GstVideoDecoder
This base class is for video decoders turning encoded data into raw video frames.
The GstVideoDecoder base class and derived subclasses should cooperate as follows:
Configuration
-
Initially, GstVideoDecoder calls start when the decoder element is activated, which allows the subclass to perform any global setup.
-
GstVideoDecoder calls set_format to inform the subclass of caps describing input video data that it is about to receive, including possibly configuration data. While unlikely, it might be called more than once, if changing input parameters require reconfiguration.
-
Incoming data buffers are processed as needed, described in Data Processing below.
-
GstVideoDecoder calls stop at end of all processing.
Data processing
-
The base class gathers input data, and optionally allows subclass to parse this into subsequently manageable chunks, typically corresponding to and referred to as 'frames'.
-
Each input frame is provided in turn to the subclass' handle_frame callback. The ownership of the frame is given to the handle_frame callback.
-
If codec processing results in decoded data, the subclass should call gst_video_decoder_finish_frame to have decoded data pushed. downstream. Otherwise, the subclass must call gst_video_decoder_drop_frame, to allow the base class to do timestamp and offset tracking, and possibly to requeue the frame for a later attempt in the case of reverse playback.
Shutdown phase
- The GstVideoDecoder class calls stop to inform the subclass that data parsing will be stopped.
Additional Notes
-
Seeking/Flushing
- When the pipeline is seeked or otherwise flushed, the subclass is informed via a call to its reset callback, with the hard parameter set to true. This indicates the subclass should drop any internal data queues and timestamps and prepare for a fresh set of buffers to arrive for parsing and decoding.
-
End Of Stream
- At end-of-stream, the subclass parse function may be called some final times with the at_eos parameter set to true, indicating that the element should not expect any more data to be arriving, and it should parse and remaining frames and call gst_video_decoder_have_frame if possible.
The subclass is responsible for providing pad template caps for source and sink pads. The pads need to be named "sink" and "src". It also needs to provide information about the output caps, when they are known. This may be when the base class calls the subclass' set_format function, though it might be during decoding, before calling gst_video_decoder_finish_frame. This is done via gst_video_decoder_set_output_state
The subclass is also responsible for providing (presentation) timestamps (likely based on corresponding input ones). If that is not applicable or possible, the base class provides limited framerate based interpolation.
Similarly, the base class provides some limited (legacy) seeking support if specifically requested by the subclass, as full-fledged support should rather be left to upstream demuxer, parser or alike. This simple approach caters for seeking and duration reporting using estimated input bitrates. To enable it, a subclass should call gst_video_decoder_set_estimate_rate to enable handling of incoming byte-streams.
The base class provides some support for reverse playback, in particular in case incoming data is not packetized or upstream does not provide fragments on keyframe boundaries. However, the subclass should then be prepared for the parsing and frame processing stage to occur separately (in normal forward processing, the latter immediately follows the former), The subclass also needs to ensure the parsing stage properly marks keyframes, unless it knows the upstream elements will do so properly for incoming data.
The bare minimum that a functional subclass needs to implement is:
-
Provide pad templates
-
Inform the base class of output caps via gst_video_decoder_set_output_state
-
Parse input data, if it is not considered packetized from upstream Data will be provided to parse which should invoke gst_video_decoder_add_to_frame and gst_video_decoder_have_frame to separate the data belonging to each video frame.
-
Accept data in handle_frame and provide decoded results to gst_video_decoder_finish_frame, or call gst_video_decoder_drop_frame.
GstVideoDecoder
GObject ╰──GInitiallyUnowned ╰──GstObject ╰──GstElement ╰──GstVideoDecoder
The opaque GstVideoDecoder data structure.
Class structure
GstVideoDecoderClass
Subclasses can override any of the available virtual methods or not, as needed. At minimum handle_frame needs to be overridden, and set_format and likely as well. If non-packetized input is supported or expected, parse needs to be overridden as well.
GstVideo.VideoDecoderClass
Subclasses can override any of the available virtual methods or not, as needed. At minimum handle_frame needs to be overridden, and set_format and likely as well. If non-packetized input is supported or expected, parse needs to be overridden as well.
GstVideo.VideoDecoderClass
Subclasses can override any of the available virtual methods or not, as needed. At minimum handle_frame needs to be overridden, and set_format and likely as well. If non-packetized input is supported or expected, parse needs to be overridden as well.
GstVideoDecoder
GObject ╰──GInitiallyUnowned ╰──GstObject ╰──GstElement ╰──GstVideoDecoder
The opaque GstVideoDecoder data structure.
GstVideoDecoder
GObject ╰──GInitiallyUnowned ╰──GstObject ╰──GstElement ╰──GstVideoDecoder
The opaque GstVideoDecoder data structure.
Methods
gst_video_decoder_add_to_frame
gst_video_decoder_add_to_frame (GstVideoDecoder * decoder, int n_bytes)
Removes next n_bytes of input data and adds it to currently parsed frame.
GstVideo.VideoDecoder.prototype.add_to_frame
function GstVideo.VideoDecoder.prototype.add_to_frame(n_bytes: Number): {
// javascript wrapper for 'gst_video_decoder_add_to_frame'
}
Removes next n_bytes of input data and adds it to currently parsed frame.
GstVideo.VideoDecoder.add_to_frame
def GstVideo.VideoDecoder.add_to_frame (self, n_bytes):
#python wrapper for 'gst_video_decoder_add_to_frame'
Removes next n_bytes of input data and adds it to currently parsed frame.
gst_video_decoder_allocate_output_buffer
GstBuffer * gst_video_decoder_allocate_output_buffer (GstVideoDecoder * decoder)
Helper function that allocates a buffer to hold a video frame for decoder's current GstVideoCodecState.
You should use gst_video_decoder_allocate_output_frame instead of this function, if possible at all.
Parameters:
decoder
–
allocated buffer, or NULL if no buffer could be allocated (e.g. when downstream is flushing or shutting down)
GstVideo.VideoDecoder.prototype.allocate_output_buffer
function GstVideo.VideoDecoder.prototype.allocate_output_buffer(): {
// javascript wrapper for 'gst_video_decoder_allocate_output_buffer'
}
Helper function that allocates a buffer to hold a video frame for decoder's current GstVideo.VideoCodecState.
You should use GstVideo.VideoDecoder.prototype.allocate_output_frame instead of this function, if possible at all.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
allocated buffer, or NULL if no buffer could be allocated (e.g. when downstream is flushing or shutting down)
GstVideo.VideoDecoder.allocate_output_buffer
def GstVideo.VideoDecoder.allocate_output_buffer (self):
#python wrapper for 'gst_video_decoder_allocate_output_buffer'
Helper function that allocates a buffer to hold a video frame for decoder's current GstVideo.VideoCodecState.
You should use GstVideo.VideoDecoder.allocate_output_frame instead of this function, if possible at all.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
allocated buffer, or NULL if no buffer could be allocated (e.g. when downstream is flushing or shutting down)
gst_video_decoder_allocate_output_frame
GstFlowReturn gst_video_decoder_allocate_output_frame (GstVideoDecoder * decoder, GstVideoCodecFrame * frame)
Helper function that allocates a buffer to hold a video frame for decoder's current GstVideoCodecState. Subclass should already have configured video state and set src pad caps.
The buffer allocated here is owned by the frame and you should only keep references to the frame, not the buffer.
GST_FLOW_OK if an output buffer could be allocated
GstVideo.VideoDecoder.prototype.allocate_output_frame
function GstVideo.VideoDecoder.prototype.allocate_output_frame(frame: GstVideo.VideoCodecFrame): {
// javascript wrapper for 'gst_video_decoder_allocate_output_frame'
}
Helper function that allocates a buffer to hold a video frame for decoder's current GstVideo.VideoCodecState. Subclass should already have configured video state and set src pad caps.
The buffer allocated here is owned by the frame and you should only keep references to the frame, not the buffer.
Gst.FlowReturn.OK if an output buffer could be allocated
GstVideo.VideoDecoder.allocate_output_frame
def GstVideo.VideoDecoder.allocate_output_frame (self, frame):
#python wrapper for 'gst_video_decoder_allocate_output_frame'
Helper function that allocates a buffer to hold a video frame for decoder's current GstVideo.VideoCodecState. Subclass should already have configured video state and set src pad caps.
