[FFmpeg-devel] sgi without rle

[Anne-Laure de Smit]

On Wed, Sep 30, 2009 at 10:29 AM, Benoit Fouet <benoit.fouet at free.fr> wrote:

> Hi,
>
> On 2009-09-30 09:54, Anne-Laure de Smit wrote:
> > On Thu, Sep 24, 2009 at 10:43 AM, Anne-Laure de Smit <
> > annelaure.desmit at gmail.com> wrote:
> >
> >>
> >> On Thu, Sep 17, 2009 at 11:40 PM, Vitor Sessak <vitor1001 at gmail.com
> >wrote:
> >>
> >>> Anne-Laure de Smit wrote:
> >>>
> >>>> Hi,
> >>>>
> >>>> I want to modify sgienc.c for that image sgi are not compressed
> (without
> >>>> rle). How can I do this?
> >>>>
> >>> First of all, look at sgidec.c to see in what compressed and
> uncompressed
> >>> sgi images differs (and how uncompressed data is stored). Then, you
> need a
> >>> way to specify through the command line if the user want compression or
> not.
> >>> I suggest  "-compression_level" command line parameter that will set
> >>> avctx->compression_level (as is done in tiffenc.c). Then, finally, in
> >>> encode_frame(), just write the uncompressed data to the buffer if the
> >>> avctx->compression_level is set to zero.
> >>>
> >>> -Vitor
> >>>
> >> Thank you very much for your help.
> >> I propose the attached patch.
> >> For use it:
> >> Uncompressed images:
> >> ffmpeg -i file.bmp -compression_level 0 out.sgi
> >> RLE compressed images:
> >> ffmpeg -i file.bmp -compression_level 1 out.sgi
> >>
> >> Anne-Laure
> >>
> >> Ping.
>
> > Index: libavcodec/sgienc.c
> > ===================================================================
> > --- libavcodec/sgienc.c       (revision 20008)
> > +++ libavcodec/sgienc.c       (working copy)
> > @@ -83,7 +83,7 @@
> >
> >      /* Encode header. */
> >      bytestream_put_be16(&buf, SGI_MAGIC);
> > -    bytestream_put_byte(&buf, 1); /* RLE */
> > +    bytestream_put_byte(&buf, avctx->compression_level != 0); /* RLE
> > 1 - VERBATIM 0*/
>
> 0 */
>
> > @@ -139,6 +140,20 @@
> >      }
> >
> >      av_free(encode_buf);
> > +    } else {
> > +        for (z = 0; z < depth; z++) {
> > +            in_buf = p->data[0] + p->linesize[0] * (height - 1) + z;
> > +
> > +            for (y = 0; y < height; y++) {
> > +
> > +                for (x = 0; x < width; x++)
> > +                    bytestream_put_byte(&buf,in_buf[depth * x]);
> > +
> > +                in_buf -= p->linesize[0];
>
> how about the following:
>
> for (x = 0; x < width*depth; x += depth)
>    bytestream_put_byte(&buf,in_buf[x]);
>
> Ben
>

Yes you're right, it's the same thing but I used the same syntax that the
code before. But Maybe your code is better, clearer. I changed my patch with
your code.
Anne-Laure

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