29deb2123e13c23bab5d9af4ce5e0ea66c0e0bd0
[libav.git] / libavcodec / qtrleenc.c
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 Libav.
9 *
10 * Libav 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 * Libav 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 Libav; 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 /**
43 * This array will contain at ith position the value of the best RLE code
44 * if the line started at pixel i
45 * There can be 3 values :
46 * skip (0) : skip as much as possible pixels because they are equal to the
47 * previous frame ones
48 * repeat (<-1) : repeat that pixel -rle_code times, still as much as
49 * possible
50 * copy (>0) : copy the raw next rle_code pixels */
51 signed char *rlecode_table;
52 /**
53 * This array will contain the length of the best rle encoding of the line
54 * starting at ith pixel */
55 int *length_table;
56 /**
57 * Will contain at ith position the number of consecutive pixels equal to the previous
58 * frame starting from pixel i */
59 uint8_t* skip_table;
60
61 /** Encoded frame is a key frame */
62 int key_frame;
63 } QtrleEncContext;
64
65 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
66 {
67 QtrleEncContext *s = avctx->priv_data;
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
76 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
77 {
78 QtrleEncContext *s = avctx->priv_data;
79
80 if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
81 return -1;
82 }
83 s->avctx=avctx;
84
85 switch (avctx->pix_fmt) {
86 case AV_PIX_FMT_RGB555BE:
87 s->pixel_size = 2;
88 break;
89 case AV_PIX_FMT_RGB24:
90 s->pixel_size = 3;
91 break;
92 case AV_PIX_FMT_ARGB:
93 s->pixel_size = 4;
94 break;
95 default:
96 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
97 break;
98 }
99 avctx->bits_per_coded_sample = s->pixel_size*8;
100
101 s->rlecode_table = av_mallocz(s->avctx->width);
102 s->skip_table = av_mallocz(s->avctx->width);
103 s->length_table = av_mallocz((s->avctx->width + 1)*sizeof(int));
104 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
105 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
106 return -1;
107 }
108 if (avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height) < 0) {
109 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
110 return -1;
111 }
112
113 s->max_buf_size = s->avctx->width*s->avctx->height*s->pixel_size*2 /* image base material */
114 + 15 /* header + footer */
115 + s->avctx->height*2 /* skip code+rle end */
116 + s->avctx->width/MAX_RLE_BULK + 1 /* rle codes */;
117
118 return 0;
119 }
120
121 /**
122 * Compute the best RLE sequence for a line
123 */
124 static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
125 {
126 int width=s->avctx->width;
127 int i;
128 signed char rlecode;
129
130 /* We will use it to compute the best bulk copy sequence */
131 unsigned int bulkcount;
132 /* This will be the number of pixels equal to the preivous frame one's
133 * starting from the ith pixel */
134 unsigned int skipcount;
135 /* This will be the number of consecutive equal pixels in the current
136 * frame, starting from the ith one also */
137 unsigned int repeatcount;
138
139 /* The cost of the three different possibilities */
140 int total_bulk_cost;
141 int total_skip_cost;
142 int total_repeat_cost;
143
144 int temp_cost;
145 int j;
146
147 uint8_t *this_line = p-> data[0] + line*p-> linesize[0] +
148 (width - 1)*s->pixel_size;
149 uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] +
150 (width - 1)*s->pixel_size;
151
152 s->length_table[width] = 0;
153 skipcount = 0;
154
155 for (i = width - 1; i >= 0; i--) {
156
157 if (!s->key_frame && !memcmp(this_line, prev_line, s->pixel_size))
158 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
159 else
160 skipcount = 0;
161
162 total_skip_cost = s->length_table[i + skipcount] + 2;
163 s->skip_table[i] = skipcount;
164
165
166 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
167 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
168 else
169 repeatcount = 1;
170
171 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
172
173 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
174 * so let's make it aware */
175 if (i == 0) {
176 total_skip_cost--;
177 total_repeat_cost++;
178 }
179
180 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
181 /* repeat is the best */
182 s->length_table[i] = total_repeat_cost;
183 s->rlecode_table[i] = -repeatcount;
184 }
185 else if (skipcount > 0) {
186 /* skip is the best choice here */
187 s->length_table[i] = total_skip_cost;
188 s->rlecode_table[i] = 0;
189 }
190 else {
191 /* We cannot do neither skip nor repeat
192 * thus we search for the best bulk copy to do */
