qtrleenc: add rgb555 output
[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 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 "avcodec.h"
26 #include "bytestream.h"
27
28 /** Maximum RLE code for bulk copy */
29 #define MAX_RLE_BULK 127
30 /** Maximum RLE code for repeat */
31 #define MAX_RLE_REPEAT 128
32 /** Maximum RLE code for skip */
33 #define MAX_RLE_SKIP 254
34
35 typedef struct QtrleEncContext {
36 AVCodecContext *avctx;
37 AVFrame frame;
38 int pixel_size;
39 AVPicture previous_frame;
40 unsigned int max_buf_size;
41 /**
42 * This array will contain at ith position the value of the best RLE code
43 * if the line started at pixel i
44 * There can be 3 values :
45 * skip (0) : skip as much as possible pixels because they are equal to the
46 * previous frame ones
47 * repeat (<-1) : repeat that pixel -rle_code times, still as much as
48 * possible
49 * copy (>0) : copy the raw next rle_code pixels */
50 signed char *rlecode_table;
51 /**
52 * This array will contain the length of the best rle encoding of the line
53 * starting at ith pixel */
54 int *length_table;
55 /**
56 * Will contain at ith position the number of consecutive pixels equal to the previous
57 * frame starting from pixel i */
58 uint8_t* skip_table;
59 } QtrleEncContext;
60
61 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
62 {
63 QtrleEncContext *s = avctx->priv_data;
64
65 if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {
66 return -1;
67 }
68 s->avctx=avctx;
69
70 switch (avctx->pix_fmt) {
71 case PIX_FMT_RGB555BE:
72 s->pixel_size = 2;
73 break;
74 case PIX_FMT_RGB24:
75 s->pixel_size = 3;
76 break;
77 case PIX_FMT_ARGB:
78 s->pixel_size = 4;
79 break;
80 default:
81 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
82 break;
83 }
84 avctx->bits_per_coded_sample = s->pixel_size*8;
85
86 s->rlecode_table = av_mallocz(s->avctx->width);
87 s->skip_table = av_mallocz(s->avctx->width);
88 s->length_table = av_mallocz((s->avctx->width + 1)*sizeof(int));
89 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
90 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
91 return -1;
92 }
93 if (avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height) < 0) {
94 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
95 return -1;
96 }
97
98 s->max_buf_size = s->avctx->width*s->avctx->height*s->pixel_size /* image base material */
99 + 15 /* header + footer */
100 + s->avctx->height*2 /* skip code+rle end */
101 + s->avctx->width/MAX_RLE_BULK + 1 /* rle codes */;
102 avctx->coded_frame = &s->frame;
103 return 0;
104 }
105
106 /**
107 * Computes the best RLE sequence for a line
108 */
109 static void qtrle_encode_line(QtrleEncContext *s, AVFrame *p, int line, uint8_t **buf)
110 {
111 int width=s->avctx->width;
112 int i;
113 signed char rlecode;
114
115 /* We will use it to compute the best bulk copy sequence */
116 unsigned int bulkcount;
117 /* This will be the number of pixels equal to the preivous frame one's
118 * starting from the ith pixel */
119 unsigned int skipcount;
120 /* This will be the number of consecutive equal pixels in the current
121 * frame, starting from the ith one also */
122 unsigned int av_uninit(repeatcount);
123
124 /* The cost of the three different possibilities */
125 int total_bulk_cost;
126 int total_skip_cost;
127 int total_repeat_cost;
128
129 int temp_cost;
130 int j;
131
132 uint8_t *this_line = p-> data[0] + line*p-> linesize[0] +
133 (width - 1)*s->pixel_size;
134 uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] +
135 (width - 1)*s->pixel_size;
136
137 s->length_table[width] = 0;
138 skipcount = 0;
139
140 for (i = width - 1; i >= 0; i--) {
141
142 if (!s->frame.key_frame && !memcmp(this_line, prev_line, s->pixel_size))
143 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
144 else
145 skipcount = 0;
146
147 total_skip_cost = s->length_table[i + skipcount] + 2;
148 s->skip_table[i] = skipcount;
149
150
151 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
152 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
153 else
154 repeatcount = 1;
155
156 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
157
158 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
159 * so let's make it aware */
160 if (i == 0) {
161 total_skip_cost--;
162 total_repeat_cost++;
163 }
164
165 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
166 /* repeat is the best */
167 s->length_table[i] = total_repeat_cost;
168 s->rlecode_table[i] = -repeatcount;
169 }
170 else if (skipcount > 0) {
171 /* skip is the best choice here */
172 s->length_table[i] = total_skip_cost;
173 s->rlecode_table[i] = 0;
