Libav
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00001 /* 00002 * Quicktime Animation (RLE) Video Encoder 00003 * Copyright (C) 2007 Clemens Fruhwirth 00004 * Copyright (C) 2007 Alexis Ballier 00005 * 00006 * This file is based on flashsvenc.c. 00007 * 00008 * This file is part of FFmpeg. 00009 * 00010 * FFmpeg is free software; you can redistribute it and/or 00011 * modify it under the terms of the GNU Lesser General Public 00012 * License as published by the Free Software Foundation; either 00013 * version 2.1 of the License, or (at your option) any later version. 00014 * 00015 * FFmpeg is distributed in the hope that it will be useful, 00016 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00017 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00018 * Lesser General Public License for more details. 00019 * 00020 * You should have received a copy of the GNU Lesser General Public 00021 * License along with FFmpeg; if not, write to the Free Software 00022 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00023 */ 00024 00025 #include "avcodec.h" 00026 #include "bytestream.h" 00027 00029 #define MAX_RLE_BULK 127 00030 00031 #define MAX_RLE_REPEAT 128 00032 00033 #define MAX_RLE_SKIP 254 00034 00035 typedef struct QtrleEncContext { 00036 AVCodecContext *avctx; 00037 AVFrame frame; 00038 int pixel_size; 00039 AVPicture previous_frame; 00040 unsigned int max_buf_size; 00050 signed char *rlecode_table; 00054 int *length_table; 00058 uint8_t* skip_table; 00059 } QtrleEncContext; 00060 00061 static av_cold int qtrle_encode_init(AVCodecContext *avctx) 00062 { 00063 QtrleEncContext *s = avctx->priv_data; 00064 00065 if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) { 00066 return -1; 00067 } 00068 s->avctx=avctx; 00069 00070 switch (avctx->pix_fmt) { 00071 case PIX_FMT_RGB555BE: 00072 s->pixel_size = 2; 00073 break; 00074 case PIX_FMT_RGB24: 00075 s->pixel_size = 3; 00076 break; 00077 case PIX_FMT_ARGB: 00078 s->pixel_size = 4; 00079 break; 00080 default: 00081 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n"); 00082 break; 00083 } 00084 avctx->bits_per_coded_sample = s->pixel_size*8; 00085 00086 s->rlecode_table = av_mallocz(s->avctx->width); 00087 s->skip_table = av_mallocz(s->avctx->width); 00088 s->length_table = av_mallocz((s->avctx->width + 1)*sizeof(int)); 00089 if (!s->skip_table || !s->length_table || !s->rlecode_table) { 00090 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n"); 00091 return -1; 00092 } 00093 if (avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height) < 0) { 00094 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n"); 00095 return -1; 00096 } 00097 00098 s->max_buf_size = s->avctx->width*s->avctx->height*s->pixel_size /* image base material */ 00099 + 15 /* header + footer */ 00100 + s->avctx->height*2 /* skip code+rle end */ 00101 + s->avctx->width/MAX_RLE_BULK + 1 /* rle codes */; 00102 avctx->coded_frame = &s->frame; 00103 return 0; 00104 } 00105 00109 static void qtrle_encode_line(QtrleEncContext *s, AVFrame *p, int line, uint8_t **buf) 00110 { 00111 int width=s->avctx->width; 00112 int i; 00113 signed char rlecode; 00114 00115 /* We will use it to compute the best bulk copy sequence */ 00116 unsigned int bulkcount; 00117 /* This will be the number of pixels equal to the preivous frame one's 00118 * starting from the ith pixel */ 00119 unsigned int skipcount; 00120 /* This will be the number of consecutive equal pixels in the current 00121 * frame, starting from the ith one also */ 00122 unsigned int av_uninit(repeatcount); 00123 00124 /* The cost of the three different possibilities */ 00125 int total_bulk_cost; 00126 int total_skip_cost; 00127 int total_repeat_cost; 00128 00129 int temp_cost; 00130 int j; 00131 00132 uint8_t *this_line = p-> data[0] + line*p-> linesize[0] + 00133 (width - 1)*s->pixel_size; 00134 uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] + 00135 (width - 1)*s->pixel_size; 00136 00137 s->length_table[width] = 0; 00138 skipcount = 0; 00139 00140 for (i = width - 1; i >= 0; i--) { 00141 00142 if (!s->frame.key_frame && !memcmp(this_line, prev_line, s->pixel_size)) 00143 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP); 00144 else 00145 skipcount = 0; 00146 00147 total_skip_cost = s->length_table[i + skipcount] + 2; 00148 s->skip_table[i] = skipcount; 00149 00150 00151 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size)) 00152 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT); 00153 else 00154 repeatcount = 1; 00155 00156 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size; 00157 00158 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy 00159 * so let's make it aware */ 00160 if (i == 0) { 00161 total_skip_cost--; 00162 total_repeat_cost++; 00163 } 00164 00165 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) { 00166 /* repeat is the best */ 00167 s->length_table[i] = total_repeat_cost; 00168 s->rlecode_table[i] = -repeatcount; 00169 } 00170 else if (skipcount > 0) { 00171 /* skip is the