license header consistency cosmetics.
[libav.git] / libavcodec / qtrleenc.c
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1/*
2 * Quicktime Animation (RLE) Video Encoder
3 * Copyright (C) 2007 Clemens Fruhwirth
4 * Copyright (C) 2007 Alexis Ballier
5 *
4f31c990 6 * This file is based on flashsvenc.c.
d3b7406c 7 *
4f31c990 8 * This file is part of FFmpeg.
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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, version 2.1, as published by the Free Software Foundation
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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22 */
23
24#include "avcodec.h"
25#include "bytestream.h"
26
27/** Maximum RLE code for bulk copy */
28#define MAX_RLE_BULK 127
29/** Maximum RLE code for repeat */
30#define MAX_RLE_REPEAT 128
31/** Maximum RLE code for skip */
32#define MAX_RLE_SKIP 254
33
34typedef struct QtrleEncContext {
35 AVCodecContext *avctx;
36 AVFrame frame;
37 int pixel_size;
38 AVPicture previous_frame;
39 unsigned int max_buf_size;
40 /**
41 * This array will contain at ith position the value of the best RLE code
42 * if the line started at pixel i
43 * There can be 3 values :
44 * skip (0) : skip as much as possible pixels because they are equal to the
45 * previous frame ones
46 * repeat (<-1) : repeat that pixel -rle_code times, still as much as
47 * possible
48 * copy (>0) : copy the raw next rle_code pixels */
49 signed char *rlecode_table;
50 /**
51 * This array will contain the length of the best rle encoding of the line
52 * starting at ith pixel */
53 int *length_table;
54 /**
55 * Will contain at ith position the number of consecutive pixels equal to the previous
56 * frame starting from pixel i */
57 uint8_t* skip_table;
58} QtrleEncContext;
59
98a6fff9 60static av_cold int qtrle_encode_init(AVCodecContext *avctx)
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61{
62 QtrleEncContext *s = avctx->priv_data;
63
64 if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
65 return -1;
66 }
67 s->avctx=avctx;
68
69 switch (avctx->pix_fmt) {
70/* case PIX_FMT_RGB555:
71 s->pixel_size = 2;
72 break;*/
73 case PIX_FMT_RGB24:
74 s->pixel_size = 3;
75 break;
76 default:
77 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
78 break;
79 }
80 avctx->bits_per_sample = s->pixel_size*8;
81
82 s->rlecode_table = av_mallocz(s->avctx->width);
83 s->skip_table = av_mallocz(s->avctx->width);
84 s->length_table = av_mallocz((s->avctx->width + 1)*sizeof(int));
85 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
86 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
87 return -1;
88 }
89 if (avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height) < 0) {
90 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
91 return -1;
92 }
93
94 s->max_buf_size = s->avctx->width*s->avctx->height*s->pixel_size /* image base material */
95 + 15 /* header + footer */
96 + s->avctx->height*2 /* skip code+rle end */
97 + s->avctx->width/MAX_RLE_BULK + 1 /* rle codes */;
98 avctx->coded_frame = &s->frame;
99 return 0;
100}
101
102/**
103 * Computes the best RLE sequence for a line
104 */
105static void qtrle_encode_line(QtrleEncContext *s, AVFrame *p, int line, uint8_t **buf)
106{
107 int width=s->avctx->width;
108 int i;
109 signed char rlecode;
110
111 /* We will use it to compute the best bulk copy sequence */
112 unsigned int bulkcount;
113 /* This will be the number of pixels equal to the preivous frame one's
114 * starting from the ith pixel */
115 unsigned int skipcount;
116 /* This will be the number of consecutive equal pixels in the current
117 * frame, starting from the ith one also */
118 unsigned int repeatcount;
119
120 /* The cost of the three different possibilities */
121 int total_bulk_cost;
122 int total_skip_cost;
123 int total_repeat_cost;
124
125 int temp_cost;
126 int j;
127
128 uint8_t *this_line = p-> data[0] + line*p->linesize[0] + (width - 1)*s->pixel_size;
129 uint8_t *prev_line = s->previous_frame.data[0] + line*p->linesize[0] + (width - 1)*s->pixel_size;
130
131 s->length_table[width] = 0;
132 skipcount = 0;
133
134 for (i = width - 1; i >= 0; i--) {
135
136 if (!s->frame.key_frame && !memcmp(this_line, prev_line, s->pixel_size))
137 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
138 else
139 skipcount = 0;
140
141 total_skip_cost = s->length_table[i + skipcount] + 2;
142 s->skip_table[i] = skipcount;
143
144
145 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
146 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
147 else
148 repeatcount = 1;
149
150 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
151
152 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
153 * so let's make it aware */
154 if (i == 0) {
155 total_skip_cost--;
156 total_repeat_cost++;
157 }
158
159 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
160 /* repeat is the best */
161 s->length_table[i] = total_repeat_cost;
