text: /*
   * LCL (LossLess Codec Library) Codec
   * Copyright (c) 2002-2004 Roberto Togni
   *
   * 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
   * LCL (LossLess Codec Library) Video Codec
   * Decoder for MSZH and ZLIB codecs
   * Experimental encoder for ZLIB RGB24
   *
   * Fourcc: MSZH, ZLIB
   *
   * Original Win32 dll:
   * Ver2.23 By Kenji Oshima 2000.09.20
   * avimszh.dll, avizlib.dll
   *
   * A description of the decoding algorithm can be found here:
   *   http://www.pcisys.net/~melanson/codecs
   *
   * Supports: BGR24 (RGB 24bpp)
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  
  #include "libavutil/avassert.h"
  #include "avcodec.h"
  #include "internal.h"
  #include "lcl.h"
  #include "libavutil/internal.h"
  #include "libavutil/mem.h"
  
  #include <zlib.h>
  
  typedef struct LclEncContext {
  
      AVCodecContext *avctx;
  
      // Image type
      int imgtype;
      // Compression type
      int compression;
      // Flags
      int flags;
      z_stream zstream;
  } LclEncContext;
  
  static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                          const AVFrame *p, int *got_packet)
  {
      LclEncContext *c = avctx->priv_data;
      int i, ret;
      int zret; // Zlib return code
      int max_size = deflateBound(&c->zstream, avctx->width * avctx->height * 3);
  
      if ((ret = ff_alloc_packet2(avctx, pkt, max_size, 0)) < 0)
          return ret;
  
      if(avctx->pix_fmt != AV_PIX_FMT_BGR24){
          av_log(avctx, AV_LOG_ERROR, "Format not supported!\n");
          return -1;
      }
  
      zret = deflateReset(&c->zstream);
      if (zret != Z_OK) {
          av_log(avctx, AV_LOG_ERROR, "Deflate reset error: %d\n", zret);
          return -1;
      }
      c->zstream.next_out  = pkt->data;
      c->zstream.avail_out = pkt->size;
  
      for(i = avctx->height - 1; i >= 0; i--) {
          c->zstream.next_in = p->data[0]+p->linesize[0]*i;
          c->zstream.avail_in = avctx->width*3;
          zret = deflate(&c->zstream, Z_NO_FLUSH);
          if (zret != Z_OK) {
              av_log(avctx, AV_LOG_ERROR, "Deflate error: %d\n", zret);
              return -1;
          }
      }
      zret = deflate(&c->zstream, Z_FINISH);
      if (zret != Z_STREAM_END) {
          av_log(avctx, AV_LOG_ERROR, "Deflate error: %d\n", zret);
          return -1;
      }
  
      pkt->size   = c->zstream.total_out;
      pkt->flags |= AV_PKT_FLAG_KEY;
      *got_packet = 1;
  
      return 0;
  }
  
  static av_cold int encode_init(AVCodecContext *avctx)
  {
      LclEncContext *c = avctx->priv_data;
      int zret; // Zlib return code
  
      c->avctx= avctx;
  
      av_assert0(avctx->width && avctx->height);
  
      avctx->extradata = av_mallocz(8 + AV_INPUT_BUFFER_PADDING_SIZE);
      if (!avctx->extradata)
          return AVERROR(ENOMEM);
  
  #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
  
      c->compression = avctx->compression_level == FF_COMPRESSION_DEFAULT ?
                              COMP_ZLIB_NORMAL :
                              av_clip(avctx->compression_level, 0, 9);
      c->flags = 0;
      c->imgtype = IMGTYPE_RGB24;
      avctx->bits_per_coded_sample= 24;
  
      avctx->extradata[0]= 4;
      avctx->extradata[1]= 0;
      avctx->extradata[2]= 0;
      avctx->extradata[3]= 0;
      avctx->extradata[4]= c->imgtype;
      avctx->extradata[5]= c->compression;
      avctx->extradata[6]= c->flags;
      avctx->extradata[7]= CODEC_ZLIB;
      c->avctx->extradata_size= 8;
  
      c->zstream.zalloc = Z_NULL;
      c->zstream.zfree = Z_NULL;
      c->zstream.opaque = Z_NULL;
      zret = deflateInit(&c->zstream, c->compression);
      if (zret != Z_OK) {
          av_log(avctx, AV_LOG_ERROR, "Deflate init error: %d\n", zret);
          return AVERROR_UNKNOWN;
      }
  
      return 0;
  }
  
  static av_cold int encode_end(AVCodecContext *avctx)
  {
      LclEncContext *c = avctx->priv_data;
  
      av_freep(&avctx->extradata);
      deflateEnd(&c->zstream);
  
      return 0;
  }
  
  AVCodec ff_zlib_encoder = {
      .name           = "zlib",
      .long_name      = NULL_IF_CONFIG_SMALL("LCL (LossLess Codec Library) ZLIB"),
      .type           = AVMEDIA_TYPE_VIDEO,
      .id             = AV_CODEC_ID_ZLIB,
      .priv_data_size = sizeof(LclEncContext),
      .init           = encode_init,
      .encode2        = encode_frame,
      .close          = encode_end,
      .capabilities   = AV_CODEC_CAP_FRAME_THREADS | AV_CODEC_CAP_INTRA_ONLY,
      .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_BGR24, AV_PIX_FMT_NONE },
      .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE |
                        FF_CODEC_CAP_INIT_CLEANUP,
  };
  