/*
  * TechSmith Camtasia decoder
  * Copyright (c) 2004 Konstantin Shishkov
  *

  * 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

  * TechSmith Camtasia decoder
  *
  * Fourcc: TSCC
  *
  * Codec is very simple:
  *  it codes picture (picture difference, really)
  *  with algorithm almost identical to Windows RLE8,
  *  only without padding and with greater pixel sizes,
  *  then this coded picture is packed with ZLib
  *

  * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested

  *
  */
 
 #include <stdio.h>
 #include <stdlib.h>
 
 #include "avcodec.h"

 #include "internal.h"

 #include "msrledec.h"

 
 #include <zlib.h>
 
 typedef struct TsccContext {
 
     AVCodecContext *avctx;

     AVFrame *frame;

 
     // Bits per pixel
     int bpp;
     // Decompressed data size
     unsigned int decomp_size;
     // Decompression buffer
     unsigned char* decomp_buf;

     GetByteContext gb;

     int height;
     z_stream zstream;

 
     uint32_t pal[256];

 } CamtasiaContext;
 

 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
                         AVPacket *avpkt)

 {

     const uint8_t *buf = avpkt->data;
     int buf_size = avpkt->size;

     CamtasiaContext * const c = avctx->priv_data;

     AVFrame *frame = c->frame;

     int ret;

     if ((ret = ff_reget_buffer(avctx, frame)) < 0)

         return ret;

     ret = inflateReset(&c->zstream);
     if (ret != Z_OK) {
         av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);

         return AVERROR_UNKNOWN;

     }

     c->zstream.next_in   = buf;
     c->zstream.avail_in  = buf_size;

     c->zstream.next_out = c->decomp_buf;
     c->zstream.avail_out = c->decomp_size;

     ret = inflate(&c->zstream, Z_FINISH);

     // Z_DATA_ERROR means empty picture

     if ((ret != Z_OK) && (ret != Z_STREAM_END) && (ret != Z_DATA_ERROR)) {
         av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);

         return AVERROR_UNKNOWN;

     }

     if (ret != Z_DATA_ERROR) {

         bytestream2_init(&c->gb, c->decomp_buf,
                          c->decomp_size - c->zstream.avail_out);

         ff_msrle_decode(avctx, frame, c->bpp, &c->gb);

     }

     /* make the palette available on the way out */

     if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {

         const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
 
         if (pal) {

             frame->palette_has_changed = 1;

             memcpy(c->pal, pal, AVPALETTE_SIZE);

         }

         memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);

     }
 

     if ((ret = av_frame_ref(data, frame)) < 0)
         return ret;

     *got_frame      = 1;

 
     /* always report that the buffer was completely consumed */
     return buf_size;
 }
 

 static av_cold int decode_init(AVCodecContext *avctx)

 {

     CamtasiaContext * const c = avctx->priv_data;

     int zret; // Zlib return code
 
     c->avctx = avctx;
 
     c->height = avctx->height;
 
     // Needed if zlib unused or init aborted before inflateInit

     memset(&c->zstream, 0, sizeof(z_stream));

     switch(avctx->bits_per_coded_sample){

     case  8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
     case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;

     case 24:

              avctx->pix_fmt = AV_PIX_FMT_BGR24;

              break;

     case 32: avctx->pix_fmt = AV_PIX_FMT_0RGB32; break;

     default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);

              return AVERROR_PATCHWELCOME;

     }

     c->bpp = avctx->bits_per_coded_sample;

     // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too

     c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;

 
     /* Allocate decompression buffer */
     if (c->decomp_size) {

         if (!(c->decomp_buf = av_malloc(c->decomp_size))) {

             av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");

             return AVERROR(ENOMEM);

         }
     }

     c->zstream.zalloc = Z_NULL;
     c->zstream.zfree = Z_NULL;
     c->zstream.opaque = Z_NULL;

     zret = inflateInit(&c->zstream);

     if (zret != Z_OK) {
         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);

         return AVERROR_UNKNOWN;

     }
 

     c->frame = av_frame_alloc();
 

     return 0;
 }
 

 static av_cold int decode_end(AVCodecContext *avctx)

 {

     CamtasiaContext * const c = avctx->priv_data;

     av_freep(&c->decomp_buf);

     av_frame_free(&c->frame);

     inflateEnd(&c->zstream);

 
     return 0;
 }
 

 AVCodec ff_tscc_decoder = {

     .name           = "camtasia",

     .long_name      = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),

     .type           = AVMEDIA_TYPE_VIDEO,

     .id             = AV_CODEC_ID_TSCC,

     .priv_data_size = sizeof(CamtasiaContext),
     .init           = decode_init,
     .close          = decode_end,
     .decode         = decode_frame,

     .capabilities   = AV_CODEC_CAP_DR1,

 };