[FFmpeg-devel] [PATCH] avformat/movenc: Reduce size of the allocated MOVIentry array

[Anton Khirnov]

Quoting James Almer (2020-03-26 15:18:53)
> On 3/26/2020 11:06 AM, Anton Khirnov wrote:
> > Quoting James Almer (2020-03-25 18:56:44)
> >> Increase it in a linear way instead.
> >> Helps reduce memory usage, especially on long, non fragmented output.
> >>
> >> Signed-off-by: James Almer <jamrial at gmail.com>
> >> ---
> >> An alternative is using av_fast_realloc(), in a similar fashion as
> >> ff_add_index_entry(), which will keep the memory usage more closely tied to the
> >> amount of entries needed, but the amount of reallocations will be much higher,
> >> so i don't know if the tradeof is beneficial.
> > 
> > Wait, wouldn't fast_realloc() do pretty much the same as your patch? Why
> > should the number of reallocations be higher?
> 
> I meant mimicking the behavior of ff_add_index_entry(), doing something like
> 
> cluster = av_fast_realloc(trk->cluster,
>                           &trk->cluster_capacity,
>                           (trk->entry + 1) * sizeof(*trk->cluster));
> trk->cluster = cluster;
> 
> Which will get rid of the fixed MOV_INDEX_CLUSTER_SIZE increase per
> realloc, and resulting in more, smaller size increment reallocs (but of
> course not after every single new entry, which is the entire point of
> av_fast_realloc()).

Ah, got it.

I'd say your patch is better, but it probably doesn't matter much.

-- 
Anton Khirnov