/*
  * Alias PIX image encoder
  * Copyright (C) 2014 Vittorio Giovara <vittorio.giovara@gmail.com>
  *

  * 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 "avcodec.h"
 #include "bytestream.h"
 #include "internal.h"
 
 #define ALIAS_HEADER_SIZE 10
 
 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                         const AVFrame *frame, int *got_packet)
 {
     int width, height, bits_pixel, i, j, length, ret;
     uint8_t *in_buf, *buf;
 

 #if FF_API_CODED_FRAME
 FF_DISABLE_DEPRECATION_WARNINGS

     avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
     avctx->coded_frame->key_frame = 1;

 FF_ENABLE_DEPRECATION_WARNINGS
 #endif

 
     width  = avctx->width;
     height = avctx->height;
 
     if (width > 65535 || height > 65535 ||
         width * height >= INT_MAX / 4 - ALIAS_HEADER_SIZE) {
         av_log(avctx, AV_LOG_ERROR, "Invalid image size %dx%d.\n", width, height);
         return AVERROR_INVALIDDATA;
     }
 
     switch (avctx->pix_fmt) {
     case AV_PIX_FMT_GRAY8:
         bits_pixel = 8;
         break;
     case AV_PIX_FMT_BGR24:
         bits_pixel = 24;
         break;
     default:
         return AVERROR(EINVAL);
     }
 
     length = ALIAS_HEADER_SIZE + 4 * width * height; // max possible

     if ((ret = ff_alloc_packet2(avctx, pkt, length, ALIAS_HEADER_SIZE + height*2)) < 0) {

         av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", length);
         return ret;
     }
 
     buf = pkt->data;
 
     /* Encode header. */
     bytestream_put_be16(&buf, width);
     bytestream_put_be16(&buf, height);
     bytestream_put_be32(&buf, 0); /* X, Y offset */
     bytestream_put_be16(&buf, bits_pixel);
 
     for (j = 0; j < height; j++) {
         in_buf = frame->data[0] + frame->linesize[0] * j;
         for (i = 0; i < width; ) {
             int count = 0;
             int pixel;
 
             if (avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
                 pixel = *in_buf;
                 while (count < 255 && count + i < width && pixel == *in_buf) {
                     count++;
                     in_buf++;
                 }
                 bytestream_put_byte(&buf, count);
                 bytestream_put_byte(&buf, pixel);
             } else { /* AV_PIX_FMT_BGR24 */
                 pixel = AV_RB24(in_buf);
                 while (count < 255 && count + i < width &&
                        pixel == AV_RB24(in_buf)) {
                     count++;
                     in_buf += 3;
                 }
                 bytestream_put_byte(&buf, count);
                 bytestream_put_be24(&buf, pixel);
             }
             i += count;
         }
     }
 
     /* Total length */
     av_shrink_packet(pkt, buf - pkt->data);
     pkt->flags |= AV_PKT_FLAG_KEY;
     *got_packet = 1;
 
     return 0;
 }
 
 AVCodec ff_alias_pix_encoder = {
     .name      = "alias_pix",
     .long_name = NULL_IF_CONFIG_SMALL("Alias/Wavefront PIX image"),
     .type      = AVMEDIA_TYPE_VIDEO,
     .id        = AV_CODEC_ID_ALIAS_PIX,
     .encode2   = encode_frame,
     .pix_fmts  = (const enum AVPixelFormat[]) {
         AV_PIX_FMT_BGR24, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
     },
 };