[FFmpeg-devel] sgi without rle

[Benoit Fouet]

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