VSE Rendering black frames from video clip.

Support Compositing and Post Processing
1

I am running 2.85.1 r38019, but I was getting the same issue under 2.58.
The OS is Win XP Pro SP3.

I have been searching all over and I can’t find any reference to this issue.

I import a video clip into the VSE. If I scrub through the clip every frame looks good in the preview window. If I hit Alt-A to play the clip in the preview, it may work the first time through, but after that the last 15 frames or so are black. If I render I get the same 15 black frames. It doesn’t matter if I render to a movie clip or to still shots. If render to stills, then change the start the render again from the first black frame, it will render all the stills correctly.

In all cases the last frame is black no matter what I do.

I have tried various clips, including clips generated from Blender, with the same results.

All of the clips are in NTSC SD Widescreen, because that is what my camcorder creates.

Here is the metadata from MediaInfo on one of my clips.

General
Complete name                    : C:\Documents and Settings\eruud\My Documents\Videos\TestClip.mpg
Format                           : MPEG-PS
File size                        : 1.74 MiB
Duration                         : 2s 16ms
Overall bit rate                 : 7 257 Kbps

Video
ID                               : 224 (0xE0)
Format                           : MPEG Video
Format version                   : Version 2
Format profile                   : Main@Main
Format settings, BVOP            : Yes
Format settings, Matrix          : Custom
Format settings, GOP             : M=3, N=15
Duration                         : 1s 935ms
Bit rate mode                    : Variable
Bit rate                         : 6 729 Kbps
Maximum bit rate                 : 8 400 Kbps
Width                            : 720 pixels
Height                           : 480 pixels
Display aspect ratio             : 2.35:1
Frame rate                       : 29.970 fps
Standard                         : NTSC
Color space                      : YUV
Chroma subsampling               : 4:2:0
Bit depth                        : 8 bits
Scan type                        : Interlaced
Scan order                       : Top Field First
Compression mode                 : Lossy
Bits/(Pixel*Frame)               : 0.650
Stream size                      : 1.55 MiB (89%)

Audio
ID                               : 189 (0xBD)-128 (0x80)
Format                           : AC-3
Format/Info                      : Audio Coding 3
Mode extension                   : CM (complete main)
Muxing mode                      : DVD-Video
Duration                         : 2s 16ms
Bit rate mode                    : Constant
Bit rate                         : 384 Kbps
Channel(s)                       : 2 channels
Channel positions                : Front: L R
Sampling rate                    : 48.0 KHz
Bit depth                        : 16 bits
Compression mode                 : Lossy
Delay relative to video          : -67ms
Stream size                      : 94.5 KiB (5%)
2

MPEG can be a (decode) problem, have you considered turning your clips into frame sequences or another Codec (try using Mpeg Streamclip or similar)? Also have you tried rendering out in frame sequences, as it could be a problem with output file type. If it is try another Codec for output.

3

To get around the problem for now, I did turn them into frame sequences using Blender. I just had to do each clip in two stages to get all of the frames. I really don’t want to do it with all the footage I am working with if I don’t have to.

I’ll take a look at Mpeg Streamclip.

Ultimately, I need the final output to go to DVD. I use DVD Lab Pro for DVD authoring, and it works really well with mpeg.

4

I use DVD Lab Pro for DVD authoring, and it works really well with mpeg.

Sadly you can’t say that about Blender

5

Mpeg Streamclip does do a nice job of create an image sequence and it doesn’t produce any black frames. I did notice that it creates two less frames than Blender says are in the clip. For example Blender says a clip is 120 frames long and shows a black frame for frame 120. Mpeg Sreamclip finds 118 frames.

At least with Mpeg Streamclip I can do it in one pass.

I’ll have to go back to my original plan and use Blender VSE only for the clips that I want to add in Blender elements. I’ll keep using Kdenlive as my NLE. It will mean I still have to keep switching from one OS to another, unless someone knows of a linux alternative to Streamclip.