/*
  * DPX (.dpx) image encoder
  * Copyright (c) 2011 Peter Ross <pross@xvid.org>
  *
  * 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
  */
 
 #include "libavutil/intreadwrite.h"
 #include "libavutil/imgutils.h"
 #include "avcodec.h"
 
 typedef struct DPXContext {
     AVFrame picture;
     int big_endian;
     int bits_per_component;
     int descriptor;
 } DPXContext;
 
 static av_cold int encode_init(AVCodecContext *avctx)
 {
     DPXContext *s = avctx->priv_data;
 
     avctx->coded_frame = &s->picture;

     avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;

     avctx->coded_frame->key_frame = 1;
 
     s->big_endian         = 1;
     s->bits_per_component = 8;
     s->descriptor         = 50; /* RGB */
 
     switch (avctx->pix_fmt) {
     case PIX_FMT_RGB24:
         break;
     case PIX_FMT_RGBA:
         s->descriptor = 51; /* RGBA */
         break;
     case PIX_FMT_RGB48LE:
         s->big_endian = 0;
     case PIX_FMT_RGB48BE:
         s->bits_per_component = avctx->bits_per_raw_sample ? avctx->bits_per_raw_sample : 16;
         break;
     default:
         av_log(avctx, AV_LOG_INFO, "unsupported pixel format\n");
         return -1;
     }
 
     return 0;
 }
 
 #define write16(p, value) \
 do { \
     if (s->big_endian) AV_WB16(p, value); \
     else               AV_WL16(p, value); \
 } while(0)
 
 #define write32(p, value) \
 do { \
     if (s->big_endian) AV_WB32(p, value); \
     else               AV_WL32(p, value); \
 } while(0)
 

 static void encode_rgb48_10bit(AVCodecContext *avctx, const AVPicture *pic, uint8_t *dst)
 {
     DPXContext *s = avctx->priv_data;
     const uint8_t *src = pic->data[0];
     int x, y;
 
     for (y = 0; y < avctx->height; y++) {
         for (x = 0; x < avctx->width; x++) {
             int value;
             if ((avctx->pix_fmt & 1)) {
                 value = ((AV_RB16(src + 6*x + 4) & 0xFFC0) >> 4)
                       | ((AV_RB16(src + 6*x + 2) & 0xFFC0) << 6)
                       | ((AV_RB16(src + 6*x + 0) & 0xFFC0) << 16);
             } else {
                 value = ((AV_RL16(src + 6*x + 4) & 0xFFC0) >> 4)
                       | ((AV_RL16(src + 6*x + 2) & 0xFFC0) << 6)
                       | ((AV_RL16(src + 6*x + 0) & 0xFFC0) << 16);
             }
             write32(dst, value);
             dst += 4;
         }
         src += pic->linesize[0];
     }
 }
 

 static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data)
 {
     DPXContext *s = avctx->priv_data;
     int size;
 
 #define HEADER_SIZE 1664  /* DPX Generic header */
     if (buf_size < HEADER_SIZE)
         return -1;
 
     memset(buf, 0, HEADER_SIZE);
 
     /* File information header */
     write32(buf,       MKBETAG('S','D','P','X'));
     write32(buf +   4, HEADER_SIZE);
     memcpy (buf +   8, "V1.0", 4);
     write32(buf +  20, 1); /* new image */
     write32(buf +  24, HEADER_SIZE);
     memcpy (buf + 160, LIBAVCODEC_IDENT, FFMIN(sizeof(LIBAVCODEC_IDENT), 100));
     write32(buf + 660, 0xFFFFFFFF); /* unencrypted */
 
     /* Image information header */
     write16(buf + 768, 0); /* orientation; left to right, top to bottom */
     write16(buf + 770, 1); /* number of elements */
     write32(buf + 772, avctx->width);
     write32(buf + 776, avctx->height);
     buf[800] = s->descriptor;
     buf[801] = 2; /* linear transfer */
     buf[802] = 2; /* linear colorimetric */
     buf[803] = s->bits_per_component;

     write16(buf + 804, s->bits_per_component == 10 ? 1 : 0); /* packing method */

 
     /* Image source information header */
     write32(buf + 1628, avctx->sample_aspect_ratio.num);
     write32(buf + 1632, avctx->sample_aspect_ratio.den);
 

     switch(s->bits_per_component) {
     case 8:
     case 16:

         size = avpicture_layout(data, avctx->pix_fmt,

                                 avctx->width, avctx->height,
                                 buf + HEADER_SIZE, buf_size - HEADER_SIZE);
         if (size < 0)
             return size;

         break;
     case 10:
         size = avctx->height * avctx->width * 4;
         if (buf_size < HEADER_SIZE + size)
             return -1;

         encode_rgb48_10bit(avctx, data, buf + HEADER_SIZE);

         break;
     default:

         av_log(avctx, AV_LOG_ERROR, "Unsupported bit depth: %d\n", s->bits_per_component);

         return -1;
     }

 
     size += HEADER_SIZE;
 
     write32(buf + 16, size); /* file size */
     return size;
 }
 
 AVCodec ff_dpx_encoder = {

     .name = "dpx",
     .type = AVMEDIA_TYPE_VIDEO,
     .id   = CODEC_ID_DPX,
     .priv_data_size = sizeof(DPXContext),
     .init   = encode_init,

     .encode = encode_frame,

     .pix_fmts = (const enum PixelFormat[]){

         PIX_FMT_RGB24,
         PIX_FMT_RGBA,
         PIX_FMT_RGB48LE,
         PIX_FMT_RGB48BE,
         PIX_FMT_NONE},
     .long_name = NULL_IF_CONFIG_SMALL("DPX image"),
 };