diff options
| -rw-r--r-- | Documentation/DocBook/media/v4l/io.xml | 12 | ||||
| -rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-decoder-cmd.xml | 12 | ||||
| -rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml | 10 | ||||
| -rw-r--r-- | Documentation/DocBook/media/v4l/vidioc-qbuf.xml | 8 |
4 files changed, 40 insertions, 2 deletions
diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index 1c17f802b471..cff2ffd3c8a6 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -1129,6 +1129,18 @@ in this buffer has not been created by the CPU but by some DMA-capable unit, in which case caches have not been used.</entry> </row> <row> + <entry><constant>V4L2_BUF_FLAG_LAST</constant></entry> + <entry>0x00100000</entry> + <entry>Last buffer produced by the hardware. mem2mem codec drivers +set this flag on the capture queue for the last buffer when the +<link linkend="vidioc-querybuf">VIDIOC_QUERYBUF</link> or +<link linkend="vidioc-qbuf">VIDIOC_DQBUF</link> ioctl is called. Due to hardware +limitations, the last buffer may be empty. In this case the driver will set the +<structfield>bytesused</structfield> field to 0, regardless of the format. Any +Any subsequent call to the <link linkend="vidioc-qbuf">VIDIOC_DQBUF</link> ioctl +will not block anymore, but return an &EPIPE;.</entry> + </row> + <row> <entry><constant>V4L2_BUF_FLAG_TIMESTAMP_MASK</constant></entry> <entry>0x0000e000</entry> <entry>Mask for timestamp types below. To test the diff --git a/Documentation/DocBook/media/v4l/vidioc-decoder-cmd.xml b/Documentation/DocBook/media/v4l/vidioc-decoder-cmd.xml index 9215627b04c7..73eb5cfe698a 100644 --- a/Documentation/DocBook/media/v4l/vidioc-decoder-cmd.xml +++ b/Documentation/DocBook/media/v4l/vidioc-decoder-cmd.xml @@ -197,7 +197,17 @@ be muted when playing back at a non-standard speed. this command does nothing. This command has two flags: if <constant>V4L2_DEC_CMD_STOP_TO_BLACK</constant> is set, then the decoder will set the picture to black after it stopped decoding. Otherwise the last image will -repeat. If <constant>V4L2_DEC_CMD_STOP_IMMEDIATELY</constant> is set, then the decoder +repeat. mem2mem decoders will stop producing new frames altogether. They will send +a <constant>V4L2_EVENT_EOS</constant> event when the last frame has been decoded +and all frames are ready to be dequeued and will set the +<constant>V4L2_BUF_FLAG_LAST</constant> buffer flag on the last buffer of the +capture queue to indicate there will be no new buffers produced to dequeue. This +buffer may be empty, indicated by the driver setting the +<structfield>bytesused</structfield> field to 0. Once the +<constant>V4L2_BUF_FLAG_LAST</constant> flag was set, the +<link linkend="vidioc-qbuf">VIDIOC_DQBUF</link> ioctl will not block anymore, +but return an &EPIPE;. +If <constant>V4L2_DEC_CMD_STOP_IMMEDIATELY</constant> is set, then the decoder stops immediately (ignoring the <structfield>pts</structfield> value), otherwise it will keep decoding until timestamp >= pts or until the last of the pending data from its internal buffers was decoded. diff --git a/Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml b/Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml index 0619ca5d2d36..fc1d4625a78c 100644 --- a/Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml +++ b/Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml @@ -129,7 +129,15 @@ this command.</entry> encoding will continue until the end of the current <wordasword>Group Of Pictures</wordasword>, otherwise encoding will stop immediately. When the encoder is already stopped, this command does -nothing.</entry> +nothing. mem2mem encoders will send a <constant>V4L2_EVENT_EOS</constant> event +when the last frame has been decoded and all frames are ready to be dequeued and +will set the <constant>V4L2_BUF_FLAG_LAST</constant> buffer flag on the last +buffer of the capture queue to indicate there will be no new buffers produced to +dequeue. This buffer may be empty, indicated by the driver setting the +<structfield>bytesused</structfield> field to 0. Once the +<constant>V4L2_BUF_FLAG_LAST</constant> flag was set, the +<link linkend="vidioc-qbuf">VIDIOC_DQBUF</link> ioctl will not block anymore, +but return an &EPIPE;.</entry> </row> <row> <entry><constant>V4L2_ENC_CMD_PAUSE</constant></entry> diff --git a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml index 3504a7f2f382..6cfc53b83a20 100644 --- a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml +++ b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml @@ -186,6 +186,14 @@ In that case the application should be able to safely reuse the buffer and continue streaming. </para> </listitem> + <term><errorcode>EPIPE</errorcode></term> + <listitem> + <para><constant>VIDIOC_DQBUF</constant> returns this on an empty +capture queue for mem2mem codecs if a buffer with the +<constant>V4L2_BUF_FLAG_LAST</constant> was already dequeued and no new buffers +are expected to become available. + </para> + </listitem> </varlistentry> </variablelist> </refsect1> |