1 /*
2 * Quicktime Animation (RLE) Video Encoder
3 * Copyright (C) 2007 Clemens Fruhwirth
4 * Copyright (C) 2007 Alexis Ballier
5 *
6 * This file is based on flashsvenc.c.
7 *
8 * This file is part of FFmpeg.
9 *
10 * FFmpeg is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
14 *
15 * FFmpeg is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
19 *
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25 #include "libavutil/imgutils.h"
26 #include "avcodec.h"
27 #include "bytestream.h"
28 #include "internal.h"
29
30 /** Maximum RLE code for bulk copy */
31 #define MAX_RLE_BULK 127
32 /** Maximum RLE code for repeat */
33 #define MAX_RLE_REPEAT 128
34 /** Maximum RLE code for skip */
35 #define MAX_RLE_SKIP 254
36
37 typedef struct QtrleEncContext {
38 AVCodecContext *avctx;
39 int pixel_size;
40 AVFrame *previous_frame;
41 unsigned int max_buf_size;
42 int logical_width;
43 /**
44 * This array will contain at ith position the value of the best RLE code
45 * if the line started at pixel i
46 * There can be 3 values :
47 * skip (0) : skip as much as possible pixels because they are equal to the
48 * previous frame ones
49 * repeat (<-1) : repeat that pixel -rle_code times, still as much as
50 * possible
51 * copy (>0) : copy the raw next rle_code pixels */
52 signed char *rlecode_table;
53 /**
54 * This array will contain the length of the best rle encoding of the line
55 * starting at ith pixel */
56 int *length_table;
57 /**
58 * Will contain at ith position the number of consecutive pixels equal to the previous
59 * frame starting from pixel i */
60 uint8_t* skip_table;
61
62 /** Encoded frame is a key frame */
63 int key_frame;
64 } QtrleEncContext;
65
qtrle_encode_end(AVCodecContext * avctx)66 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
67 {
68 QtrleEncContext *s = avctx->priv_data;
69
70 av_frame_free(&s->previous_frame);
71 av_free(s->rlecode_table);
72 av_free(s->length_table);
73 av_free(s->skip_table);
74 return 0;
75 }
76
qtrle_encode_init(AVCodecContext * avctx)77 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
78 {
79 QtrleEncContext *s = avctx->priv_data;
80
81 if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
82 return AVERROR(EINVAL);
83 }
84 s->avctx=avctx;
85 s->logical_width=avctx->width;
86
87 switch (avctx->pix_fmt) {
88 case AV_PIX_FMT_GRAY8:
89 if (avctx->width % 4) {
90 av_log(avctx, AV_LOG_ERROR, "Width not being a multiple of 4 is not supported\n");
91 return AVERROR(EINVAL);
92 }
93 s->logical_width = avctx->width / 4;
94 s->pixel_size = 4;
95 break;
96 case AV_PIX_FMT_RGB555BE:
97 s->pixel_size = 2;
98 break;
99 case AV_PIX_FMT_RGB24:
100 s->pixel_size = 3;
101 break;
102 case AV_PIX_FMT_ARGB:
103 s->pixel_size = 4;
104 break;
105 default:
106 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
107 break;
108 }
109 avctx->bits_per_coded_sample = avctx->pix_fmt == AV_PIX_FMT_GRAY8 ? 40 : s->pixel_size*8;
110
111 s->rlecode_table = av_mallocz(s->logical_width);
112 s->skip_table = av_mallocz(s->logical_width);
113 s->length_table = av_mallocz_array(s->logical_width + 1, sizeof(int));
114 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
115 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
116 return AVERROR(ENOMEM);
117 }
118 s->previous_frame = av_frame_alloc();
119 if (!s->previous_frame) {
120 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
121 return AVERROR(ENOMEM);
122 }
123
124 s->max_buf_size = s->logical_width*s->avctx->height*s->pixel_size*2 /* image base material */
125 + 15 /* header + footer */
126 + s->avctx->height*2 /* skip code+rle end */
127 + s->logical_width/MAX_RLE_BULK + 1 /* rle codes */;
128
129 return 0;
130 }
131
132 /**
133 * Compute the best RLE sequence for a line
134 */
qtrle_encode_line(QtrleEncContext * s,const AVFrame * p,int line,uint8_t ** buf)135 static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
136 {
137 int width=s->logical_width;
138 int i;
139 signed char rlecode;
140
141 /* This will be the number of pixels equal to the previous frame one's
142 * starting from the ith pixel */
143 unsigned int skipcount;
144 /* This will be the number of consecutive equal pixels in the current
145 * frame, starting from the ith one also */
146 unsigned int av_uninit(repeatcount);
147
148 /* The cost of the three different possibilities */
149 int total_skip_cost;
150 int total_repeat_cost;
151
152 int base_bulk_cost;
153 int lowest_bulk_cost;
154 int lowest_bulk_cost_index;
155 int sec_lowest_bulk_cost;
156 int sec_lowest_bulk_cost_index;
157
158 const uint8_t *this_line = p->data[0] + line * p->linesize[0] + width * s->pixel_size;
159 /* There might be no earlier frame if the current frame is a keyframe.
