text: /*
   * PC Paintbrush PCX (.pcx) image encoder
   * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
   *
   * 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
   */
  
  /**
   * @file
   * PCX image encoder
   * @author Daniel Verkamp
   * @see http://www.qzx.com/pc-gpe/pcx.txt
   */
  
  #include "internal.h"
  #include "bytestream.h"
  #include "XMFFmpeg/libavutil/imgutils.h"
  
  typedef struct PCXContext {
      AVFrame picture;
  } PCXContext;
  
  static const uint32_t monoblack_pal[16] = { 0x000000, 0xFFFFFF };
  
  static av_cold int pcx_encode_init(AVCodecContext *avctx)
  {
      PCXContext *s = (PCXContext *)avctx->priv_data;
  
      avcodec_get_frame_defaults(&s->picture);
      avctx->coded_frame = &s->picture;
  
      return 0;
  }
  
  /**
   * PCX run-length encoder
   * @param dst output buffer
   * @param dst_size size of output buffer
   * @param src input buffer
   * @param src_plane_size size of one plane of input buffer in bytes
   * @param nplanes number of planes in input buffer
   * @return number of bytes written to dst or -1 on error
   * @bug will not work for nplanes != 1 && bpp != 8
   */
  static int pcx_rle_encode(      uint8_t *dst, int dst_size,
                            const uint8_t *src, int src_plane_size, int nplanes)
  {
      int p;
      const uint8_t *dst_start = dst;
  
      // check worst-case upper bound on dst_size
      if (dst_size < 2LL * src_plane_size * nplanes || src_plane_size <= 0)
          return -1;
  
      for (p = 0; p < nplanes; p++) {
          int count = 1;
          const uint8_t *src_plane = src + p;
          const uint8_t *src_plane_end = src_plane + src_plane_size * nplanes;
          uint8_t prev = *src_plane;
          src_plane += nplanes;
  
          for (; ; src_plane += nplanes) {
              if (src_plane < src_plane_end && *src_plane == prev && count < 0x3F) {
                  // current byte is same as prev
                  ++count;
              } else {
                  // output prev * count
                  if (count != 1 || prev >= 0xC0)
                      *dst++ = 0xC0 | count;
                  *dst++ = prev;
  
                  if (src_plane == src_plane_end)
                      break;
  
                  // start new run
                  count = 1;
                  prev = *src_plane;
              }
          }
      }
  
      return dst - dst_start;
  }
  
  static int pcx_encode_frame(AVCodecContext *avctx,
                              unsigned char *buf, int buf_size, void *data)
  {
      PCXContext *s = (PCXContext *)avctx->priv_data;
      AVFrame *const pict = &s->picture;
      const uint8_t *buf_start = buf;
      const uint8_t *buf_end   = buf + buf_size;
  
      int bpp, nplanes, i, y, line_bytes, written;
      const uint32_t *pal = NULL;
      uint32_t palette256[256];
      const uint8_t *src;
  
      *pict = *(AVFrame *)data;
      pict->pict_type = AV_PICTURE_TYPE_I;
      pict->key_frame = 1;
  
      if (avctx->width > 65535 || avctx->height > 65535) {
          av_log(avctx, AV_LOG_ERROR, "image dimensions do not fit in 16 bits\n");
          return -1;
      }
  
      switch (avctx->pix_fmt) {
      case PIX_FMT_RGB24:
          bpp = 8;
          nplanes = 3;
          break;
      case PIX_FMT_RGB8:
      case PIX_FMT_BGR8:
      case PIX_FMT_RGB4_BYTE:
      case PIX_FMT_BGR4_BYTE:
      case PIX_FMT_GRAY8:
          bpp = 8;
          nplanes = 1;
          ff_set_systematic_pal2(palette256, avctx->pix_fmt);
          pal = palette256;
          break;
      case PIX_FMT_PAL8:
          bpp = 8;
          nplanes = 1;
          pal = (uint32_t *)pict->data[1];
          break;
      case PIX_FMT_MONOBLACK:
          bpp = 1;
          nplanes = 1;
          pal = monoblack_pal;
          break;
      default:
          av_log(avctx, AV_LOG_ERROR, "unsupported pixfmt\n");
          return -1;
      }
  
      line_bytes = (avctx->width * bpp + 7) >> 3;
      line_bytes = (line_bytes + 1) & ~1;
  
      bytestream_put_byte(&buf, 10);                  // manufacturer
      bytestream_put_byte(&buf, 5);                   // version
      bytestream_put_byte(&buf, 1);                   // encoding
      bytestream_put_byte(&buf, bpp);                 // bits per pixel per plane
      bytestream_put_le16(&buf, 0);                   // x min
      bytestream_put_le16(&buf, 0);                   // y min
      bytestream_put_le16(&buf, avctx->width - 1);    // x max
      bytestream_put_le16(&buf, avctx->height - 1);   // y max
      bytestream_put_le16(&buf, 0);                   // horizontal DPI
      bytestream_put_le16(&buf, 0);                   // vertical DPI
      for (i = 0; i < 16; i++)
          bytestream_put_be24(&buf, pal ? pal[i] : 0);// palette (<= 16 color only)
      bytestream_put_byte(&buf, 0);                   // reserved
      bytestream_put_byte(&buf, nplanes);             // number of planes
      bytestream_put_le16(&buf, line_bytes);          // scanline plane size in bytes
  
      while (buf - buf_start < 128)
          *buf++= 0;
  
      src = pict->data[0];
  
      for (y = 0; y < avctx->height; y++) {
          if ((written = pcx_rle_encode(buf, buf_end - buf,
                                        src, line_bytes, nplanes)) < 0) {
              av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
              return -1;
          }
          buf += written;
          src += pict->linesize[0];
      }
  
      if (nplanes == 1 && bpp == 8) {
          if (buf_end - buf < 257) {
              av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
              return -1;
          }
          bytestream_put_byte(&buf, 12);
          for (i = 0; i < 256; i++) {
              bytestream_put_be24(&buf, pal[i]);
          }
      }
  
      return buf - buf_start;
  }
  
  static const enum PixelFormat _ff_pcx_encoder[] = 
  {
  	PIX_FMT_RGB24,
  	PIX_FMT_RGB8, PIX_FMT_BGR8, PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE, PIX_FMT_GRAY8, PIX_FMT_PAL8,
  	PIX_FMT_MONOBLACK,
  	PIX_FMT_NONE
  };
  AVCodec ff_pcx_encoder = {
      /*.name					= */	"pcx",
      /*.type					= */	AVMEDIA_TYPE_VIDEO,
      /*.id					= */	CODEC_ID_PCX,
      /*.priv_data_size		= */	sizeof(PCXContext),
      /*.init					= */	pcx_encode_init,
      /*.encode				= */	pcx_encode_frame,
      /*.close				= */	0,
      /*.decode				= */	0,
      /*.capabilities			= */	0,
  	/*.next					= */	0,
  	/*.flush				= */	0,
  	/*.supported_framerates	= */	0,
  	/*.pix_fmts				= */	_ff_pcx_encoder,
      /*.long_name			= */	NULL_IF_CONFIG_SMALL("PC Paintbrush PCX image"),
  };
  