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 AVPicture 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 } QtrleEncContext;
62
qtrle_encode_end(AVCodecContext * avctx)63 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
64 {
65 QtrleEncContext *s = avctx->priv_data;
66
67 av_frame_free(&avctx->coded_frame);
68
69 avpicture_free(&s->previous_frame);
70 av_free(s->rlecode_table);
71 av_free(s->length_table);
72 av_free(s->skip_table);
73 return 0;
74 }
75
qtrle_encode_init(AVCodecContext * avctx)76 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
77 {
78 QtrleEncContext *s = avctx->priv_data;
79 int ret;
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 if ((ret = avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height)) < 0) {
119 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
120 return ret;
121 }
122
123 s->max_buf_size = s->logical_width*s->avctx->height*s->pixel_size*2 /* image base material */
124 + 15 /* header + footer */
125 + s->avctx->height*2 /* skip code+rle end */
126 + s->logical_width/MAX_RLE_BULK + 1 /* rle codes */;
127
128 avctx->coded_frame = av_frame_alloc();
129 if (!avctx->coded_frame) {
130 qtrle_encode_end(avctx);
131 return AVERROR(ENOMEM);
132 }
133
134 return 0;
135 }
136
137 /**
138 * Compute the best RLE sequence for a line
139 */
qtrle_encode_line(QtrleEncContext * s,const AVFrame * p,int line,uint8_t ** buf)140 static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
141 {
142 int width=s->logical_width;
143 int i;
144 signed char rlecode;
145
146 /* This will be the number of pixels equal to the preivous frame one's
147 * starting from the ith pixel */
148 unsigned int skipcount;
149 /* This will be the number of consecutive equal pixels in the current
150 * frame, starting from the ith one also */
151 unsigned int av_uninit(repeatcount);
152
153 /* The cost of the three different possibilities */
154 int total_skip_cost;
155 int total_repeat_cost;
156
157 int base_bulk_cost;
158 int lowest_bulk_cost;
159 int lowest_bulk_cost_index;
160 int sec_lowest_bulk_cost;
161 int sec_lowest_bulk_cost_index;
162
163 uint8_t *this_line = p-> data[0] + line*p-> linesize[0] +
164 (width - 1)*s->pixel_size;
165 uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] +
166 (width - 1)*s->pixel_size;
167
168 s->length_table[width] = 0;
169 skipcount = 0;
170
171 /* Initial values */
172 lowest_bulk_cost = INT_MAX / 2;
173 lowest_bulk_cost_index = width;
174 sec_lowest_bulk_cost = INT_MAX / 2;
175 sec_lowest_bulk_cost_index = width;
176
177 base_bulk_cost = 1 + s->pixel_size;
178
179 for (i = width - 1; i >= 0; i--) {
180
181 int prev_bulk_cost;
182
183 /* If our lowest bulk cost index is too far away, replace it
184 * with the next lowest bulk cost */
185 if (FFMIN(width, i + MAX_RLE_BULK) < lowest_bulk_cost_index) {
186 lowest_bulk_cost = sec_lowest_bulk_cost;
187 lowest_bulk_cost_index = sec_lowest_bulk_cost_index;
188
189 sec_lowest_bulk_cost = INT_MAX / 2;
190 sec_lowest_bulk_cost_index = width;
191 }
192
193 /* Deal with the first pixel's bulk cost */
194 if (!i) {
195 base_bulk_cost++;
196 lowest_bulk_cost++;
197 sec_lowest_bulk_cost++;
198 }
199
200 /* Look at the bulk cost of the previous loop and see if it is
201 * a new lower bulk cost */
202 prev_bulk_cost = s->length_table[i + 1] + base_bulk_cost;
203 if (prev_bulk_cost <= sec_lowest_bulk_cost) {
204 /* If it's lower than the 2nd lowest, then it may be lower
205 * than the lowest */
206 if (prev_bulk_cost <= lowest_bulk_cost) {
207
208 /* If we have found a new lowest bulk cost,
209 * then the 2nd lowest bulk cost is now farther than the
210 * lowest bulk cost, and will never be used */
211 sec_lowest_bulk_cost = INT_MAX / 2;
212
213 lowest_bulk_cost = prev_bulk_cost;
214 lowest_bulk_cost_index = i + 1;
215 } else {
216 /* Then it must be the 2nd lowest bulk cost */
217 sec_lowest_bulk_cost = prev_bulk_cost;
218 sec_lowest_bulk_cost_index = i + 1;
219 }
220 }
221
222 if (!s->avctx->coded_frame->key_frame && !memcmp(this_line, prev_line, s->pixel_size))
223 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
224 else
225 skipcount = 0;
226
227 total_skip_cost = s->length_table[i + skipcount] + 2;
228 s->skip_table[i] = skipcount;
229
230
231 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
232 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
233 else
234 repeatcount = 1;
235
236 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
237
238 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
239 * so let's make it aware */
240 if (i == 0) {
241 total_skip_cost--;
242 total_repeat_cost++;
243 }
244
245 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
246 /* repeat is the best */
247 s->length_table[i] = total_repeat_cost;
248 s->rlecode_table[i] = -repeatcount;
249 }
250 else if (skipcount > 0) {
251 /* skip is the best choice here */
252 s->length_table[i] = total_skip_cost;
253 s->rlecode_table[i] = 0;
254 }
255 else {
256 /* We cannot do neither skip nor repeat
