Make some functions which aren't used outside their declaring source file
[libav.git] / libavcodec / flashsvenc.c
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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
67typedef struct FlashSVContext {
68 AVCodecContext *avctx;
69 uint8_t *previous_frame;
70 AVFrame frame;
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71 int image_width, image_height;
72 int block_width, block_height;
73 uint8_t* tmpblock;
74 uint8_t* encbuffer;
75 int block_size;
76 z_stream zstream;
8736d68a 77 int last_key_frame;
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78} FlashSVContext;
79
80static 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
101static 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
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116 // Needed if zlib unused or init aborted before deflateInit
117 memset(&(s->zstream), 0, sizeof(z_stream));
118/*
119 s->zstream.zalloc = NULL; //av_malloc;
120 s->zstream.zfree = NULL; //av_free;
121 s->zstream.opaque = NULL;
122 zret = deflateInit(&(s->zstream), 9);
123 if (zret != Z_OK) {
124 av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
125 return -1;
126 }
127*/
128
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129 s->last_key_frame=0;
130
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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
146static 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);
8adc51f2 214 buf_pos += zsize+2;
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215 //av_log(avctx, AV_LOG_ERROR, "buf_pos = %d\n", buf_pos);
216 } else {
217 pred_blocks++;
218 bytestream_put_be16(&ptr,0);
8adc51f2 219 buf_pos += 2;
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220 }
221 }
222 }
223
224 if (pred_blocks)
225 *I_frame = 0;
226 else
227 *I_frame = 1;
228
229 return buf_pos;
230}
231
232
233static int flashsv_encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data)
234{
235 FlashSVContext * const s = (FlashSVContext *)avctx->priv_data;
236 AVFrame *pict = data;
237 AVFrame * const p = &s->frame;
238 int res;
239 int I_frame = 0;
240 int opt_w, opt_h;
241
242 *p = *pict;
243
8736d68a 244 /* First frame needs to be a keyframe */
64472fcf 245 if (avctx->frame_number == 0) {
b6607559 246 s->previous_frame = av_mallocz(p->linesize[0]*s->image_height);
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247 if (!s->previous_frame) {
248 av_log(avctx, AV_LOG_ERROR, "Memory allocation failed.\n");
249 return -1;
250 }
251 I_frame = 1;
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252 }
253
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254 /* Check the placement of keyframes */
255 if (avctx->gop_size > 0) {
256 if (avctx->frame_number >= s->last_key_frame + avctx->gop_size) {
257 I_frame = 1;
258 }
259 }
260
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261#if 0
262 int w, h;
263 int optim_sizes[16][16];
264 int smallest_size;
265 //Try all possible combinations and store the encoded frame sizes
266 for (w=1 ; w<17 ; w++) {
267 for (h=1 ; h<17 ; h++) {
268 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);
269 //av_log(avctx, AV_LOG_ERROR, "[%d][%d]size = %d\n",w,h,optim_sizes[w-1][h-1]);
270 }
271 }
272
273 //Search for the smallest framesize and encode the frame with those parameters
274 smallest_size=optim_sizes[0][0];
275 opt_w = 0;
276 opt_h = 0;
277 for (w=0 ; w<16 ; w++) {
278 for (h=0 ; h<16 ; h++) {
279 if (optim_sizes[w][h] < smallest_size) {
280 smallest_size = optim_sizes[w][h];
281 opt_w = w;
282 opt_h = h;
283 }
284 }
285 }
286 res = encode_bitstream(s, p, buf, buf_size, (opt_w+1)*16, (opt_h+1)*16, s->previous_frame);
287 av_log(avctx, AV_LOG_ERROR, "[%d][%d]optimal size = %d, res = %d|\n", opt_w, opt_h, smallest_size, res);
288
289 if (buf_size < res)
290 av_log(avctx, AV_LOG_ERROR, "buf_size %d < res %d\n", buf_size, res);
291
292#else
293 opt_w=1;
294 opt_h=1;
295
296 if (buf_size < s->image_width*s->image_height*3) {
297 //Conservative upper bound check for compressed data
298 av_log(avctx, AV_LOG_ERROR, "buf_size %d < %d\n", buf_size, s->image_width*s->image_height*3);
299 return -1;
300 }
301
302 res = encode_bitstream(s, p, buf, buf_size, opt_w*16, opt_h*16, s->previous_frame, &I_frame);
303#endif
053185c2 304 //save the current frame
b6607559 305 memcpy(s->previous_frame, p->data[0], s->image_height*p->linesize[0]);
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306
307 //mark the frame type so the muxer can mux it correctly
308 if (I_frame) {
309 p->pict_type = FF_I_TYPE;
310 p->key_frame = 1;
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311 s->last_key_frame = avctx->frame_number;
312 av_log(avctx, AV_LOG_DEBUG, "Inserting key frame at frame %d\n",avctx->frame_number);
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313 } else {
314 p->pict_type = FF_P_TYPE;
315 p->key_frame = 0;
316 }
317
318 avctx->coded_frame = p;
319
320 return res;
321}
322
323static int flashsv_encode_end(AVCodecContext *avctx)
324{
325 FlashSVContext *s = (FlashSVContext *)avctx->priv_data;
326
327 deflateEnd(&(s->zstream));
328
329 av_free(s->encbuffer);
330 av_free(s->previous_frame);
331 av_free(s->tmpblock);
332
333 return 0;
334}
335
336AVCodec flashsv_encoder = {
337 "flashsv",
338 CODEC_TYPE_VIDEO,
339 CODEC_ID_FLASHSV,
340 sizeof(FlashSVContext),
341 flashsv_encode_init,
342 flashsv_encode_frame,
343 flashsv_encode_end,
344 .pix_fmts = (enum PixelFormat[]){PIX_FMT_BGR24, -1},
345};
346