Hi, Thanks for working on this! On Wed, Mar 25, 2015 at 2:46 AM, Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> wrote: > From: Peter Seiderer <ps.report@xxxxxxx> > > This v4l2_buffer flag can be used by drivers to mark a capture buffer > as the last generated buffer, for example after a V4L2_DEC_CMD_STOP > command was issued. > The DocBook is updated to mention mem2mem codecs and the mem2mem draining flow > signals in the VIDIOC_DECODER_CMD V4L2_DEC_CMD_STOP and VIDIOC_ENCODER_CMD > V4L2_ENC_CMD_STOP documentation. > > Signed-off-by: Peter Seiderer <ps.report@xxxxxxx> > Signed-off-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx> > --- > Changes since v3: > - Added DocBook update mentioning V4L2_BUF_FLAG_LAST in the encoder/decoder > stop command documentation. > --- > Documentation/DocBook/media/v4l/io.xml | 10 ++++++++++ > Documentation/DocBook/media/v4l/vidioc-decoder-cmd.xml | 6 +++++- > Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml | 5 ++++- > include/trace/events/v4l2.h | 3 ++- > include/uapi/linux/videodev2.h | 2 ++ > 5 files changed, 23 insertions(+), 3 deletions(-) > > diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml > index 1c17f80..f3b8bc0 100644 > --- a/Documentation/DocBook/media/v4l/io.xml > +++ b/Documentation/DocBook/media/v4l/io.xml > @@ -1129,6 +1129,16 @@ 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. After the > +queue is drained, the <link linkend="vidioc-qbuf">VIDIOC_DQBUF</link> ioctl will Perhaps just s/After the queue is drained, the/Any subsequent/ ? This would make it more clear I feel. DQBUF of LAST is the end of draining. > +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 9215627..cbb7135 100644 > --- a/Documentation/DocBook/media/v4l/vidioc-decoder-cmd.xml > +++ b/Documentation/DocBook/media/v4l/vidioc-decoder-cmd.xml > @@ -197,7 +197,11 @@ 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 after the last frame was decoded and s/was decoded/has been decoded and all frames are ready to be dequeued/ > +will set the <constant>V4L2_BUF_FLAG_LAST</constant> buffer flag when there will > +be no new buffers produced to dequeue. To make the timing description more explicit, s/when there will be no new buffers produced to dequeue./on the final buffer being dequeued/ perhaps? EOS indicates "no more buffers will be produced and all are ready to be dequeued", while LAST indicates "final buffer being dequeued". > +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 0619ca5..e9cf601 100644 > --- a/Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml > +++ b/Documentation/DocBook/media/v4l/vidioc-encoder-cmd.xml > @@ -129,7 +129,10 @@ 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 > +after the last frame was encoded and will set the > +<constant>V4L2_BUF_FLAG_LAST</constant> buffer flag on the capture queue when > +there will be no new buffers produced to dequeue</entry> I'd propose the same here. -- Thanks, Pawel -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
