Long name spelling fixes
[libav.git] / libavcodec / flashsv.c
1 /*
2 * Flash Screen Video decoder
3 * Copyright (C) 2004 Alex Beregszaszi
4 * Copyright (C) 2006 Benjamin Larsson
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23 /**
24 * @file flashsv.c
25 * Flash Screen Video decoder
26 * @author Alex Beregszaszi
27 * @author Benjamin Larsson
28 */
29
30 /* Bitstream description
31 * The picture is divided into blocks that are zlib compressed.
32 *
33 * The decoder is fed complete frames, the frameheader contains:
34 * 4bits of block width
35 * 12bits of frame width
36 * 4bits of block height
37 * 12bits of frame height
38 *
39 * Directly after the header are the compressed blocks. The blocks
40 * have their compressed size represented with 16bits in the beginnig.
41 * If the size = 0 then the block is unchanged from the previous frame.
42 * All blocks are decompressed until the buffer is consumed.
43 *
44 * Encoding ideas, a basic encoder would just use a fixed block size.
45 * Block sizes can be multipels of 16, from 16 to 256. The blocks don't
46 * have to be quadratic. A brute force search with a set of diffrent
47 * block sizes should give a better result then to just use a fixed size.
48 */
49
50 #include <stdio.h>
51 #include <stdlib.h>
52
53 #include "avcodec.h"
54 #include "bitstream.h"
55
56 #include <zlib.h>
57
58 typedef struct FlashSVContext {
59 AVCodecContext *avctx;
60 AVFrame frame;
61 int image_width, image_height;
62 int block_width, block_height;
63 uint8_t* tmpblock;
64 int block_size;
65 z_stream zstream;
66 } FlashSVContext;
67
68
69 static void copy_region(uint8_t *sptr, uint8_t *dptr,
70 int dx, int dy, int h, int w, int stride)
71 {
72 int i;
73
74 for (i = dx+h; i > dx; i--)
75 {
76 memcpy(dptr+(i*stride)+dy*3, sptr, w*3);
77 sptr += w*3;
78 }
79 }
80
81
82 static av_cold int flashsv_decode_init(AVCodecContext *avctx)
83 {
84 FlashSVContext *s = avctx->priv_data;
85 int zret; // Zlib return code
86
87 s->avctx = avctx;
88 s->zstream.zalloc = Z_NULL;
89 s->zstream.zfree = Z_NULL;
90 s->zstream.opaque = Z_NULL;
91 zret = inflateInit(&(s->zstream));
92 if (zret != Z_OK) {
93 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
94 return 1;
95 }
96 avctx->pix_fmt = PIX_FMT_BGR24;
97 s->frame.data[0] = NULL;
98
99 return 0;
100 }
101
102
103 static int flashsv_decode_frame(AVCodecContext *avctx,
104 void *data, int *data_size,
105 const uint8_t *buf, int buf_size)
106 {
107 FlashSVContext *s = avctx->priv_data;
108 int h_blocks, v_blocks, h_part, v_part, i, j;
109 GetBitContext gb;
110
111 /* no supplementary picture */
112 if (buf_size == 0)
113 return 0;
114
115 if(s->frame.data[0])
116 avctx->release_buffer(avctx, &s->frame);
117
118 init_get_bits(&gb, buf, buf_size * 8);
119
120 /* start to parse the bitstream */
121 s->block_width = 16* (get_bits(&gb, 4)+1);
122 s->image_width = get_bits(&gb,12);
123 s->block_height= 16* (get_bits(&gb, 4)+1);
124 s->image_height= get_bits(&gb,12);
125
126 /* calculate amount of blocks and the size of the border blocks */
127 h_blocks = s->image_width / s->block_width;
128 h_part = s->image_width % s->block_width;
129 v_blocks = s->image_height / s->block_height;
130 v_part = s->image_height % s->block_height;
131
132 /* the block size could change between frames, make sure the buffer
133 * is large enough, if not, get a larger one */
134 if(s->block_size < s->block_width*s->block_height) {
135 if (s->tmpblock != NULL)
136 av_free(s->tmpblock);
137 if ((s->tmpblock = av_malloc(3*s->block_width*s->block_height)) == NULL) {
138 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
139 return -1;
140 }
141 }
