This allow option string to contain separator so you could set as
"field=value ! format".
This is useful as some encoders use the output format to specify
compression types (for instance with some H264 encoders you can
specify the profile to use).
Signed-off-by: Frediano Ziglio <fziglio@redhat.com>
Acked-by: Pavel Grunt <pgrunt@redhat.com>
configure will use GStreamer 1.0 if present and fall back to
GStreamer 0.10 otherwise.
ffenc_mjpeg takes its bitrate as a long so extend set_gstenc_bitrate().
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
This is faster and lets the encoder leverage past bitrate shaping
history to attain the target faster.
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
This typically happens when sending very small frames (less than
16 pixels in one dimension) to the x264enc encoder.
This avoids repeatedly wasting time rebuilding the pipeline.
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
The video encoder uses the client reports and/or notifications of
server frame drops as its feedback mechanisms. In particular it keeps
track of the maximum video margin and reduces the bit rate whenever the
margin goes below certain thresholds or decreases too sharply.
It uses these to figure out the lowest bit rate that causes negative
feedback, and the highest bit rate that allows a return to positive
feedbacks. It then works to narrow this range and settles on the lower
end once the spread has gone below a given threshold.
All the while it monitors the effective bit rate to ensure the target
bit rate does not grow significantly beyond what the GStreamer encoder
will produce: this avoids target bit rate 'bubbles' which would
invariably be followed by a bit rate crash with accompanying frame loss.
As soon as the network feedback indicates a significant degradation the
bit rate is lowered to minimize the risk of frame loss and/or long
freezes.
It also relies on the existing shaping of the GStreamer output bit rate
to minimize the pipeline reconfigurations.
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
The GStreamer codecs don't follow the specified bit rate very closely:
they can decide to exceed it for ten seconds or more if they consider
the scene deserves it. Such long bursts are enough to cause network
congestion, resulting in many lost frames which cause significant
display corruption.
So the GStreamer video encoder now uses a short 300ms virtual buffer
to shape the compressed video output and ensure we don't exceed the
target bit rate for any significant length of time.
It could instead rely on the network feedback (when available) to lower
the bit rate. However frequent GStreamer bit rate changes lower the
overall compression level and also result in a lower average bit rate,
both of which result in lower video quality.
The GStreamer video encoder also keeps track of the encoded frame size
so it can gather statistics and call update_client_playback_delay()
with accurate information and also annotate the client report debug
traces with the corresponding bit rate information.
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
Note that we can only avoid copies for the first 1 Mpixels or so.
That's because Spice splits larger frames into more chunks than we can
fit GstMemory fragments in a GStreamer buffer. So if there are more
pixels we will avoid copies for the first 3840 KB and copy the rest.
Furthermore, while in practice the GStreamer encoder will only modify
the RedDrawable refcount during the encode_frame(), in theory the
refcount could be decremented from the GStreamer thread after
encode_frame() returns.
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
If an error occurs for whatever reason (e.g. codec not supporting odd
frame sizes), the GStreamer pipeline will drop the current buffer,
causing the encoder to be stuck waiting for the sample. So this patch
tracks error notifications and ensures we don't wait for a sample if
none will come.
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
This way the video encoder is not forced to use malloc()/free().
This also allows more flexibility in how the video encoder manages the
buffer which allows for a zero-copy implementation in both video
encoders.
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
The Spice server administrator can specify the encoder and codec
preferences to optimize for CPU or bandwidth usage. Preferences are
described in a semi-colon separated list of encoder:codec pairs.
The server has a default preference list which can explicitly be
selected by specifying 'auto'.
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
This introduces a pared down GStreamer-based video encoder to serve as
the basis for later enhancements.
In this form the new encoder supports both regular and sized streams
but lacks any rate control. It should still work fine if bandwidth is
sufficient such as on LANs.
Signed-off-by: Francois Gouget <fgouget@codeweavers.com>