162 s->rlecode_table[i] = -repeatcount;
163 }
164 else if (skipcount > 0) {
165 /* skip is the best choice here */
166 s->length_table[i] = total_skip_cost;
167 s->rlecode_table[i] = 0;
168 }
169 else {
170 /* We cannot do neither skip nor repeat
171 * thus we search for the best bulk copy to do */
172
173 int limit = FFMIN(width - i, MAX_RLE_BULK);
174
175 temp_cost = 1 + s->pixel_size + !i;
176 total_bulk_cost = INT_MAX;
177
178 for (j = 1; j <= limit; j++) {
179 if (s->length_table[i + j] + temp_cost < total_bulk_cost) {
180 /* We have found a better bulk copy ... */
181 total_bulk_cost = s->length_table[i + j] + temp_cost;
182 bulkcount = j;
183 }
184 temp_cost += s->pixel_size;
185 }
186
187 s->length_table[i] = total_bulk_cost;
188 s->rlecode_table[i] = bulkcount;
189 }
190
191 this_line -= s->pixel_size;
192 prev_line -= s->pixel_size;
193 }
194
195 /* Good ! Now we have the best sequence for this line, let's ouput it */
196
197 /* We do a special case for the first pixel so that we avoid testing it in
198 * the whole loop */
199
200 i=0;
201 this_line = p-> data[0] + line*p->linesize[0];
202 prev_line = s->previous_frame.data[0] + line*p->linesize[0];
203
204 if (s->rlecode_table[0] == 0) {
205 bytestream_put_byte(buf, s->skip_table[0] + 1);
206 i += s->skip_table[0];
207 }
208 else bytestream_put_byte(buf, 1);
209
210
211 while (i < width) {
212 rlecode = s->rlecode_table[i];
213 bytestream_put_byte(buf, rlecode);
214 if (rlecode == 0) {
215 /* Write a skip sequence */
216 bytestream_put_byte(buf, s->skip_table[i] + 1);
217 i += s->skip_table[i];
218 }
219 else if (rlecode > 0) {
220 /* bulk copy */
221 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
222 i += rlecode;
223 }
224 else {
225 /* repeat the bits */
226 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
227 i -= rlecode;
228 }
229 }
230 bytestream_put_byte(buf, -1); // end RLE line
231}
232
233/** Encodes frame including header */
234static int encode_frame(QtrleEncContext *s, AVFrame *p, uint8_t *buf)
235{
236 int i;
237 int start_line = 0;
238 int end_line = s->avctx->height;
239 uint8_t *orig_buf = buf;
240
241 if (!s->frame.key_frame) {
242 for (start_line = 0; start_line < s->avctx->height; start_line++)
243 if (memcmp(p->data[0] + start_line*p->linesize[0],
244 s->previous_frame.data[0] + start_line*p->linesize[0],
245 p->linesize[0]))
246 break;
247
248 for (end_line=s->avctx->height; end_line > start_line; end_line--)
249 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
250 s->previous_frame.data[0] + (end_line - 1)*p->linesize[0],
251 p->linesize[0]))
252 break;
253 }
254
255 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
256
4a9dfdc1 257 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
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258 bytestream_put_be16(&buf, 0); // header
259 else {
260 bytestream_put_be16(&buf, 8); // header
261 bytestream_put_be16(&buf, start_line); // starting line
262 bytestream_put_be16(&buf, 0); // unknown
263 bytestream_put_be16(&buf, end_line - start_line); // lines to update
264 bytestream_put_be16(&buf, 0); // unknown
265 }
266 for (i = start_line; i < end_line; i++)
267 qtrle_encode_line(s, p, i, &buf);
268
269 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
270 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
271 return buf - orig_buf;
272}
273
274static int qtrle_encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data)
275{
276 QtrleEncContext * const s = avctx->priv_data;
277 AVFrame *pict = data;
278 AVFrame * const p = &s->frame;
279 int chunksize;
280
281 *p = *pict;
282
283 if (buf_size < s->max_buf_size) {
284 /* Upper bound check for compressed data */
285 av_log(avctx, AV_LOG_ERROR, "buf_size %d < %d\n", buf_size, s->max_buf_size);
286 return -1;
287 }
288
289 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
290 /* I-Frame */
291 p->pict_type = FF_I_TYPE;
292 p->key_frame = 1;
293 } else {
294 /* P-Frame */
295 p->pict_type = FF_P_TYPE;
296 p->key_frame = 0;
297 }
298
299 chunksize = encode_frame(s, pict, buf);
300
301 /* save the current frame */
302 av_picture_copy(&s->previous_frame, (AVPicture *)p, avctx->pix_fmt, avctx->width, avctx->height);
303 return chunksize;
304}
305
98a6fff9 306static av_cold int qtrle_encode_end(AVCodecContext *avctx)
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307{
308 QtrleEncContext *s = avctx->priv_data;
309
310 avpicture_free(&s->previous_frame);
311 av_free(s->rlecode_table);
312 av_free(s->length_table);
313 av_free(s->skip_table);
314 return 0;
315}
316
317AVCodec qtrle_encoder = {
318 "qtrle",
319 CODEC_TYPE_VIDEO,
320 CODEC_ID_QTRLE,
321 sizeof(QtrleEncContext),
322 qtrle_encode_init,
323 qtrle_encode_frame,
324 qtrle_encode_end,
eacced45 325 .pix_fmts = (enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_NONE},
fe4bf374 326 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
d3b7406c 327};