[Kdenlive-devel] exposing parallelism

[Dan Dennedy]

On Wed, Feb 16, 2011 at 8:15 AM, Till Theato <root at ttill.de> wrote:
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> On 02/16/2011 09:11 AM, Dan Dennedy wrote:
>> I want to expose parallelism in Kdenlive. There are basically three settings:
>>
>> 1. playback threads (real_time=x on sdl)
>> 2. rendering threads (real_time=x on avformat)
>> 3. encoding threads (threads=y on avformat)
>>
>> I am thinking maybe 1 and 2 should be the same to made it more
>> predictable right now. Where do you think this goes in the settings
>> dialog and how to label it? "Processing threads" ? Then, I think
>
> Might be suited best in Environment -> MLT environment?

Good suggestion. I will also add a label to indicate that it is experimental.

>> encoding threads belongs on the Render dialog (along with bitrate).
>> Even though it does not always apply - only some encoders handle it -
>> it should not bother other encoders. Thoughts?
>
> Maybe the profiles could have a flag indicating their support.
> Additionally a flag regarding bitrate support (+ some presets) and one
> for 2 pass would make our profiles.xml a lot easier to maintain.

Also good suggestion about the flags.

> We would then for example have only one MPEG-4 profile with a spinbox

heh, yep, but that leaves room to add things like GOP size, B-frames,
qscale, motion estimation method, and all sorts of interesting ffmpeg
options.

> for the number of threads, a editable combobox for the bitrate and a
> checkbox for 2 pass.
>
> Of course on a larger scale there could be done much more to the
> rendering dialog ...

I think bitrate, passes, and threads will go a long, long way. I do
not think we need to get carried away with changes here, but there are
2 other big problems based on support feedback. The Destination combo
is way too easy to overlook. Also, does anyone ever use the Format
combo? Letting someone choose PAL with a non-25-fps project or NTSC
with a non-29.97 project is just inviting trouble - these are known
limitations. We need to remove it and also disable the strict PAL- or
NTSC-formats (DV, HDV) if the project does not match: another flag to
add in the profiles.xml. Subsequently, we can move the Destination
combo to the current location of Format. Alternatively, we can make
the Format list contain folders like the Effect list.

>
> regards Till
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