Black video window using ffdshow

[David1105]

Use ffdshow to resize a input video file of .MOV.

The graph is like:

QT Source filter -> ffdshow raw video filter -> AVI Mux -> File Writer (.AVI)

The original .MOV has video size of 192 x 242. When resizing it to 384 x 484 with Output/Supported output colorspaces selected as RGB24, the playback of output .AVI file shows only a black video window. (This problem exists with using ZPlayer, VLC, or Media Player Classic to play .AVI back.)

Does anyone know of the problem? Can you give me some pointers so that I may debug into ffdhsow if the problem is related?

Thanks!

[foxyshadis]

Does the graph play if you remove the muxer and add a renderer instead? I'm thinking a possibility might be that QT Source isn't decoding, but I'd think ffdshow raw would reject compressed video.

[David1105]

No, it doesn't play even after the AVI Mux and File Writter is removed and replaced with Video Renderer.

I forgot to mention that the situation ONLY happen with Resize and RGB24 selection of ffdshow configuration. In others it works fine in general. For example, if you uncheck Resize and leave RGB24 and start encoding, the AVI file plays back fine.

[clsid]

You could try using Gabest MP4/MOV splitter instead of the QT Source Filter. And use ffdshow to decode the audio/video.

[David1105]

It works now with what you suggested.

Is the original QT Source filter the source of problem? Why?

Aslo, how can be sure that using Gabest in this case generates AVI ouput file of RGB24?

BTW, you need to be careful since "With the Haali Media Splitter installed, the Gabest MP4 Splitter can't be used. So it's not advisable to have both files installed on your system in the same time."

[clsid]

The Windows QT Source Filter is ancient. It doesn't work with many mov files.

The splitter has nothing to do with the output format. The decoder does that.

[David1105]

The graph showing the problem (Please refer to the thread "Black video window using ffdshow" for details.):

File Source (.AVI) -> Avi Splitter -> XviD MPEG-4 Video Decoder (File is xvid video) -> ffdshow raw video filter -> AVI Mux -> File Writer (.AVI)

To re-pro the problem, make sure that the ffdshow filter is not doing the decoding of the xvid video. For example this graph is fine:

File Source (.AVI) -> Avi Splitter -> ffdshow MPEG-4 Video Decoder (File is xvid video) -> ffdshow raw video filter -> AVI Mux -> File Writer (.AVI)


Also, with this graph:

File Source (Input.AVI: 640 x 480/RGB24) -> Avi Splitter -> ffdshow raw video filter -> AVI Mux -> File Writer (Output.AVI 320 x 240/RGB32 or RGB24)

Note that Input.AVI is of RGB24 but Output.AVI of either RGB32 or 24, whenever resizing, Output.AVI plays back with black window.

Any dieas? Thanks!

[clsid]

In GraphEdit, right-click on 'ffdshow raw video filter' and select 'Properties'. On the 'Codecs' page, set 'Raw video' to 'All supported'.

[David1105]

I just checked this setting, it has always been set to "All supported."

BTW, after such AVI to AVI resizing, the resultant AVI file is somehow inflated, for exmaple, from 1955 KB to 77,508 KB (320 X 240 to 160 X 120). What's happening with this?

[clsid]

You are saving it as uncompressed video. That is why it is so large.

[bond]

merged