174 }
175 else {
176 /* We cannot do neither skip nor repeat
177 * thus we search for the best bulk copy to do */
178
179 int limit = FFMIN(width - i, MAX_RLE_BULK);
180
181 temp_cost = 1 + s->pixel_size + !i;
182 total_bulk_cost = INT_MAX;
183
184 for (j = 1; j <= limit; j++) {
185 if (s->length_table[i + j] + temp_cost < total_bulk_cost) {
186 /* We have found a better bulk copy ... */
187 total_bulk_cost = s->length_table[i + j] + temp_cost;
188 bulkcount = j;
189 }
190 temp_cost += s->pixel_size;
191 }
192
193 s->length_table[i] = total_bulk_cost;
194 s->rlecode_table[i] = bulkcount;
195 }
196
197 this_line -= s->pixel_size;
198 prev_line -= s->pixel_size;
199 }
200
201 /* Good ! Now we have the best sequence for this line, let's ouput it */
202
203 /* We do a special case for the first pixel so that we avoid testing it in
204 * the whole loop */
205
206 i=0;
207 this_line = p-> data[0] + line*p->linesize[0];
208
209 if (s->rlecode_table[0] == 0) {
210 bytestream_put_byte(buf, s->skip_table[0] + 1);
211 i += s->skip_table[0];
212 }
213 else bytestream_put_byte(buf, 1);
214
215
216 while (i < width) {
217 rlecode = s->rlecode_table[i];
218 bytestream_put_byte(buf, rlecode);
219 if (rlecode == 0) {
220 /* Write a skip sequence */
221 bytestream_put_byte(buf, s->skip_table[i] + 1);
222 i += s->skip_table[i];
223 }
224 else if (rlecode > 0) {
225 /* bulk copy */
226 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
227 i += rlecode;
228 }
229 else {
230 /* repeat the bits */
231 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
232 i -= rlecode;
233 }
234 }
235 bytestream_put_byte(buf, -1); // end RLE line
236 }
237
238 /** Encodes frame including header */
239 static int encode_frame(QtrleEncContext *s, AVFrame *p, uint8_t *buf)
240 {
241 int i;
242 int start_line = 0;
243 int end_line = s->avctx->height;
244 uint8_t *orig_buf = buf;
245
246 if (!s->frame.key_frame) {
247 unsigned line_size = s->avctx->width * s->pixel_size;
248 for (start_line = 0; start_line < s->avctx->height; start_line++)
249 if (memcmp(p->data[0] + start_line*p->linesize[0],
250 s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0],
251 line_size))
252 break;
253
254 for (end_line=s->avctx->height; end_line > start_line; end_line--)
255 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
256 s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0],
257 line_size))
258 break;
259 }
260
261 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
262
263 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
264 bytestream_put_be16(&buf, 0); // header
265 else {
266 bytestream_put_be16(&buf, 8); // header
267 bytestream_put_be16(&buf, start_line); // starting line
268 bytestream_put_be16(&buf, 0); // unknown
269 bytestream_put_be16(&buf, end_line - start_line); // lines to update
270 bytestream_put_be16(&buf, 0); // unknown
271 }
272 for (i = start_line; i < end_line; i++)
273 qtrle_encode_line(s, p, i, &buf);
274
275 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
276 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
277 return buf - orig_buf;
278 }
279
280 static int qtrle_encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data)
281 {
282 QtrleEncContext * const s = avctx->priv_data;
283 AVFrame *pict = data;
284 AVFrame * const p = &s->frame;
285 int chunksize;
286
287 *p = *pict;
288
289 if (buf_size < s->max_buf_size) {
290 /* Upper bound check for compressed data */
291 av_log(avctx, AV_LOG_ERROR, "buf_size %d < %d\n", buf_size, s->max_buf_size);
292 return -1;
293 }
294
295 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
296 /* I-Frame */
297 p->pict_type = FF_I_TYPE;
298 p->key_frame = 1;
299 } else {
300 /* P-Frame */
301 p->pict_type = FF_P_TYPE;
302 p->key_frame = 0;
303 }
304
305 chunksize = encode_frame(s, pict, buf);
306
307 /* save the current frame */
308 av_picture_copy(&s->previous_frame, (AVPicture *)p, avctx->pix_fmt, avctx->width, avctx->height);
309 return chunksize;
310 }
311
312 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
313 {
314 QtrleEncContext *s = avctx->priv_data;
315
316 avpicture_free(&s->previous_frame);
317 av_free(s->rlecode_table);
318 av_free(s->length_table);
319 av_free(s->skip_table);
320 return 0;
321 }
322
323 AVCodec qtrle_encoder = {
324 "qtrle",
325 CODEC_TYPE_VIDEO,
326 CODEC_ID_QTRLE,
327 sizeof(QtrleEncContext),
328 qtrle_encode_init,
329 qtrle_encode_frame,
330 qtrle_encode_end,
331 .pix_fmts = (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGB555BE, PIX_FMT_ARGB, PIX_FMT_NONE},
332 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
333 };