[FFmpeg-devel] [PATCH] avoid crashes if input stream size changes without using -r

[Reimar Döffinger]

On Sun, Jul 05, 2009 at 01:45:45PM +0200, Reimar D?ffinger wrote:
> Hello,
> I don't know why, but currently FFmpeg only checks for an input stream
> size change when it is using resizing.
> Which means when you not use resizing it passes incorrectly size frames
> to the encoder and just crashes, as demonstrated by
> vp62/smclockvp62hsp.avi.1.0 from issue 1240.
> Here the container resolution is 32x65568 but the codec changes it to
> 32x32 - passing that 32x32 frame to e.g. the raw encoder (for framecrc)
> initialized for 32x65568 obviously crashes.
> Attached patch mostly just moves some code around to avoid this and
> print an error instead.

> Index: ffmpeg.c
> ===================================================================
> --- ffmpeg.c	(revision 19346)
> +++ ffmpeg.c	(working copy)
> @@ -861,6 +861,7 @@
>                           int *frame_size)
>  {
>      int nb_frames, i, ret;
> +    int size_change;
>      int64_t topBand, bottomBand, leftBand, rightBand;
>      AVFrame *final_picture, *formatted_picture, *resampling_dst, *padding_src;
>      AVFrame picture_crop_temp, picture_pad_temp;
> @@ -935,14 +936,22 @@
>          }
>      }
>  
> +    size_change =  (ost->resample_height != (ist->st->codec->height - (ost->topBand  + ost->bottomBand)))
> +                || (ost->resample_width  != (ist->st->codec->width  - (ost->leftBand + ost->rightBand)))
> +                || (ost->resample_pix_fmt!= ist->st->codec->pix_fmt);
> +    if(size_change) {
> +        fprintf(stderr,"Input Stream #%d.%d frame size changed to %dx%d, %s\n", ist->file_index, ist->index, ist->st->codec->width, ist->st->codec->height,avcodec_get_pix_fmt_name(ist->st->codec->pix_fmt));
> +        if (!ost->video_resample) {
> +            if (exit_on_error)
> +                av_exit(1);
> +            return;
> +        }
> +    }

Sorry, that's of course nonsense, resample_width/resample_height etc.
are never set when resampling is not used so this just breaks things
completely.
I still think that something _similar_ to that is needed, I just don't
know which are the right variables...