The buffer allocated here is owned by the frame and you should only keep references to the frame, not the buffer.
Gst.FlowReturn.OK if an output buffer could be allocated
gst_video_decoder_allocate_output_frame_with_params
GstFlowReturn gst_video_decoder_allocate_output_frame_with_params (GstVideoDecoder * decoder, GstVideoCodecFrame * frame, GstBufferPoolAcquireParams * params)
Same as gst_video_decoder_allocate_output_frame except it allows passing GstBufferPoolAcquireParams to the sub call gst_buffer_pool_acquire_buffer.
Parameters:
decoder
–
frame
–
params
–
GST_FLOW_OK if an output buffer could be allocated
Since : 1.12
GstVideo.VideoDecoder.prototype.allocate_output_frame_with_params
function GstVideo.VideoDecoder.prototype.allocate_output_frame_with_params(frame: GstVideo.VideoCodecFrame, params: Gst.BufferPoolAcquireParams): {
// javascript wrapper for 'gst_video_decoder_allocate_output_frame_with_params'
}
Same as GstVideo.VideoDecoder.prototype.allocate_output_frame except it allows passing Gst.BufferPoolAcquireParams to the sub call gst_buffer_pool_acquire_buffer.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
params
(
Gst.BufferPoolAcquireParams
)
–
Gst.FlowReturn.OK if an output buffer could be allocated
Since : 1.12
GstVideo.VideoDecoder.allocate_output_frame_with_params
def GstVideo.VideoDecoder.allocate_output_frame_with_params (self, frame, params):
#python wrapper for 'gst_video_decoder_allocate_output_frame_with_params'
Same as GstVideo.VideoDecoder.allocate_output_frame except it allows passing Gst.BufferPoolAcquireParams to the sub call gst_buffer_pool_acquire_buffer.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
params
(
Gst.BufferPoolAcquireParams
)
–
Gst.FlowReturn.OK if an output buffer could be allocated
Since : 1.12
gst_video_decoder_drop_frame
GstFlowReturn gst_video_decoder_drop_frame (GstVideoDecoder * dec, GstVideoCodecFrame * frame)
Similar to gst_video_decoder_finish_frame, but drops frame in any case and posts a QoS message with the frame's details on the bus. In any case, the frame is considered finished and released.
a GstFlowReturn, usually GST_FLOW_OK.
GstVideo.VideoDecoder.prototype.drop_frame
function GstVideo.VideoDecoder.prototype.drop_frame(frame: GstVideo.VideoCodecFrame): {
// javascript wrapper for 'gst_video_decoder_drop_frame'
}
Similar to GstVideo.VideoDecoder.prototype.finish_frame, but drops frame in any case and posts a QoS message with the frame's details on the bus. In any case, the frame is considered finished and released.
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
the GstVideo.VideoCodecFrame to drop
a Gst.FlowReturn, usually GST_FLOW_OK.
GstVideo.VideoDecoder.drop_frame
def GstVideo.VideoDecoder.drop_frame (self, frame):
#python wrapper for 'gst_video_decoder_drop_frame'
Similar to GstVideo.VideoDecoder.finish_frame, but drops frame in any case and posts a QoS message with the frame's details on the bus. In any case, the frame is considered finished and released.
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
the GstVideo.VideoCodecFrame to drop
a Gst.FlowReturn, usually GST_FLOW_OK.
gst_video_decoder_finish_frame
GstFlowReturn gst_video_decoder_finish_frame (GstVideoDecoder * decoder, GstVideoCodecFrame * frame)
frame should have a valid decoded data buffer, whose metadata fields are then appropriately set according to frame data and pushed downstream. If no output data is provided, frame is considered skipped. In any case, the frame is considered finished and released.
After calling this function the output buffer of the frame is to be considered read-only. This function will also change the metadata of the buffer.
a GstFlowReturn resulting from sending data downstream
GstVideo.VideoDecoder.prototype.finish_frame
function GstVideo.VideoDecoder.prototype.finish_frame(frame: GstVideo.VideoCodecFrame): {
// javascript wrapper for 'gst_video_decoder_finish_frame'
}
frame should have a valid decoded data buffer, whose metadata fields are then appropriately set according to frame data and pushed downstream. If no output data is provided, frame is considered skipped. In any case, the frame is considered finished and released.
After calling this function the output buffer of the frame is to be considered read-only. This function will also change the metadata of the buffer.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
a decoded GstVideo.VideoCodecFrame
a Gst.FlowReturn resulting from sending data downstream
GstVideo.VideoDecoder.finish_frame
def GstVideo.VideoDecoder.finish_frame (self, frame):
#python wrapper for 'gst_video_decoder_finish_frame'
frame should have a valid decoded data buffer, whose metadata fields are then appropriately set according to frame data and pushed downstream. If no output data is provided, frame is considered skipped. In any case, the frame is considered finished and released.
After calling this function the output buffer of the frame is to be considered read-only. This function will also change the metadata of the buffer.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
a decoded GstVideo.VideoCodecFrame
a Gst.FlowReturn resulting from sending data downstream
gst_video_decoder_get_allocator
gst_video_decoder_get_allocator (GstVideoDecoder * decoder, GstAllocator ** allocator, GstAllocationParams * params)
Lets GstVideoDecoder sub-classes to know the memory allocator used by the base class and its params.
Unref the allocator after use it.
Parameters:
decoder
–
allocator
(
[out]
[allow-none]
[transfer: full]
)
–
the GstAllocator used
params
(
[out]
[allow-none]
[transfer: full]
)
–
the GstAllocationParams of allocator
GstVideo.VideoDecoder.prototype.get_allocator
function GstVideo.VideoDecoder.prototype.get_allocator(): {
// javascript wrapper for 'gst_video_decoder_get_allocator'
}
Lets GstVideo.VideoDecoder sub-classes to know the memory allocator used by the base class and its params.
Unref the allocator after use it.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
GstVideo.VideoDecoder.get_allocator
def GstVideo.VideoDecoder.get_allocator (self):
#python wrapper for 'gst_video_decoder_get_allocator'
Lets GstVideo.VideoDecoder sub-classes to know the memory allocator used by the base class and its params.
Unref the allocator after use it.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
gst_video_decoder_get_buffer_pool
GstBufferPool * gst_video_decoder_get_buffer_pool (GstVideoDecoder * decoder)
Parameters:
decoder
–
the instance of the GstBufferPool used by the decoder; free it after use it
GstVideo.VideoDecoder.prototype.get_buffer_pool
function GstVideo.VideoDecoder.prototype.get_buffer_pool(): {
// javascript wrapper for 'gst_video_decoder_get_buffer_pool'
}
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
the instance of the Gst.BufferPool used by the decoder; free it after use it
GstVideo.VideoDecoder.get_buffer_pool
def GstVideo.VideoDecoder.get_buffer_pool (self):
#python wrapper for 'gst_video_decoder_get_buffer_pool'
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
the instance of the Gst.BufferPool used by the decoder; free it after use it
gst_video_decoder_get_estimate_rate
gint gst_video_decoder_get_estimate_rate (GstVideoDecoder * dec)
Parameters:
dec
–
currently configured byte to time conversion setting
GstVideo.VideoDecoder.prototype.get_estimate_rate
function GstVideo.VideoDecoder.prototype.get_estimate_rate(): {
// javascript wrapper for 'gst_video_decoder_get_estimate_rate'
}
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
currently configured byte to time conversion setting
GstVideo.VideoDecoder.get_estimate_rate
def GstVideo.VideoDecoder.get_estimate_rate (self):
#python wrapper for 'gst_video_decoder_get_estimate_rate'
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
currently configured byte to time conversion setting
gst_video_decoder_get_frame
GstVideoCodecFrame * gst_video_decoder_get_frame (GstVideoDecoder * decoder, int frame_number)
Get a pending unfinished GstVideoCodecFrame
pending unfinished GstVideoCodecFrame identified by frame_number.
GstVideo.VideoDecoder.prototype.get_frame
function GstVideo.VideoDecoder.prototype.get_frame(frame_number: Number): {
// javascript wrapper for 'gst_video_decoder_get_frame'
}
Get a pending unfinished GstVideo.VideoCodecFrame
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame_number
(
Number
)
–
system_frame_number of a frame
pending unfinished GstVideo.VideoCodecFrame identified by frame_number.
