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053185c2 BL |
1 | /* |
2 | * Flash Screen Video encoder | |
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 | /* Encoding development sponsored by http://fh-campuswien.ac.at */ | |
24 | ||
25 | /** | |
26 | * @file flashsvenc.c | |
27 | * Flash Screen Video encoder | |
28 | * @author Alex Beregszaszi | |
29 | * @author Benjamin Larsson | |
30 | */ | |
31 | ||
32 | /* Bitstream description | |
33 | * The picture is divided into blocks that are zlib-compressed. | |
34 | * | |
35 | * The decoder is fed complete frames, the frameheader contains: | |
36 | * 4bits of block width | |
37 | * 12bits of frame width | |
38 | * 4bits of block height | |
39 | * 12bits of frame height | |
40 | * | |
41 | * Directly after the header are the compressed blocks. The blocks | |
42 | * have their compressed size represented with 16bits in the beginig. | |
43 | * If the size = 0 then the block is unchanged from the previous frame. | |
44 | * All blocks are decompressed until the buffer is consumed. | |
45 | * | |
46 | * Encoding ideas, a basic encoder would just use a fixed block size. | |
47 | * Block sizes can be multipels of 16, from 16 to 256. The blocks don't | |
48 | * have to be quadratic. A brute force search with a set of different | |
49 | * block sizes should give a better result than to just use a fixed size. | |
50 | */ | |
51 | ||
52 | /* TODO: | |
53 | * Don't reencode the frame in brute force mode if the frame is a dupe. Speed up. | |
54 | * Make the difference check faster. | |
55 | */ | |
56 | ||
57 | #include <stdio.h> | |
58 | #include <stdlib.h> | |
59 | #include <zlib.h> | |
60 | ||
61 | #include "common.h" | |
62 | #include "avcodec.h" | |
63 | #include "bitstream.h" | |
64 | #include "bytestream.h" | |
65 | ||
66 | ||
67 | typedef struct FlashSVContext { | |
68 | AVCodecContext *avctx; | |
69 | uint8_t *previous_frame; | |
70 | AVFrame frame; | |
71 | int first_frame; | |
72 | int image_width, image_height; | |
73 | int block_width, block_height; | |
74 | uint8_t* tmpblock; | |
75 | uint8_t* encbuffer; | |
76 | int block_size; | |
77 | z_stream zstream; | |
78 | } FlashSVContext; | |
79 | ||
80 | static int copy_region_enc(uint8_t *sptr, uint8_t *dptr, | |
81 | int dx, int dy, int h, int w, int stride, uint8_t *pfptr) { | |
82 | int i,j; | |
83 | uint8_t *nsptr; | |
84 | uint8_t *npfptr; | |
85 | int diff = 0; | |
86 | ||
87 | for (i = dx+h; i > dx; i--) { | |
88 | nsptr = sptr+(i*stride)+dy*3; | |
89 | npfptr = pfptr+(i*stride)+dy*3; | |
90 | for (j=0 ; j<w*3 ; j++) { | |
91 | diff |=npfptr[j]^nsptr[j]; | |
92 | dptr[j] = nsptr[j]; | |
93 | } | |
94 | dptr += w*3; | |
95 | } | |
96 | if (diff) | |
97 | return 1; | |
98 | return 0; | |
99 | } | |
100 | ||
101 | static int flashsv_encode_init(AVCodecContext *avctx) | |
102 | { | |
103 | FlashSVContext *s = (FlashSVContext *)avctx->priv_data; | |
104 | ||
105 | s->avctx = avctx; | |
106 | ||
107 | if ((avctx->width > 4095) || (avctx->height > 4095)) { | |
108 | av_log(avctx, AV_LOG_ERROR, "Input dimensions too large, input must be max 4096x4096 !\n"); | |
109 | return -1; | |
110 | } | |
111 | ||
112 | if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) { | |
113 | return -1; | |
114 | } | |
115 | ||
116 | s->first_frame = 1; | |
117 | ||
118 | // Needed if zlib unused or init aborted before deflateInit | |
119 | memset(&(s->zstream), 0, sizeof(z_stream)); | |
120 | /* | |
121 | s->zstream.zalloc = NULL; //av_malloc; | |
122 | s->zstream.zfree = NULL; //av_free; | |
123 | s->zstream.opaque = NULL; | |
124 | zret = deflateInit(&(s->zstream), 9); | |
