1/*
2 * CamStudio decoder
3 * Copyright (c) 2006 Reimar Doeffinger
4 *
5 * This file is part of Libav.
6 *
7 * Libav 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 * Libav 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 Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21#include <stdio.h>
22#include <stdlib.h>
23
24#include "avcodec.h"
25
26#if CONFIG_ZLIB
27#include <zlib.h>
28#endif
29#include "libavutil/lzo.h"
30
31typedef struct {
32    AVFrame pic;
33    int linelen, height, bpp;
34    unsigned int decomp_size;
35    unsigned char* decomp_buf;
36} CamStudioContext;
37
38static void copy_frame_default(AVFrame *f, const uint8_t *src, int src_stride,
39                               int linelen, int height) {
40    int i;
41    uint8_t *dst = f->data[0];
42    dst += (height - 1) * f->linesize[0];
43    for (i = height; i; i--) {
44        memcpy(dst, src, linelen);
45        src += src_stride;
46        dst -= f->linesize[0];
47    }
48}
49
50static void add_frame_default(AVFrame *f, const uint8_t *src, int src_stride,
51                              int linelen, int height) {
52    int i, j;
53    uint8_t *dst = f->data[0];
54    dst += (height - 1) * f->linesize[0];
55    for (i = height; i; i--) {
56        for (j = linelen; j; j--)
57            *dst++ += *src++;
58        src += src_stride - linelen;
59        dst -= f->linesize[0] + linelen;
60    }
61}
62
63#if !HAVE_BIGENDIAN
64#define copy_frame_16(f, s, l, h) copy_frame_default(f, s, l, l, h)
65#define copy_frame_32(f, s, l, h) copy_frame_default(f, s, l, l, h)
66#define add_frame_16(f, s, l, h) add_frame_default(f, s, l, l, h)
67#define add_frame_32(f, s, l, h) add_frame_default(f, s, l, l, h)
68#else
69static void copy_frame_16(AVFrame *f, const uint8_t *src,
70                          int linelen, int height) {
71    int i, j;
72    uint8_t *dst = f->data[0];
73    dst += (height - 1) * f->linesize[0];
74    for (i = height; i; i--) {
75        for (j = linelen / 2; j; j--) {
76          dst[0] = src[1];
77          dst[1] = src[0];
78          src += 2;
79          dst += 2;
80        }
81        dst -= f->linesize[0] + linelen;
82    }
83}
84
85static void copy_frame_32(AVFrame *f, const uint8_t *src,
86                          int linelen, int height) {
87    int i, j;
88    uint8_t *dst = f->data[0];
89    dst += (height - 1) * f->linesize[0];
90    for (i = height; i; i--) {
91        for (j = linelen / 4; j; j--) {
92          dst[0] = src[3];
93          dst[1] = src[2];
94          dst[2] = src[1];
95          dst[3] = src[0];
96          src += 4;
97          dst += 4;
98        }
99        dst -= f->linesize[0] + linelen;
100    }
101}
102
103static void add_frame_16(AVFrame *f, const uint8_t *src,
104                         int linelen, int height) {
105    int i, j;
106    uint8_t *dst = f->data[0];
107    dst += (height - 1) * f->linesize[0];
108    for (i = height; i; i--) {
109        for (j = linelen / 2; j; j--) {
110          dst[0] += src[1];
111          dst[1] += src[0];
112          src += 2;
113          dst += 2;
114        }
115        dst -= f->linesize[0] + linelen;
116    }
117}
118
119static void add_frame_32(AVFrame *f, const uint8_t *src,
120                         int linelen, int height) {
121    int i, j;
122    uint8_t *dst = f->data[0];
123    dst += (height - 1) * f->linesize[0];
124    for (i = height; i; i--) {
125        for (j = linelen / 4; j; j--) {
126          dst[0] += src[3];
127          dst[1] += src[2];
128          dst[2] += src[1];
129          dst[3] += src[0];
130          src += 4;
131          dst += 4;
132        }
133        dst -= f->linesize[0] + linelen;
134    }
135}
136#endif
137
138static int decode_frame(AVCodecContext *avctx, void *data, int *data_size,
139                        AVPacket *avpkt) {
140    const uint8_t *buf = avpkt->data;
141    int buf_size = avpkt->size;
142    CamStudioContext *c = avctx->priv_data;
143    AVFrame *picture = data;
144
145    if (buf_size < 2) {
146        av_log(avctx, AV_LOG_ERROR, "coded frame too small\n");
147        return -1;
148    }
149
150    if (c->pic.data[0])
151        avctx->release_buffer(avctx, &c->pic);
152    c->pic.reference = 1;
153    c->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_READABLE |