257 * thus we use the best bulk copy */
258
259 s->length_table[i] = lowest_bulk_cost;
260 s->rlecode_table[i] = lowest_bulk_cost_index - i;
261
262 }
263
264 /* These bulk costs increase every iteration */
265 lowest_bulk_cost += s->pixel_size;
266 sec_lowest_bulk_cost += s->pixel_size;
267
268 this_line -= s->pixel_size;
269 prev_line -= s->pixel_size;
270 }
271
272 /* Good ! Now we have the best sequence for this line, let's output it */
273
274 /* We do a special case for the first pixel so that we avoid testing it in
275 * the whole loop */
276
277 i=0;
278 this_line = p-> data[0] + line*p->linesize[0];
279
280 if (s->rlecode_table[0] == 0) {
281 bytestream_put_byte(buf, s->skip_table[0] + 1);
282 i += s->skip_table[0];
283 }
284 else bytestream_put_byte(buf, 1);
285
286
287 while (i < width) {
288 rlecode = s->rlecode_table[i];
289 bytestream_put_byte(buf, rlecode);
290 if (rlecode == 0) {
291 /* Write a skip sequence */
292 bytestream_put_byte(buf, s->skip_table[i] + 1);
293 i += s->skip_table[i];
294 }
295 else if (rlecode > 0) {
296 /* bulk copy */
297 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
298 int j;
299 // QT grayscale colorspace has 0=white and 255=black, we will
300 // ignore the palette that is included in the AVFrame because
301 // AV_PIX_FMT_GRAY8 has defined color mapping
302 for (j = 0; j < rlecode*s->pixel_size; ++j)
303 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
304 } else {
305 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
306 }
307 i += rlecode;
308 }
309 else {
310 /* repeat the bits */
311 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
312 int j;
313 // QT grayscale colorspace has 0=white and 255=black, ...
314 for (j = 0; j < s->pixel_size; ++j)
315 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
316 } else {
317 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
318 }
319 i -= rlecode;
320 }
321 }
322 bytestream_put_byte(buf, -1); // end RLE line
323 }
324
325 /** Encode frame including header */
encode_frame(QtrleEncContext * s,const AVFrame * p,uint8_t * buf)326 static int encode_frame(QtrleEncContext *s, const AVFrame *p, uint8_t *buf)
327 {
328 int i;
329 int start_line = 0;
330 int end_line = s->avctx->height;
331 uint8_t *orig_buf = buf;
332
333 if (!s->avctx->coded_frame->key_frame) {
334 unsigned line_size = s->logical_width * s->pixel_size;
335 for (start_line = 0; start_line < s->avctx->height; start_line++)
336 if (memcmp(p->data[0] + start_line*p->linesize[0],
337 s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0],
338 line_size))
339 break;
340
341 for (end_line=s->avctx->height; end_line > start_line; end_line--)
342 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
343 s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0],
344 line_size))
345 break;
346 }
347
348 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
349
350 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
351 bytestream_put_be16(&buf, 0); // header
352 else {
353 bytestream_put_be16(&buf, 8); // header
354 bytestream_put_be16(&buf, start_line); // starting line
355 bytestream_put_be16(&buf, 0); // unknown
356 bytestream_put_be16(&buf, end_line - start_line); // lines to update
357 bytestream_put_be16(&buf, 0); // unknown
358 }
359 for (i = start_line; i < end_line; i++)
360 qtrle_encode_line(s, p, i, &buf);
361
362 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
363 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
364 return buf - orig_buf;
365 }
366
qtrle_encode_frame(AVCodecContext * avctx,AVPacket * pkt,const AVFrame * pict,int * got_packet)367 static int qtrle_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
368 const AVFrame *pict, int *got_packet)
369 {
370 QtrleEncContext * const s = avctx->priv_data;
371 AVFrame * const p = avctx->coded_frame;
372 int ret;
373
374 if ((ret = ff_alloc_packet2(avctx, pkt, s->max_buf_size)) < 0)
375 return ret;
376
377 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
378 /* I-Frame */
379 p->pict_type = AV_PICTURE_TYPE_I;
380 p->key_frame = 1;
381 } else {
382 /* P-Frame */
383 p->pict_type = AV_PICTURE_TYPE_P;
384 p->key_frame = 0;
385 }
386
387 pkt->size = encode_frame(s, pict, pkt->data);
388
389 /* save the current frame */
390 av_picture_copy(&s->previous_frame, (const AVPicture *)pict,
391 avctx->pix_fmt, avctx->width, avctx->height);
392
393 if (p->key_frame)
394 pkt->flags |= AV_PKT_FLAG_KEY;
395 *got_packet = 1;
396
397 return 0;
398 }
399
400 AVCodec ff_qtrle_encoder = {
401 .name = "qtrle",
402 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
403 .type = AVMEDIA_TYPE_VIDEO,
404 .id = AV_CODEC_ID_QTRLE,
405 .priv_data_size = sizeof(QtrleEncContext),
406 .init = qtrle_encode_init,
407 .encode2 = qtrle_encode_frame,
408 .close = qtrle_encode_end,
409 .pix_fmts = (const enum AVPixelFormat[]){
410 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGB555BE, AV_PIX_FMT_ARGB, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
411 },
412 };
413