[x264-devel] Problem with x264 multithreding enabled

[Alessandro Ferrari]

2009/9/16 Steven Walters <kemuri9 at gmail.com>

> On Wed, Sep 16, 2009 at 4:43 AM, Alessandro Ferrari
> <alessandroferrari87 at gmail.com> wrote:
> > Hi,
> >      i'm developing a program using x264 api starting by the source code
> of
> > x264.c, and I encurr in a problem that probably i miss any operations. I
> > need to minimize the frame delay, so for this reason initially i have
> > developed forcing using only one thread. The program in this case works
> > correctly. Then, for maximize the performance i simply set the
> i_threads=2
> > to enabling multi-threading, and I expect a frame delay of one frame, but
> > the result is very different. I test the encoder on a sequence of 100
> > frames, and for all 100 frames the encoder function return a zero value
> for
> > i_nal, at the end in the flush _delayed_frame loop  i  have again  2
> encoder
> > function calling with i_nal null, and then at the third passing i have
> > i_nal=1 but i have this error:
> > test_x264_2thread: common/frame.c:971: x264_frame_push_unused: Assertion
> > `frame->i_reference_count > 0' failed.
> > The strange things is that with param.i_threads=1 always works without
> > problem.
> > If i force the settings of x264.c by specifying it before calling the
> > encoder function to be equal at the settings that i specify in my program
> i
> > haven't this error. What could be the problem?
> > I also include my encoding functions:
> >
> > Thanks for the attention.
> > Best regards.
> >
>
> with threads >1, the lookahead thread is enabled by default as well
> which adds more delay itself.
> It does not seem you are compensating for this in your logic so try
> disabling it by adding a
> param.i_sync_lookahead = 0;
> line in your section where you modify the parameters.
>

Thanks, but i haven't this field in my version of x264, i have download
around a month ago, probably it's added very recently. The lookahead thread
is activated by default also in x264 version pre i_sync_lookahead? thanks.
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