154                          FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
155    if (avctx->get_buffer(avctx, &c->pic) < 0) {
156        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
157        return -1;
158    }
159
160    // decompress data
161    switch ((buf[0] >> 1) & 7) {
162        case 0: { // lzo compression
163            int outlen = c->decomp_size, inlen = buf_size - 2;
164            if (av_lzo1x_decode(c->decomp_buf, &outlen, &buf[2], &inlen))
165                av_log(avctx, AV_LOG_ERROR, "error during lzo decompression\n");
166            break;
167        }
168        case 1: { // zlib compression
169#if CONFIG_ZLIB
170            unsigned long dlen = c->decomp_size;
171            if (uncompress(c->decomp_buf, &dlen, &buf[2], buf_size - 2) != Z_OK)
172                av_log(avctx, AV_LOG_ERROR, "error during zlib decompression\n");
173            break;
174#else
175            av_log(avctx, AV_LOG_ERROR, "compiled without zlib support\n");
176            return -1;
177#endif
178        }
179        default:
180            av_log(avctx, AV_LOG_ERROR, "unknown compression\n");
181            return -1;
182    }
183
184    // flip upside down, add difference frame
185    if (buf[0] & 1) { // keyframe
186        c->pic.pict_type = AV_PICTURE_TYPE_I;
187        c->pic.key_frame = 1;
188        switch (c->bpp) {
189          case 16:
190              copy_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height);
191              break;
192          case 32:
193              copy_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height);
194              break;
195          default:
196              copy_frame_default(&c->pic, c->decomp_buf, FFALIGN(c->linelen, 4),
197                                 c->linelen, c->height);
198        }
199    } else {
200        c->pic.pict_type = AV_PICTURE_TYPE_P;
201        c->pic.key_frame = 0;
202        switch (c->bpp) {
203          case 16:
204              add_frame_16(&c->pic, c->decomp_buf, c->linelen, c->height);
205              break;
206          case 32:
207              add_frame_32(&c->pic, c->decomp_buf, c->linelen, c->height);
208              break;
209          default:
210              add_frame_default(&c->pic, c->decomp_buf, FFALIGN(c->linelen, 4),
211                                c->linelen, c->height);
212        }
213    }
214
215    *picture = c->pic;
216    *data_size = sizeof(AVFrame);
217    return buf_size;
218}
219
220static av_cold int decode_init(AVCodecContext *avctx) {
221    CamStudioContext *c = avctx->priv_data;
222    int stride;
223    switch (avctx->bits_per_coded_sample) {
224        case 16: avctx->pix_fmt = PIX_FMT_RGB555; break;
225        case 24: avctx->pix_fmt = PIX_FMT_BGR24; break;
226        case 32: avctx->pix_fmt = PIX_FMT_RGB32; break;
227        default:
228            av_log(avctx, AV_LOG_ERROR,
229                   "CamStudio codec error: invalid depth %i bpp\n",
230                   avctx->bits_per_coded_sample);
231            return AVERROR_INVALIDDATA;
232    }
233    c->bpp = avctx->bits_per_coded_sample;
234    c->pic.data[0] = NULL;
235    c->linelen = avctx->width * avctx->bits_per_coded_sample / 8;
236    c->height = avctx->height;
237    stride = c->linelen;
238    if (avctx->bits_per_coded_sample == 24)
239        stride = FFALIGN(stride, 4);
240    c->decomp_size = c->height * stride;
241    c->decomp_buf = av_malloc(c->decomp_size + AV_LZO_OUTPUT_PADDING);
242    if (!c->decomp_buf) {
243        av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
244        return AVERROR(ENOMEM);
245    }
246    return 0;
247}
248
249static av_cold int decode_end(AVCodecContext *avctx) {
250    CamStudioContext *c = avctx->priv_data;
251    av_freep(&c->decomp_buf);
252    if (c->pic.data[0])
253        avctx->release_buffer(avctx, &c->pic);
254    return 0;
255}
256
257AVCodec ff_cscd_decoder = {
258    .name           = "camstudio",
259    .type           = AVMEDIA_TYPE_VIDEO,
260    .id             = CODEC_ID_CSCD,
261    .priv_data_size = sizeof(CamStudioContext),
262    .init           = decode_init,
263    .close          = decode_end,
264    .decode         = decode_frame,
265    .capabilities   = CODEC_CAP_DR1,
266    .long_name = NULL_IF_CONFIG_SMALL("CamStudio"),
267};
268
269