Frame accuracy trim on WMV shows artifacts

Hello snapcoyote, as i see the source video before_split.wmv has the same pauses after seeking in vlc related to audio as the trimmed one. So I think  that it's not VideoSplitter problem. I'll try to find out why this happens.

Hi.  I tried the beta version with GOP mode and it does seem to seek better in vlc now.  However, it still does not play as cleanly as windows media player.  There is a short silence in the audio after the seek before it kicks in when I play in vlc.

I am still waiting for the vendor to respond to your Mainconcept initialization question and will let you know.

Hello snapcoyote,

Here is version that resolves issue with seeking of trimmed file with GOP mode.
SolveigMM_Video_Splitter_3_0_1206_2_Beta

Conformed.
i'll investigate what's wrong.

Could you also tell what kind of encoder server is used and which version of Mainconcept encoder. I need to know complete intialization params which was set to encoder. Params that you wrote before is not enough.

I'll try it out but I'm hoping there will be a better solution.  If not, I may have to use GOP accuracy instead.

There is one other thing I noticed when splitting VC1 files.  When I try accuracy mode GOP, the trimmed file plays and seeks fine in windows media player.  When I try to seek using vlc player, it takes a long time for vlc to seek within the file.

So it is not possible to partially encode using the default Microsoft VC1 Encoder when the file is encoded using Mainconcept?

Not Exactly. It's possible, but with it's own parameters.
Check this version SolveigMM_Video_Splitter_3_0_1205_30_Beta
Trimmed file should play fine using Windows Media Player, WM Video Decoder, Mainconcept VC1 decoder.
But it crashes VLC player and hangs on ffdshow video decoder if libavcodec is set for VC1.

VC1 spec says that  sequence layer(decoding params) could be changed during the stream. so such files are valid, but for vlc and libavcodec seems it's not.

Are there other available free VC1 codecs I can use that are compatible with Mainconcept?

I don't think that it exists.

Thanks for your reply.  Unfortunately, the splitter software is installed on a different machine so it only has the default microsoft codecs.  Only the encoding server has the Mainconcept VC1 codecs which is licensed to a vendor.

So it is not possible to partially encode using the default Microsoft VC1 Encoder when the file is encoded using Mainconcept?  Are there other available free VC1 codecs I can use that are compatible with Mainconcept?

hello snapcoyote,

The file with these parameters couldn' be partialy rencoded using Microsoft VC-1 Encoder, one of the reasons is EBDU start codes enabled.
But that's not main problem. there are other parameters that will break playback  if they wouldn't  match.

As a solution for this kind of files using this version SolveigMM Video Splitter 3.0 Beta

You can select MainConcept VC1 Encoder for Smart Trimming option using Tools->Preferences, and set encoder parameters that will fit the source video.


The keys parameter which i set:



The result file plays fine using Microsoft WM Video Decoder DMO. But using VLC Player the reencoded part is broken, I suppose that not all parameters that i set match source video.
Unfortunately, force selected  encoder active only for current session of the Video Splitter, and couldn't be set using XTL batch list.

Of course this question is not closed, because it's  hard  to work with this workaround.

Hi.

Here are the settings you requested.  It was created by an encoding server.  Let me know if it is enough for you to test.

Video
Format: VC-1
Format profile: Advanced@L1
Codec ID: WVC1
Codec ID/Hint: Microsoft
Description of the codec: MainConcept VC1 codec  - Advanced, progressive, 1 Mbps 1-Pass CBR
Bit rate: 1500 Kbps
Width: 640 pixels
Height: 480 pixels
Display aspect ratio: 4:3
Frame rate: 29.970 fps
Chroma subsampling : 4:2:0
Bit depth: 8 bits
Scan type: Progressive
Compression mode: Lossy
Rate Control Mode: CBR
GOP Mode: Fixed
GOP Size: 30
Number of B Frames: 1
Closed GOP Cadence: 1
Adaptive Quantization: off
Scene change detection (inserts I-frames on scene changes): true


Audio
Format: WMA
Format version: Version 2
Codec ID/Info: Windows Media Audio
Description of the codec: MainConcept WMA Std codec  - WMA Std. 44100Hz 48 Kbps 2-ch 1-Pass CBR
Bit rate: 48.0 Kbps
Channel(s): 2 channels
Sampling rate : 44.1 KHz
Bit depth: 16 bits

Hello snapcoyote,

i saw in headers that file was made by mainconcept vc1 encoder.
Did you make this file by yourself?
if so, could you provide us  for test encoder and settings which was set to it by e-mail?

Hello snapcoyote,

Thank you for files.

The problem was reproduced.
We will let you know as soon as we'll find out its reason and fix it.

I tried creating a more accurate XTL file by saving the project and it produced the same issue using both the visual Splitter and batchsplit tool.

Hi.  It is registered under National Basketball Association.

Ok, thanks. We'll check an issue quite shortly. The easiest way to get a right XTL, is to configure your project in the Splitter (visually) and save the project.

Hi.  It is registered under National Basketball Association.

Hi snapcoyote,

Could you please let us know your real name to identify your purchase (as we only support registered users)?