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status of high-definition video?

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florin
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status of high-definition video?

Mon Nov 05, 2007 7:53 pm

At this moment, how well can kdenlive deal with high definition video? Can it edit, process, cut, etc?



Currently, I do all my digital SD video processing on Linux. Capture with dvgrab, trim/edit/cut with Kino (this step is optional), convert to DVD-compatible MPEG2 with transcode/mjpegtools (see this link http://florin.myip.org/soft/conv-dvd/ for my conversion script), author with dvdauthor and burn with dvd+rw-tools.

Suppose I purchase an HDV camera. Which of the above steps are currently doable on Linux? Can kdenlive be used for any of them?



Florin Andrei



http://florin.myip.org/

jmpoure_drupal
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In my opinion :

:arrow: Kdenlive 0.5 is fully compatible with HDV mpeg2 streams.

:arrow: Using a recent version of ffmpeg+libavcodec SVN, it offers support for AVCHD streams (untested). For AVCHD, there is still some work to be done in MLT, including multi-thread decoding by default to display video files smoothly. The option exists in MLT, but is not enabled by default.



Kdenlive is based on MLT video editing framework, which relies on ffmpeg.

jmpoure_drupal
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Re: status of high-definition video?

Thu Nov 08, 2007 10:35 am

I compiled ffmpeg from SVN today.



Then I could play a Canon HG10 avchd file in Kdenlive.

Basically, it works fine. I could play and use the video in preview mode.

My computer is a recent dual-core AMD64x2.

But ...



Kdenlive is slow to display the video in preview mode.

The sound is also bad, because Kdenlive is floded.



Explaination : Kdenlive reaches 100% of the first core on my AMDx2.

The second core remains unused.



I will look into MLT to understand how to enable multi-thread decoding.

jmpoure_drupal
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Okay, here is a copy of Dan message:



Quote:
When using Kdenlive, the activity of by AMDx2 processor sometimes reaches 50%. Is MLT multi-threaded?


Answer: Yes, but only in a trivial sense because there is no parallel

processing. It just uses the threading for latency between the consumer

and all the processing ahead of it. For example, while one thread in the

the SDL consumer is updating the display, another thread is preparing

the next or additional frames in a serial fashion. This is what the

generic consumer property "real_time" controls. When set to 1, there is

a queue that can fill causing it to skip processing frame to maintain

"realtime." When set to 0, the framework consumer multithreading is

disabled.



Quote:
Can it take advantage of ffmpeg AVCHD multi-threaded decoding?


Answer: Maybe just by setting some options in consumer_avformat.c.

Would someone be so kind to dig into consumer_avformat.c to enquire if multi-threaded decoding could be enabled by default.



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