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

Michael Niedermayer michaelni
Tue Jan 27 19:56:57 CET 2009


On Tue, Jan 27, 2009 at 05:12:31PM +0530, Jai Menon wrote:
> Hi,
> 
> On Tue, Jan 27, 2009 at 4:52 PM, Michael Niedermayer <michaelni at gmx.at> wrote:
> > On Tue, Jan 27, 2009 at 10:26:19AM +0530, Jai Menon wrote:
[...]
> > [...]
> >> +    switch(image->numcomps)
> >> +    {
> >> +        case 1:  avctx->pix_fmt = PIX_FMT_GRAY8;
> >> +                 break;
> >
> > the  { should likely be on the same line as the switch and case and
> > switch should not be indented relative to each other.
> > Anyway this is just a suggestion, not important if you dislike it
> 
> can i keep it this way? :-)
> its easier on my eyes.

ok

[...]
> +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(!dec) {
> +        av_log (avctx, AV_LOG_ERROR, "Error initializing decoder\n");
> +        return -1;
> +    }
> +    opj_set_event_mgr((opj_common_ptr)dec, NULL, NULL);
> +    // Tie decoder with decoding parameters
> +    opj_setup_decoder(dec, &ctx->dec_params);
> +    stream = opj_cio_open((opj_common_ptr)dec, buf, buf_size);
> +    if(!stream) {
> +        av_log (avctx, AV_LOG_ERROR, "Codestream could not be opened for reading\n");
> +        opj_destroy_decompress(dec);
> +        return -1;
> +    }
> +    // Decode the codestream
> +    image = opj_decode_with_info(dec, stream, NULL);
> +    opj_cio_close(stream);
> +    if(!image) {
> +        av_log (avctx, AV_LOG_ERROR, "Error decoding codestream\n");
> +        opj_destroy_decompress(dec);
> +        return -1;
> +    }

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

tab
grep '	' in the file will tell you if there are more


> +    if (avcodec_check_dimensions(avctx, width, height) < 0) {
> +        av_log(avctx, AV_LOG_ERROR, "%dx%d dimension invalid \n", width, height);

> +        ret = -1;

unneded

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

Into a blind darkness they enter who follow after the Ignorance,
they as if into a greater darkness enter who devote themselves
to the Knowledge alone. -- Isha Upanishad
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