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 "codec_internal.h"
29 #include "encode.h"
30
31 /** Maximum RLE code for bulk copy */
32 #define MAX_RLE_BULK 127
33 /** Maximum RLE code for repeat */
34 #define MAX_RLE_REPEAT 128
35 /** Maximum RLE code for skip */
36 #define MAX_RLE_SKIP 254
37
38 typedef struct QtrleEncContext {
39 AVCodecContext *avctx;
40 int pixel_size;
41 AVFrame *previous_frame;
42 unsigned int max_buf_size;
43 int logical_width;
44 /**
45 * This array will contain at ith position the value of the best RLE code
46 * if the line started at pixel i
47 * There can be 3 values :
48 * skip (0) : skip as much as possible pixels because they are equal to the
49 * previous frame ones
50 * repeat (<-1) : repeat that pixel -rle_code times, still as much as
51 * possible
52 * copy (>0) : copy the raw next rle_code pixels */
53 signed char *rlecode_table;
54 /**
55 * This array will contain the length of the best rle encoding of the line
56 * starting at ith pixel */
57 int *length_table;
58 /**
59 * Will contain at ith position the number of consecutive pixels equal to the previous
60 * frame starting from pixel i */
61 uint8_t* skip_table;
62
63 /** Encoded frame is a key frame */
64 int key_frame;
65 } QtrleEncContext;
66
qtrle_encode_end(AVCodecContext * avctx)67 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
68 {
69 QtrleEncContext *s = avctx->priv_data;
70
71 av_frame_free(&s->previous_frame);
72 av_free(s->rlecode_table);
73 av_free(s->length_table);
74 av_free(s->skip_table);
75 return 0;
76 }
77
qtrle_encode_init(AVCodecContext * avctx)78 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
79 {
80 QtrleEncContext *s = avctx->priv_data;
81
82 if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
83 return AVERROR(EINVAL);
84 }
85 s->avctx=avctx;
86 s->logical_width=avctx->width;
87
88 switch (avctx->pix_fmt) {
89 case AV_PIX_FMT_GRAY8:
90 if (avctx->width % 4) {
91 av_log(avctx, AV_LOG_ERROR, "Width not being a multiple of 4 is not supported\n");
92 return AVERROR(EINVAL);
93 }
94 s->logical_width = avctx->width / 4;
95 s->pixel_size = 4;
96 break;
97 case AV_PIX_FMT_RGB555BE:
98 s->pixel_size = 2;
99 break;
100 case AV_PIX_FMT_RGB24:
101 s->pixel_size = 3;
102 break;
103 case AV_PIX_FMT_ARGB:
104 s->pixel_size = 4;
105 break;
106 default:
107 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
108 break;
109 }
110 avctx->bits_per_coded_sample = avctx->pix_fmt == AV_PIX_FMT_GRAY8 ? 40 : s->pixel_size*8;
111
112 s->rlecode_table = av_mallocz(s->logical_width);
113 s->skip_table = av_mallocz(s->logical_width);
114 s->length_table = av_calloc(s->logical_width + 1, sizeof(*s->length_table));
115 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
116 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
117 return AVERROR(ENOMEM);
118 }
119 s->previous_frame = av_frame_alloc();
120 if (!s->previous_frame) {
121 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
122 return AVERROR(ENOMEM);
123 }
124
125 s->max_buf_size = s->logical_width*s->avctx->height*s->pixel_size*2 /* image base material */
126 + 15 /* header + footer */
127 + s->avctx->height*2 /* skip code+rle end */
128 + s->logical_width/MAX_RLE_BULK + 1 /* rle codes */;
129
130 return 0;
131 }
132
133 /**
134 * Compute the best RLE sequence for a line
135 */
qtrle_encode_line(QtrleEncContext * s,const AVFrame * p,int line,uint8_t ** buf)136 static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
137 {
138 int width=s->logical_width;
139 int i;
140 signed char rlecode;
141
142 /* This will be the number of pixels equal to the previous frame one's
143 * starting from the ith pixel */
144 unsigned int skipcount;
145 /* This will be the number of consecutive equal pixels in the current
146 * frame, starting from the ith one also */
147 unsigned int av_uninit(repeatcount);
148
149 /* The cost of the three different possibilities */
150 int total_skip_cost;
151 int total_repeat_cost;
152
153 int base_bulk_cost;
154 int lowest_bulk_cost;
155 int lowest_bulk_cost_index;
156 int sec_lowest_bulk_cost;
157 int sec_lowest_bulk_cost_index;
158
159 const uint8_t *this_line = p->data[0] + line * p->linesize[0] + width * s->pixel_size;
160 /* There might be no earlier frame if the current frame is a keyframe.
