or both.

Sets the data source to be a camera, and sets the system to use direct capture for input. The first hardware device (pre-processor if both encoder and pre-processor are used, encoder otherwise) must support direct capture.

Sets the data source to be memory buffers.

Sets pre-processing options for YUV to YUV data format conversion. By default, the hardware device input and output data formats are used. For encoder devices, the device input format and the closest matching format supported by the encoding process are used. Typically calling this method is not necessary.

Indicates a loss of consecutive macroblocks in raster scan order to the encoder.

Writes an uncompressed input picture. The picture must remain valid and unmodified until it is returned with the MdvroReturnPicture() callback. This method must not be called if direct capture is used.