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 "internal.h"
43#include "msrledec.h"
44
45#include <zlib.h>
46
47typedef struct TsccContext {
48
49    AVCodecContext *avctx;
50    AVFrame *frame;
51
52    // Bits per pixel
53    int bpp;
54    // Decompressed data size
55    unsigned int decomp_size;
56    // Decompression buffer
57    unsigned char* decomp_buf;
58    GetByteContext gb;
59    int height;
60    z_stream zstream;
61
62    uint32_t pal[256];
63} CamtasiaContext;
64
65static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
66                        AVPacket *avpkt)
67{
68    const uint8_t *buf = avpkt->data;
69    int buf_size = avpkt->size;
70    CamtasiaContext * const c = avctx->priv_data;
71    const unsigned char *encoded = buf;
72    AVFrame *frame = c->frame;
73    int zret; // Zlib return code
74    int ret, len = buf_size;
75
76    if ((ret = ff_reget_buffer(avctx, frame)) < 0)
77        return ret;
78
79    zret = inflateReset(&c->zstream);
80    if (zret != Z_OK) {
81        av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", zret);
82        return AVERROR_UNKNOWN;
83    }
84    c->zstream.next_in = (uint8_t*)encoded;
85    c->zstream.avail_in = len;
86    c->zstream.next_out = c->decomp_buf;
87    c->zstream.avail_out = c->decomp_size;
88    zret = inflate(&c->zstream, Z_FINISH);
89    // Z_DATA_ERROR means empty picture
90    if ((zret != Z_OK) && (zret != Z_STREAM_END) && (zret != Z_DATA_ERROR)) {
91        av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", zret);
92        return AVERROR_UNKNOWN;
93    }
94
95
96    if (zret != Z_DATA_ERROR) {
97        bytestream2_init(&c->gb, c->decomp_buf,
98                         c->decomp_size - c->zstream.avail_out);
99        ff_msrle_decode(avctx, (AVPicture*)frame, c->bpp, &c->gb);
100    }
101
102    /* make the palette available on the way out */
103    if (c->avctx->pix_fmt == AV_PIX_FMT_PAL8) {
104        const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
105
106        if (pal) {
107            frame->palette_has_changed = 1;
108            memcpy(c->pal, pal, AVPALETTE_SIZE);
109        }
110        memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
111    }
112
113    if ((ret = av_frame_ref(data, frame)) < 0)
114        return ret;
115    *got_frame      = 1;
116
117    /* always report that the buffer was completely consumed */
118    return buf_size;
119}
120
121static av_cold int decode_init(AVCodecContext *avctx)
122{
123    CamtasiaContext * const c = avctx->priv_data;
124    int zret; // Zlib return code
125
126    c->avctx = avctx;
127
128    c->height = avctx->height;
129
130    // Needed if zlib unused or init aborted before inflateInit
131    memset(&c->zstream, 0, sizeof(z_stream));
132    switch(avctx->bits_per_coded_sample){
133    case  8: avctx->pix_fmt = AV_PIX_FMT_PAL8; break;
134    case 16: avctx->pix_fmt = AV_PIX_FMT_RGB555; break;
135    case 24:
136             avctx->pix_fmt = AV_PIX_FMT_BGR24;
137             break;
138    case 32: avctx->pix_fmt = AV_PIX_FMT_RGB32; break;
139    default: av_log(avctx, AV_LOG_ERROR, "Camtasia error: unknown depth %i bpp\n", avctx->bits_per_coded_sample);
140             return AVERROR_PATCHWELCOME;
141    }
142    c->bpp = avctx->bits_per_coded_sample;
143    // buffer size for RLE 'best' case when 2-byte code precedes each pixel and there may be padding after it too
144    c->decomp_size = (((avctx->width * c->bpp + 7) >> 3) + 3 * avctx->width + 2) * avctx->height + 2;
145
146    /* Allocate decompression buffer */
147    if (c->decomp_size) {
148        if ((c->decomp_buf = av_malloc(c->decomp_size)) == NULL) {
149            av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
150            return AVERROR(ENOMEM);
151        }
152    }
153
154    c->zstream.zalloc = Z_NULL;
155    c->zstream.zfree = Z_NULL;
156    c->zstream.opaque = Z_NULL;
157    zret = inflateInit(&c->zstream);
158    if (zret != Z_OK) {
159        av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
160        return AVERROR_UNKNOWN;
161    }
162
163    c->frame = av_frame_alloc();
164
165    return 0;
166}
167
168static av_cold int decode_end(AVCodecContext *avctx)
169{
170    CamtasiaContext * const c = avctx->priv_data;
171
172    av_freep(&c->decomp_buf);
173    av_frame_free(&c->frame);
174
175    inflateEnd(&c->zstream);
176
177    return 0;
178}
179
180AVCodec ff_tscc_decoder = {
181    .name           = "camtasia",
182    .long_name      = NULL_IF_CONFIG_SMALL("TechSmith Screen Capture Codec"),
183    .type           = AVMEDIA_TYPE_VIDEO,
184    .id             = AV_CODEC_ID_TSCC,
185    .priv_data_size = sizeof(CamtasiaContext),
186    .init           = decode_init,
187    .close          = decode_end,
188    .decode         = decode_frame,
189    .capabilities   = CODEC_CAP_DR1,
190};
191