125 | if (zret != Z_OK) { | |
126 | av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret); | |
127 | return -1; | |
128 | } | |
129 | */ | |
130 | ||
131 | s->image_width = avctx->width; | |
132 | s->image_height = avctx->height; | |
133 | ||
134 | s->tmpblock = av_mallocz(3*256*256); | |
135 | s->encbuffer = av_mallocz(s->image_width*s->image_height*3); | |
136 | ||
137 | if (!s->tmpblock || !s->encbuffer) { | |
138 | av_log(avctx, AV_LOG_ERROR, "Memory allocation failed.\n"); | |
139 | return -1; | |
140 | } | |
141 | ||
142 | return 0; | |
143 | } | |
144 | ||
145 | ||
146 | static int encode_bitstream(FlashSVContext *s, AVFrame *p, uint8_t *buf, int buf_size, | |
147 | int block_width, int block_height, uint8_t *previous_frame, int* I_frame) { | |
148 | ||
149 | PutBitContext pb; | |
150 | int h_blocks, v_blocks, h_part, v_part, i, j; | |
151 | int buf_pos, res; | |
152 | int pred_blocks = 0; | |
153 | ||
154 | init_put_bits(&pb, buf, buf_size*8); | |
155 | ||
156 | put_bits(&pb, 4, (block_width/16)-1); | |
157 | put_bits(&pb, 12, s->image_width); | |
158 | put_bits(&pb, 4, (block_height/16)-1); | |
159 | put_bits(&pb, 12, s->image_height); | |
160 | flush_put_bits(&pb); | |
161 | buf_pos=4; | |
162 | ||
163 | h_blocks = s->image_width / block_width; | |
164 | h_part = s->image_width % block_width; | |
165 | v_blocks = s->image_height / block_height; | |
166 | v_part = s->image_height % block_height; | |
167 | ||
168 | /* loop over all block columns */ | |
169 | for (j = 0; j < v_blocks + (v_part?1:0); j++) | |
170 | { | |
171 | ||
172 | int hp = j*block_height; // horiz position in frame | |
173 | int hs = (j<v_blocks)?block_height:v_part; // size of block | |
174 | ||
175 | /* loop over all block rows */ | |
176 | for (i = 0; i < h_blocks + (h_part?1:0); i++) | |
177 | { | |
178 | int wp = i*block_width; // vert position in frame | |
179 | int ws = (i<h_blocks)?block_width:h_part; // size of block | |
180 | int ret=Z_OK; | |
181 | uint8_t *ptr; | |
182 | ||
183 | ptr = buf+buf_pos; | |
184 | ||
185 | //copy the block to the temp buffer before compression (if it differs from the previous frame's block) | |
186 | res = copy_region_enc(p->data[0], s->tmpblock, s->image_height-(hp+hs+1), wp, hs, ws, p->linesize[0], previous_frame); | |
187 | ||
188 | if (res || *I_frame) { | |
189 | unsigned long zsize; | |
190 | zsize = 3*block_width*block_height; | |
191 | ret = compress2(ptr+2, &zsize, s->tmpblock, 3*ws*hs, 9); | |
192 | ||
193 | ||
194 | //ret = deflateReset(&(s->zstream)); | |
195 | if (ret != Z_OK) | |
196 | av_log(s->avctx, AV_LOG_ERROR, "error while compressing block %dx%d\n", i, j); | |
197 | /* | |
198 | s->zstream.next_in = s->tmpblock; | |
199 | s->zstream.avail_in = 3*ws*hs; | |
200 | s->zstream.total_in = 0; | |
201 | ||
202 | s->zstream.next_out = ptr+2; | |
203 | s->zstream.avail_out = buf_size-buf_pos-2; | |
204 | s->zstream.total_out = 0; | |
205 | ||
206 | ret = deflate(&(s->zstream), Z_FINISH); | |
207 | if ((ret != Z_OK) && (ret != Z_STREAM_END)) | |
208 | av_log(s->avctx, AV_LOG_ERROR, "error while compressing block %dx%d\n", i, j); | |
209 | ||
210 | size = s->zstream.total_out; | |
211 | //av_log(avctx, AV_LOG_INFO, "compressed blocks: %d\n", size); | |
212 | */ | |
213 | bytestream_put_be16(&ptr,(unsigned int)zsize); | |
214 | buf_pos += zsize; | |
215 | //av_log(avctx, AV_LOG_ERROR, "buf_pos = %d\n", buf_pos); | |
216 | } else { | |
217 | pred_blocks++; | |
218 | bytestream_put_be16(&ptr,0); | |
219 | } | |
220 | } | |
221 | } | |
222 | ||
223 | if (pred_blocks) | |
224 | *I_frame = 0; | |
225 | else | |
226 | *I_frame = 1; | |
