Re: [PATCH 2/8] videodev2.h: add V4L2_DEC_CMD_FLUSH
On Fri, Aug 30, 2019 at 6:45 PM Hans Verkuil wrote:
>
> On 8/30/19 11:38 AM, Alexandre Courbot wrote:
> > On Fri, Aug 23, 2019 at 4:45 AM Jernej Skrabec
> > wrote:
> >>
> >> From: Hans Verkuil
> >>
> >> Add this new V4L2_DEC_CMD_FLUSH decoder command and document it.
> >>
> >> Signed-off-by: Hans Verkuil
> >> Signed-off-by: Jernej Skrabec
> >> ---
> >> Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst | 11 ++-
> >> Documentation/media/videodev2.h.rst.exceptions | 1 +
> >> include/uapi/linux/videodev2.h | 1 +
> >> 3 files changed, 12 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> >> b/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> >> index 57f0066f4cff..0bffef6058f7 100644
> >> --- a/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> >> +++ b/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> >> @@ -208,7 +208,16 @@ introduced in Linux 3.3. They are, however, mandatory
> >> for stateful mem2mem decod
> >> been started yet, the driver will return an ``EPERM`` error code.
> >> When
> >> the decoder is already running, this command does nothing. No
> >> flags are defined for this command.
> >> -
> >> +* - ``V4L2_DEC_CMD_FLUSH``
> >> + - 4
> >> + - Flush any held capture buffers. Only valid for stateless decoders,
> >> +and only if ``V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF`` was
> >> set.
> >> + This command is typically used when the application reached the
> >> + end of the stream and the last output buffer had the
> >> + ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag set. This would prevent
> >> + dequeueing the last capture buffer containing the last decoded
> >> frame.
> >> + So this command can be used to explicitly flush that last decoded
> >> + frame.
> >
> > Just for safety, can we also specify that it is valid to call this
> > command even if no buffer was held (in which case it is a no-op), as
> > this can help make user-space code simpler?
>
> Ah yes, thanks for the reminder.
>
> Jernej, when you post the next version of this series, can you change the text
> above to:
>
> - Flush any held capture buffers. Only valid for stateless decoders.
> This command is typically used when the application reached the
> end of the stream and the last output buffer had the
> ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag set. This would prevent
> dequeueing the capture buffer containing the last decoded frame.
> So this command can be used to explicitly flush that final decoded
> frame. This command does nothing if there are no held capture buffers.
With the above,
Reviewed-by: Alexandre Courbot
Thanks!
>
> Regards,
>
> Hans
>
> >
> >>
> >> Return Value
> >>
> >> diff --git a/Documentation/media/videodev2.h.rst.exceptions
> >> b/Documentation/media/videodev2.h.rst.exceptions
> >> index adeb6b7a15cb..a79028e4d929 100644
> >> --- a/Documentation/media/videodev2.h.rst.exceptions
> >> +++ b/Documentation/media/videodev2.h.rst.exceptions
> >> @@ -434,6 +434,7 @@ replace define V4L2_DEC_CMD_START decoder-cmds
> >> replace define V4L2_DEC_CMD_STOP decoder-cmds
> >> replace define V4L2_DEC_CMD_PAUSE decoder-cmds
> >> replace define V4L2_DEC_CMD_RESUME decoder-cmds
> >> +replace define V4L2_DEC_CMD_FLUSH decoder-cmds
> >>
> >> replace define V4L2_DEC_CMD_START_MUTE_AUDIO decoder-cmds
> >> replace define V4L2_DEC_CMD_PAUSE_TO_BLACK decoder-cmds
> >> diff --git a/include/uapi/linux/videodev2.h
> >> b/include/uapi/linux/videodev2.h
> >> index 4fa9f543742d..91a79e16089c 100644
> >> --- a/include/uapi/linux/videodev2.h
> >> +++ b/include/uapi/linux/videodev2.h
> >> @@ -1978,6 +1978,7 @@ struct v4l2_encoder_cmd {
> >> #define V4L2_DEC_CMD_STOP(1)
> >> #define V4L2_DEC_CMD_PAUSE (2)
> >> #define V4L2_DEC_CMD_RESUME (3)
> >> +#define V4L2_DEC_CMD_FLUSH (4)
> >>
> >> /* Flags for V4L2_DEC_CMD_START */
> >> #define V4L2_DEC_CMD_START_MUTE_AUDIO (1 << 0)
> >> --
> >> 2.22.1
> >>
>
Re: [PATCH 2/8] videodev2.h: add V4L2_DEC_CMD_FLUSH
On 8/30/19 11:38 AM, Alexandre Courbot wrote:
> On Fri, Aug 23, 2019 at 4:45 AM Jernej Skrabec
> wrote:
>>
>> From: Hans Verkuil
>>
>> Add this new V4L2_DEC_CMD_FLUSH decoder command and document it.
