• Main Page
  • Related Pages
  • Modules
  • Data Structures
  • Files
  • File List
  • Globals

libavcodec/libopenjpeg.c

Go to the documentation of this file.
00001 /*
00002  * JPEG 2000 decoding support via OpenJPEG
00003  * Copyright (c) 2009 Jaikrishnan Menon <realityman@gmx.net>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include "avcodec.h"
00028 #include "libavutil/intreadwrite.h"
00029 #define  OPJ_STATIC
00030 #include <openjpeg.h>
00031 
00032 #define JP2_SIG_TYPE    0x6A502020
00033 #define JP2_SIG_VALUE   0x0D0A870A
00034 
00035 typedef struct {
00036     opj_dparameters_t dec_params;
00037     AVFrame image;
00038 } LibOpenJPEGContext;
00039 
00040 static int check_image_attributes(opj_image_t *image)
00041 {
00042     return image->comps[0].dx == image->comps[1].dx &&
00043            image->comps[1].dx == image->comps[2].dx &&
00044            image->comps[0].dy == image->comps[1].dy &&
00045            image->comps[1].dy == image->comps[2].dy &&
00046            image->comps[0].prec == image->comps[1].prec &&
00047            image->comps[1].prec == image->comps[2].prec;
00048 }
00049 
00050 static av_cold int libopenjpeg_decode_init(AVCodecContext *avctx)
00051 {
00052     LibOpenJPEGContext *ctx = avctx->priv_data;
00053 
00054     opj_set_default_decoder_parameters(&ctx->dec_params);
00055     avctx->coded_frame = &ctx->image;
00056     return 0;
00057 }
00058 
00059 static int libopenjpeg_decode_frame(AVCodecContext *avctx,
00060                                     void *data, int *data_size,
00061                                     AVPacket *avpkt)
00062 {
00063     const uint8_t *buf = avpkt->data;
00064     int buf_size = avpkt->size;
00065     LibOpenJPEGContext *ctx = avctx->priv_data;
00066     AVFrame *picture = &ctx->image, *output = data;
00067     opj_dinfo_t *dec;
00068     opj_cio_t *stream;
00069     opj_image_t *image;
00070     int width, height, has_alpha = 0, ret = -1;
00071     int x, y, index;
00072     uint8_t *img_ptr;
00073     int adjust[4];
00074 
00075     *data_size = 0;
00076 
00077     // Check if input is a raw jpeg2k codestream or in jp2 wrapping
00078     if((AV_RB32(buf) == 12) &&
00079        (AV_RB32(buf + 4) == JP2_SIG_TYPE) &&
00080        (AV_RB32(buf + 8) == JP2_SIG_VALUE)) {
00081         dec = opj_create_decompress(CODEC_JP2);
00082     } else {
00083         // If the AVPacket contains a jp2c box, then skip to
00084         // the starting byte of the codestream.
00085         if (AV_RB32(buf + 4) == AV_RB32("jp2c"))
00086             buf += 8;
00087         dec = opj_create_decompress(CODEC_J2K);
00088     }
00089 
00090     if(!dec) {
00091         av_log(avctx, AV_LOG_ERROR, "Error initializing decoder.\n");
00092         return -1;
00093     }
00094     opj_set_event_mgr((opj_common_ptr)dec, NULL, NULL);
00095 
00096     ctx->dec_params.cp_reduce = avctx->lowres;
00097     // Tie decoder with decoding parameters
00098     opj_setup_decoder(dec, &ctx->dec_params);
00099     stream = opj_cio_open((opj_common_ptr)dec, buf, buf_size);
00100     if(!stream) {
00101         av_log(avctx, AV_LOG_ERROR, "Codestream could not be opened for reading.\n");
00102         opj_destroy_decompress(dec);
00103         return -1;
00104     }
00105 
00106     // Decode the codestream
00107     image = opj_decode_with_info(dec, stream, NULL);
00108     opj_cio_close(stream);