GstVideo.VideoDecoder.get_frame
def GstVideo.VideoDecoder.get_frame (self, frame_number):
#python wrapper for 'gst_video_decoder_get_frame'
Get a pending unfinished GstVideo.VideoCodecFrame
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame_number
(
int
)
–
system_frame_number of a frame
pending unfinished GstVideo.VideoCodecFrame identified by frame_number.
gst_video_decoder_get_frames
GList * gst_video_decoder_get_frames (GstVideoDecoder * decoder)
Get all pending unfinished GstVideoCodecFrame
Parameters:
decoder
–
pending unfinished GstVideoCodecFrame.
GstVideo.VideoDecoder.prototype.get_frames
function GstVideo.VideoDecoder.prototype.get_frames(): {
// javascript wrapper for 'gst_video_decoder_get_frames'
}
Get all pending unfinished GstVideo.VideoCodecFrame
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
pending unfinished GstVideo.VideoCodecFrame.
GstVideo.VideoDecoder.get_frames
def GstVideo.VideoDecoder.get_frames (self):
#python wrapper for 'gst_video_decoder_get_frames'
Get all pending unfinished GstVideo.VideoCodecFrame
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
pending unfinished GstVideo.VideoCodecFrame.
gst_video_decoder_get_latency
gst_video_decoder_get_latency (GstVideoDecoder * decoder, GstClockTime * min_latency, GstClockTime * max_latency)
Query the configured decoder latency. Results will be returned via min_latency and max_latency.
Parameters:
decoder
–
min_latency
(
[out]
[allow-none]
)
–
address of variable in which to store the configured minimum latency, or NULL
max_latency
(
[out]
[allow-none]
)
–
address of variable in which to store the configured mximum latency, or NULL
GstVideo.VideoDecoder.prototype.get_latency
function GstVideo.VideoDecoder.prototype.get_latency(): {
// javascript wrapper for 'gst_video_decoder_get_latency'
}
Query the configured decoder latency. Results will be returned via min_latency and max_latency.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
GstVideo.VideoDecoder.get_latency
def GstVideo.VideoDecoder.get_latency (self):
#python wrapper for 'gst_video_decoder_get_latency'
Query the configured decoder latency. Results will be returned via min_latency and max_latency.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
gst_video_decoder_get_max_decode_time
GstClockTimeDiff gst_video_decoder_get_max_decode_time (GstVideoDecoder * decoder, GstVideoCodecFrame * frame)
Determines maximum possible decoding time for frame that will allow it to decode and arrive in time (as determined by QoS events). In particular, a negative result means decoding in time is no longer possible and should therefore occur as soon/skippy as possible.
max decoding time.
GstVideo.VideoDecoder.prototype.get_max_decode_time
function GstVideo.VideoDecoder.prototype.get_max_decode_time(frame: GstVideo.VideoCodecFrame): {
// javascript wrapper for 'gst_video_decoder_get_max_decode_time'
}
Determines maximum possible decoding time for frame that will allow it to decode and arrive in time (as determined by QoS events). In particular, a negative result means decoding in time is no longer possible and should therefore occur as soon/skippy as possible.
max decoding time.
GstVideo.VideoDecoder.get_max_decode_time
def GstVideo.VideoDecoder.get_max_decode_time (self, frame):
#python wrapper for 'gst_video_decoder_get_max_decode_time'
Determines maximum possible decoding time for frame that will allow it to decode and arrive in time (as determined by QoS events). In particular, a negative result means decoding in time is no longer possible and should therefore occur as soon/skippy as possible.
max decoding time.
gst_video_decoder_get_max_errors
gint gst_video_decoder_get_max_errors (GstVideoDecoder * dec)
Parameters:
dec
–
currently configured decoder tolerated error count.
GstVideo.VideoDecoder.prototype.get_max_errors
function GstVideo.VideoDecoder.prototype.get_max_errors(): {
// javascript wrapper for 'gst_video_decoder_get_max_errors'
}
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
currently configured decoder tolerated error count.
GstVideo.VideoDecoder.get_max_errors
def GstVideo.VideoDecoder.get_max_errors (self):
#python wrapper for 'gst_video_decoder_get_max_errors'
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
currently configured decoder tolerated error count.
gst_video_decoder_get_needs_format
gboolean gst_video_decoder_get_needs_format (GstVideoDecoder * dec)
Queries decoder required format handling.
Parameters:
dec
–
TRUE if required format handling is enabled.
Since : 1.4
GstVideo.VideoDecoder.prototype.get_needs_format
function GstVideo.VideoDecoder.prototype.get_needs_format(): {
// javascript wrapper for 'gst_video_decoder_get_needs_format'
}
Queries decoder required format handling.
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
Since : 1.4
GstVideo.VideoDecoder.get_needs_format
def GstVideo.VideoDecoder.get_needs_format (self):
#python wrapper for 'gst_video_decoder_get_needs_format'
Queries decoder required format handling.
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
Since : 1.4
gst_video_decoder_get_oldest_frame
GstVideoCodecFrame * gst_video_decoder_get_oldest_frame (GstVideoDecoder * decoder)
Get the oldest pending unfinished GstVideoCodecFrame
Parameters:
decoder
–
oldest pending unfinished GstVideoCodecFrame.
GstVideo.VideoDecoder.prototype.get_oldest_frame
function GstVideo.VideoDecoder.prototype.get_oldest_frame(): {
// javascript wrapper for 'gst_video_decoder_get_oldest_frame'
}
Get the oldest pending unfinished GstVideo.VideoCodecFrame
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
oldest pending unfinished GstVideo.VideoCodecFrame.
GstVideo.VideoDecoder.get_oldest_frame
def GstVideo.VideoDecoder.get_oldest_frame (self):
#python wrapper for 'gst_video_decoder_get_oldest_frame'
Get the oldest pending unfinished GstVideo.VideoCodecFrame
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
oldest pending unfinished GstVideo.VideoCodecFrame.
gst_video_decoder_get_output_state
GstVideoCodecState * gst_video_decoder_get_output_state (GstVideoDecoder * decoder)
Get the GstVideoCodecState currently describing the output stream.
Parameters:
decoder
–
GstVideoCodecState describing format of video data.
GstVideo.VideoDecoder.prototype.get_output_state
function GstVideo.VideoDecoder.prototype.get_output_state(): {
// javascript wrapper for 'gst_video_decoder_get_output_state'
}
Get the GstVideo.VideoCodecState currently describing the output stream.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
GstVideo.VideoCodecState describing format of video data.
GstVideo.VideoDecoder.get_output_state
def GstVideo.VideoDecoder.get_output_state (self):
#python wrapper for 'gst_video_decoder_get_output_state'
Get the GstVideo.VideoCodecState currently describing the output stream.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
GstVideo.VideoCodecState describing format of video data.
gst_video_decoder_get_packetized
gboolean gst_video_decoder_get_packetized (GstVideoDecoder * decoder)
Queries whether input data is considered packetized or not by the base class.
Parameters:
decoder
–
TRUE if input data is considered packetized.
GstVideo.VideoDecoder.prototype.get_packetized
function GstVideo.VideoDecoder.prototype.get_packetized(): {
// javascript wrapper for 'gst_video_decoder_get_packetized'
}
Queries whether input data is considered packetized or not by the base class.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
TRUE if input data is considered packetized.
GstVideo.VideoDecoder.get_packetized
def GstVideo.VideoDecoder.get_packetized (self):
#python wrapper for 'gst_video_decoder_get_packetized'
Queries whether input data is considered packetized or not by the base class.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
TRUE if input data is considered packetized.
gst_video_decoder_get_pending_frame_size
gsize gst_video_decoder_get_pending_frame_size (GstVideoDecoder * decoder)
Returns the number of bytes previously added to the current frame by calling gst_video_decoder_add_to_frame.
