libavcodec/dpx.c

   1 /*
   2  * DPX (.dpx) image decoder
   3  * Copyright (c) 2009 Jimmy Christensen
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 #include "libavutil/intreadwrite.h"
  23 #include "bytestream.h"
  24 #include "avcodec.h"
  25
  26 typedef struct DPXContext {
  27     AVFrame picture;
  28 } DPXContext;
  29
  30
  31 static unsigned int read32(const uint8_t **ptr, int is_big)
  32 {
  33     unsigned int temp;
  34     if (is_big) {
  35         temp = AV_RB32(*ptr);
  36     } else {
  37         temp = AV_RL32(*ptr);
  38     }
  39     *ptr += 4;
  40     return temp;
  41 }
  42
  43 static inline unsigned make_16bit(unsigned value)
  44 {
  45     // mask away invalid bits
  46     value &= 0xFFC0;
  47     // correctly expand to 16 bits
  48     return value + (value >> 10);
  49 }
  50
  51 static int decode_frame(AVCodecContext *avctx,
  52                         void *data,
  53                         int *data_size,
  54                         AVPacket *avpkt)
  55 {
  56     const uint8_t *buf = avpkt->data;
  57     int buf_size       = avpkt->size;
  58     DPXContext *const s = avctx->priv_data;
  59     AVFrame *picture  = data;
  60     AVFrame *const p = &s->picture;
  61     uint8_t *ptr;
  62
  63     int magic_num, offset, endian;
  64     int x, y;
  65     int w, h, stride, bits_per_color, descriptor, elements, target_packet_size, source_packet_size;
  66
  67     unsigned int rgbBuffer;
  68
  69     magic_num = AV_RB32(buf);
  70     buf += 4;
  71
  72     /* Check if the files "magic number" is "SDPX" which means it uses
  73      * big-endian or XPDS which is for little-endian files */
  74     if (magic_num == AV_RL32("SDPX")) {
  75         endian = 0;
  76     } else if (magic_num == AV_RB32("SDPX")) {
  77         endian = 1;
  78     } else {
  79         av_log(avctx, AV_LOG_ERROR, "DPX marker not found\n");
  80         return -1;
  81     }
  82
  83     offset = read32(&buf, endian);
  84     // Need to end in 0x304 offset from start of file
  85     buf = avpkt->data + 0x304;
  86     w = read32(&buf, endian);
  87     h = read32(&buf, endian);
  88
  89     // Need to end in 0x320 to read the descriptor
  90     buf += 20;
  91     descriptor = buf[0];
  92
  93     // Need to end in 0x323 to read the bits per color
  94     buf += 3;
  95     bits_per_color = buf[0];
  96
  97     switch (descriptor) {
  98         case 51: // RGBA
  99             elements = 4;
 100             break;
 101         case 50: // RGB
 102             elements = 3;
 103             break;
 104         default:
 105             av_log(avctx, AV_LOG_ERROR, "Unsupported descriptor %d\n", descriptor);
 106             return -1;
 107     }
 108
 109     switch (bits_per_color) {
 110         case 8:
 111             if (elements == 4) {
 112                 avctx->pix_fmt = PIX_FMT_RGBA;
 113             } else {
 114                 avctx->pix_fmt = PIX_FMT_RGB24;
 115             }
 116             source_packet_size = elements;
 117             target_packet_size = elements;
 118             break;
 119         case 10:
 120             avctx->pix_fmt = PIX_FMT_RGB48;
 121             target_packet_size = 6;
 122             source_packet_size = elements * 2;
 123             break;
 124         case 12:
 125         case 16:
 126             if (endian) {
 127                 avctx->pix_fmt = PIX_FMT_RGB48BE;
 128             } else {
 129                 avctx->pix_fmt = PIX_FMT_RGB48LE;
 130             }
 131             target_packet_size = 6;
 132             source_packet_size = elements * 2;
 133             break;
 134         default:
 135             av_log(avctx, AV_LOG_ERROR, "Unsupported color depth : %d\n", bits_per_color);
 136             return -1;
 137     }
 138
 139     if (s->picture.data[0])
 140         avctx->release_buffer(avctx, &s->picture);
 141     if (avcodec_check_dimensions(avctx, w, h))
 142         return -1;
 143     if (w != avctx->width || h != avctx->height)
 144         avcodec_set_dimensions(avctx, w, h);
 145     if (avctx->get_buffer(avctx, p) < 0) {
 146         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 147         return -1;
 148     }
 149
 150     // Move pointer to offset from start of file
 151     buf =  avpkt->data + offset;
 152
 153     ptr    = p->data[0];
 154     stride = p->linesize[0];
 155
 156     switch (bits_per_color) {
 157         case 10:
 158             for (x = 0; x < avctx->height; x++) {
 159                uint16_t *dst = (uint16_t*)ptr;
 160                for (y = 0; y < avctx->width; y++) {
 161                    rgbBuffer = read32(&buf, endian);
 162                    // Read out the 10-bit colors and convert to 16-bit
 163                    *dst++ = make_16bit(rgbBuffer >> 16);
 164                    *dst++ = make_16bit(rgbBuffer >>  6);
 165                    *dst++ = make_16bit(rgbBuffer <<  4);
 166                }
 167                ptr += stride;
 168             }
 169             break;
 170         case 8:
 171         case 12: // Treat 12-bit as 16-bit
 172         case 16:
 173             if (source_packet_size == target_packet_size) {
 174                 for (x = 0; x < avctx->height; x++) {
 175                     memcpy(ptr, buf, target_packet_size*avctx->width);
 176                     ptr += stride;
 177                     buf += source_packet_size*avctx->width;
 178                 }
 179             } else {
 180                 for (x = 0; x < avctx->height; x++) {
 181                     uint8_t *dst = ptr;
 182                     for (y = 0; y < avctx->width; y++) {
 183                         memcpy(dst, buf, target_packet_size);
 184                         dst += target_packet_size;
 185                         buf += source_packet_size;
 186                     }
 187                     ptr += stride;
 188                 }
 189             }
 190             break;
 191     }
 192
 193     *picture   = s->picture;
 194     *data_size = sizeof(AVPicture);
 195
 196     return buf_size;
 197 }
 198
 199 static av_cold int decode_init(AVCodecContext *avctx)
 200 {
 201     DPXContext *s = avctx->priv_data;
 202     avcodec_get_frame_defaults(&s->picture);
 203     avctx->coded_frame = &s->picture;
 204     return 0;
 205 }
 206
 207 static av_cold int decode_end(AVCodecContext *avctx)
 208 {
 209     DPXContext *s = avctx->priv_data;
 210     if (s->picture.data[0])
 211         avctx->release_buffer(avctx, &s->picture);
 212
 213     return 0;
 214 }
 215
 216 AVCodec dpx_decoder = {
 217     "dpx",
 218     CODEC_TYPE_VIDEO,
 219     CODEC_ID_DPX,
 220     sizeof(DPXContext),
 221     decode_init,
 222     NULL,
 223     decode_end,
 224     decode_frame,
 225     0,
 226     NULL,
 227     .long_name = NULL_IF_CONFIG_SMALL("DPX image"),
 228 };