00109     if(!image) {
00110         av_log(avctx, AV_LOG_ERROR, "Error decoding codestream.\n");
00111         opj_destroy_decompress(dec);
00112         return -1;
00113     }
00114     width  = image->comps[0].w << avctx->lowres;
00115     height = image->comps[0].h << avctx->lowres;
00116     if(avcodec_check_dimensions(avctx, width, height) < 0) {
00117         av_log(avctx, AV_LOG_ERROR, "%dx%d dimension invalid.\n", width, height);
00118         goto done;
00119     }
00120     avcodec_set_dimensions(avctx, width, height);
00121 
00122     switch(image->numcomps)
00123     {
00124         case 1:  avctx->pix_fmt = PIX_FMT_GRAY8;
00125                  break;
00126         case 3:  if(check_image_attributes(image)) {
00127                      avctx->pix_fmt = PIX_FMT_RGB24;
00128                  } else {
00129                      avctx->pix_fmt = PIX_FMT_GRAY8;
00130                      av_log(avctx, AV_LOG_ERROR, "Only first component will be used.\n");
00131                  }
00132                  break;
00133         case 4:  has_alpha = 1;
00134                  avctx->pix_fmt = PIX_FMT_RGBA;
00135                  break;
00136         default: av_log(avctx, AV_LOG_ERROR, "%d components unsupported.\n", image->numcomps);
00137                  goto done;
00138     }
00139 
00140     if(picture->data[0])
00141         avctx->release_buffer(avctx, picture);
00142 
00143     if(avctx->get_buffer(avctx, picture) < 0) {
00144         av_log(avctx, AV_LOG_ERROR, "Couldn't allocate image buffer.\n");
00145         return -1;
00146     }
00147 
00148     for(x = 0; x < image->numcomps; x++) {
00149         adjust[x] = FFMAX(image->comps[x].prec - 8, 0);
00150     }
00151 
00152     for(y = 0; y < avctx->height; y++) {
00153         index = y*avctx->width;
00154         img_ptr = picture->data[0] + y*picture->linesize[0];
00155         for(x = 0; x < avctx->width; x++, index++) {
00156             *img_ptr++ = image->comps[0].data[index] >> adjust[0];
00157             if(image->numcomps > 2 && check_image_attributes(image)) {
00158                 *img_ptr++ = image->comps[1].data[index] >> adjust[1];
00159                 *img_ptr++ = image->comps[2].data[index] >> adjust[2];
00160                 if(has_alpha)
00161                     *img_ptr++ = image->comps[3].data[index] >> adjust[3];
00162             }
00163         }
00164     }
00165 
00166     *output    = ctx->image;
00167     *data_size = sizeof(AVPicture);
00168     ret = buf_size;
00169 
00170 done:
00171     opj_image_destroy(image);
00172     opj_destroy_decompress(dec);
00173     return ret;
00174 }
00175 
00176 static av_cold int libopenjpeg_decode_close(AVCodecContext *avctx)
00177 {
00178     LibOpenJPEGContext *ctx = avctx->priv_data;
00179 
00180     if(ctx->image.data[0])
00181         avctx->release_buffer(avctx, &ctx->image);
00182     return 0 ;
00183 }
00184 
00185 
00186 AVCodec libopenjpeg_decoder = {
00187     "libopenjpeg",
00188     AVMEDIA_TYPE_VIDEO,
00189     CODEC_ID_JPEG2000,
00190     sizeof(LibOpenJPEGContext),
00191     libopenjpeg_decode_init,
00192     NULL,
00193     libopenjpeg_decode_close,
00194     libopenjpeg_decode_frame,
00195     CODEC_CAP_DR1,
00196     .long_name = NULL_IF_CONFIG_SMALL("OpenJPEG based JPEG 2000 decoder"),
00197 } ;

Generated on Fri Sep 16 2011 17:17:38 for FFmpeg by  doxygen 1.7.1