2 * Quicktime Animation (RLE) Video Encoder
3 * Copyright (C) 2007 Clemens Fruhwirth
4 * Copyright (C) 2007 Alexis Ballier
6 * This file is based on flashsvenc.c.
8 * This file is part of FFmpeg.
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.
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.
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
25 #include "libavutil/imgutils.h"
27 #include "bytestream.h"
29 /** Maximum RLE code for bulk copy */
30 #define MAX_RLE_BULK 127
31 /** Maximum RLE code for repeat */
32 #define MAX_RLE_REPEAT 128
33 /** Maximum RLE code for skip */
34 #define MAX_RLE_SKIP 254
36 typedef struct QtrleEncContext {
37 AVCodecContext *avctx;
40 AVPicture previous_frame;
41 unsigned int max_buf_size;
44 * This array will contain at ith position the value of the best RLE code
45 * if the line started at pixel i
46 * There can be 3 values :
47 * skip (0) : skip as much as possible pixels because they are equal to the
49 * repeat (<-1) : repeat that pixel -rle_code times, still as much as
51 * copy (>0) : copy the raw next rle_code pixels */
52 signed char *rlecode_table;
54 * This array will contain the length of the best rle encoding of the line
55 * starting at ith pixel */
58 * Will contain at ith position the number of consecutive pixels equal to the previous
59 * frame starting from pixel i */
63 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
65 QtrleEncContext *s = avctx->priv_data;
67 if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
71 s->logical_width=avctx->width;
73 switch (avctx->pix_fmt) {
75 s->logical_width = avctx->width / 4;
78 case PIX_FMT_RGB555BE:
88 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
91 avctx->bits_per_coded_sample = avctx->pix_fmt == PIX_FMT_GRAY8 ? 40 : s->pixel_size*8;
93 s->rlecode_table = av_mallocz(s->logical_width);
94 s->skip_table = av_mallocz(s->logical_width);
95 s->length_table = av_mallocz((s->logical_width + 1)*sizeof(int));
96 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
97 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
100 if (avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height) < 0) {
101 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
105 s->max_buf_size = s->logical_width*s->avctx->height*s->pixel_size /* image base material */
106 + 15 /* header + footer */
107 + s->avctx->height*2 /* skip code+rle end */
108 + s->logical_width/MAX_RLE_BULK + 1 /* rle codes */;
109 avctx->coded_frame = &s->frame;
114 * Compute the best RLE sequence for a line
116 static void qtrle_encode_line(QtrleEncContext *s, AVFrame *p, int line, uint8_t **buf)
118 int width=s->logical_width;
122 /* We will use it to compute the best bulk copy sequence */
123 unsigned int bulkcount;
124 /* This will be the number of pixels equal to the preivous frame one's
125 * starting from the ith pixel */
126 unsigned int skipcount;
127 /* This will be the number of consecutive equal pixels in the current
128 * frame, starting from the ith one also */
129 unsigned int av_uninit(repeatcount);
131 /* The cost of the three different possibilities */
134 int total_repeat_cost;
139 uint8_t *this_line = p-> data[0] + line*p-> linesize[0] +
140 (width - 1)*s->pixel_size;
141 uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] +
142 (width - 1)*s->pixel_size;
144 s->length_table[width] = 0;
147 for (i = width - 1; i >= 0; i--) {
149 if (!s->frame.key_frame && !memcmp(this_line, prev_line, s->pixel_size))
150 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
154 total_skip_cost = s->length_table[i + skipcount] + 2;
155 s->skip_table[i] = skipcount;
158 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
159 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
163 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
165 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
166 * so let's make it aware */
172 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
173 /* repeat is the best */
174 s->length_table[i] = total_repeat_cost;
175 s->rlecode_table[i] = -repeatcount;
177 else if (skipcount > 0) {
178 /* skip is the best choice here */
179 s->length_table[i] = total_skip_cost;
180 s->rlecode_table[i] = 0;
183 /* We cannot do neither skip nor repeat
184 * thus we search for the best bulk copy to do */
186 int limit = FFMIN(width - i, MAX_RLE_BULK);
188 temp_cost = 1 + s->pixel_size + !i;
