1/*
2 * TechSmith Camtasia decoder
3 * Copyright (c) 2004 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * TechSmith Camtasia decoder
25 *
26 * Fourcc: TSCC
27 *
28 * Codec is very simple:
29 *  it codes picture (picture difference, really)
30 *  with algorithm almost identical to Windows RLE8,
31 *  only without padding and with greater pixel sizes,
32 *  then this coded picture is packed with ZLib
33 *
34 * Supports: BGR8,BGR555,BGR24 - only BGR8 and BGR555 tested
35 *
36 */
37
38#include <stdio.h>
39#include <stdlib.h>
40
41#include "avcodec.h"
42#include "msrledec.h"
43
44#include <zlib.h>
45
46
47/*
48 * Decoder context
49 */
50typedef struct TsccContext {
51
52    AVCodecContext *avctx;
53    AVFrame pic;
54
55    // Bits per pixel
56    int bpp;
57    // Decompressed data size
58    unsigned int decomp_size;
59    // Decompression buffer
60    unsigned char* decomp_buf;
61    int height;
62    z_stream zstream;
63} CamtasiaContext;
64
65/*
66 *
67 * Decode a frame
68 *
69 */
70static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
71{
72    const uint8_t *buf = avpkt->data;
73    int buf_size = avpkt->size;
74    CamtasiaContext * const c = avctx->priv_data;
75    const unsigned char *encoded = buf;
76    unsigned char *outptr;
77    int zret; // Zlib return code
78    int len = buf_size;
79
80    if(c->pic.data[0])
81            avctx->release_buffer(avctx, &c->pic);
82
83    c->pic.reference = 1;
84    c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
85    if(avctx->get_buffer(avctx, &c->pic) < 0){
86        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
87        return -1;
88    }
89
90    outptr = c->pic.data[0]; // Output image pointer
91
92    zret = inflateReset(&(c->zstream));
93    if (zret != Z_OK) {
94        av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
95        return -1;
96    }
97    c->zstream.next_in = encoded;
98    c->zstream.avail_in = len;
99    c->zstream.next_out = c->decomp_buf;
100    c->zstream.avail_out = c->decomp_size;
101    zret = inflate(&(c->zstream), Z_FINISH);
102    // Z_DATA_ERROR means empty picture
103    if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) {
104        av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
105        return -1;
106    }
107
108
109    if(zret != Z_DATA_ERROR)
110        ff_msrle_decode(avctx, (AVPicture*)&c->pic, c->bpp, c->decomp_buf, c->decomp_size - c->zstream.avail_out);
111
112    /* make the palette available on the way out */
113    if (c->avctx->pix_fmt == PIX_FMT_PAL8) {
114        memcpy(c->pic.data[1], c->avctx->palctrl->palette, AVPALETTE_SIZE);
115        if (c->avctx->palctrl->palette_changed) {
116            c->pic.palette_has_changed = 1;
117            c->avctx->palctrl->palette_changed = 0;
118        }
119    }
120
121    *data_size = sizeof(AVFrame);
122    *(AVFrame*)data = c->pic;
123
124    /* always report that the buffer was completely consumed */
125    return buf_size;
126}
127
128
129
130/*
131 *
132 * Init tscc decoder
133 *
134 */
135static av_cold int decode_init(AVCodecContext *avctx)
136{
137    CamtasiaContext * const c = avctx->priv_data;
138    int zret; // Zlib return code
139
140    c->avctx = avctx;
141
142    c->height = avctx->height;
143
144    // Needed if zlib unused or init aborted before inflateInit
145    memset(&(c->zstream), 0, sizeof(z_stream));
146    switch(avctx->bits_per_coded_sample){
147    case  8: avctx->pix_fmt = PIX_FMT_PAL8; break;
148    case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
149    case 24:
150             avctx->pix_fmt = PIX_FMT_BGR24;
151             break;
152    case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
153    default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
154             return -1;
155    }
156    c->bpp = avctx->bits_per_coded_sample;
157    // buffer size for RLE 'best' case when 2-byte code preceeds each pixel and there may be padding after it too
158    c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
159
160    /* Allocate decompression buffer */
161    if (c->decomp_size) {
162        if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) {
163            av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
164            return 1;
165        }
166    }
167
168    c->zstream.zalloc = Z_NULL;
169    c->zstream.zfree = Z_NULL;
170    c->zstream.opaque = Z_NULL;
171    zret = inflateInit(&(c->zstream));
172    if (zret != Z_OK) {
173        av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
174        return 1;
175    }
176
177    return 0;
178}
179
180
181
182/*
183 *
184 * Uninit tscc decoder
185 *
186 */
187static av_cold int decode_end(AVCodecContext *avctx)
188{
189    CamtasiaContext * const c = avctx->priv_data;
190
191    av_freep(&c->decomp_buf);
192
193    if (c->pic.data[0])
194        avctx->release_buffer(avctx, &c->pic);
195    inflateEnd(&(c->zstream));
196
197    return 0;
198}
199
200AVCodec tscc_decoder = {
201        "camtasia",
202        AVMEDIA_TYPE_VIDEO,
203        CODEC_ID_TSCC,
204        sizeof(CamtasiaContext),
205        decode_init,
206        NULL,
207        decode_end,
208        decode_frame,
209        CODEC_CAP_DR1,
210        .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
211};
212
213