161 * So just use a pointer to the current frame to avoid a check
162 * to avoid NULL - s->pixel_size (which is undefined behaviour). */
163 const uint8_t *prev_line = s->key_frame ? this_line
164 : s->previous_frame->data[0]
165 + line * s->previous_frame->linesize[0]
166 + width * 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 this_line -= s->pixel_size;
184 prev_line -= s->pixel_size;
185
186 /* If our lowest bulk cost index is too far away, replace it
187 * with the next lowest bulk cost */
188 if (FFMIN(width, i + MAX_RLE_BULK) < lowest_bulk_cost_index) {
189 lowest_bulk_cost = sec_lowest_bulk_cost;
190 lowest_bulk_cost_index = sec_lowest_bulk_cost_index;
191
192 sec_lowest_bulk_cost = INT_MAX / 2;
193 sec_lowest_bulk_cost_index = width;
194 }
195
196 /* Deal with the first pixel's bulk cost */
197 if (!i) {
198 base_bulk_cost++;
199 lowest_bulk_cost++;
200 sec_lowest_bulk_cost++;
201 }
202
203 /* Look at the bulk cost of the previous loop and see if it is
204 * a new lower bulk cost */
205 prev_bulk_cost = s->length_table[i + 1] + base_bulk_cost;
206 if (prev_bulk_cost <= sec_lowest_bulk_cost) {
207 /* If it's lower than the 2nd lowest, then it may be lower
208 * than the lowest */
209 if (prev_bulk_cost <= lowest_bulk_cost) {
210
211 /* If we have found a new lowest bulk cost,
212 * then the 2nd lowest bulk cost is now farther than the
213 * lowest bulk cost, and will never be used */
214 sec_lowest_bulk_cost = INT_MAX / 2;
215
216 lowest_bulk_cost = prev_bulk_cost;
217 lowest_bulk_cost_index = i + 1;
218 } else {
219 /* Then it must be the 2nd lowest bulk cost */
220 sec_lowest_bulk_cost = prev_bulk_cost;
221 sec_lowest_bulk_cost_index = i + 1;
222 }
223 }
224
225 if (!s->key_frame && !memcmp(this_line, prev_line, s->pixel_size))
226 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
227 else
228 skipcount = 0;
229
230 total_skip_cost = s->length_table[i + skipcount] + 2;
231 s->skip_table[i] = skipcount;
232
233
234 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
235 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
236 else
237 repeatcount = 1;
238
239 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
240
241 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
242 * so let's make it aware */
243 if (i == 0) {
244 total_skip_cost--;
245 total_repeat_cost++;
246 }
247
248 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
249 /* repeat is the best */
250 s->length_table[i] = total_repeat_cost;
251 s->rlecode_table[i] = -repeatcount;
252 }
253 else if (skipcount > 0) {
254 /* skip is the best choice here */
255 s->length_table[i] = total_skip_cost;
256 s->rlecode_table[i] = 0;
257 }
258 else {
259 /* We cannot do neither skip nor repeat
260 * thus we use the best bulk copy */
261
262 s->length_table[i] = lowest_bulk_cost;
263 s->rlecode_table[i] = lowest_bulk_cost_index - i;
264
265 }
266
267 /* These bulk costs increase every iteration */
268 lowest_bulk_cost += s->pixel_size;
269 sec_lowest_bulk_cost += 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->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 int ret;
372
373 if ((ret = ff_alloc_packet(avctx, pkt, s->max_buf_size)) < 0)
374 return ret;
375
376 if (avctx->gop_size == 0 || !s->previous_frame->data[0] ||
377 (s->avctx->frame_number % avctx->gop_size) == 0) {
378 /* I-Frame */
379 s->key_frame = 1;
380 } else {
381 /* P-Frame */
382 s->key_frame = 0;
383 }
384
385 pkt->size = encode_frame(s, pict, pkt->data);
386
387 /* save the current frame */
388 av_frame_unref(s->previous_frame);
389 ret = av_frame_ref(s->previous_frame, pict);
390 if (ret < 0) {
391 av_log(avctx, AV_LOG_ERROR, "cannot add reference\n");
392 return ret;
393 }
394
395 if (s->key_frame)
396 pkt->flags |= AV_PKT_FLAG_KEY;
397 *got_packet = 1;
398
399 return 0;
400 }
401
402 const FFCodec ff_qtrle_encoder = {
403 .p.name = "qtrle",
404 .p.long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
405 .p.type = AVMEDIA_TYPE_VIDEO,
406 .p.id = AV_CODEC_ID_QTRLE,
407 .priv_data_size = sizeof(QtrleEncContext),
408 .init = qtrle_encode_init,
409 FF_CODEC_ENCODE_CB(qtrle_encode_frame),
410 .close = qtrle_encode_end,
411 .p.pix_fmts = (const enum AVPixelFormat[]){
412 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGB555BE, AV_PIX_FMT_ARGB, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
413 },
414 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
415 };
416