On 12/31/2016 01:54 AM, Mark Thompson wrote:
On 30/12/16 00:14, Zhao Yakui wrote:
On 12/30/2016 02:52 AM, Mark Thompson wrote:
On 29/12/16 07:09, Zhao Yakui wrote:
On 12/29/2016 03:08 PM, Xiang, Haihao wrote:
On 12/29/2016 01:22 PM, Xiang, Haihao wrote:
User can use VAEncMiscParameterRateControl to update bitrate, so we
should ignore
the bitrate in the sequence parameter if
VAEncMiscParameterRateControl is present.
This makes sense. The MiscRateControl mentions that it can override
the
bps setting in sequence parameter.
Hence it is not needed to reset brc if
VAEncMiscParameterRateControl doesn't change
the used bitrate.
Does it still need to send the VAEncMiscParameterRateControl
parameter
if the bps is not changed for the new sequence?
Yes if bits_per_second in the sequence parameter is not equal to the
value for the previous Begin/Render/End sequence except bits_per_second
in the sequence parameter is 0.
OK.
It makes sense.
This looks good to me.
I'm not sure this behaviour is correct. Should not the most recently given
bitrate value from the user, either from sequence parameters or RC parameters,
be used? When is_new_sequence is set, the user will have provided a set of
sequence parameters (because we are making an IDR frame), so the bitrate there
is provided by the user and should override any previous RC parameters given
before that frame (but not any on this one).
That is, I think it should work like:
Hi, Mark
Thanks for patch review and nice consideration.
As we know, IDR frame can indicate that a new video sequence is started.
During the decoding, the previous frames before IDR are discarded and not used.
Maybe it will be better that the encoding parameter related with RC is resent
after a new sequence. That is to say: The bps in SPS is used for the
initialization for a new sequence. If the MiscRC is sent, it will override the
bps in SPS. If there is no RC, the bps in SPS will be used.
In such case the user-space middleware only needs to follow the same logic
for every video sequence. Otherwise the different logic is considered for each
video sequence.
Hmm, yes. That would entail discarding the contents of
encoder_context->misc_param[VAEncMiscParameterTypeRateControl] when new
sequence parameters are provided? (In the same way that ROI parameters are
discarded after every frame.) I think that's a much nicer answer than what I had,
and is more consistent as well.
Yes. It need to discard the content of
encoder_context->misc_param[VAEncMiscParameterTypeRateControl] when the
new sequence is provided.
Unfortunately the current code doesn't discard it.
Will you please send out the patch that discards the
encoder_context->misc_param[VAEncMiscParameterTypeRateControl]?
Thanks
Yakui
Thanks,
- Mark
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