[FFmpeg-devel] [PATCH] libopenjpeg wrapper for jpeg2k decoding

[Michael Niedermayer]

On Mon, Feb 02, 2009 at 04:48:17PM +0530, Jai Menon wrote:
> Hi,
> 
> 2009/1/29 Michael Niedermayer <michaelni at gmx.at>:
> > On Thu, Jan 29, 2009 at 11:35:31AM +0530, Jai Menon wrote:
> >> Hi,
> >>
> >> On Thu, Jan 29, 2009 at 4:27 AM, Michael Niedermayer <michaelni at gmx.at> wrote:
> >> > On Wed, Jan 28, 2009 at 02:23:46PM +0530, Jai Menon wrote:
> 
> [...]
> 
> > dec is written to twice with no read in between, this applies to more vars
> 
> fixed.
> 
> [...]
> 
> > sec hole when width/height changes
> 
> fixed (i think).
> 
> i also reworked most of the code to use get/release_buffer
> revised patch attached.
[...]
> +static int libopenjpeg_decode_frame(AVCodecContext *avctx,
> +                                    void *data, int *data_size,
> +                                    const uint8_t *buf, int buf_size)
> +{
> +    LibOpenJPEGContext *ctx = avctx->priv_data;
> +    AVFrame *picture = &ctx->image, *output = data;
> +    opj_dinfo_t *dec;

> +    opj_cio_t *stream = NULL;

written twice before read


> +    opj_image_t *image = NULL;
> +    int width, height, has_alpha = 0, ret = -1;
> +    int x, y, index;
> +    uint8_t *img_ptr;
> +    float scale;
> +
> +    *data_size = 0;
> +
> +    // Check if input is a raw jpeg2k codestream or in jp2 wrapping
> +    if((AV_RB32(buf) == 12) && 
> +       (AV_RB32(buf + 4) == JP2_SIG_TYPE) &&
> +       (AV_RB32(buf + 8) == JP2_SIG_VALUE)) {
> +         dec = opj_create_decompress(CODEC_JP2);

> +    }
> +    else dec = opj_create_decompress(CODEC_J2K);

diego likely wont like this kind of } placement style


[...]
> +    scale = 255.0f / (float)((1 << image->comps[0].prec) - 1);
> +    for(y = 0; y < height; y++) {
> +        index = y*width;
> +        img_ptr = picture->data[0] + y*picture->linesize[0];
> +        for(x = 0; x < width; x++, index++) {
> +            *img_ptr++ = image->comps[0].data[index] * scale;
> +            if(image->numcomps > 2 && check_image_attributes(image)) {
> +                *img_ptr++ = image->comps[1].data[index] * scale;
> +                *img_ptr++ = image->comps[2].data[index] * scale;
> +                if(has_alpha)
> +                    *img_ptr++ = image->comps[3].data[index] * scale;
> +            }
> +        }
> +    }

lrintf()

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The educated differ from the uneducated as much as the living from the
dead. -- Aristotle 
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