Parameters:
decoder
–
The number of bytes pending for the current frame
Since : 1.4
GstVideo.VideoDecoder.prototype.get_pending_frame_size
function GstVideo.VideoDecoder.prototype.get_pending_frame_size(): {
// javascript wrapper for 'gst_video_decoder_get_pending_frame_size'
}
Returns the number of bytes previously added to the current frame by calling GstVideo.VideoDecoder.prototype.add_to_frame.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
The number of bytes pending for the current frame
Since : 1.4
GstVideo.VideoDecoder.get_pending_frame_size
def GstVideo.VideoDecoder.get_pending_frame_size (self):
#python wrapper for 'gst_video_decoder_get_pending_frame_size'
Returns the number of bytes previously added to the current frame by calling GstVideo.VideoDecoder.add_to_frame.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
The number of bytes pending for the current frame
Since : 1.4
gst_video_decoder_get_qos_proportion
gdouble gst_video_decoder_get_qos_proportion (GstVideoDecoder * decoder)
Parameters:
decoder
–
a GstVideoDecoder current QoS proportion, or NULL
The current QoS proportion.
Since : 1.0.3
GstVideo.VideoDecoder.prototype.get_qos_proportion
function GstVideo.VideoDecoder.prototype.get_qos_proportion(): {
// javascript wrapper for 'gst_video_decoder_get_qos_proportion'
}
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
a GstVideo.VideoDecoder current QoS proportion, or null
The current QoS proportion.
Since : 1.0.3
GstVideo.VideoDecoder.get_qos_proportion
def GstVideo.VideoDecoder.get_qos_proportion (self):
#python wrapper for 'gst_video_decoder_get_qos_proportion'
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
a GstVideo.VideoDecoder current QoS proportion, or None
The current QoS proportion.
Since : 1.0.3
gst_video_decoder_have_frame
GstFlowReturn gst_video_decoder_have_frame (GstVideoDecoder * decoder)
Gathers all data collected for currently parsed frame, gathers corresponding metadata and passes it along for further processing, i.e. handle_frame.
Parameters:
decoder
–
GstVideo.VideoDecoder.prototype.have_frame
function GstVideo.VideoDecoder.prototype.have_frame(): {
// javascript wrapper for 'gst_video_decoder_have_frame'
}
Gathers all data collected for currently parsed frame, gathers corresponding metadata and passes it along for further processing, i.e. handle_frame.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
GstVideo.VideoDecoder.have_frame
def GstVideo.VideoDecoder.have_frame (self):
#python wrapper for 'gst_video_decoder_have_frame'
Gathers all data collected for currently parsed frame, gathers corresponding metadata and passes it along for further processing, i.e. handle_frame.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
gst_video_decoder_merge_tags
gst_video_decoder_merge_tags (GstVideoDecoder * decoder, const GstTagList * tags, GstTagMergeMode mode)
Sets the audio decoder tags and how they should be merged with any upstream stream tags. This will override any tags previously-set with gst_audio_decoder_merge_tags.
Note that this is provided for convenience, and the subclass is not required to use this and can still do tag handling on its own.
MT safe.
Parameters:
decoder
–
tags
(
[allow-none]
)
–
a GstTagList to merge, or NULL to unset previously-set tags
mode
–
the GstTagMergeMode to use, usually GST_TAG_MERGE_REPLACE
GstVideo.VideoDecoder.prototype.merge_tags
function GstVideo.VideoDecoder.prototype.merge_tags(tags: Gst.TagList, mode: Gst.TagMergeMode): {
// javascript wrapper for 'gst_video_decoder_merge_tags'
}
Sets the audio decoder tags and how they should be merged with any upstream stream tags. This will override any tags previously-set with GstAudio.AudioDecoder.prototype.merge_tags.
Note that this is provided for convenience, and the subclass is not required to use this and can still do tag handling on its own.
MT safe.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
tags
(
Gst.TagList
)
–
a Gst.TagList to merge, or NULL to unset previously-set tags
mode
(
Gst.TagMergeMode
)
–
the Gst.TagMergeMode to use, usually Gst.TagMergeMode.REPLACE
GstVideo.VideoDecoder.merge_tags
def GstVideo.VideoDecoder.merge_tags (self, tags, mode):
#python wrapper for 'gst_video_decoder_merge_tags'
Sets the audio decoder tags and how they should be merged with any upstream stream tags. This will override any tags previously-set with GstAudio.AudioDecoder.merge_tags.
Note that this is provided for convenience, and the subclass is not required to use this and can still do tag handling on its own.
MT safe.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
tags
(
Gst.TagList
)
–
a Gst.TagList to merge, or NULL to unset previously-set tags
mode
(
Gst.TagMergeMode
)
–
the Gst.TagMergeMode to use, usually Gst.TagMergeMode.REPLACE
gst_video_decoder_negotiate
gboolean gst_video_decoder_negotiate (GstVideoDecoder * decoder)
Negotiate with downstream elements to currently configured GstVideoCodecState. Unmark GST_PAD_FLAG_NEED_RECONFIGURE in any case. But mark it again if negotiate fails.
Parameters:
decoder
–
GstVideo.VideoDecoder.prototype.negotiate
function GstVideo.VideoDecoder.prototype.negotiate(): {
// javascript wrapper for 'gst_video_decoder_negotiate'
}
Negotiate with downstream elements to currently configured GstVideo.VideoCodecState. Unmark GST_PAD_FLAG_NEED_RECONFIGURE in any case. But mark it again if negotiate fails.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
GstVideo.VideoDecoder.negotiate
def GstVideo.VideoDecoder.negotiate (self):
#python wrapper for 'gst_video_decoder_negotiate'
Negotiate with downstream elements to currently configured GstVideo.VideoCodecState. Unmark GST_PAD_FLAG_NEED_RECONFIGURE in any case. But mark it again if negotiate fails.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
gst_video_decoder_proxy_getcaps
GstCaps * gst_video_decoder_proxy_getcaps (GstVideoDecoder * decoder, GstCaps * caps, GstCaps * filter)
Returns caps that express caps (or sink template caps if caps == NULL) restricted to resolution/format/... combinations supported by downstream elements.
Parameters:
decoder
–
caps
(
[allow-none]
)
–
initial caps
filter
(
[allow-none]
)
–
filter caps
a GstCaps owned by caller
Since : 1.6
GstVideo.VideoDecoder.prototype.proxy_getcaps
function GstVideo.VideoDecoder.prototype.proxy_getcaps(caps: Gst.Caps, filter: Gst.Caps): {
// javascript wrapper for 'gst_video_decoder_proxy_getcaps'
}
Returns caps that express caps (or sink template caps if caps == NULL) restricted to resolution/format/... combinations supported by downstream elements.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
caps
(
Gst.Caps
)
–
initial caps
filter
(
Gst.Caps
)
–
filter caps
Since : 1.6
GstVideo.VideoDecoder.proxy_getcaps
def GstVideo.VideoDecoder.proxy_getcaps (self, caps, filter):
#python wrapper for 'gst_video_decoder_proxy_getcaps'
Returns caps that express caps (or sink template caps if caps == NULL) restricted to resolution/format/... combinations supported by downstream elements.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
caps
(
Gst.Caps
)
–
initial caps
filter
(
Gst.Caps
)
–
filter caps
Since : 1.6
gst_video_decoder_release_frame
gst_video_decoder_release_frame (GstVideoDecoder * dec, GstVideoCodecFrame * frame)
Similar to gst_video_decoder_drop_frame, but simply releases frame without any processing other than removing it from list of pending frames, after which it is considered finished and released.
Since : 1.2.2
GstVideo.VideoDecoder.prototype.release_frame
function GstVideo.VideoDecoder.prototype.release_frame(frame: GstVideo.VideoCodecFrame): {
// javascript wrapper for 'gst_video_decoder_release_frame'
}
Similar to GstVideo.VideoDecoder.prototype.drop_frame, but simply releases frame without any processing other than removing it from list of pending frames, after which it is considered finished and released.
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
the GstVideo.VideoCodecFrame to release
Since : 1.2.2
GstVideo.VideoDecoder.release_frame
def GstVideo.VideoDecoder.release_frame (self, frame):
#python wrapper for 'gst_video_decoder_release_frame'
Similar to GstVideo.VideoDecoder.drop_frame, but simply releases frame without any processing other than removing it from list of pending frames, after which it is considered finished and released.
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
the GstVideo.VideoCodecFrame to release
Since : 1.2.2
gst_video_decoder_set_estimate_rate
gst_video_decoder_set_estimate_rate (GstVideoDecoder * dec, gboolean enabled)
Allows baseclass to perform byte to time estimated conversion.