>>
>> Signed-off-by: Hans Verkuil
>> Signed-off-by: Jernej Skrabec
>> ---
>> Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst | 11 ++-
>> Documentation/media/videodev2.h.rst.exceptions | 1 +
>> include/uapi/linux/videodev2.h | 1 +
>> 3 files changed, 12 insertions(+), 1 deletion(-)
>>
>> diff --git a/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
>> b/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
>> index 57f0066f4cff..0bffef6058f7 100644
>> --- a/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
>> +++ b/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
>> @@ -208,7 +208,16 @@ introduced in Linux 3.3. They are, however, mandatory
>> for stateful mem2mem decod
>> been started yet, the driver will return an ``EPERM`` error code.
>> When
>> the decoder is already running, this command does nothing. No
>> flags are defined for this command.
>> -
>> +* - ``V4L2_DEC_CMD_FLUSH``
>> + - 4
>> + - Flush any held capture buffers. Only valid for stateless decoders,
>> +and only if ``V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF`` was set.
>> + This command is typically used when the application reached the
>> + end of the stream and the last output buffer had the
>> + ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag set. This would prevent
>> + dequeueing the last capture buffer containing the last decoded frame.
>> + So this command can be used to explicitly flush that last decoded
>> + frame.
>
> Just for safety, can we also specify that it is valid to call this
> command even if no buffer was held (in which case it is a no-op), as
> this can help make user-space code simpler?
Ah yes, thanks for the reminder.
Jernej, when you post the next version of this series, can you change the text
above to:
- Flush any held capture buffers. Only valid for stateless decoders.
This command is typically used when the application reached the
end of the stream and the last output buffer had the
``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag set. This would prevent
dequeueing the capture buffer containing the last decoded frame.
So this command can be used to explicitly flush that final decoded
frame. This command does nothing if there are no held capture buffers.
Regards,
Hans
>
>>
>> Return Value
>>
>> diff --git a/Documentation/media/videodev2.h.rst.exceptions
>> b/Documentation/media/videodev2.h.rst.exceptions
>> index adeb6b7a15cb..a79028e4d929 100644
>> --- a/Documentation/media/videodev2.h.rst.exceptions
>> +++ b/Documentation/media/videodev2.h.rst.exceptions
>> @@ -434,6 +434,7 @@ replace define V4L2_DEC_CMD_START decoder-cmds
>> replace define V4L2_DEC_CMD_STOP decoder-cmds
>> replace define V4L2_DEC_CMD_PAUSE decoder-cmds
>> replace define V4L2_DEC_CMD_RESUME decoder-cmds
>> +replace define V4L2_DEC_CMD_FLUSH decoder-cmds
>>
>> replace define V4L2_DEC_CMD_START_MUTE_AUDIO decoder-cmds
>> replace define V4L2_DEC_CMD_PAUSE_TO_BLACK decoder-cmds
>> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
>> index 4fa9f543742d..91a79e16089c 100644
>> --- a/include/uapi/linux/videodev2.h
>> +++ b/include/uapi/linux/videodev2.h
>> @@ -1978,6 +1978,7 @@ struct v4l2_encoder_cmd {
>> #define V4L2_DEC_CMD_STOP(1)
>> #define V4L2_DEC_CMD_PAUSE (2)
>> #define V4L2_DEC_CMD_RESUME (3)
>> +#define V4L2_DEC_CMD_FLUSH (4)
>>
>> /* Flags for V4L2_DEC_CMD_START */
>> #define V4L2_DEC_CMD_START_MUTE_AUDIO (1 << 0)
>> --
>> 2.22.1
>>
Re: [PATCH 2/8] videodev2.h: add V4L2_DEC_CMD_FLUSH
On Fri, Aug 23, 2019 at 4:45 AM Jernej Skrabec wrote:
>
> From: Hans Verkuil
>
> Add this new V4L2_DEC_CMD_FLUSH decoder command and document it.
>
> Signed-off-by: Hans Verkuil
> Signed-off-by: Jernej Skrabec
> ---
> Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst | 11 ++-
> Documentation/media/videodev2.h.rst.exceptions | 1 +
> include/uapi/linux/videodev2.h | 1 +
> 3 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> b/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> index 57f0066f4cff..0bffef6058f7 100644
> --- a/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> @@ -208,7 +208,16 @@ introduced in Linux 3.3. They are, however, mandatory
> for stateful mem2mem decod
> been started yet, the driver will return an ``EPERM`` error code. When
> the decoder is already running, this command does nothing. No
> flags are defined for this command.
> -
> +* - ``V4L2_DEC_CMD_FLUSH``
> + - 4
> + - Flush any held capture buffers. Only valid for stateless decoders,
> +and only if ``V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF`` was set.
> + This command is typically used when the application reached the
> + end of the stream and the last output buffer had the
> + ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag set. This would prevent
> + dequeueing the last capture buffer containing the last decoded frame.