160 * So just use a pointer to the current frame to avoid a check
161 * to avoid NULL - s->pixel_size (which is undefined behaviour). */
162 const uint8_t *prev_line = s->key_frame ? this_line
163 : s->previous_frame->data[0]
164 + line * s->previous_frame->linesize[0]
165 + width * s->pixel_size;
166
167 s->length_table[width] = 0;
168 skipcount = 0;
169
170 /* Initial values */
171 lowest_bulk_cost = INT_MAX / 2;
172 lowest_bulk_cost_index = width;
173 sec_lowest_bulk_cost = INT_MAX / 2;
174 sec_lowest_bulk_cost_index = width;
175
176 base_bulk_cost = 1 + s->pixel_size;
177
178 for (i = width - 1; i >= 0; i--) {
179
180 int prev_bulk_cost;
181
182 this_line -= s->pixel_size;
183 prev_line -= s->pixel_size;
184
185 /* If our lowest bulk cost index is too far away, replace it
186 * with the next lowest bulk cost */
187 if (FFMIN(width, i + MAX_RLE_BULK) < lowest_bulk_cost_index) {
188 lowest_bulk_cost = sec_lowest_bulk_cost;
189 lowest_bulk_cost_index = sec_lowest_bulk_cost_index;
190
191 sec_lowest_bulk_cost = INT_MAX / 2;
192 sec_lowest_bulk_cost_index = width;
193 }
194
195 /* Deal with the first pixel's bulk cost */
196 if (!i) {
197 base_bulk_cost++;
198 lowest_bulk_cost++;
199 sec_lowest_bulk_cost++;
200 }
201
202 /* Look at the bulk cost of the previous loop and see if it is
203 * a new lower bulk cost */
204 prev_bulk_cost = s->length_table[i + 1] + base_bulk_cost;
205 if (prev_bulk_cost <= sec_lowest_bulk_cost) {
206 /* If it's lower than the 2nd lowest, then it may be lower
207 * than the lowest */
208 if (prev_bulk_cost <= lowest_bulk_cost) {
209
210 /* If we have found a new lowest bulk cost,
211 * then the 2nd lowest bulk cost is now farther than the
212 * lowest bulk cost, and will never be used */
213 sec_lowest_bulk_cost = INT_MAX / 2;
214
215 lowest_bulk_cost = prev_bulk_cost;
216 lowest_bulk_cost_index = i + 1;
217 } else {
218 /* Then it must be the 2nd lowest bulk cost */
219 sec_lowest_bulk_cost = prev_bulk_cost;
220 sec_lowest_bulk_cost_index = i + 1;
221 }
222 }
223
224 if (!s->key_frame && !memcmp(this_line, prev_line, s->pixel_size))
225 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
226 else
227 skipcount = 0;
228
229 total_skip_cost = s->length_table[i + skipcount] + 2;
230 s->skip_table[i] = skipcount;
231
232
233 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
234 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
235 else
236 repeatcount = 1;
237
238 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
239
240 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
241 * so let's make it aware */
242 if (i == 0) {
243 total_skip_cost--;
244 total_repeat_cost++;
245 }
246
247 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
248 /* repeat is the best */
249 s->length_table[i] = total_repeat_cost;
250 s->rlecode_table[i] = -repeatcount;
251 }
252 else if (skipcount > 0) {
253 /* skip is the best choice here */
254 s->length_table[i] = total_skip_cost;
255 s->rlecode_table[i] = 0;
256 }
257 else {
258 /* We cannot do neither skip nor repeat
259 * thus we use the best bulk copy */
260
261 s->length_table[i] = lowest_bulk_cost;
262 s->rlecode_table[i] = lowest_bulk_cost_index - i;
263
264 }
265
266 /* These bulk costs increase every iteration */
267 lowest_bulk_cost += s->pixel_size;
268 sec_lowest_bulk_cost += s->pixel_size;
269 }
270
271 /* Good! Now we have the best sequence for this line, let's output it. */
272
273 /* We do a special case for the first pixel so that we avoid testing it in
274 * the whole loop */
275
276 i=0;
277 this_line = p-> data[0] + line*p->linesize[0];
278
279 if (s->rlecode_table[0] == 0) {
280 bytestream_put_byte(buf, s->skip_table[0] + 1);
281 i += s->skip_table[0];
282 }
283 else bytestream_put_byte(buf, 1);
284
285
286 while (i < width) {
287 rlecode = s->rlecode_table[i];
288 bytestream_put_byte(buf, rlecode);
289 if (rlecode == 0) {
290 /* Write a skip sequence */
291 bytestream_put_byte(buf, s->skip_table[i] + 1);
292 i += s->skip_table[i];
293 }
294 else if (rlecode > 0) {
295 /* bulk copy */
296 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
297 int j;
298 // QT grayscale colorspace has 0=white and 255=black, we will
299 // ignore the palette that is included in the AVFrame because
300 // AV_PIX_FMT_GRAY8 has defined color mapping
301 for (j = 0; j < rlecode*s->pixel_size; ++j)
302 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
303 } else {
304 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
305 }
306 i += rlecode;
307 }
308 else {
309 /* repeat the bits */
310 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
311 int j;
312 // QT grayscale colorspace has 0=white and 255=black, ...