GstVideo.VideoDecoder.prototype.set_estimate_rate
function GstVideo.VideoDecoder.prototype.set_estimate_rate(enabled: Number): {
// javascript wrapper for 'gst_video_decoder_set_estimate_rate'
}
Allows baseclass to perform byte to time estimated conversion.
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
enabled
(
Number
)
–
whether to enable byte to time conversion
GstVideo.VideoDecoder.set_estimate_rate
def GstVideo.VideoDecoder.set_estimate_rate (self, enabled):
#python wrapper for 'gst_video_decoder_set_estimate_rate'
Allows baseclass to perform byte to time estimated conversion.
Parameters:
dec
(
GstVideo.VideoDecoder
)
–
enabled
(
bool
)
–
whether to enable byte to time conversion
gst_video_decoder_set_interlaced_output_state
GstVideoCodecState * gst_video_decoder_set_interlaced_output_state (GstVideoDecoder * decoder, GstVideoFormat fmt, GstVideoInterlaceMode interlace_mode, guint width, guint height, GstVideoCodecState * reference)
Same as gst_video_decoder_set_output_state() but also allows you to also set the interlacing mode.
Parameters:
decoder
–
fmt
–
interlace_mode
–
width
–
The width in pixels
height
–
The height in pixels
reference
(
[allow-none]
[transfer: none]
)
–
An optional reference GstVideoCodecState
the newly configured output state.
Since : 1.16.
GstVideo.VideoDecoder.prototype.set_interlaced_output_state
function GstVideo.VideoDecoder.prototype.set_interlaced_output_state(fmt: GstVideo.VideoFormat, interlace_mode: GstVideo.VideoInterlaceMode, width: Number, height: Number, reference: GstVideo.VideoCodecState): {
// javascript wrapper for 'gst_video_decoder_set_interlaced_output_state'
}
Same as GstVideo.VideoDecoder.prototype.set_output_state() but also allows you to also set the interlacing mode.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
fmt
(
GstVideo.VideoFormat
)
–
interlace_mode
(
GstVideo.VideoInterlaceMode
)
–
width
(
Number
)
–
The width in pixels
height
(
Number
)
–
The height in pixels
reference
(
GstVideo.VideoCodecState
)
–
An optional reference GstVideo.VideoCodecState
the newly configured output state.
Since : 1.16.
GstVideo.VideoDecoder.set_interlaced_output_state
def GstVideo.VideoDecoder.set_interlaced_output_state (self, fmt, interlace_mode, width, height, reference):
#python wrapper for 'gst_video_decoder_set_interlaced_output_state'
Same as GstVideo.VideoDecoder.set_output_state() but also allows you to also set the interlacing mode.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
fmt
(
GstVideo.VideoFormat
)
–
interlace_mode
(
GstVideo.VideoInterlaceMode
)
–
width
(
int
)
–
The width in pixels
height
(
int
)
–
The height in pixels
reference
(
GstVideo.VideoCodecState
)
–
An optional reference GstVideo.VideoCodecState
the newly configured output state.
Since : 1.16.
gst_video_decoder_set_latency
gst_video_decoder_set_latency (GstVideoDecoder * decoder, GstClockTime min_latency, GstClockTime max_latency)
Lets GstVideoDecoder sub-classes tell the baseclass what the decoder latency is. Will also post a LATENCY message on the bus so the pipeline can reconfigure its global latency.
GstVideo.VideoDecoder.prototype.set_latency
function GstVideo.VideoDecoder.prototype.set_latency(min_latency: Number, max_latency: Number): {
// javascript wrapper for 'gst_video_decoder_set_latency'
}
Lets GstVideo.VideoDecoder sub-classes tell the baseclass what the decoder latency is. Will also post a LATENCY message on the bus so the pipeline can reconfigure its global latency.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
min_latency
(
Number
)
–
minimum latency
max_latency
(
Number
)
–
maximum latency
GstVideo.VideoDecoder.set_latency
def GstVideo.VideoDecoder.set_latency (self, min_latency, max_latency):
#python wrapper for 'gst_video_decoder_set_latency'
Lets GstVideo.VideoDecoder sub-classes tell the baseclass what the decoder latency is. Will also post a LATENCY message on the bus so the pipeline can reconfigure its global latency.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
min_latency
(
int
)
–
minimum latency
max_latency
(
int
)
–
maximum latency
gst_video_decoder_set_max_errors
gst_video_decoder_set_max_errors (GstVideoDecoder * dec, gint num)
Sets numbers of tolerated decoder errors, where a tolerated one is then only warned about, but more than tolerated will lead to fatal error. You can set -1 for never returning fatal errors. Default is set to GST_VIDEO_DECODER_MAX_ERRORS.
The '-1' option was added in 1.4
GstVideo.VideoDecoder.prototype.set_max_errors
function GstVideo.VideoDecoder.prototype.set_max_errors(num: Number): {
// javascript wrapper for 'gst_video_decoder_set_max_errors'
}
Sets numbers of tolerated decoder errors, where a tolerated one is then only warned about, but more than tolerated will lead to fatal error. You can set -1 for never returning fatal errors. Default is set to GST_VIDEO_DECODER_MAX_ERRORS.
The '-1' option was added in 1.4
GstVideo.VideoDecoder.set_max_errors
def GstVideo.VideoDecoder.set_max_errors (self, num):
#python wrapper for 'gst_video_decoder_set_max_errors'
Sets numbers of tolerated decoder errors, where a tolerated one is then only warned about, but more than tolerated will lead to fatal error. You can set -1 for never returning fatal errors. Default is set to GST_VIDEO_DECODER_MAX_ERRORS.
The '-1' option was added in 1.4
gst_video_decoder_set_needs_format
gst_video_decoder_set_needs_format (GstVideoDecoder * dec, gboolean enabled)
Configures decoder format needs. If enabled, subclass needs to be negotiated with format caps before it can process any data. It will then never be handed any data before it has been configured. Otherwise, it might be handed data without having been configured and is then expected being able to do so either by default or based on the input data.
Since : 1.4
GstVideo.VideoDecoder.prototype.set_needs_format
function GstVideo.VideoDecoder.prototype.set_needs_format(enabled: Number): {
// javascript wrapper for 'gst_video_decoder_set_needs_format'
}
Configures decoder format needs. If enabled, subclass needs to be negotiated with format caps before it can process any data. It will then never be handed any data before it has been configured. Otherwise, it might be handed data without having been configured and is then expected being able to do so either by default or based on the input data.
Since : 1.4
GstVideo.VideoDecoder.set_needs_format
def GstVideo.VideoDecoder.set_needs_format (self, enabled):
#python wrapper for 'gst_video_decoder_set_needs_format'
Configures decoder format needs. If enabled, subclass needs to be negotiated with format caps before it can process any data. It will then never be handed any data before it has been configured. Otherwise, it might be handed data without having been configured and is then expected being able to do so either by default or based on the input data.
Since : 1.4
gst_video_decoder_set_output_state
GstVideoCodecState * gst_video_decoder_set_output_state (GstVideoDecoder * decoder, GstVideoFormat fmt, guint width, guint height, GstVideoCodecState * reference)
Creates a new GstVideoCodecState with the specified fmt, width and height as the output state for the decoder. Any previously set output state on decoder will be replaced by the newly created one.
If the subclass wishes to copy over existing fields (like pixel aspec ratio, or framerate) from an existing GstVideoCodecState, it can be provided as a reference.
If the subclass wishes to override some fields from the output state (like pixel-aspect-ratio or framerate) it can do so on the returned GstVideoCodecState.
The new output state will only take effect (set on pads and buffers) starting from the next call to gst_video_decoder_finish_frame().
Parameters:
decoder
–
fmt
–
width
–
The width in pixels
height
–
The height in pixels
reference
(
[allow-none]
[transfer: none]
)
–
An optional reference GstVideoCodecState
the newly configured output state.
GstVideo.VideoDecoder.prototype.set_output_state
function GstVideo.VideoDecoder.prototype.set_output_state(fmt: GstVideo.VideoFormat, width: Number, height: Number, reference: GstVideo.VideoCodecState): {
// javascript wrapper for 'gst_video_decoder_set_output_state'
}
Creates a new GstVideo.VideoCodecState with the specified fmt, width and height as the output state for the decoder. Any previously set output state on decoder will be replaced by the newly created one.
