Blender renders past set endframe #45011

System Information
Windows XP SP3 and NVIDIA GeForce GT220

Blender Version
Broken: 2.71

Short description of error
When importing a movie and a sound file into the VSE and setting start- and endframe, the result after rendering will sometimes not coincide with the start- and endframes. More specifically, the audio is rendered correctly but the video plays back at twice or three times the normal rate, and accordingly the last videoframe lies beyond the endframe that was set in the .blend file.fallout-lp4.blend

Exact steps for others to reproduce the error
Simply run "animate" on the attached .blend file, where some dummy files should be used for "........Fraps/Movies/fallout2.wav" and "......*..*Fraps/Movies/FALLOUTW_2015_05_25_15_05_19_906.avi"

Changed status to: 'Open'

Added subscriber: @Dimethicone

Added subscriber: @mont29

Changed status from 'Open' to: 'Archived'

Please:

Only report bugs about latest Blender version (and after testing they are still relevant in latest build from our buildbot).
At least generate correct timecode for your video files, if they use some advanced encoding (all flavours of mpeg4, etc.), otherwise Blender cannot guarantee correct seeking in such files.

Sorry for not testing it with the latest build (would probably seem common sense). Generating timecode by enabling "Proxy / Timecode" and setting "Timecode" to "Record Run" and then running "Rebuild Proxy and Timecode Indices" has actually fixed this problem, even though I'm still a bit puzzled because I never had this problem before, despite always having source material encoded with the same codec. I have even used the same source material (which is pretty harmless lossless, keyframes only) and rendered several different sections, without any problem.

So in order to facilitate my understanding, could you please confirm if the following pseudo-code for the Blender rendering process is correct (at least morally)?

for $frame from $startframe to $endframe
{
   $timestamp = time_to_timestamp( ($frame-$startframe)/$framerate);
   read_seek($timestamp);
   $image = avcodec_decode_video2(...);
   output_image($image);
}

Is it correct that timecode is needed in the routine time_to_timestamp (which I'm aware may not actually exist as a single routine, but you get the idea), and that missing timecodes can lead to faulty timestamps?

Also, generating proxies/timecode took three hours for my 45 minute video. Is this normal? Or is there a way to only generate timecode indices, but not proxies (which seems what's taking so long)?

Thanks for your efforts!

I have no idea of hands of how exactly timecode is used, but yes, with many modern codecs, it's the only way to ensure correctness of frame seeking.

And you do can generate only the timecode, just disable all 'proxy' sizes options in the panel.

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Blender renders past set endframe #45011