227 | ||
228 | return buf_pos; | |
229 | } | |
230 | ||
231 | ||
232 | static int flashsv_encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data) | |
233 | { | |
234 | FlashSVContext * const s = (FlashSVContext *)avctx->priv_data; | |
235 | AVFrame *pict = data; | |
236 | AVFrame * const p = &s->frame; | |
237 | int res; | |
238 | int I_frame = 0; | |
239 | int opt_w, opt_h; | |
240 | ||
241 | *p = *pict; | |
242 | ||
243 | if (s->first_frame) { | |
244 | s->previous_frame = av_mallocz(p->linesize[0]*s->image_height*3); | |
245 | if (!s->previous_frame) { | |
246 | av_log(avctx, AV_LOG_ERROR, "Memory allocation failed.\n"); | |
247 | return -1; | |
248 | } | |
249 | I_frame = 1; | |
250 | s->first_frame = 0; | |
251 | } | |
252 | ||
253 | #if 0 | |
254 | int w, h; | |
255 | int optim_sizes[16][16]; | |
256 | int smallest_size; | |
257 | //Try all possible combinations and store the encoded frame sizes | |
258 | for (w=1 ; w<17 ; w++) { | |
259 | for (h=1 ; h<17 ; h++) { | |
260 | optim_sizes[w-1][h-1] = encode_bitstream(s, p, s->encbuffer, s->image_width*s->image_height*4, w*16, h*16, s->previous_frame); | |
261 | //av_log(avctx, AV_LOG_ERROR, "[%d][%d]size = %d\n",w,h,optim_sizes[w-1][h-1]); | |
262 | } | |
263 | } | |
264 | ||
265 | //Search for the smallest framesize and encode the frame with those parameters | |
266 | smallest_size=optim_sizes[0][0]; | |
267 | opt_w = 0; | |
268 | opt_h = 0; | |
269 | for (w=0 ; w<16 ; w++) { | |
270 | for (h=0 ; h<16 ; h++) { | |
271 | if (optim_sizes[w][h] < smallest_size) { | |
272 | smallest_size = optim_sizes[w][h]; | |
273 | opt_w = w; | |
274 | opt_h = h; | |
275 | } | |
276 | } | |
277 | } | |
278 | res = encode_bitstream(s, p, buf, buf_size, (opt_w+1)*16, (opt_h+1)*16, s->previous_frame); | |
279 | av_log(avctx, AV_LOG_ERROR, "[%d][%d]optimal size = %d, res = %d|\n", opt_w, opt_h, smallest_size, res); | |
280 | ||
281 | if (buf_size < res) | |
282 | av_log(avctx, AV_LOG_ERROR, "buf_size %d < res %d\n", buf_size, res); | |
283 | ||
284 | #else | |
285 | opt_w=1; | |
286 | opt_h=1; | |
287 | ||
288 | if (buf_size < s->image_width*s->image_height*3) { | |
289 | //Conservative upper bound check for compressed data | |
290 | av_log(avctx, AV_LOG_ERROR, "buf_size %d < %d\n", buf_size, s->image_width*s->image_height*3); | |
291 | return -1; | |
292 | } | |
293 | ||
294 | res = encode_bitstream(s, p, buf, buf_size, opt_w*16, opt_h*16, s->previous_frame, &I_frame); | |
295 | #endif | |
296 | ||
297 | //save the current frame | |
298 | memcpy(s->previous_frame, p->data[0], s->image_height*p->linesize[0]*3); | |
299 | ||
300 | //mark the frame type so the muxer can mux it correctly | |
301 | if (I_frame) { | |
302 | p->pict_type = FF_I_TYPE; | |
303 | p->key_frame = 1; | |
304 | } else { | |
305 | p->pict_type = FF_P_TYPE; | |
306 | p->key_frame = 0; | |
307 | } | |
308 | ||
309 | avctx->coded_frame = p; | |
310 | ||
311 | return res; | |
312 | } | |
313 | ||
314 | static int flashsv_encode_end(AVCodecContext *avctx) | |
315 | { | |
316 | FlashSVContext *s = (FlashSVContext *)avctx->priv_data; | |
317 | ||
318 | deflateEnd(&(s->zstream)); | |
319 | ||
320 | av_free(s->encbuffer); | |
321 | av_free(s->previous_frame); | |
322 | av_free(s->tmpblock); | |
323 | ||
324 | return 0; | |
325 | } | |
326 | ||
327 | AVCodec flashsv_encoder = { | |
328 | "flashsv", | |
329 | CODEC_TYPE_VIDEO, | |
330 | CODEC_ID_FLASHSV, | |
331 | sizeof(FlashSVContext), | |
332 | flashsv_encode_init, | |
333 | flashsv_encode_frame, | |
334 | flashsv_encode_end, | |
335 | .pix_fmts = (enum PixelFormat[]){PIX_FMT_BGR24, -1}, | |
336 | }; | |
337 |