If the subclass wishes to copy over existing fields (like pixel aspec ratio, or framerate) from an existing GstVideo.VideoCodecState, it can be provided as a reference.
If the subclass wishes to override some fields from the output state (like pixel-aspect-ratio or framerate) it can do so on the returned GstVideo.VideoCodecState.
The new output state will only take effect (set on pads and buffers) starting from the next call to GstVideo.VideoDecoder.prototype.finish_frame().
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
fmt
(
GstVideo.VideoFormat
)
–
width
(
Number
)
–
The width in pixels
height
(
Number
)
–
The height in pixels
reference
(
GstVideo.VideoCodecState
)
–
An optional reference GstVideo.VideoCodecState
the newly configured output state.
GstVideo.VideoDecoder.set_output_state
def GstVideo.VideoDecoder.set_output_state (self, fmt, width, height, reference):
#python wrapper for 'gst_video_decoder_set_output_state'
Creates a new GstVideo.VideoCodecState with the specified fmt, width and height as the output state for the decoder. Any previously set output state on decoder will be replaced by the newly created one.
If the subclass wishes to copy over existing fields (like pixel aspec ratio, or framerate) from an existing GstVideo.VideoCodecState, it can be provided as a reference.
If the subclass wishes to override some fields from the output state (like pixel-aspect-ratio or framerate) it can do so on the returned GstVideo.VideoCodecState.
The new output state will only take effect (set on pads and buffers) starting from the next call to GstVideo.VideoDecoder.finish_frame().
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
fmt
(
GstVideo.VideoFormat
)
–
width
(
int
)
–
The width in pixels
height
(
int
)
–
The height in pixels
reference
(
GstVideo.VideoCodecState
)
–
An optional reference GstVideo.VideoCodecState
the newly configured output state.
gst_video_decoder_set_packetized
gst_video_decoder_set_packetized (GstVideoDecoder * decoder, gboolean packetized)
Allows baseclass to consider input data as packetized or not. If the input is packetized, then the parse method will not be called.
Parameters:
decoder
–
packetized
–
whether the input data should be considered as packetized.
GstVideo.VideoDecoder.prototype.set_packetized
function GstVideo.VideoDecoder.prototype.set_packetized(packetized: Number): {
// javascript wrapper for 'gst_video_decoder_set_packetized'
}
Allows baseclass to consider input data as packetized or not. If the input is packetized, then the parse method will not be called.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
packetized
(
Number
)
–
whether the input data should be considered as packetized.
GstVideo.VideoDecoder.set_packetized
def GstVideo.VideoDecoder.set_packetized (self, packetized):
#python wrapper for 'gst_video_decoder_set_packetized'
Allows baseclass to consider input data as packetized or not. If the input is packetized, then the parse method will not be called.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
packetized
(
bool
)
–
whether the input data should be considered as packetized.
gst_video_decoder_set_use_default_pad_acceptcaps
gst_video_decoder_set_use_default_pad_acceptcaps (GstVideoDecoder * decoder, gboolean use)
Lets GstVideoDecoder sub-classes decide if they want the sink pad to use the default pad query handler to reply to accept-caps queries.
By setting this to true it is possible to further customize the default handler with GST_PAD_SET_ACCEPT_INTERSECT and GST_PAD_SET_ACCEPT_TEMPLATE
Parameters:
decoder
–
use
–
if the default pad accept-caps query handling should be used
Since : 1.6
GstVideo.VideoDecoder.prototype.set_use_default_pad_acceptcaps
function GstVideo.VideoDecoder.prototype.set_use_default_pad_acceptcaps(use: Number): {
// javascript wrapper for 'gst_video_decoder_set_use_default_pad_acceptcaps'
}
Lets GstVideo.VideoDecoder sub-classes decide if they want the sink pad to use the default pad query handler to reply to accept-caps queries.
By setting this to true it is possible to further customize the default handler with GST_PAD_SET_ACCEPT_INTERSECT (not introspectable) and GST_PAD_SET_ACCEPT_TEMPLATE (not introspectable)
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
use
(
Number
)
–
if the default pad accept-caps query handling should be used
Since : 1.6
GstVideo.VideoDecoder.set_use_default_pad_acceptcaps
def GstVideo.VideoDecoder.set_use_default_pad_acceptcaps (self, use):
#python wrapper for 'gst_video_decoder_set_use_default_pad_acceptcaps'
Lets GstVideo.VideoDecoder sub-classes decide if they want the sink pad to use the default pad query handler to reply to accept-caps queries.
By setting this to true it is possible to further customize the default handler with GST_PAD_SET_ACCEPT_INTERSECT (not introspectable) and GST_PAD_SET_ACCEPT_TEMPLATE (not introspectable)
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
use
(
bool
)
–
if the default pad accept-caps query handling should be used
Since : 1.6
Properties
max-errors
“max-errors” gint
Maximum number of tolerated consecutive decode errors. See gst_video_decoder_set_max_errors for more details.
Flags : Read / Write
max-errors
“max-errors” Number
Maximum number of tolerated consecutive decode errors. See GstVideo.VideoDecoder.prototype.set_max_errors for more details.
Flags : Read / Write
max_errors
“self.props.max_errors” int
Maximum number of tolerated consecutive decode errors. See GstVideo.VideoDecoder.set_max_errors for more details.
Flags : Read / Write
qos
“qos” gboolean
If set to TRUE the decoder will handle QoS events received from downstream elements. This includes dropping output frames which are detected as late using the metrics reported by those events.
Flags : Read / Write
Virtual Methods
close
gboolean close (GstVideoDecoder * decoder)
Optional. Called when the element changes to GST_STATE_NULL. Allows closing external resources.
Parameters:
decoder
–
close
function close(decoder: GstVideo.VideoDecoder): {
// javascript implementation of the 'close' virtual method
}
Optional. Called when the element changes to GST_STATE_NULL. Allows closing external resources.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
close
def close (decoder):
#python implementation of the 'close' virtual method
Optional. Called when the element changes to GST_STATE_NULL. Allows closing external resources.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
decide_allocation
gboolean decide_allocation (GstVideoDecoder * decoder, GstQuery * query)
Optional. Setup the allocation parameters for allocating output buffers. The passed in query contains the result of the downstream allocation query. Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
–
query
–
decide_allocation
function decide_allocation(decoder: GstVideo.VideoDecoder, query: Gst.Query): {
// javascript implementation of the 'decide_allocation' virtual method
}
Optional. Setup the allocation parameters for allocating output buffers. The passed in query contains the result of the downstream allocation query. Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
query
(
Gst.Query
)
–
decide_allocation
def decide_allocation (decoder, query):
#python implementation of the 'decide_allocation' virtual method
Optional. Setup the allocation parameters for allocating output buffers. The passed in query contains the result of the downstream allocation query. Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
query
(
Gst.Query
)
–
drain
GstFlowReturn drain (GstVideoDecoder * decoder)
Optional. Called to request subclass to decode any data it can at this point, but that more data may arrive after. (e.g. at segment end). Sub-classes should be prepared to handle new data afterward, or seamless segment processing will break. Since: 1.6
Parameters:
decoder
–
drain
function drain(decoder: GstVideo.VideoDecoder): {
// javascript implementation of the 'drain' virtual method
}
Optional. Called to request subclass to decode any data it can at this point, but that more data may arrive after. (e.g. at segment end). Sub-classes should be prepared to handle new data afterward, or seamless segment processing will break. Since: 1.6
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
drain
def drain (decoder):
#python implementation of the 'drain' virtual method
Optional. Called to request subclass to decode any data it can at this point, but that more data may arrive after. (e.g. at segment end). Sub-classes should be prepared to handle new data afterward, or seamless segment processing will break. Since: 1.6
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
finish
GstFlowReturn finish (GstVideoDecoder * decoder)
Optional. Called to request subclass to dispatch any pending remaining data at EOS. Sub-classes can refuse to decode new data after.