189 total_bulk_cost = INT_MAX;
191 for (j = 1; j <= limit; j++) {
192 if (s->length_table[i + j] + temp_cost < total_bulk_cost) {
193 /* We have found a better bulk copy ... */
194 total_bulk_cost = s->length_table[i + j] + temp_cost;
197 temp_cost += s->pixel_size;
200 s->length_table[i] = total_bulk_cost;
201 s->rlecode_table[i] = bulkcount;
204 this_line -= s->pixel_size;
205 prev_line -= s->pixel_size;
208 /* Good ! Now we have the best sequence for this line, let's ouput it */
210 /* We do a special case for the first pixel so that we avoid testing it in
214 this_line = p-> data[0] + line*p->linesize[0];
216 if (s->rlecode_table[0] == 0) {
217 bytestream_put_byte(buf, s->skip_table[0] + 1);
218 i += s->skip_table[0];
220 else bytestream_put_byte(buf, 1);
224 rlecode = s->rlecode_table[i];
225 bytestream_put_byte(buf, rlecode);
227 /* Write a skip sequence */
228 bytestream_put_byte(buf, s->skip_table[i] + 1);
229 i += s->skip_table[i];
231 else if (rlecode > 0) {
233 if (s->avctx->pix_fmt == PIX_FMT_GRAY8) {
235 // QT grayscale colorspace has 0=white and 255=black, we will
236 // ignore the palette that is included in the AVFrame because
237 // PIX_FMT_GRAY8 has defined color mapping
238 for (j = 0; j < rlecode*s->pixel_size; ++j)
239 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
241 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
246 /* repeat the bits */
247 if (s->avctx->pix_fmt == PIX_FMT_GRAY8) {
249 // QT grayscale colorspace has 0=white and 255=black, ...
250 for (j = 0; j < s->pixel_size; ++j)
251 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
253 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
258 bytestream_put_byte(buf, -1); // end RLE line
261 /** Encode frame including header */
262 static int encode_frame(QtrleEncContext *s, AVFrame *p, uint8_t *buf)
266 int end_line = s->avctx->height;
267 uint8_t *orig_buf = buf;
269 if (!s->frame.key_frame) {
270 unsigned line_size = s->logical_width * s->pixel_size;
271 for (start_line = 0; start_line < s->avctx->height; start_line++)
272 if (memcmp(p->data[0] + start_line*p->linesize[0],
273 s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0],
277 for (end_line=s->avctx->height; end_line > start_line; end_line--)
278 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
279 s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0],
284 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
286 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
287 bytestream_put_be16(&buf, 0); // header
289 bytestream_put_be16(&buf, 8); // header
290 bytestream_put_be16(&buf, start_line); // starting line
291 bytestream_put_be16(&buf, 0); // unknown
292 bytestream_put_be16(&buf, end_line - start_line); // lines to update
293 bytestream_put_be16(&buf, 0); // unknown
295 for (i = start_line; i < end_line; i++)
296 qtrle_encode_line(s, p, i, &buf);
298 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
299 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
300 return buf - orig_buf;
303 static int qtrle_encode_frame(AVCodecContext *avctx, uint8_t *buf, int buf_size, void *data)
305 QtrleEncContext * const s = avctx->priv_data;
306 AVFrame *pict = data;
307 AVFrame * const p = &s->frame;
312 if (buf_size < s->max_buf_size) {
313 /* Upper bound check for compressed data */
314 av_log(avctx, AV_LOG_ERROR, "buf_size %d < %d\n", buf_size, s->max_buf_size);
318 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
320 p->pict_type = AV_PICTURE_TYPE_I;
324 p->pict_type = AV_PICTURE_TYPE_P;
328 chunksize = encode_frame(s, pict, buf);
330 /* save the current frame */
331 av_picture_copy(&s->previous_frame, (AVPicture *)p, avctx->pix_fmt, avctx->width, avctx->height);
335 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
337 QtrleEncContext *s = avctx->priv_data;
339 avpicture_free(&s->previous_frame);
340 av_free(s->rlecode_table);
341 av_free(s->length_table);
342 av_free(s->skip_table);
346 AVCodec ff_qtrle_encoder = {
348 .type = AVMEDIA_TYPE_VIDEO,
349 .id = CODEC_ID_QTRLE,
350 .priv_data_size = sizeof(QtrleEncContext),
351 .init = qtrle_encode_init,
352 .encode = qtrle_encode_frame,
353 .close = qtrle_encode_end,
354 .pix_fmts = (const enum PixelFormat[]){PIX_FMT_RGB24, PIX_FMT_RGB555BE, PIX_FMT_ARGB, PIX_FMT_GRAY8, PIX_FMT_NONE},
355 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),