Also document stable frames and what it means for testing tools.
Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
[hverkuil: add media: prefix to Subject]
Add AV1 information in visl documentation.
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Detlev Casanova <detlev.casanova@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
The canonical location for the tracefs filesystem is at
/sys/kernel/tracing.
But, from Documentation/trace/ftrace.rst:
Before 4.1, all ftrace tracing control files were within the debugfs
file system, which is typically located at /sys/kernel/debug/tracing.
For backward compatibility, when mounting the debugfs file system,
the tracefs file system will be automatically mounted at:
/sys/kernel/debug/tracing
Update the visl decoder driver documentation to use this tracefs path.
Signed-off-by: Ross Zwisler <zwisler@google.com>
Reviewed-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
A virtual stateless device for stateless uAPI development purposes.
This tool's objective is to help the development and testing of
userspace applications that use the V4L2 stateless API to decode media.
A userspace implementation can use visl to run a decoding loop even when
no hardware is available or when the kernel uAPI for the codec has not
been upstreamed yet. This can reveal bugs at an early stage.
This driver can also trace the contents of the V4L2 controls submitted
to it. It can also dump the contents of the vb2 buffers through a
debugfs interface. This is in many ways similar to the tracing
infrastructure available for other popular encode/decode APIs out there
and can help develop a userspace application by using another (working)
one as a reference.
Note that no actual decoding of video frames is performed by visl. The
V4L2 test pattern generator is used to write various debug information
to the capture buffers instead.
Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