Parameters:
decoder
–
finish
function finish(decoder: GstVideo.VideoDecoder): {
// javascript implementation of the 'finish' virtual method
}
Optional. Called to request subclass to dispatch any pending remaining data at EOS. Sub-classes can refuse to decode new data after.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
finish
def finish (decoder):
#python implementation of the 'finish' virtual method
Optional. Called to request subclass to dispatch any pending remaining data at EOS. Sub-classes can refuse to decode new data after.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
flush
gboolean flush (GstVideoDecoder * decoder)
Optional. Flush all remaining data from the decoder without pushing it downstream. Since: 1.2
Parameters:
decoder
–
flush
function flush(decoder: GstVideo.VideoDecoder): {
// javascript implementation of the 'flush' virtual method
}
Optional. Flush all remaining data from the decoder without pushing it downstream. Since: 1.2
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
flush
def flush (decoder):
#python implementation of the 'flush' virtual method
Optional. Flush all remaining data from the decoder without pushing it downstream. Since: 1.2
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
getcaps
GstCaps * getcaps (GstVideoDecoder * decoder, GstCaps * filter)
Optional. Allows for a custom sink getcaps implementation. If not implemented, default returns gst_video_decoder_proxy_getcaps applied to sink template caps.
Parameters:
decoder
–
filter
–
getcaps
function getcaps(decoder: GstVideo.VideoDecoder, filter: Gst.Caps): {
// javascript implementation of the 'getcaps' virtual method
}
Optional. Allows for a custom sink getcaps implementation. If not implemented, default returns gst_video_decoder_proxy_getcaps applied to sink template caps.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
filter
(
Gst.Caps
)
–
getcaps
def getcaps (decoder, filter):
#python implementation of the 'getcaps' virtual method
Optional. Allows for a custom sink getcaps implementation. If not implemented, default returns gst_video_decoder_proxy_getcaps applied to sink template caps.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
filter
(
Gst.Caps
)
–
handle_frame
GstFlowReturn handle_frame (GstVideoDecoder * decoder, GstVideoCodecFrame * frame)
Provides input data frame to subclass.
Parameters:
decoder
–
frame
–
handle_frame
function handle_frame(decoder: GstVideo.VideoDecoder, frame: GstVideo.VideoCodecFrame): {
// javascript implementation of the 'handle_frame' virtual method
}
Provides input data frame to subclass.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
handle_frame
def handle_frame (decoder, frame):
#python implementation of the 'handle_frame' virtual method
Provides input data frame to subclass.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
negotiate
gboolean negotiate (GstVideoDecoder * decoder)
Optional. Negotiate with downstream and configure buffer pools, etc. Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
–
negotiate
function negotiate(decoder: GstVideo.VideoDecoder): {
// javascript implementation of the 'negotiate' virtual method
}
Optional. Negotiate with downstream and configure buffer pools, etc. Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
negotiate
def negotiate (decoder):
#python implementation of the 'negotiate' virtual method
Optional. Negotiate with downstream and configure buffer pools, etc. Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
open
gboolean open (GstVideoDecoder * decoder)
Optional. Called when the element changes to GST_STATE_READY. Allows opening external resources.
Parameters:
decoder
–
open
function open(decoder: GstVideo.VideoDecoder): {
// javascript implementation of the 'open' virtual method
}
Optional. Called when the element changes to GST_STATE_READY. Allows opening external resources.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
open
def open (decoder):
#python implementation of the 'open' virtual method
Optional. Called when the element changes to GST_STATE_READY. Allows opening external resources.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
parse
GstFlowReturn parse (GstVideoDecoder * decoder, GstVideoCodecFrame * frame, GstAdapter * adapter, gboolean at_eos)
Required for non-packetized input. Allows chopping incoming data into manageable units (frames) for subsequent decoding.
Parameters:
decoder
–
frame
–
adapter
–
at_eos
–
parse
function parse(decoder: GstVideo.VideoDecoder, frame: GstVideo.VideoCodecFrame, adapter: GstBase.Adapter, at_eos: Number): {
// javascript implementation of the 'parse' virtual method
}
Required for non-packetized input. Allows chopping incoming data into manageable units (frames) for subsequent decoding.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
adapter
(
GstBase.Adapter
)
–
at_eos
(
Number
)
–
parse
def parse (decoder, frame, adapter, at_eos):
#python implementation of the 'parse' virtual method
Required for non-packetized input. Allows chopping incoming data into manageable units (frames) for subsequent decoding.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
adapter
(
GstBase.Adapter
)
–
at_eos
(
bool
)
–
propose_allocation
gboolean propose_allocation (GstVideoDecoder * decoder, GstQuery * query)
Optional. Propose buffer allocation parameters for upstream elements. Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
–
query
–
propose_allocation
function propose_allocation(decoder: GstVideo.VideoDecoder, query: Gst.Query): {
// javascript implementation of the 'propose_allocation' virtual method
}
Optional. Propose buffer allocation parameters for upstream elements. Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
query
(
Gst.Query
)
–
propose_allocation
def propose_allocation (decoder, query):
#python implementation of the 'propose_allocation' virtual method
Optional. Propose buffer allocation parameters for upstream elements. Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
query
(
Gst.Query
)
–
reset
gboolean reset (GstVideoDecoder * decoder, gboolean hard)
Optional. Allows subclass (decoder) to perform post-seek semantics reset. Deprecated.
Parameters:
decoder
–
hard
–
reset
function reset(decoder: GstVideo.VideoDecoder, hard: Number): {
// javascript implementation of the 'reset' virtual method
}
Optional. Allows subclass (decoder) to perform post-seek semantics reset. Deprecated.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
hard
(
Number
)
–
reset
def reset (decoder, hard):
#python implementation of the 'reset' virtual method
Optional. Allows subclass (decoder) to perform post-seek semantics reset. Deprecated.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
hard
(
bool
)
–
set_format
gboolean set_format (GstVideoDecoder * decoder, GstVideoCodecState * state)
Notifies subclass of incoming data format (caps).
Parameters:
decoder
–
state
–
set_format
function set_format(decoder: GstVideo.VideoDecoder, state: GstVideo.VideoCodecState): {
// javascript implementation of the 'set_format' virtual method
}
Notifies subclass of incoming data format (caps).
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
state
(
GstVideo.VideoCodecState
)
–
set_format
def set_format (decoder, state):
#python implementation of the 'set_format' virtual method
Notifies subclass of incoming data format (caps).
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
state
(
GstVideo.VideoCodecState
)
–
sink_event
gboolean sink_event (GstVideoDecoder * decoder, GstEvent * event)
Optional. Event handler on the sink pad. This function should return TRUE if the event was handled and should be discarded (i.e. not unref'ed). Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
–
event
–
sink_event
function sink_event(decoder: GstVideo.VideoDecoder, event: Gst.Event): {
// javascript implementation of the 'sink_event' virtual method
}
Optional. Event handler on the sink pad. This function should return TRUE if the event was handled and should be discarded (i.e. not unref'ed). Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
event
(
Gst.Event
)
–
sink_event
def sink_event (decoder, event):
#python implementation of the 'sink_event' virtual method
Optional. Event handler on the sink pad. This function should return TRUE if the event was handled and should be discarded (i.e. not unref'ed). Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
event
(
Gst.Event
)
–
sink_query
gboolean sink_query (GstVideoDecoder * decoder, GstQuery * query)
Optional. Query handler on the sink pad. This function should return TRUE if the query could be performed. Subclasses should chain up to the parent implementation to invoke the default handler. Since: 1.4
Parameters:
decoder
–
query
–
sink_query
function sink_query(decoder: GstVideo.VideoDecoder, query: Gst.Query): {
// javascript implementation of the 'sink_query' virtual method
}
Optional. Query handler on the sink pad. This function should return TRUE if the query could be performed. Subclasses should chain up to the parent implementation to invoke the default handler. Since: 1.4
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
query
(
Gst.Query
)
–
sink_query
def sink_query (decoder, query):
#python implementation of the 'sink_query' virtual method
Optional. Query handler on the sink pad. This function should return TRUE if the query could be performed. Subclasses should chain up to the parent implementation to invoke the default handler. Since: 1.4
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
query
(
Gst.Query
)
–
src_event
gboolean src_event (GstVideoDecoder * decoder, GstEvent * event)
Optional. Event handler on the source pad. This function should return TRUE if the event was handled and should be discarded (i.e. not unref'ed). Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
–
event
–
src_event
function src_event(decoder: GstVideo.VideoDecoder, event: Gst.Event): {
// javascript implementation of the 'src_event' virtual method
}
Optional. Event handler on the source pad. This function should return TRUE if the event was handled and should be discarded (i.e. not unref'ed). Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
event
(
Gst.Event
)
–
src_event
def src_event (decoder, event):
#python implementation of the 'src_event' virtual method
Optional. Event handler on the source pad. This function should return TRUE if the event was handled and should be discarded (i.e. not unref'ed). Subclasses should chain up to the parent implementation to invoke the default handler.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
event
(
Gst.Event
)
–
src_query
gboolean src_query (GstVideoDecoder * decoder, GstQuery * query)
Optional. Query handler on the source pad. This function should return TRUE if the query could be performed. Subclasses should chain up to the parent implementation to invoke the default handler. Since: 1.4
Parameters:
decoder
–
query
–
src_query
function src_query(decoder: GstVideo.VideoDecoder, query: Gst.Query): {
// javascript implementation of the 'src_query' virtual method
}
Optional. Query handler on the source pad. This function should return TRUE if the query could be performed. Subclasses should chain up to the parent implementation to invoke the default handler. Since: 1.4
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
query
(
Gst.Query
)
–
src_query
def src_query (decoder, query):
#python implementation of the 'src_query' virtual method
Optional. Query handler on the source pad. This function should return TRUE if the query could be performed. Subclasses should chain up to the parent implementation to invoke the default handler. Since: 1.4
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
query
(
Gst.Query
)
–
start
gboolean start (GstVideoDecoder * decoder)
Optional. Called when the element starts processing. Allows opening external resources.
