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
27 * Flash Screen Video encoder
28 * @author Alex Beregszaszi
29 * @author Benjamin Larsson
30 *
31 * A description of the bitstream format for Flash Screen Video version 1/2
32 * is part of the SWF File Format Specification (version 10), which can be
33 * downloaded from http://www.adobe.com/devnet/swf.html.
34 */
35
36 /*
37 * Encoding ideas: A basic encoder would just use a fixed block size.
38 * Block sizes can be multiples of 16, from 16 to 256. The blocks don't
39 * have to be quadratic. A brute force search with a set of different
40 * block sizes should give a better result than to just use a fixed size.
41 *
42 * TODO:
43 * Don't reencode the frame in brute force mode if the frame is a dupe.
44 * Speed up. Make the difference check faster.
45 */
46
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <zlib.h>
50
56
57
68
70 int h,
int w,
int stride, uint8_t *pfptr)
71 {
73 uint8_t *nsptr;
74 uint8_t *npfptr;
76
77 for (
i = dx +
h;
i > dx;
i--) {
78 nsptr = sptr +
i *
stride + dy * 3;
79 npfptr = pfptr +
i *
stride + dy * 3;
80 for (j = 0; j <
w * 3; j++) {
81 diff |= npfptr[j] ^ nsptr[j];
82 dptr[j] = nsptr[j];
83 }
85 }
87 return 1;
88 return 0;
89 }
90
92 {
94
97
98 return 0;
99 }
100
102 {
104
106
109 "Input dimensions too large, input must be max 4095x4095 !\n");
111 }
112
113 s->last_key_frame = 0;
114
115 s->image_width = avctx->
width;
116 s->image_height = avctx->
height;
117
118 s->encbuffer =
av_mallocz(
s->image_width *
s->image_height * 3);
119
123 }
124
125 return 0;
126 }
127
128
130 int buf_size, int block_width, int block_height,
131 uint8_t *previous_frame, int *I_frame)
132 {
133
135 int h_blocks, v_blocks, h_part, v_part,
i, j;
136 int buf_pos, res;
137 int pred_blocks = 0;
138
140
141 put_bits(&pb, 4, block_width / 16 - 1);
143 put_bits(&pb, 4, block_height / 16 - 1);
146 buf_pos = 4;
147
148 h_blocks =
s->image_width / block_width;
149 h_part =
s->image_width % block_width;
150 v_blocks =
s->image_height / block_height;
151 v_part =
s->image_height % block_height;
152
153 /* loop over all block columns */
154 for (j = 0; j < v_blocks + (v_part ? 1 : 0); j++) {
155
156 int y_pos = j * block_height; // vertical position in frame
157 int cur_blk_height = (j < v_blocks) ? block_height : v_part;
158
159 /* loop over all block rows */
160 for (
i = 0;
i < h_blocks + (h_part ? 1 : 0);
i++) {
161 int x_pos =
i * block_width;
// horizontal position in frame
162 int cur_blk_width = (
i < h_blocks) ? block_width : h_part;
164 uint8_t *ptr = buf + buf_pos;
165
166 /* copy the block to the temp buffer before compression
167 * (if it differs from the previous frame's block) */
169 s->image_height - (y_pos + cur_blk_height + 1),
170 x_pos, cur_blk_height, cur_blk_width,
172
173 if (res || *I_frame) {
174 unsigned long zsize = 3 * block_width * block_height;
175 ret = compress2(ptr + 2, &zsize,
s->tmpblock,
176 3 * cur_blk_width * cur_blk_height, 9);
177
180 "error while compressing block %dx%d\n",
i, j);
181
182 bytestream_put_be16(&ptr, zsize);
183 buf_pos += zsize + 2;
184 ff_dlog(
s->avctx,
"buf_pos = %d\n", buf_pos);
185 } else {
186 pred_blocks++;
187 bytestream_put_be16(&ptr, 0);
188 buf_pos += 2;
189 }
190 }
191 }
192
193 if (pred_blocks)
194 *I_frame = 0;
195 else
196 *I_frame = 1;
197
198 return buf_pos;
199 }
200
201
203 const AVFrame *pict,
int *got_packet)
204 {
206 const AVFrame *
const p = pict;
207 uint8_t *pfptr;
208 int res;
209 int I_frame = 0;
210 int opt_w = 4, opt_h = 4;
211
212 /* First frame needs to be a keyframe */
215 if (!
s->previous_frame) {
218 }
219 I_frame = 1;
220 }
221
223 pfptr =
s->previous_frame - (
s->image_height - 1) * p->
linesize[0];
224 else
225 pfptr =
s->previous_frame;
226
227 /* Check the placement of keyframes */
230 I_frame = 1;
231 }
232
234 return res;
235
237 pfptr, &I_frame);
238
239 //save the current frame
241 memcpy(
s->previous_frame, p->
data[0],
s->image_height * p->
linesize[0]);
242 else
243 memcpy(
s->previous_frame,
246
247 //mark the frame type so the muxer can mux it correctly
248 if (I_frame) {
251 }
252
253 if (I_frame)
255 *got_packet = 1;
256
257 return 0;
258 }
259
271 };