Add ff_ prefix to data symbols of encoders, decoders, hwaccel, parsers, bsf.
[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
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 "get_bits.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 AVPacket *avpkt)
106 {
107 const uint8_t *buf = avpkt->data;
108 int buf_size = avpkt->size;
109 FlashSVContext *s = avctx->priv_data;
110 int h_blocks, v_blocks, h_part, v_part, i, j;
111 GetBitContext gb;
112
113 /* no supplementary picture */
114 if (buf_size == 0)
115 return 0;
116 if (buf_size < 4)
117 return -1;
118
119 init_get_bits(&gb, buf, buf_size * 8);
120
121 /* start to parse the bitstream */
122 s->block_width = 16* (get_bits(&gb, 4)+1);
123 s->image_width = get_bits(&gb,12);
124 s->block_height= 16* (get_bits(&gb, 4)+1);
125 s->image_height= get_bits(&gb,12);
126
127 /* calculate amount of blocks and the size of the border blocks */
128 h_blocks = s->image_width / s->block_width;
129 h_part = s->image_width % s->block_width;
130 v_blocks = s->image_height / s->block_height;
131 v_part = s->image_height % s->block_height;
132
133 /* the block size could change between frames, make sure the buffer
134 * is large enough, if not, get a larger one */
135 if(s->block_size < s->block_width*s->block_height) {
136 if (s->tmpblock != NULL)
137 av_free(s->tmpblock);
138 if ((s->tmpblock = av_malloc(3*s->block_width*s->block_height)) == NULL) {
139 av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
140 return -1;
141 }
142 }
143 s->block_size = s->block_width*s->block_height;
144
145 /* init the image size once */
146 if((avctx->width==0) && (avctx->height==0)){
147 avctx->width = s->image_width;
148 avctx->height = s->image_height;
149 }
150
151 /* check for changes of image width and image height */
152 if ((avctx->width != s->image_width) || (avctx->height != s->image_height)) {
153 av_log(avctx, AV_LOG_ERROR, "Frame width or height differs from first frames!\n");
154 av_log(avctx, AV_LOG_ERROR, "fh = %d, fv %d vs ch = %d, cv = %d\n",avctx->height,
155 avctx->width,s->image_height,s->image_width);
156 return -1;
157 }
158
159 av_log(avctx, AV_LOG_DEBUG, "image: %dx%d block: %dx%d num: %dx%d part: %dx%d\n",
160 s->image_width, s->image_height, s->block_width, s->block_height,
161 h_blocks, v_blocks, h_part, v_part);
162
163 s->frame.reference = 1;
164 s->frame.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;
165 if(avctx->reget_buffer(avctx, &s->frame) < 0){
166 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
167 return -1;
168 }
169
170 /* loop over all block columns */
171 for (j = 0; j < v_blocks + (v_part?1:0); j++)
172 {
173
174 int hp = j*s->block_height; // horiz position in frame
175 int hs = (j<v_blocks)?s->block_height:v_part; // size of block
176
177
178 /* loop over all block rows */
179 for (i = 0; i < h_blocks + (h_part?1:0); i++)
180 {
181 int wp = i*s->block_width; // vert position in frame
182 int ws = (i<h_blocks)?s->block_width:h_part; // size of block
183
184 /* get the size of the compressed zlib chunk */
185 int size = get_bits(&gb, 16);
186 if (8 * size > get_bits_left(&gb)) {
187 avctx->release_buffer(avctx, &s->frame);
188 s->frame.data[0] = NULL;
189 return -1;
190 }
191
192 if (size == 0) {
193 /* no change, don't do anything */
194 } else {
195 /* decompress block */
196 int ret = inflateReset(&(s->zstream));
197 if (ret != Z_OK)
198 {
199 av_log(avctx, AV_LOG_ERROR, "error in decompression (reset) of block %dx%d\n", i, j);
200 /* return -1; */
201 }
202 s->zstream.next_in = buf+(get_bits_count(&gb)/8);
203 s->zstream.avail_in = size;
204 s->zstream.next_out = s->tmpblock;
205 s->zstream.avail_out = s->block_size*3;
206 ret = inflate(&(s->zstream), Z_FINISH);
207 if (ret == Z_DATA_ERROR)
208 {
209 av_log(avctx, AV_LOG_ERROR, "Zlib resync occurred\n");
210 inflateSync(&(s->zstream));
211 ret = inflate(&(s->zstream), Z_FINISH);
212 }
213
214 if ((ret != Z_OK) && (ret != Z_STREAM_END))
215 {
216 av_log(avctx, AV_LOG_ERROR, "error in decompression of block %dx%d: %d\n", i, j, ret);
217 /* return -1; */
218 }
219 copy_region(s->tmpblock, s->frame.data[0], s->image_height-(hp+hs+1), wp, hs, ws, s->frame.linesize[0]);
220 skip_bits_long(&gb, 8*size); /* skip the consumed bits */
221 }
222 }
223 }
224
225 *data_size = sizeof(AVFrame);
226 *(AVFrame*)data = s->frame;
227
228 if ((get_bits_count(&gb)/8) != buf_size)
229 av_log(avctx, AV_LOG_ERROR, "buffer not fully consumed (%d != %d)\n",
230 buf_size, (get_bits_count(&gb)/8));
231
232 /* report that the buffer was completely consumed */
233 return buf_size;
234 }
235
236
237 static av_cold int flashsv_decode_end(AVCodecContext *avctx)
238 {
239 FlashSVContext *s = avctx->priv_data;
240 inflateEnd(&(s->zstream));
241 /* release the frame if needed */
242 if (s->frame.data[0])
243 avctx->release_buffer(avctx, &s->frame);
244
245 /* free the tmpblock */
246 if (s->tmpblock != NULL)
247 av_free(s->tmpblock);
248
249 return 0;
250 }
251
252
253 AVCodec ff_flashsv_decoder = {
254 "flashsv",
255 AVMEDIA_TYPE_VIDEO,
256 CODEC_ID_FLASHSV,
257 sizeof(FlashSVContext),
258 flashsv_decode_init,
259 NULL,
260 flashsv_decode_end,
261 flashsv_decode_frame,
262 CODEC_CAP_DR1,
263 .pix_fmts = (const enum PixelFormat[]){PIX_FMT_BGR24, PIX_FMT_NONE},
264 .long_name = NULL_IF_CONFIG_SMALL("Flash Screen Video v1"),
265 };