#619 Can't record MPEG4 videos from NTSC machines

[Tristan Miller]

I am using VICE 2.4.18, rev 29455M compiled with --enable-static-ffmpeg and --enable-gnomeui. This version of VICE can be used to record a video using the "Save media file…" command of the "Snapshot" menu. However, on emulated NTSC machines, video recording does not work at all when the video codec is set to MPEG4 (DivX).

Trying to record an MPEG4 (DivX) video from an emulated NTSC machine results in an error dialog with the text "ffmpegdrv: Cannot open video stream" and the following message printed to the console:

FFMPEG: Driver: avi, ac: 86017, vc: 13

Sound: Closing device pulse' Sound: Opened devicepulse', speed 44100Hz, fragment size 1.5ms, buffer size 100ms
reSID: MOS6581, filter on, sampling rate 44100Hz - fast
Output #0, avi, to '/tmp/foo-mpeg4.avi':
Stream #0:0: Video: mpeg4 (XVID / 0x44495658), yuv420p, 384x256, q=2-31, 800 kb/s, 59.83 tbn, 59.83 tbc
Stream #0:1: Audio: mp3, 44100 Hz, mono, s32p, 64 kb/s
[mpeg4 @ 0x3dbfcc0] removing common factors from framerate
[mpeg4 @ 0x3dbfcc0] timebase 3419/204546 not supported by MPEG 4 standard, the maximum admitted value for the timebase denominator is 65535

ffmpegdrv: could not open video codec

ffmpegdrv: Closed successfully
Sound: Opened recording device device soundmovie' Sound: Closing devicepulse'
Sound: Closing recording device soundmovie' Sound: Opened devicepulse', speed 44100Hz, fragment size 1.5ms, buffer size 100ms
reSID: MOS6581, filter on, sampling rate 44100Hz - fast

So it looks like the codec doesn't like the video frame rate set by VICE. This problem occurs only with emulated NTSC machines, not with emulated PAL machines.

[gpz]

confirmed

[Andreas Matthies]

Fixed in rev 29511.

[Querino]

Windows Port:

well, recording now works, but the emulator window becomes a strange window width if i switch from PAL to NTSC.
before this fix, only the height of the window changed.

/EDIT: SORRY, it did that already before, if "true aspect ratio" is enabled.

so yes, this works now. :)