best choice here */ 00172 s->length_table[i] = total_skip_cost; 00173 s->rlecode_table[i] = 0; 00174 } 00175 else { 00176 /* We cannot do neither skip nor repeat 00177 * thus we search for the best bulk copy to do */ 00178 00179 int limit = FFMIN(width - i, MAX_RLE_BULK); 00180 00181 temp_cost = 1 + s->pixel_size + !i; 00182 total_bulk_cost = INT_MAX; 00183 00184 for (j = 1; j <= limit; j++) { 00185 if (s->length_table[i + j] + temp_cost < total_bulk_cost) { 00186 /* We have found a better bulk copy ... */ 00187 total_bulk_cost = s->length_table[i + j] + temp_cost; 00188 bulkcount = j; 00189 } 00190 temp_cost += s->pixel_size; 00191 } 00192 00193 s->length_table[i] = total_bulk_cost; 00194 s->rlecode_table[i] = bulkcount; 00195 } 00196 00197 this_line -= s->pixel_size; 00198 prev_line -= s->pixel_size; 00199 } 00200 00201 /* Good ! Now we have the best sequence for this line, let's ouput it */ 00202 00203 /* We do a special case for the first pixel so that we avoid testing it in 00204 * the whole loop */ 00205 00206 i=0; 00207 this_line = p-> data[0] + line*p->linesize[0]; 00208 00209 if (s->rlecode_table[0] == 0) { 00210 bytestream_put_byte(buf, s->skip_table[0] + 1); 00211 i += s->skip_table[0]; 00212 } 00213 else bytestream_put_byte(buf, 1); 00214 00215 00216 while (i < width) { 00217 rlecode = s->rlecode_table[i]; 00218 bytestream_put_byte(buf, rlecode); 00219 if (rlecode == 0) { 00220 /* Write a skip sequence */ 00221 bytestream_put_byte(buf, s->skip_table[i] + 1); 00222 i += s->skip_table[i]; 00223 } 00224 else if (rlecode > 0) { 00225 /* bulk copy */ 00226 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size); 00227 i += rlecode; 00228 } 00229 else { 00230 /* repeat the bits */ 00231 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size); 00232 i -= rlecode; 00233 } 00234 } 00235 bytestream_put_byte(buf, -1); // end RLE line 00236 } 00237 00239 static int encode_frame(QtrleEncContext *s, AVFrame *p, uint8_t *buf) 00240 { 00241 int i; 00242 int start_line = 0; 00243 int end_line = s->avctx->height; 00244 uint8_t *orig_buf = buf; 00245 00246 if (!s->frame.key_frame) { 00247 unsigned line_size = s->avctx->width * s->pixel_size; 00248 for (start_line = 0; start_line < s->avctx->height; start_line++) 00249 if (memcmp(p->data[0] + start_line*p->linesize[0], 00250 s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0], 00251 line_size)) 00252 break; 00253 00254 for (end_line=s->avctx->height; end_line > start_line; end_line--) 00255 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0], 00256 s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0], 00257 line_size)) 00258 break; 00259 } 00260 00261 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later 00262 00263 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height) 00264 bytestream_put_be16(&buf, 0); // header 00265 else { 00266 bytestream_put_be16(&buf, 8); // header 00267 bytestream_put_be16(&buf, start_line); // starting line 00268 bytestream_put_be16(&buf, 0); // unknown 00269 bytestream_put_be16(&buf, end_line - start_line); // lines to update 00270 bytestream_put_be16(&buf, 0); // unknown 00271 } 00272 for (i = start_line; i < end_line; i++) 00273 qtrle_encode_line(s, p, i, &buf); 00274 00275 bytestream_put_byte(&buf, 0); // zero skip code = frame finished 00276 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size 00277 return buf - orig_buf; 00278 } 00279 00280 static int qtrle_encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data) 00281 { 00282 QtrleEncContext * const s = avctx->priv_data; 00283 AVFrame *pict = data; 00284 AVFrame * const p = &s->frame; 00285 int chunksize; 00286 00287 *p = *pict; 00288 00289 if (buf_size < s->max_buf_size) { 00290 /* Upper bound check for compressed data */ 00291 av_log(avctx, AV_LOG_ERROR, "buf_size %d < %d\n", buf_size, s->max_buf_size); 00292 return -1; 00293 } 00294 00295 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) { 00296 /* I-Frame */ 00297 p->pict_type = FF_I_TYPE; 00298 p->key_frame = 1; 00299 } else { 00300 /* P-Frame */ 00301 p->pict_type = FF_P_TYPE; 00302 p->key_frame = 0; 00303 } 00304 00305 chunksize = encode_frame(s, pict, buf); 00306 00307 /* save the current frame */ 00308 av_picture_copy(&s->previous_frame, (AVPicture *)p, avctx->pix_fmt, avctx->width, avctx->height); 00309 return chunksize; 00310 } 00311 00312 static av_cold int qtrle_encode_end(AVCodecContext *avctx) 00313 { 00314 QtrleEncContext *s = avctx->priv_data; 00315 00316 avpicture_free(&s->previous_frame); 00317 av_free(s->rlecode_table); 00318 av_free(s->length_table); 00319 av_free(s->skip_table); 00320 return 0; 00321 } 00322 00323 AVCodec qtrle_encoder = { 00324 "qtrle", 00325 AVMEDIA_TYPE_VIDEO, 00326 CODEC_ID_QTRLE, 00327 sizeof(QtrleEncContext), 00328 qtrle_encode_init, 00329 qtrle_encode_frame, 00330 qtrle_encode_end, 00331 .pix_fmts = (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGB555BE, PIX_FMT_ARGB, PIX_FMT_NONE}, 00332 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"), 00333 };