313 for (j = 0; j < s->pixel_size; ++j)
314 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
315 } else {
316 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
317 }
318 i -= rlecode;
319 }
320 }
321 bytestream_put_byte(buf, -1); // end RLE line
322 }
323
324 /** Encode frame including header */
encode_frame(QtrleEncContext * s,const AVFrame * p,uint8_t * buf)325 static int encode_frame(QtrleEncContext *s, const AVFrame *p, uint8_t *buf)
326 {
327 int i;
328 int start_line = 0;
329 int end_line = s->avctx->height;
330 uint8_t *orig_buf = buf;
331
332 if (!s->key_frame) {
333 unsigned line_size = s->logical_width * s->pixel_size;
334 for (start_line = 0; start_line < s->avctx->height; start_line++)
335 if (memcmp(p->data[0] + start_line*p->linesize[0],
336 s->previous_frame->data[0] + start_line * s->previous_frame->linesize[0],
337 line_size))
338 break;
339
340 for (end_line=s->avctx->height; end_line > start_line; end_line--)
341 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
342 s->previous_frame->data[0] + (end_line - 1) * s->previous_frame->linesize[0],
343 line_size))
344 break;
345 }
346
347 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
348
349 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
350 bytestream_put_be16(&buf, 0); // header
351 else {
352 bytestream_put_be16(&buf, 8); // header
353 bytestream_put_be16(&buf, start_line); // starting line
354 bytestream_put_be16(&buf, 0); // unknown
355 bytestream_put_be16(&buf, end_line - start_line); // lines to update
356 bytestream_put_be16(&buf, 0); // unknown
357 }
358 for (i = start_line; i < end_line; i++)
359 qtrle_encode_line(s, p, i, &buf);
360
361 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
362 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
363 return buf - orig_buf;
364 }
365
qtrle_encode_frame(AVCodecContext * avctx,AVPacket * pkt,const AVFrame * pict,int * got_packet)366 static int qtrle_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
367 const AVFrame *pict, int *got_packet)
368 {
369 QtrleEncContext * const s = avctx->priv_data;
370 int ret;
371
372 if ((ret = ff_alloc_packet2(avctx, pkt, s->max_buf_size, 0)) < 0)
373 return ret;
374
375 if (avctx->gop_size == 0 || !s->previous_frame->data[0] ||
376 (s->avctx->frame_number % avctx->gop_size) == 0) {
377 /* I-Frame */
378 s->key_frame = 1;
379 } else {
380 /* P-Frame */
381 s->key_frame = 0;
382 }
383
384 pkt->size = encode_frame(s, pict, pkt->data);
385
386 /* save the current frame */
387 av_frame_unref(s->previous_frame);
388 ret = av_frame_ref(s->previous_frame, pict);
389 if (ret < 0) {
390 av_log(avctx, AV_LOG_ERROR, "cannot add reference\n");
391 return ret;
392 }
393
394 #if FF_API_CODED_FRAME
395 FF_DISABLE_DEPRECATION_WARNINGS
396 avctx->coded_frame->key_frame = s->key_frame;
397 avctx->coded_frame->pict_type = s->key_frame ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
398 FF_ENABLE_DEPRECATION_WARNINGS
399 #endif
400
401 if (s->key_frame)
402 pkt->flags |= AV_PKT_FLAG_KEY;
403 *got_packet = 1;
404
405 return 0;
406 }
407
408 AVCodec ff_qtrle_encoder = {
409 .name = "qtrle",
410 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
411 .type = AVMEDIA_TYPE_VIDEO,
412 .id = AV_CODEC_ID_QTRLE,
413 .priv_data_size = sizeof(QtrleEncContext),
414 .init = qtrle_encode_init,
415 .encode2 = qtrle_encode_frame,
416 .close = qtrle_encode_end,
417 .pix_fmts = (const enum AVPixelFormat[]){
418 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGB555BE, AV_PIX_FMT_ARGB, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
419 },
420 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP,
421 };
422