[Libav-user] avpicture_free crashing when using with sws_scale()

[Stefano Sabatini]

On date Tuesday 2013-06-25 03:52:41 -0700, Pradeep Karosiya encoded:
> Hi 
> 
> I'm trying to encode images into video. I'm following muxing.c and scaling.c
> examples. 
> Though I'm able to encode a video, I'm not able to get rid of memory leaks.
> I tried many different things
> related related to allocation of AVPicture but still memory leaks. 
> Specifically my code crashed when I call avpicture_free due to heap error.
> Here is the snippet of code
> void WriteFrame(const uchar* buf)  //Input buffer contained image data
> {
> if(need_conversion)
> {
>         AVPicture inpic;

>         avpicture_alloc(&inpic,(PixelFormat)input_pix_fmt, width, height);

Here you're allocating an image in inpic, and setting the data and
linesize pointers.

>         avpicture_fill(&inpic, (uint8_t*)buf, (PixelFormat)input_pix_fmt,
> width, height);

Here you're filling inpic with the buffer in buf (assuming align =
1). Now you destroyed the reference to the previously allocated data
-> leak.

>         struct SwsContext *img_convert_ctx = NULL;
>         img_convert_ctx = sws_getContext(
>             width,
>             height,
>             PIX_FMT_BGR24,
>             c->width,
>             c->height,
>             c->pix_fmt,
>             SWS_BICUBIC,
>             NULL, NULL, NULL);
> 
>         if (sws_scale(
>             img_convert_ctx, 
>             inpic.data,
>             inpic.linesize, 0,
>             height,
>             dst_picture.data, 
>             dst_picture.linesize) < 0 )
>         {
>             std::cout<<"Conversion Failed "<<std::endl
>         }
> 

>         avpicture_free(&inpic);  //Crashing here

here you're freeing the buf data, which maybe does not belong to the
heap?

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