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 35typedef 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 61static 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_RGB555: 72 s->pixel_size = 2; 73 break;*/ 74 case PIX_FMT_RGB24: 75 s->pixel_size = 3; 76 break; 77 default: 78 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n"); 79 break; 80 } 81 avctx->bits_per_coded_sample = s->pixel_size*8; 82 83 s->rlecode_table = av_mallocz(s->avctx->width); 84 s->skip_table = av_mallocz(s->avctx->width); 85 s->length_table = av_mallocz((s->avctx->width + 1)*sizeof(int)); 86 if (!s->skip_table || !s->length_table || !s->rlecode_table) { 87 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n"); 88 return -1; 89 } 90 if (avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height) < 0) { 91 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n"); 92 return -1; 93 } 94 95 s->max_buf_size = s->avctx->width*s->avctx->height*s->pixel_size /* image base material */ 96 + 15 /* header + footer */ 97 + s->avctx->height*2 /* skip code+rle end */ 98 + s->avctx->width/MAX_RLE_BULK + 1 /* rle codes */; 99 avctx->coded_frame = &s->frame; 100 return 0; 101} 102 103/** 104 * Computes the best RLE sequence for a line 105 */ 106static void qtrle_encode_line(QtrleEncContext *s, AVFrame *p, int line, uint8_t **buf) 107{ 108 int width=s->avctx->width; 109 int i; 110 signed char rlecode; 111 112 /* We will use it to compute the best bulk copy sequence */ 113 unsigned int bulkcount; 114 /* This will be the number of pixels equal to the preivous frame one's 115 * starting from the ith pixel */ 116 unsigned int skipcount; 117 /* This will be the number of consecutive equal pixels in the current 118 * frame, starting from the ith one also */ 119 unsigned int av_uninit(repeatcount); 120 121 /* The cost of the three different possibilities */ 122 int total_bulk_cost; 123 int total_skip_cost; 124 int total_repeat_cost; 125 126 int temp_cost; 127 int j; 128 129 uint8_t *this_line = p-> data[0] + line*p->linesize[0] + (width - 1)*s->pixel_size; 130 uint8_t *prev_line = s->previous_frame.data[0] + line*p->linesize[0] + (width - 1)*s->pixel_size; 131 132 s->length_table[width] = 0; 133 skipcount = 0; 134 135 for (i = width - 1; i >= 0; i--) { 136 137 if (!s->frame.key_frame && !memcmp(this_line, prev_line, s->pixel_size)) 138 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP); 139 else 140 skipcount = 0; 141 142 total_skip_cost = s->length_table[i + skipcount] + 2; 143 s->skip_table[i] = skipcount; 144 145 146 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size)) 147 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT); 148 else 149 repeatcount = 1; 150 151 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size; 152 153 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy 154 * so let's make it aware */ 155 if (i == 0) { 156 total_skip_cost--; 157 total_repeat_cost++; 158 } 159 160 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) { 161 /* repeat is the best */ 162 s->length_table[i] = total_repeat_cost; 163 s->rlecode_table[i] = -repeatcount; 164 } 165 else if (skipcount > 0) { 166 /* skip is the best choice here */ 167 s->length_table[i] = total_skip_cost; 168 s->rlecode_table[i] = 0; 169 } 170 else { 171 /* We cannot do neither skip nor repeat 172 * thus we search for the best bulk copy to do */ 173 174 int limit = FFMIN(width - i, MAX_RLE_BULK); 175 176 temp_cost = 1 + s->pixel_size + !i; 177 total_bulk_cost = INT_MAX; 178 179 for (j = 1; j <= limit; j++) { 180 if (s->length_table[i + j] + temp_cost < total_bulk_cost) { 181 /* We have found a better bulk copy ... */ 182 total_bulk_cost = s->length_table[i + j] + temp_cost; 183 bulkcount = j; 184 } 185 temp_cost += s->pixel_size; 186 } 187 188 s->length_table[i] = total_bulk_cost; 189 s->rlecode_table[i] = bulkcount; 190 } 191 192 this_line -= s->pixel_size; 193 prev_line -= s->pixel_size; 194 } 195 196 /* Good ! Now we have the best sequence for this line, let's ouput it */ 197 198 /* We do a special case for the first pixel so that we avoid testing it in 199 * the whole loop */ 200 201 i=0; 202 this_line = p-> data[0] + line*p->linesize[0]; 203 prev_line = s->previous_frame.data[0] + line*p->linesize[0]; 204 205 if (s->rlecode_table[0] == 0) { 206 bytestream_put_byte(buf, s->skip_table[0] + 1); 207 i += s->skip_table[0]; 208 } 209 else bytestream_put_byte(buf, 1); 210 211 212 while (i < width) { 213 rlecode = s->rlecode_table[i]; 214 bytestream_put_byte(buf, rlecode); 215 if (rlecode == 0) { 216 /* Write a skip sequence */ 217 bytestream_put_byte(buf, s->skip_table[i] + 1); 218 i += s->skip_table[i]; 219 } 220 else if (rlecode > 0) { 221 /* bulk copy */ 222 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size); 223 i += rlecode; 224 } 225 else { 226 /* repeat the bits */ 227 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size); 228 i -= rlecode; 229 } 230 } 231 bytestream_put_byte(buf, -1); // end RLE line 232} 233 234/** Encodes frame including header */ 235static int encode_frame(QtrleEncContext *s, AVFrame *p, uint8_t *buf) 236{ 237 int i; 238 int start_line = 0; 239 int end_line = s->avctx->height; 240 uint8_t *orig_buf = buf; 241 242 if (!s->frame.key_frame) { 243 for (start_line = 0; start_line < s->avctx->height; start_line++) 244 if (memcmp(p->data[0] + start_line*p->linesize[0], 245 s->previous_frame.data[0] + start_line*p->linesize[0], 246 p->linesize[0])) 247 break; 248 249 for (end_line=s->avctx->height; end_line > start_line; end_line--) 250 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0], 251 s->previous_frame.data[0] + (end_line - 1)*p->linesize[0], 252 p->linesize[0])) 253 break; 254 } 255 256 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later 257 258 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height) 259 bytestream_put_be16(&buf, 0); // header 260 else { 261 bytestream_put_be16(&buf, 8); // header 262 bytestream_put_be16(&buf, start_line); // starting line 263 bytestream_put_be16(&buf, 0); // unknown 264 bytestream_put_be16(&buf, end_line - start_line); // lines to update 265 bytestream_put_be16(&buf, 0); // unknown 266 } 267 for (i = start_line; i < end_line; i++) 268 qtrle_encode_line(s, p, i, &buf); 269 270 bytestream_put_byte(&buf, 0); // zero skip code = frame finished 271 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size 272 return buf - orig_buf; 273} 274 275static int qtrle_encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data) 276{ 277 QtrleEncContext * const s = avctx->priv_data; 278 AVFrame *pict = data; 279 AVFrame * const p = &s->frame; 280 int chunksize; 281 282 *p = *pict; 283 284 if (buf_size < s->max_buf_size) { 285 /* Upper bound check for compressed data */ 286 av_log(avctx, AV_LOG_ERROR, "buf_size %d < %d\n", buf_size, s->max_buf_size); 287 return -1; 288 } 289 290 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) { 291 /* I-Frame */ 292 p->pict_type = FF_I_TYPE; 293 p->key_frame = 1; 294 } else { 295 /* P-Frame */ 296 p->pict_type = FF_P_TYPE; 297 p->key_frame = 0; 298 } 299 300 chunksize = encode_frame(s, pict, buf); 301 302 /* save the current frame */ 303 av_picture_copy(&s->previous_frame, (AVPicture *)p, avctx->pix_fmt, avctx->width, avctx->height); 304 return chunksize; 305} 306 307static av_cold int qtrle_encode_end(AVCodecContext *avctx) 308{ 309 QtrleEncContext *s = avctx->priv_data; 310 311 avpicture_free(&s->previous_frame); 312 av_free(s->rlecode_table); 313 av_free(s->length_table); 314 av_free(s->skip_table); 315 return 0; 316} 317 318AVCodec qtrle_encoder = { 319 "qtrle", 320 CODEC_TYPE_VIDEO, 321 CODEC_ID_QTRLE, 322 sizeof(QtrleEncContext), 323 qtrle_encode_init, 324 qtrle_encode_frame, 325 qtrle_encode_end, 326 .pix_fmts = (enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_NONE}, 327 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"), 328}; 329