Parameters:
decoder
–
start
function start(decoder: GstVideo.VideoDecoder): {
// javascript implementation of the 'start' virtual method
}
Optional. Called when the element starts processing. Allows opening external resources.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
start
def start (decoder):
#python implementation of the 'start' virtual method
Optional. Called when the element starts processing. Allows opening external resources.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
stop
gboolean stop (GstVideoDecoder * decoder)
Optional. Called when the element stops processing. Allows closing external resources.
Parameters:
decoder
–
stop
function stop(decoder: GstVideo.VideoDecoder): {
// javascript implementation of the 'stop' virtual method
}
Optional. Called when the element stops processing. Allows closing external resources.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
stop
def stop (decoder):
#python implementation of the 'stop' virtual method
Optional. Called when the element stops processing. Allows closing external resources.
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
transform_meta
gboolean transform_meta (GstVideoDecoder * decoder, GstVideoCodecFrame * frame, GstMeta * meta)
Optional. Transform the metadata on the input buffer to the output buffer. By default this method is copies all meta without tags and meta with only the "video" tag. subclasses can implement this method and return TRUE if the metadata is to be copied. Since: 1.6
Parameters:
decoder
–
frame
–
meta
–
transform_meta
function transform_meta(decoder: GstVideo.VideoDecoder, frame: GstVideo.VideoCodecFrame, meta: Gst.Meta): {
// javascript implementation of the 'transform_meta' virtual method
}
Optional. Transform the metadata on the input buffer to the output buffer. By default this method is copies all meta without tags and meta with only the "video" tag. subclasses can implement this method and return TRUE if the metadata is to be copied. Since: 1.6
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
meta
(
Gst.Meta
)
–
transform_meta
def transform_meta (decoder, frame, meta):
#python implementation of the 'transform_meta' virtual method
Optional. Transform the metadata on the input buffer to the output buffer. By default this method is copies all meta without tags and meta with only the "video" tag. subclasses can implement this method and return TRUE if the metadata is to be copied. Since: 1.6
Parameters:
decoder
(
GstVideo.VideoDecoder
)
–
frame
(
GstVideo.VideoCodecFrame
)
–
meta
(
Gst.Meta
)
–
Function Macros
GST_VIDEO_DECODER_CAST
#define GST_VIDEO_DECODER_CAST(obj) ((GstVideoDecoder *)(obj))
GST_VIDEO_DECODER_ERROR
#define GST_VIDEO_DECODER_ERROR(el, w, domain, code, text, debug, ret) \ G_STMT_START { \ gchar *__txt = _gst_element_error_printf text; \ gchar *__dbg = _gst_element_error_printf debug; \ GstVideoDecoder *__dec = GST_VIDEO_DECODER (el); \ ret = _gst_video_decoder_error (__dec, w, GST_ ## domain ## _ERROR, \ GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \ GST_FUNCTION, __LINE__); \ } G_STMT_END
Utility function that video decoder elements can use in case they encountered a data processing error that may be fatal for the current "data unit" but need not prevent subsequent decoding. Such errors are counted and if there are too many, as configured in the context's max_errors, the pipeline will post an error message and the application will be requested to stop further media processing. Otherwise, it is considered a "glitch" and only a warning is logged. In either case, ret is set to the proper value to return to upstream/caller (indicating either GST_FLOW_ERROR or GST_FLOW_OK).
Parameters:
el
–
the base video decoder element that generates the error
w
–
element defined weight of the error, added to error count
domain
–
like CORE, LIBRARY, RESOURCE or STREAM (see Core Library-GstGError)
code
–
error code defined for that domain (see Core Library-GstGError)
text
–
the message to display (format string and args enclosed in parentheses)
debug
–
debugging information for the message (format string and args enclosed in parentheses)
ret
–
variable to receive return value
GST_VIDEO_DECODER_INPUT_SEGMENT
#define GST_VIDEO_DECODER_INPUT_SEGMENT(obj) (GST_VIDEO_DECODER_CAST (obj)->input_segment)
Gives the segment of the element.
Parameters:
obj
–
base decoder instance
GST_VIDEO_DECODER_OUTPUT_SEGMENT
#define GST_VIDEO_DECODER_OUTPUT_SEGMENT(obj) (GST_VIDEO_DECODER_CAST (obj)->output_segment)
Gives the segment of the element.
Parameters:
obj
–
base decoder instance
GST_VIDEO_DECODER_SINK_PAD
#define GST_VIDEO_DECODER_SINK_PAD(obj) (((GstVideoDecoder *) (obj))->sinkpad)
Gives the pointer to the sink GstPad object of the element.
Parameters:
obj
–
GST_VIDEO_DECODER_SRC_PAD
#define GST_VIDEO_DECODER_SRC_PAD(obj) (((GstVideoDecoder *) (obj))->srcpad)
Gives the pointer to the source GstPad object of the element.
Parameters:
obj
–
GST_VIDEO_DECODER_STREAM_LOCK
#define GST_VIDEO_DECODER_STREAM_LOCK(decoder) g_rec_mutex_lock (&GST_VIDEO_DECODER (decoder)->stream_lock)
Obtain a lock to protect the decoder function from concurrent access.
Parameters:
decoder
–
video decoder instance
GST_VIDEO_DECODER_STREAM_UNLOCK
#define GST_VIDEO_DECODER_STREAM_UNLOCK(decoder) g_rec_mutex_unlock (&GST_VIDEO_DECODER (decoder)->stream_lock)
Release the lock that protects the decoder function from concurrent access.
Parameters:
decoder
–
video decoder instance
Constants
GST_TYPE_VIDEO_DECODER
#define GST_TYPE_VIDEO_DECODER \ (gst_video_decoder_get_type())
GST_VIDEO_DECODER_FLOW_NEED_DATA
#define GST_VIDEO_DECODER_FLOW_NEED_DATA GST_FLOW_CUSTOM_SUCCESS
Returned while parsing to indicate more data is needed.
GST_VIDEO_DECODER_MAX_ERRORS
#define GST_VIDEO_DECODER_MAX_ERRORS 10
Default maximum number of errors tolerated before signaling error.
GstVideo.VIDEO_DECODER_MAX_ERRORS
Default maximum number of errors tolerated before signaling error.
GstVideo.VIDEO_DECODER_MAX_ERRORS
Default maximum number of errors tolerated before signaling error.
GST_VIDEO_DECODER_SINK_NAME
#define GST_VIDEO_DECODER_SINK_NAME "sink"
The name of the templates for the sink pad.
GstVideo.VIDEO_DECODER_SINK_NAME
The name of the templates for the sink pad.
GstVideo.VIDEO_DECODER_SINK_NAME
The name of the templates for the sink pad.
GST_VIDEO_DECODER_SRC_NAME
#define GST_VIDEO_DECODER_SRC_NAME "src"
The name of the templates for the source pad.
GstVideo.VIDEO_DECODER_SRC_NAME
The name of the templates for the source pad.
GstVideo.VIDEO_DECODER_SRC_NAME
The name of the templates for the source pad.
The results of the search are