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

Jai Menon jmenon86
Thu Jan 29 07:05:31 CET 2009


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:
> [...]
>> +static int libopenjpeg_decode_frame(AVCodecContext *avctx,
>> +                                    void *data, int *data_size,
>> +                                    const uint8_t *buf, int buf_size)
>> +{
>> +    LibOpenJPEGContext *ctx = avctx->priv_data;
>> +    AVPicture *picture = data;
>> +    opj_dinfo_t *dec = NULL;
>> +    opj_cio_t *stream = NULL;
>> +    opj_image_t *image = NULL;
>> +    int width, height, has_alpha = 0, ret = -1;
>> +    int x, y, index;
>> +    int picture_size;
>> +    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);
>
> if{
> }else
> and this can be vertically aligned prettier

fixed.

> [...]
>> +    width = image->comps[0].w;
>> +    height = image->comps[0].h;
>
> vertical align

done.

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

yes, removed.
revised patch attached.

[...]

-- 
Regards,

Jai
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