PeerStreamer

/*

 * JPEG 2000 decoding support via OpenJPEG

 * Copyright (c) 2009 Jaikrishnan Menon <realityman@gmx.net>

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

* @file

* JPEG 2000 decoder using libopenjpeg

*/

#include "libavcore/imgutils.h"

#include "avcodec.h"

#include "libavutil/intreadwrite.h"

#define  OPJ_STATIC

#include <openjpeg.h>

#define JP2_SIG_TYPE    0x6A502020

#define JP2_SIG_VALUE   0x0D0A870A

typedef struct {

    opj_dparameters_t dec_params;

    AVFrame image;

} LibOpenJPEGContext;

static int check_image_attributes(opj_image_t *image)

{

    return image->comps[0].dx == image->comps[1].dx &&

           image->comps[1].dx == image->comps[2].dx &&

           image->comps[0].dy == image->comps[1].dy &&

           image->comps[1].dy == image->comps[2].dy &&

           image->comps[0].prec == image->comps[1].prec &&

           image->comps[1].prec == image->comps[2].prec;

}

static av_cold int libopenjpeg_decode_init(AVCodecContext *avctx)

{

    LibOpenJPEGContext *ctx = avctx->priv_data;

    opj_set_default_decoder_parameters(&ctx->dec_params);

    avctx->coded_frame = &ctx->image;

    return 0;

}

static int libopenjpeg_decode_frame(AVCodecContext *avctx,

                                    void *data, int *data_size,

                                    AVPacket *avpkt)

{

    const uint8_t *buf = avpkt->data;

    int buf_size = avpkt->size;

    LibOpenJPEGContext *ctx = avctx->priv_data;

    AVFrame *picture = &ctx->image, *output = data;

    opj_dinfo_t *dec;

    opj_cio_t *stream;

    opj_image_t *image;

    int width, height, has_alpha = 0, ret = -1;

    int x, y, index;

    uint8_t *img_ptr;

    int adjust[4];

    *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 {

        // If the AVPacket contains a jp2c box, then skip to

        // the starting byte of the codestream.

        if (AV_RB32(buf + 4) == AV_RB32("jp2c"))

            buf += 8;

        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);

    ctx->dec_params.cp_reduce = avctx->lowres;

    // 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 << avctx->lowres;

    height = image->comps[0].h << avctx->lowres;

    if(av_image_check_size(width, height, 0, avctx) < 0) {

        av_log(avctx, AV_LOG_ERROR, "%dx%d dimension invalid.\n", width, height);

        goto done;

    }

    avcodec_set_dimensions(avctx, width, height);

    switch(image->numcomps)

    {

        case 1:  avctx->pix_fmt = PIX_FMT_GRAY8;

                 break;

        case 3:  if(check_image_attributes(image)) {

                     avctx->pix_fmt = PIX_FMT_RGB24;

                 } else {

                     avctx->pix_fmt = PIX_FMT_GRAY8;

                     av_log(avctx, AV_LOG_ERROR, "Only first component will be used.\n");

                 }

                 break;

        case 4:  has_alpha = 1;

                 avctx->pix_fmt = PIX_FMT_RGBA;

                 break;

        default: av_log(avctx, AV_LOG_ERROR, "%d components unsupported.\n", image->numcomps);

                 goto done;

    }

    if(picture->data[0])

        avctx->release_buffer(avctx, picture);

    if(avctx->get_buffer(avctx, picture) < 0) {

        av_log(avctx, AV_LOG_ERROR, "Couldn't allocate image buffer.\n");

        return -1;

    }

    for(x = 0; x < image->numcomps; x++) {

        adjust[x] = FFMAX(image->comps[x].prec - 8, 0);

    }

    for(y = 0; y < avctx->height; y++) {

        index = y*avctx->width;

        img_ptr = picture->data[0] + y*picture->linesize[0];

        for(x = 0; x < avctx->width; x++, index++) {

            *img_ptr++ = image->comps[0].data[index] >> adjust[0];

            if(image->numcomps > 2 && check_image_attributes(image)) {

                *img_ptr++ = image->comps[1].data[index] >> adjust[1];

                *img_ptr++ = image->comps[2].data[index] >> adjust[2];

                if(has_alpha)

                    *img_ptr++ = image->comps[3].data[index] >> adjust[3];

            }

        }

    }

    *output    = ctx->image;

    *data_size = sizeof(AVPicture);

    ret = buf_size;

done:

    opj_image_destroy(image);

    opj_destroy_decompress(dec);

    return ret;

}

static av_cold int libopenjpeg_decode_close(AVCodecContext *avctx)

{

    LibOpenJPEGContext *ctx = avctx->priv_data;

    if(ctx->image.data[0])

        avctx->release_buffer(avctx, &ctx->image);

    return 0 ;

}

AVCodec ff_libopenjpeg_decoder = {

    "libopenjpeg",

    AVMEDIA_TYPE_VIDEO,

    CODEC_ID_JPEG2000,

    sizeof(LibOpenJPEGContext),

    libopenjpeg_decode_init,

    NULL,

    libopenjpeg_decode_close,

    libopenjpeg_decode_frame,

    CODEC_CAP_DR1,

    .max_lowres = 5,

    .long_name = NULL_IF_CONFIG_SMALL("OpenJPEG based JPEG 2000 decoder"),

} ;