> + So this command can be used to explicitly flush that last decoded
> + frame.
Just for safety, can we also specify that it is valid to call this
command even if no buffer was held (in which case it is a no-op), as
this can help make user-space code simpler?
>
> Return Value
>
> diff --git a/Documentation/media/videodev2.h.rst.exceptions
> b/Documentation/media/videodev2.h.rst.exceptions
> index adeb6b7a15cb..a79028e4d929 100644
> --- a/Documentation/media/videodev2.h.rst.exceptions
> +++ b/Documentation/media/videodev2.h.rst.exceptions
> @@ -434,6 +434,7 @@ replace define V4L2_DEC_CMD_START decoder-cmds
> replace define V4L2_DEC_CMD_STOP decoder-cmds
> replace define V4L2_DEC_CMD_PAUSE decoder-cmds
> replace define V4L2_DEC_CMD_RESUME decoder-cmds
> +replace define V4L2_DEC_CMD_FLUSH decoder-cmds
>
> replace define V4L2_DEC_CMD_START_MUTE_AUDIO decoder-cmds
> replace define V4L2_DEC_CMD_PAUSE_TO_BLACK decoder-cmds
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 4fa9f543742d..91a79e16089c 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -1978,6 +1978,7 @@ struct v4l2_encoder_cmd {
> #define V4L2_DEC_CMD_STOP(1)
> #define V4L2_DEC_CMD_PAUSE (2)
> #define V4L2_DEC_CMD_RESUME (3)
> +#define V4L2_DEC_CMD_FLUSH (4)
>
> /* Flags for V4L2_DEC_CMD_START */
> #define V4L2_DEC_CMD_START_MUTE_AUDIO (1 << 0)
> --
> 2.22.1
>
Re: [PATCH 2/8] videodev2.h: add V4L2_DEC_CMD_FLUSH
On Thu, 22 Aug 2019 21:44:54 +0200
Jernej Skrabec wrote:
> From: Hans Verkuil
>
> Add this new V4L2_DEC_CMD_FLUSH decoder command and document it.
>
> Signed-off-by: Hans Verkuil
> Signed-off-by: Jernej Skrabec
Reviewed-by: Boris Brezillon
> ---
> Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst | 11 ++-
> Documentation/media/videodev2.h.rst.exceptions | 1 +
> include/uapi/linux/videodev2.h | 1 +
> 3 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> b/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> index 57f0066f4cff..0bffef6058f7 100644
> --- a/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-decoder-cmd.rst
> @@ -208,7 +208,16 @@ introduced in Linux 3.3. They are, however, mandatory
> for stateful mem2mem decod
> been started yet, the driver will return an ``EPERM`` error code. When
> the decoder is already running, this command does nothing. No
> flags are defined for this command.
> -
> +* - ``V4L2_DEC_CMD_FLUSH``
> + - 4
> + - Flush any held capture buffers. Only valid for stateless decoders,
> +and only if ``V4L2_BUF_CAP_SUPPORTS_M2M_HOLD_CAPTURE_BUF`` was set.
> + This command is typically used when the application reached the
> + end of the stream and the last output buffer had the
> + ``V4L2_BUF_FLAG_M2M_HOLD_CAPTURE_BUF`` flag set. This would prevent
> + dequeueing the last capture buffer containing the last decoded frame.
> + So this command can be used to explicitly flush that last decoded
> + frame.
>
> Return Value
>
> diff --git a/Documentation/media/videodev2.h.rst.exceptions
> b/Documentation/media/videodev2.h.rst.exceptions
> index adeb6b7a15cb..a79028e4d929 100644
> --- a/Documentation/media/videodev2.h.rst.exceptions
> +++ b/Documentation/media/videodev2.h.rst.exceptions
> @@ -434,6 +434,7 @@ replace define V4L2_DEC_CMD_START decoder-cmds
> replace define V4L2_DEC_CMD_STOP decoder-cmds
> replace define V4L2_DEC_CMD_PAUSE decoder-cmds
> replace define V4L2_DEC_CMD_RESUME decoder-cmds
> +replace define V4L2_DEC_CMD_FLUSH decoder-cmds
>
> replace define V4L2_DEC_CMD_START_MUTE_AUDIO decoder-cmds
> replace define V4L2_DEC_CMD_PAUSE_TO_BLACK decoder-cmds
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 4fa9f543742d..91a79e16089c 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -1978,6 +1978,7 @@ struct v4l2_encoder_cmd {
> #define V4L2_DEC_CMD_STOP(1)
> #define V4L2_DEC_CMD_PAUSE (2)
> #define V4L2_DEC_CMD_RESUME (3)
> +#define V4L2_DEC_CMD_FLUSH (4)
>
> /* Flags for V4L2_DEC_CMD_START */
> #define V4L2_DEC_CMD_START_MUTE_AUDIO(1 << 0)
