If the decoder was not able to decode a frame because insufficient
information was available, e.g. missing sequence or picture header,
then allow the frame to be gracefully dropped without generating
any error.
It is also possible that a frame is not meant to be displayed but
only used as a reference, so dropping that frame is also a valid
operation since GstVideoDecoder base class has extra references to
that GstVideoCodecFrame that needs to be released.
Avoid usage of goto. Simplify decode_step() process to first accumulate all
pending buffers into the GstAdapter, and then parse and decode units from
that input adapter. Stop the process once a frame is fully decoded or an
error occurred.
Make sure we always have a free surface left to use for decoding the
current frame. This means that decode_step() has to return once a frame
gets decoded. If the current adapter contains more buffers with valid
frames, they will get parsed and decoded on subsequent iterations.
Optimize pre-allocation of decoder units, thus avoiding un-necessary
memory reallocations. The heuristic used is that we could have around
one slice unit per macroblock line.
Use a GArray to hold decoder units in a frame, instead of a single-linked
list. This makes 'append' calls faster, but not that much. At least, this
makes things clearer.
Allocate decoder unit earlier in the main parse() function and don't
delegate this task to derived classes. The ultimate purpose is to get
rid of dynamic allocation of decoder units.
Create a new VA context if the encoded surface size changes because we
need to keep the underlying surface pool until the last one was released.
Otherwise, either of the following cases could have happened: (i) release
a VA surface to an inexistent pool, or (ii) release VA surface to an
existing surface pool, but with different size.
Theory of operations: all units marked as "slice" are moved to the "units"
list. Since this list only contains slice data units, the prev_slice pointer
was removed. Besides, we now maintain two extra lists of units to be decoded
before or after slice data units.
In particular, all units in the "pre_units" list will be decoded before
GstVaapiDecoder::start_frame() is called and units in the "post_units"
list will be decoded after GstVaapiDecoder::end_frame() is called.
Maintain decoded surfaces as GstVideoCodecFrame objects instead of
GstVaapiSurfaceProxy objects. The latter will tend to be reduced to
the strict minimum: a context and a surface.
Add new gst_vaapi_decoder_get_frame() function meant to be used with
gst_vaapi_decoder_decode(). The purpose is to return the next decoded
frame as a GstVideoCodecFrame and the associated GstVaapiSurfaceProxy
as the user-data object.
Use standard GstVideoCodecState throughout GstVaapiDecoder and expose
it with a new gst_vaapi_decoder_get_codec_state() function. This makes
it possible to drop picture size (width, height) information, framerate
(fps_n, fps_d) information, pixel aspect ratio (par_n, par_d) information,
and interlace mode (is_interlaced field).
This is a new API with backwards compatibility maintained. In particular,
gst_vaapi_decoder_get_caps() is still available.
Signed-off-by: Sreerenj Balachandran <sreerenj.balachandran@intel.com>
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
Align gst_vaapi_decoder_get_surface() semantics with the rest of the
API. That is, return a GstVaapiDecoderStatus and the decoded surface
as a handle to GstVaapiSurfaceProxy in parameter.
This is an API/ABI change.
Introduce new decoding process whereby a GstVideoCodecFrame is created
first. Next, input stream buffers are accumulated into a GstAdapter,
that is then passed to the _parse() function. The GstVaapiDecoder object
accumulates all parsed units and when a complete frame or field is
detected, that GstVideoCodecFrame is passed to the _decode() function.
Ultimately, the caller receives a GstVaapiSurfaceProxy if decoding
process was successful.
The start_frame() hook is called prior to traversing all decode-units
for decoding. The unit argument represents the first slice in the frame.
Some codecs (e.g. H.264) need to wait for the first slice in order to
determine the actual VA context parameters.
Split decoding process into two steps: (i) parse incoming bitstreams
into simple decoder-units until the frame or field is complete; and
(ii) decode the whole frame or field at once.
This is an ABI change.
GstVaapiSurfaceProxy does not use any particular functionality from
GObject. Actually, it only needs a basic object type with reference
counting.
This is an API and ABI change.
Improve the semantics for gst_vaapi_decoder_put_buffer() when an empty
buffer is passed on. An empty buffer is a buffer with a NULL data pointer
or with a size equals to zero. In this case, that buffer is simply
skipped and the function returns TRUE. A NULL buffer argument still
marks the end-of-stream.
Reset, i.e. destroy then create, the decoder in _setcaps() handler only
if the underlying codec type actually changed. This makes it possible
to be more tolerant with certain MPEG-2 streams that get parsed to
form caps that are compatible with the previous state but minor changes
to "codec-data".
Use g_object_notify_by_pspec() instead of g_object_notify() so that to
avoid a property name lookup. i.e. this makes notifications faster to
the `vaapidecode' element.
Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>
Drop obsolete gst_vaapi_decoder_push_surface() that was no longer used.
Change gst_vaapi_decoder_push_surface_proxy() semantics to assume PTS
is already set correctly and reference count increased, if necessary.
The new API simplifies a lot reference counting and makes it more
flexible for future additions/changes. The GstVaapiCodecInfo is
also gone. Rather, new helper macros are provided to allocate
picture, slice and quantization matrix parameter buffers.
Under some circumstances, we could have leaked a surface, thus not
releasing it to the pool of available surfaces in the VA context.
The strategy is now to use a proxy earlier and automatically ref/unref
whenever necessary. In particular, during the lifetime needed for FFmpeg.
