Does KMP Video Transform Filter add some overhead?

[mojo_lo]

hi, first of all, thanks for the awesome player! i'm so happy i discovered it as i've been looking for a player that can do all that KMPlayer can. i had been using zoom player, but found its directshow implementaion to often be unstable.

KMP does everything I can hope for in a player and does not crash like ZP did.

My problem is that I have an HD 1080i H264 clip. I use the external CoreAVC beta codec to decode as it is quite fast. Using KMP without the KMP Video Transform filter, my CPU usage is about 70% and playback is smooth. When I enable the KMP VTF, CPU usage seems to go up a few percentage points (about 5%) and playback becomes a jerkier. I don't have any other video processing filters running.

Although I don't have any scientific evidence to back this up, I'd just like to know if this is a known problem or if anyone else has experienced this. And if so, whether it will be corrected. -thx.

[z]

Does KMP Video Transform Filter add some overhead?


Hello, mojo_lo.

As the decoded raw video stream is connected to KMP video transform filter, the playback status could be affected in proportion to the input resolution of a movie regardless of video filter's usage. It's not an intentional overhead. And there is one more thing which should be remembered, that is, if you'd like to enable DxVA feature with some commercial decoders(mepg or wmv, h264), there should be no filter between renderer and decoder.

[mojo_lo]

thanks for the reply. for a 1080i clip, i'd be nuts to try to do processing so i guess the video transform filter can just be disabled.

is the extra overhead present when any filter is connected to the raw video stream? eg, if one connected ffdshow to the 1080i raw video, would one also experience this? or is the effect only present with KMP video transform filter? unfortunately I am unable to test this with ffdshow as I cannot get it to connect to coreavc in directshow.

[z]

Any kind of video filter including ffdshow which is connected to the raw video stream could bring about some overhead inevitably. ;)

[mojo_lo]

Any kind of video filter including ffdshow which is connected to the raw video stream could bring about some overhead inevitably. ;)

hi, i've also noticed that the internal mp4 source filter causes playback to stutter on some files. using Haali's filter doesn't seem to cause this. i'd like to do some more testing on both of these issues, but am having trouble relying on my subjective perceptions.

The OSD playback info is great, but it only works when the KMP video transform filter is used. It also causes playback rate to decrease quite a bit. Is there any other way to objectively measure CPU usage/FPS in KMP?

[z]

hi, i've also noticed that the internal mp4 source filter causes playback to stutter on some files.


Can you give me a link for the files?


Is there any other way to objectively measure CPU usage/FPS in KMP?


Nope.
You don't need to measure CPU usage/FPS, as it's related with decoders, not splitters.
In other words, if you just want to compare the splitters, CPU usage and FPS couldn't be a unit of measurement.

[mojo_lo]

Can you give me a link for the files?

Not sure why, but things are not stuttering anymore. They were personal files, over 1GB.

I have uploaded an mp4 AVC clip ([Only registered and activated users can see links]) (quite low quality, using Nero's HDTV preset) I made with Nero Recode with two 5.1 soundtracks and two subtitle streams. Sometimes when switching audio streams and seeking I get some stuttering in the playback and the audio drops out for a while (especially using the timeline seek to jump far ahead). Possibly this is or is related to the stuttering I experienced before.

Although Haali performs these functions pretty smoothly, it shouldn't be a problem anyway, as one doesn't switch audio streams very often. The stuttering when seeking can be a little annoying though.

[z]

There are some known issues with internal mp4 splitter. First, some h.264 encoding materials, especially in MP4 or MOV, could cause jerky palyback with internal splitter + coreavc decoder combination. The developer said that the time stamp is back and forth, so he didn't figure out the reason.

Problematic Sample with internal mp4/mov splitter:
[Only registered and activated users can see links]

The problematic filtergraph:
[Primary Filtergraph]
0) - KMP MOV/MP4 Source
1) - KMP Audio Codec
2) - CoreAVC Video Decoder
3) - Video Mixing Renderer9(Renderless)
4) - DirectSound Audio Renderer

[Video Info]
Decoder - (MPEG2) CoreAVC Video Decoder
Format - Major Type: Video - Sub Type: YV12
VideoInfo2: YV12 1280X-720, 12 bits

time stamps of kmp's mp4/mov splitter ([Only registered and activated users can see links])
time stamps of gabest's mp4 splitter ([Only registered and activated users can see links])


Tested Result by Our Power Member(Kim Jeongsam) in various environments:

KMP internal MP4 splitter + internal H.264 = OK
KMP internal MP4 splitter + CoreAVC = Jerky Playback

Gabest's MP4 splitter + internal H.264 = Jerky Playback
Gabest's MP4 splitter + CoreAVC = OK

KMP internal MP4 splitter + ffdshow = OK
Gabest's MP4 splitter + ffdshow = OK


ps.

KMP internal MP4 splitter + CoreAVC combination does not cause jerking anymore.