193
194 int limit = FFMIN(width - i, MAX_RLE_BULK);
195
196 temp_cost = 1 + s->pixel_size + !i;
197 total_bulk_cost = INT_MAX;
198
199 for (j = 1; j <= limit; j++) {
200 if (s->length_table[i + j] + temp_cost < total_bulk_cost) {
201 /* We have found a better bulk copy ... */
202 total_bulk_cost = s->length_table[i + j] + temp_cost;
203 bulkcount = j;
204 }
205 temp_cost += s->pixel_size;
206 }
207
208 s->length_table[i] = total_bulk_cost;
209 s->rlecode_table[i] = bulkcount;
210 }
211
212 this_line -= s->pixel_size;
213 prev_line -= s->pixel_size;
214 }
215
216 /* Good ! Now we have the best sequence for this line, let's ouput it */
217
218 /* We do a special case for the first pixel so that we avoid testing it in
219 * the whole loop */
220
221 i=0;
222 this_line = p-> data[0] + line*p->linesize[0];
223
224 if (s->rlecode_table[0] == 0) {
225 bytestream_put_byte(buf, s->skip_table[0] + 1);
226 i += s->skip_table[0];
227 }
228 else bytestream_put_byte(buf, 1);
229
230
231 while (i < width) {
232 rlecode = s->rlecode_table[i];
233 bytestream_put_byte(buf, rlecode);
234 if (rlecode == 0) {
235 /* Write a skip sequence */
236 bytestream_put_byte(buf, s->skip_table[i] + 1);
237 i += s->skip_table[i];
238 }
239 else if (rlecode > 0) {
240 /* bulk copy */
241 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
242 i += rlecode;
243 }
244 else {
245 /* repeat the bits */
246 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
247 i -= rlecode;
248 }
249 }
250 bytestream_put_byte(buf, -1); // end RLE line
251 }
252
253 /** Encode frame including header */
254 static int encode_frame(QtrleEncContext *s, const AVFrame *p, uint8_t *buf)
255 {
256 int i;
257 int start_line = 0;
258 int end_line = s->avctx->height;
259 uint8_t *orig_buf = buf;
260
261 if (!s->key_frame) {
262 unsigned line_size = s->avctx->width * s->pixel_size;
263 for (start_line = 0; start_line < s->avctx->height; start_line++)
264 if (memcmp(p->data[0] + start_line*p->linesize[0],
265 s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0],
266 line_size))
267 break;
268
269 for (end_line=s->avctx->height; end_line > start_line; end_line--)
270 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
271 s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0],
272 line_size))
273 break;
274 }
275
276 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
277
278 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
279 bytestream_put_be16(&buf, 0); // header
280 else {
281 bytestream_put_be16(&buf, 8); // header
282 bytestream_put_be16(&buf, start_line); // starting line
283 bytestream_put_be16(&buf, 0); // unknown
284 bytestream_put_be16(&buf, end_line - start_line); // lines to update
285 bytestream_put_be16(&buf, 0); // unknown
286 }
287 for (i = start_line; i < end_line; i++)
288 qtrle_encode_line(s, p, i, &buf);
289
290 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
291 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
292 return buf - orig_buf;
293 }
294
295 static int qtrle_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
296 const AVFrame *pict, int *got_packet)
297 {
298 QtrleEncContext * const s = avctx->priv_data;
299 enum AVPictureType pict_type;
300 int ret;
301
302 if ((ret = ff_alloc_packet(pkt, s->max_buf_size)) < 0) {
303 /* Upper bound check for compressed data */
304 av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", s->max_buf_size);
305 return ret;
306 }
307
308 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
309 /* I-Frame */
310 pict_type = AV_PICTURE_TYPE_I;
311 s->key_frame = 1;
312 } else {
313 /* P-Frame */
314 pict_type = AV_PICTURE_TYPE_P;
315 s->key_frame = 0;
316 }
317
318 pkt->size = encode_frame(s, pict, pkt->data);
319
320 /* save the current frame */
321 av_picture_copy(&s->previous_frame, (const AVPicture *)pict,
322 avctx->pix_fmt, avctx->width, avctx->height);
323
324 #if FF_API_CODED_FRAME
325 FF_DISABLE_DEPRECATION_WARNINGS
326 avctx->coded_frame->key_frame = s->key_frame;
327 avctx->coded_frame->pict_type = pict_type;
328 FF_ENABLE_DEPRECATION_WARNINGS
329 #endif
330
331 if (s->key_frame)
332 pkt->flags |= AV_PKT_FLAG_KEY;
333 *got_packet = 1;
334
335 return 0;
336 }
337
338 AVCodec ff_qtrle_encoder = {
339 .name = "qtrle",
340 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
341 .type = AVMEDIA_TYPE_VIDEO,
342 .id = AV_CODEC_ID_QTRLE,
343 .priv_data_size = sizeof(QtrleEncContext),
344 .init = qtrle_encode_init,
345 .encode2 = qtrle_encode_frame,
346 .close = qtrle_encode_end,
347 .pix_fmts = (const enum AVPixelFormat[]){
348 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGB555BE, AV_PIX_FMT_ARGB, AV_PIX_FMT_NONE
349 },
350 };