Libav 0.7.1
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 Libav.
00006  *
00007  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00027 #include "libavutil/imgutils.h"
00028 #include "avcodec.h"
00029 #include "libavutil/intreadwrite.h"
00030 #define  OPJ_STATIC
00031 #include <openjpeg.h>
00032 
00033 #define JP2_SIG_TYPE    0x6A502020
00034 #define JP2_SIG_VALUE   0x0D0A870A
00035 
00036 typedef struct {
00037     opj_dparameters_t dec_params;
00038     AVFrame image;
00039 } LibOpenJPEGContext;
00040 
00041 static int check_image_attributes(opj_image_t *image)
00042 {
00043     return image->comps[0].dx == image->comps[1].dx &&
00044            image->comps[1].dx == image->comps[2].dx &&
00045            image->comps[0].dy == image->comps[1].dy &&
00046            image->comps[1].dy == image->comps[2].dy &&
00047            image->comps[0].prec == image->comps[1].prec &&
00048            image->comps[1].prec == image->comps[2].prec;
00049 }
00050 
00051 static av_cold int libopenjpeg_decode_init(AVCodecContext *avctx)
00052 {
00053     LibOpenJPEGContext *ctx = avctx->priv_data;
00054 
00055     opj_set_default_decoder_parameters(&ctx->dec_params);
00056     avctx->coded_frame = &ctx->image;
00057     return 0;
00058 }
00059 
00060 static int libopenjpeg_decode_frame(AVCodecContext *avctx,
00061                                     void *data, int *data_size,
00062                                     AVPacket *avpkt)
00063 {
00064     const uint8_t *buf = avpkt->data;
00065     int buf_size = avpkt->size;
00066     LibOpenJPEGContext *ctx = avctx->priv_data;
00067     AVFrame *picture = &ctx->image, *output = data;
00068     opj_dinfo_t *dec;
00069     opj_cio_t *stream;
00070     opj_image_t *image;
00071     int width, height, has_alpha = 0, ret = -1;
00072     int x, y, index;
00073     uint8_t *img_ptr;
00074     int adjust[4];
00075 
00076     *data_size = 0;
00077 
00078     // Check if input is a raw jpeg2k codestream or in jp2 wrapping
00079     if((AV_RB32(buf) == 12) &&
00080        (AV_RB32(buf + 4) == JP2_SIG_TYPE) &&
00081        (AV_RB32(buf + 8) == JP2_SIG_VALUE)) {
00082         dec = opj_create_decompress(CODEC_JP2);
00083     } else {
00084         // If the AVPacket contains a jp2c box, then skip to
00085         // the starting byte of the codestream.
00086         if (AV_RB32(buf + 4) == AV_RB32("jp2c"))
00087             buf += 8;
00088         dec = opj_create_decompress(CODEC_J2K);
00089     }
00090 
00091     if(!dec) {
00092         av_log(avctx, AV_LOG_ERROR, "Error initializing decoder.\n");
00093         return -1;
00094     }
00095     opj_set_event_mgr((opj_common_ptr)dec, NULL, NULL);
00096 
00097     ctx->dec_params.cp_reduce = avctx->lowres;
00098     // Tie decoder with decoding parameters
00099     opj_setup_decoder(dec, &ctx->dec_params);
00100     stream = opj_cio_open((opj_common_ptr)dec, buf, buf_size);
00101     if(!stream) {
00102         av_log(avctx, AV_LOG_ERROR, "Codestream could not be opened for reading.\n");
00103         opj_destroy_decompress(dec);
00104         return -1;
00105     }
00106 
00107     // Decode the codestream
00108     image = opj_decode_with_info(dec, stream, NULL);
00109     opj_cio_close(stream);
00110     if(!image) {
00111         av_log(avctx, AV_LOG_ERROR, "Error decoding codestream.\n");
00112         opj_destroy_decompress(dec);
00113         return -1;
00114     }
00115     width  = image->comps[0].w << avctx->lowres;
00116     height = image->comps[0].h << avctx->lowres;
00117     if(av_image_check_size(width, height, 0, avctx) < 0) {
00118         av_log(avctx, AV_LOG_ERROR, "%dx%d dimension invalid.\n", width, height);
00119         goto done;
00120     }
00121     avcodec_set_dimensions(avctx, width, height);
00122 
00123     switch(image->numcomps)
00124     {
00125         case 1:  avctx->pix_fmt = PIX_FMT_GRAY8;
00126                  break;
00127         case 3:  if(check_image_attributes(image)) {
00128                      avctx->pix_fmt = PIX_FMT_RGB24;
00129                  } else {
00130                      avctx->pix_fmt = PIX_FMT_GRAY8;
00131                      av_log(avctx, AV_LOG_ERROR, "Only first component will be used.\n");
00132                  }
00133                  break;
00134         case 4:  has_alpha = 1;
00135                  avctx->pix_fmt = PIX_FMT_RGBA;
00136                  break;
00137         default: av_log(avctx, AV_LOG_ERROR, "%d components unsupported.\n", image->numcomps);
00138                  goto done;
00139     }
00140 
00141     if(picture->data[0])
00142         avctx->release_buffer(avctx, picture);
00143 
00144     if(avctx->get_buffer(avctx, picture) < 0) {
00145         av_log(avctx, AV_LOG_ERROR, "Couldn't allocate image buffer.\n");
00146         return -1;
00147     }
00148 
00149     for(x = 0; x < image->numcomps; x++) {
00150         adjust[x] = FFMAX(image->comps[x].prec - 8, 0);
00151     }
00152 
00153     for(y = 0; y < avctx->height; y++) {
00154         index = y*avctx->width;
00155         img_ptr = picture->data[0] + y*picture->linesize[0];
00156         for(x = 0; x < avctx->width; x++, index++) {
00157             *img_ptr++ = image->comps[0].data[index] >> adjust[0];
00158             if(image->numcomps > 2 && check_image_attributes(image)) {
00159                 *img_ptr++ = image->comps[1].data[index] >> adjust[1];
00160                 *img_ptr++ = image->comps[2].data[index] >> adjust[2];
00161                 if(has_alpha)
00162                     *img_ptr++ = image->comps[3].data[index] >> adjust[3];
00163             }
00164         }
00165     }
00166 
00167     *output    = ctx->image;
00168     *data_size = sizeof(AVPicture);
00169     ret = buf_size;
00170 
00171 done:
00172     opj_image_destroy(image);
00173     opj_destroy_decompress(dec);
00174     return ret;
00175 }
00176 
00177 static av_cold int libopenjpeg_decode_close(AVCodecContext *avctx)
00178 {
00179     LibOpenJPEGContext *ctx = avctx->priv_data;
00180 
00181     if(ctx->image.data[0])
00182         avctx->release_buffer(avctx, &ctx->image);
00183     return 0 ;
00184 }
00185 
00186 
00187 AVCodec ff_libopenjpeg_decoder = {
00188     "libopenjpeg",
00189     AVMEDIA_TYPE_VIDEO,
00190     CODEC_ID_JPEG2000,
00191     sizeof(LibOpenJPEGContext),
00192     libopenjpeg_decode_init,
00193     NULL,
00194     libopenjpeg_decode_close,
00195     libopenjpeg_decode_frame,
00196     CODEC_CAP_DR1,
00197     .max_lowres = 5,
00198     .long_name = NULL_IF_CONFIG_SMALL("OpenJPEG based JPEG 2000 decoder"),
00199 } ;