Changes between Version 7 and Version 8 of linux/media

Timestamp:

02/20/2019 10:53:01 PM (5 years ago)

Author:

Tim Harvey

Comment:

refactor page - split drivers and gstreamer sections

linux/media

@@ -268 +268 @@
 
 
-==== setup script
+[=#media-ctl-setup]
+=== setup script
 Because the combinations of sensor, cpu, and board are plentiful we have created a way to create an appropriate pipeline configuration script that needs only to know what sensor you wish to use.
 
@@ -290 +291 @@
 
 
-==== capture and streaming examples
-With the assumption that you have already configured your capture device and set it to the {{{DEVICE}}} env variable the following examples are useful examples for capture and streaming:
+[=#mem2mem]
+== IMX6 IPU MEM2MEM (Hardware CSC/scale/crop/rotate/flip)
+A Linux V4L2 MEM2MEM imx-media driver exists that allows utilizing the IMX6 IPU Image Converter hardware blocks (IC) to perform hardware colorspace conversion (CSC), scaling, cropping, rotation, and flip operations.
+
+The GStreamer {{{video4linux2}}} plugin provides an element that uses this driver to expose these capabilities to GStreamer applications.
+
+Notes:
+ - for GStreamer-1.14 the name of the element depends on the video device the driver registers with the kernel (ie v4l2video8convert if mem2mem driver registers /dev/video8)
+ - for GStreamer master (in development) the name of the element is always 'v4l2videoconvert'
+ - the {{{kmssink}}} examples below need a {{{can-scale=false}}} property to tell GStreamer not to scale via the KMS driver (as the IMX6 KMS driver does not support scaling)
+ - ensure that the input format differs from the output format otherwise GStreamer will bypass the conversion completely; note that GStreamer doesn't understand flipping or rotation as part of the format. Gstreamer master (in development) adds a 'disable-passthrough' property to the v4l2videoconvert entity that can be set to force the conversion regardless of input and output format
+ - when using imx entities (ie capture, encode/decode, mem2mem, display) you can specify 'output-io-mode=dmabuf-import' to share dmabuf pointers for a zero-copy pipeline however if using non imx entities (ie videotestsrc) you must omit these as you can not ensure the buffers share the alignment/stride necessary to share dmabuf pointers
+
+Examples:
+ * Ensure mem2mem is in your kernel:
+{{{#!bash
+~# dmesg | grep mem2mem
+[   18.356023] imx-media: Registered ipu_ic_pp mem2mem as /dev/video8
+}}}
+
+See Gstreamer examples below
+
+
+[=#coda]
+== IMX6 coda encode / decode driver
+The Linux CODA driver provides access to the IMX6 hardware encode/decode codecs and the GStreamer {{{video4linux2}}} plugin provides encode/decode elements that tap into this.
+
+Examples:
+ * Ensure CODA is in your kernel:
+{{{#!bash
+~# dmesg | grep coda    
+[   16.721698] coda 2040000.vpu: Direct firmware load for vpu_fw_imx6q.bin failed with error -2
+[   16.721724] coda 2040000.vpu: Falling back to syfs fallback for: vpu_fw_imx6q.bin
+[   18.381136] coda 2040000.vpu: Using fallback firmware vpu/vpu_fw_imx6q.bin
+[   18.433648] coda 2040000.vpu: Firmware code revision: 570363
+[   18.433683] coda 2040000.vpu: Initialized CODA960.
+[   18.433706] coda 2040000.vpu: Firmware version: 3.1.1
+[   18.442312] coda 2040000.vpu: codec registered as /dev/video[9-10]
+}}}
+
+See Gstreamer examples below
+
+
+[=#v4l2-ctl]
+== Capture examples
+With the assumption that you have already configured your capture device (see [#media-ctl-setup above) and set it to the {{{DEVICE}}} env variable the following examples are useful examples for capture and streaming:
 
 Examples:
@@ -301 +346 @@
 convert -size 720x480 -depth 16 uyvy:x.raw frame.png
 }}}
+
+
+[=#gstreamer]
+== GStreamer Capture, Dispaly, and Stream Examples
+With the assumption that you have already configured your capture device (see [#media-ctl-setup above) and set it to the {{{DEVICE}}} env variable the following examples are useful examples for capture and streaming:
+
+
+=== Capture / Display
  * Display capture source:
 {{{#!bash
@@ -308 +361 @@
 gst-launch-1.0 v4l2src device=$DEVICE ! v4l2video10convert output-io-mode=dmabuf-import ! fbdevsink
 }}}
+
+=== Capture / Encode
+
+ * Ensure GStreamer encode elements exists:
+{{{#!bash
+~# gst-inspect-1.0 | grep -e "v4l2.*enc"
+video4linux2:  v4l2h264enc: V4L2 H.264 Encoder
+video4linux2:  v4l2mpeg4enc: V4L2 MPEG4 Encoder
+}}}
+
+
  * Encode to JPEG (software based encode) and stream via RTP/UDP:
 {{{#!bash
@@ -325 +389 @@
 
 
-[=#mem2mem]
-== IMX6 ipu_ic_pp mem2mem CSC/scale/crop/rotate/flip conversion
-A Linux V4L2 MEM2MEM imx-media driver exists that allows utilizing the IMX6 IPU Image Converter hardware blocks (IC) to perform hardware colorspace conversion (CSC), scaling, cropping, rotation, and flip operations.
-
+=== Convert
 The GStreamer {{{video4linux2}}} plugin provides an element that uses this driver to expose these capabilities to GStreamer applications.
 
@@ -397 +458 @@
      kmssink can-scale=false
 }}}
-
-
-[=#coda]
-== IMX6 coda encode
-The Linux CODA driver provides access to the IMX6 hardware encode/decode codecs and the GStreamer {{{video4linux2}}} plugin provides encode/decode elements that tap into this.
-
-Examples:
- * Ensure CODA is in your kernel:
-{{{#!bash
-~# dmesg | grep coda    
-[   16.721698] coda 2040000.vpu: Direct firmware load for vpu_fw_imx6q.bin failed with error -2
-[   16.721724] coda 2040000.vpu: Falling back to syfs fallback for: vpu_fw_imx6q.bin
-[   18.381136] coda 2040000.vpu: Using fallback firmware vpu/vpu_fw_imx6q.bin
-[   18.433648] coda 2040000.vpu: Firmware code revision: 570363
-[   18.433683] coda 2040000.vpu: Initialized CODA960.
-[   18.433706] coda 2040000.vpu: Firmware version: 3.1.1
-[   18.442312] coda 2040000.vpu: codec registered as /dev/video[9-10]
-}}}
- * Ensure GStreamer encode elements exists:
-{{{#!bash
-~# gst-inspect-1.0 | grep -e "v4l2.*enc"
-video4linux2:  v4l2h264enc: V4L2 H.264 Encoder
-video4linux2:  v4l2mpeg4enc: V4L2 MPEG4 Encoder
-}}}
  * capture, scale, rotate, flip and encode using imx-media capture device mem2mem device and coda device (can use dmabufs for zero-copy)
 {{{#!bash