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 libavcodec/tscc.c
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, const uint8_t *buf, int buf_size)
71{
72    CamtasiaContext * const c = avctx->priv_data;
73    const unsigned char *encoded = buf;
74    unsigned char *outptr;
75    int zret; // Zlib return code
76    int len = buf_size;
77
78    if(c->pic.data[0])
79            avctx->release_buffer(avctx, &c->pic);
80
81    c->pic.reference = 1;
82    c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
83    if(avctx->get_buffer(avctx, &c->pic) < 0){
84        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
85        return -1;
86    }
87
88    outptr = c->pic.data[0]; // Output image pointer
89
90    zret = inflateReset(&(c->zstream));
91    if (zret != Z_OK) {
92        av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
93        return -1;
94    }
95    c->zstream.next_in = encoded;
96    c->zstream.avail_in = len;
97    c->zstream.next_out = c->decomp_buf;
98    c->zstream.avail_out = c->decomp_size;
99    zret = inflate(&(c->zstream), Z_FINISH);
100    // Z_DATA_ERROR means empty picture
101    if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) {
102        av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
103        return -1;
104    }
105
106
107    if(zret != Z_DATA_ERROR)
108        ff_msrle_decode(avctx, (AVPicture*)&c->pic, c->bpp, c->decomp_buf, c->zstream.avail_out);
109
110    /* make the palette available on the way out */
111    if (c->avctx->pix_fmt == PIX_FMT_PAL8) {
112        memcpy(c->pic.data[1], c->avctx->palctrl->palette, AVPALETTE_SIZE);
113        if (c->avctx->palctrl->palette_changed) {
114            c->pic.palette_has_changed = 1;
115            c->avctx->palctrl->palette_changed = 0;
116        }
117    }
118
119    *data_size = sizeof(AVFrame);
120    *(AVFrame*)data = c->pic;
121
122    /* always report that the buffer was completely consumed */
123    return buf_size;
124}
125
126
127
128/*
129 *
130 * Init tscc decoder
131 *
132 */
133static av_cold int decode_init(AVCodecContext *avctx)
134{
135    CamtasiaContext * const c = avctx->priv_data;
136    int zret; // Zlib return code
137
138    c->avctx = avctx;
139
140    c->pic.data[0] = NULL;
141    c->height = avctx->height;
142
143    if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
144        return 1;
145    }
146
147    // Needed if zlib unused or init aborted before inflateInit
148    memset(&(c->zstream), 0, sizeof(z_stream));
149    switch(avctx->bits_per_coded_sample){
150    case  8: avctx->pix_fmt = PIX_FMT_PAL8; break;
151    case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
152    case 24:
153             avctx->pix_fmt = PIX_FMT_BGR24;
154             break;
155    case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
156    default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
157             return -1;
158    }
159    c->bpp = avctx->bits_per_coded_sample;
160    c->decomp_size = (avctx->width * c->bpp + (avctx->width + 254) / 255 + 2) * avctx->height + 2;//RLE in the 'best' case
161
162    /* Allocate decompression buffer */
163    if (c->decomp_size) {
164        if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) {
165            av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
166            return 1;
167        }
168    }
169
170    c->zstream.zalloc = Z_NULL;
171    c->zstream.zfree = Z_NULL;
172    c->zstream.opaque = Z_NULL;
173    zret = inflateInit(&(c->zstream));
174    if (zret != Z_OK) {
175        av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
176        return 1;
177    }
178
179    return 0;
180}
181
182
183
184/*
185 *
186 * Uninit tscc decoder
187 *
188 */
189static av_cold int decode_end(AVCodecContext *avctx)
190{
191    CamtasiaContext * const c = avctx->priv_data;
192
193    av_freep(&c->decomp_buf);
194
195    if (c->pic.data[0])
196        avctx->release_buffer(avctx, &c->pic);
197    inflateEnd(&(c->zstream));
198
199    return 0;
200}
201
202AVCodec tscc_decoder = {
203        "camtasia",
204        CODEC_TYPE_VIDEO,
205        CODEC_ID_TSCC,
206        sizeof(CamtasiaContext),
207        decode_init,
208        NULL,
209        decode_end,
210        decode_frame,
211        CODEC_CAP_DR1,
212        .long_name = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
213};
214
215