142 s->block_size = s->block_width*s->block_height;
143
144 /* init the image size once */
145 if((avctx->width==0) && (avctx->height==0)){
146 avctx->width = s->image_width;
147 avctx->height = s->image_height;
148 }
149
150 /* check for changes of image width and image height */
151 if ((avctx->width != s->image_width) || (avctx->height != s->image_height)) {
152 av_log(avctx, AV_LOG_ERROR, "Frame width or height differs from first frames!\n");
153 av_log(avctx, AV_LOG_ERROR, "fh = %d, fv %d vs ch = %d, cv = %d\n",avctx->height,
154 avctx->width,s->image_height,s->image_width);
155 return -1;
156 }
157
158 av_log(avctx, AV_LOG_DEBUG, "image: %dx%d block: %dx%d num: %dx%d part: %dx%d\n",
159 s->image_width, s->image_height, s->block_width, s->block_height,
160 h_blocks, v_blocks, h_part, v_part);
161
162 s->frame.reference = 1;
163 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID;
164 if (avctx->get_buffer(avctx, &s->frame) < 0) {
165 av_log(s->avctx, AV_LOG_ERROR, "get_buffer() failed\n");
166 return -1;
167 }
168
169 /* loop over all block columns */
170 for (j = 0; j < v_blocks + (v_part?1:0); j++)
171 {
172
173 int hp = j*s->block_height; // horiz position in frame
174 int hs = (j<v_blocks)?s->block_height:v_part; // size of block
175
176
177 /* loop over all block rows */
178 for (i = 0; i < h_blocks + (h_part?1:0); i++)
179 {
180 int wp = i*s->block_width; // vert position in frame
181 int ws = (i<h_blocks)?s->block_width:h_part; // size of block
182
183 /* get the size of the compressed zlib chunk */
184 int size = get_bits(&gb, 16);
185
186 if (size == 0) {
187 /* no change, don't do anything */
188 } else {
189 /* decompress block */
190 int ret = inflateReset(&(s->zstream));
191 if (ret != Z_OK)
192 {
193 av_log(avctx, AV_LOG_ERROR, "error in decompression (reset) of block %dx%d\n", i, j);
194 /* return -1; */
195 }
196 s->zstream.next_in = buf+(get_bits_count(&gb)/8);
197 s->zstream.avail_in = size;
198 s->zstream.next_out = s->tmpblock;
199 s->zstream.avail_out = s->block_size*3;
200 ret = inflate(&(s->zstream), Z_FINISH);
201 if (ret == Z_DATA_ERROR)
202 {
203 av_log(avctx, AV_LOG_ERROR, "Zlib resync occurred\n");
204 inflateSync(&(s->zstream));
205 ret = inflate(&(s->zstream), Z_FINISH);
206 }
207
208 if ((ret != Z_OK) && (ret != Z_STREAM_END))
209 {
210 av_log(avctx, AV_LOG_ERROR, "error in decompression of block %dx%d: %d\n", i, j, ret);
211 /* return -1; */
212 }
213 copy_region(s->tmpblock, s->frame.data[0], s->image_height-(hp+hs+1), wp, hs, ws, s->frame.linesize[0]);
214 skip_bits(&gb, 8*size); /* skip the consumed bits */
215 }
216 }
217 }
218
219 *data_size = sizeof(AVFrame);
220 *(AVFrame*)data = s->frame;
221
222 if ((get_bits_count(&gb)/8) != buf_size)
223 av_log(avctx, AV_LOG_ERROR, "buffer not fully consumed (%d != %d)\n",
224 buf_size, (get_bits_count(&gb)/8));
225
226 /* report that the buffer was completely consumed */
227 return buf_size;
228 }
229
230
231 static av_cold int flashsv_decode_end(AVCodecContext *avctx)
232 {
233 FlashSVContext *s = avctx->priv_data;
234 inflateEnd(&(s->zstream));
235 /* release the frame if needed */
236 if (s->frame.data[0])
237 avctx->release_buffer(avctx, &s->frame);
238
239 /* free the tmpblock */
240 if (s->tmpblock != NULL)
241 av_free(s->tmpblock);
242
243 return 0;
244 }
245
246
247 AVCodec flashsv_decoder = {
248 "flashsv",
249 CODEC_TYPE_VIDEO,
250 CODEC_ID_FLASHSV,
251 sizeof(FlashSVContext),
252 flashsv_decode_init,
253 NULL,
254 flashsv_decode_end,
255 flashsv_decode_frame,
256 CODEC_CAP_DR1,
257 .pix_fmts = (enum PixelFormat[]){PIX_FMT_BGR24, -1},
258 .long_name = "Flash Screen Video v1",
259 };