[x264-devel] Problem With Dropped Frames

[Steven Walters]

> The newest revisions of x264 are dropping frames during encoding.
>
> Sometime after the release of version 1583, newer releases of x264 have started dropping video frames while encoding movie files. By careful experimentation, I've determined that the source of the dropped frames is x264 rather than some other source. The drop rate is about 4 to 9 frames for a movie file of 150,000 - 200,000 frames. This results is a loss of audio to video synchronization toward the end of the movie.

And what experimentation was this?
Without explaining what you did, we can not take this as fact but as
speculation.

> I've been using x264 for over a year and have used it to encode over 200 movies without any dropped frames issue up to and including v1583. My experiments with v1583 for 5 different movies showed 0 dropped frames for all 5.
>
> I can't give you a version number for when the problem started and I have purged by system of all copies of x264 of versions later than v1583 to prevent using them accidentally. But a x264 download around July 18 had the problem.

This isn't particularly useful in tracking down a bug as there's a
large number of revisions in this period.

> The x264 script lines I use are:
>
> x264 --pass 1 --bitrate 500 -o MOVIE1.mp4 MOVIE-A1.avs
> x264 --pass 2 --bitrate 500 -o MOVIEX.mp4 MOVIE-A2.avs
> -----------------------------------
> Example avisynth script lines I use are:
>
> LoadPlugin("MPEG2DEC3.dll")
> LoadPlugin("MPEGDecoder.dll")
> LoadPlugin("TIVTC.dll")
>
> MPEGSource("MOVIE.m2v")
> mpeg2source("MOVIE.d2v")
>
> trim(0, 145,264)
>
> tfm()
>
> tdecimate()
>
> ColorYUV(cont_y=35, gamma_y=70)
>
> BilinearResize(704, 368, 8, 56, -8, -60)

This script is bogus:
A) you're using incredibly outdated avisynth plugins to decode your
source into avisynth.
B) You're using 2 different mpeg-2 decoder plugins to simultaneously
decode your source, to only which the latter one is used for the
resulting output.

At this point I'm going to say that you don't seem to know exactly
what you're doing with avisynth.

You're practically telling us to go on a wild goose chase with
A) no evidence or proof of anything being wrong in x264.
B) no concrete way of reproducing the suspected issue.