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"
30 /** Maximum RLE code for bulk copy */
31 #define MAX_RLE_BULK 127
32 /** Maximum RLE code for repeat */
33 #define MAX_RLE_REPEAT 128
34 /** Maximum RLE code for skip */
35 #define MAX_RLE_SKIP 254
37 typedef struct QtrleEncContext {
38 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 */
62 /** Encoded frame is a key frame */
66 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
68 QtrleEncContext *s = avctx->priv_data;
70 av_frame_free(&avctx->coded_frame);
72 avpicture_free(&s->previous_frame);
73 av_free(s->rlecode_table);
74 av_free(s->length_table);
75 av_free(s->skip_table);
79 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
81 QtrleEncContext *s = avctx->priv_data;
84 if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
85 return AVERROR(EINVAL);
88 s->logical_width=avctx->width;
90 switch (avctx->pix_fmt) {
91 case AV_PIX_FMT_GRAY8:
92 if (avctx->width % 4) {
93 av_log(avctx, AV_LOG_ERROR, "Width not being a multiple of 4 is not supported\n");
94 return AVERROR(EINVAL);
96 s->logical_width = avctx->width / 4;
99 case AV_PIX_FMT_RGB555BE:
102 case AV_PIX_FMT_RGB24:
105 case AV_PIX_FMT_ARGB:
109 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
112 avctx->bits_per_coded_sample = avctx->pix_fmt == AV_PIX_FMT_GRAY8 ? 40 : s->pixel_size*8;
114 s->rlecode_table = av_mallocz(s->logical_width);
115 s->skip_table = av_mallocz(s->logical_width);
116 s->length_table = av_mallocz_array(s->logical_width + 1, sizeof(int));
117 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
118 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
119 return AVERROR(ENOMEM);
121 if ((ret = avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height)) < 0) {
122 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
126 s->max_buf_size = s->logical_width*s->avctx->height*s->pixel_size*2 /* image base material */
127 + 15 /* header + footer */
128 + s->avctx->height*2 /* skip code+rle end */
129 + s->logical_width/MAX_RLE_BULK + 1 /* rle codes */;
131 avctx->coded_frame = av_frame_alloc();
132 if (!avctx->coded_frame) {
133 qtrle_encode_end(avctx);
134 return AVERROR(ENOMEM);
141 * Compute the best RLE sequence for a line
143 static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
145 int width=s->logical_width;
149 /* This will be the number of pixels equal to the preivous frame one's
150 * starting from the ith pixel */
151 unsigned int skipcount;
152 /* This will be the number of consecutive equal pixels in the current
153 * frame, starting from the ith one also */
154 unsigned int av_uninit(repeatcount);
156 /* The cost of the three different possibilities */
158 int total_repeat_cost;
161 int lowest_bulk_cost;
162 int lowest_bulk_cost_index;
163 int sec_lowest_bulk_cost;
164 int sec_lowest_bulk_cost_index;
166 uint8_t *this_line = p-> data[0] + line*p-> linesize[0] +
167 (width - 1)*s->pixel_size;
168 uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] +
169 (width - 1)*s->pixel_size;
171 s->length_table[width] = 0;
175 lowest_bulk_cost = INT_MAX / 2;
176 lowest_bulk_cost_index = width;
177 sec_lowest_bulk_cost = INT_MAX / 2;
178 sec_lowest_bulk_cost_index = width;
180 base_bulk_cost = 1 + s->pixel_size;
182 for (i = width - 1; i >= 0; i--) {
186 /* If our lowest bulk cost index is too far away, replace it
187 * with the next lowest bulk cost */
188 if (FFMIN(width, i + MAX_RLE_BULK) < lowest_bulk_cost_index) {
189 lowest_bulk_cost = sec_lowest_bulk_cost;
190 lowest_bulk_cost_index = sec_lowest_bulk_cost_index;
192 sec_lowest_bulk_cost = INT_MAX / 2;
193 sec_lowest_bulk_cost_index = width;
196 /* Deal with the first pixel's bulk cost */
200 sec_lowest_bulk_cost++;
203 /* Look at the bulk cost of the previous loop and see if it is
204 * a new lower bulk cost */
205 prev_bulk_cost = s->length_table[i + 1] + base_bulk_cost;
206 if (prev_bulk_cost <= sec_lowest_bulk_cost) {
207 /* If it's lower than the 2nd lowest, then it may be lower
209 if (prev_bulk_cost <= lowest_bulk_cost) {
211 /* If we have found a new lowest bulk cost,
212 * then the 2nd lowest bulk cost is now farther than the
213 * lowest bulk cost, and will never be used */
214 sec_lowest_bulk_cost = INT_MAX / 2;
216 lowest_bulk_cost = prev_bulk_cost;
217 lowest_bulk_cost_index = i + 1;
219 /* Then it must be the 2nd lowest bulk cost */
220 sec_lowest_bulk_cost = prev_bulk_cost;
221 sec_lowest_bulk_cost_index = i + 1;
225 if (!s->key_frame && !memcmp(this_line, prev_line, s->pixel_size))
226 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
230 total_skip_cost = s->length_table[i + skipcount] + 2;
231 s->skip_table[i] = skipcount;
234 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
235 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
239 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
241 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
242 * so let's make it aware */
248 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
249 /* repeat is the best */
250 s->length_table[i] = total_repeat_cost;
251 s->rlecode_table[i] = -repeatcount;
253 else if (skipcount > 0) {
254 /* skip is the best choice here */
255 s->length_table[i] = total_skip_cost;
256 s->rlecode_table[i] = 0;
259 /* We cannot do neither skip nor repeat
260 * thus we use the best bulk copy */
262 s->length_table[i] = lowest_bulk_cost;
263 s->rlecode_table[i] = lowest_bulk_cost_index - i;
267 /* These bulk costs increase every iteration */
268 lowest_bulk_cost += s->pixel_size;
269 sec_lowest_bulk_cost += s->pixel_size;
271 this_line -= s->pixel_size;
272 prev_line -= s->pixel_size;
275 /* Good ! Now we have the best sequence for this line, let's output it */
277 /* We do a special case for the first pixel so that we avoid testing it in
281 this_line = p-> data[0] + line*p->linesize[0];
283 if (s->rlecode_table[0] == 0) {
284 bytestream_put_byte(buf, s->skip_table[0] + 1);
285 i += s->skip_table[0];
287 else bytestream_put_byte(buf, 1);
291 rlecode = s->rlecode_table[i];
292 bytestream_put_byte(buf, rlecode);
294 /* Write a skip sequence */
295 bytestream_put_byte(buf, s->skip_table[i] + 1);
296 i += s->skip_table[i];
298 else if (rlecode > 0) {
300 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
302 // QT grayscale colorspace has 0=white and 255=black, we will
303 // ignore the palette that is included in the AVFrame because
304 // AV_PIX_FMT_GRAY8 has defined color mapping
305 for (j = 0; j < rlecode*s->pixel_size; ++j)
306 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
308 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
313 /* repeat the bits */
314 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
316 // QT grayscale colorspace has 0=white and 255=black, ...
317 for (j = 0; j < s->pixel_size; ++j)
318 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
320 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
325 bytestream_put_byte(buf, -1); // end RLE line
328 /** Encode frame including header */
329 static int encode_frame(QtrleEncContext *s, const AVFrame *p, uint8_t *buf)
333 int end_line = s->avctx->height;
334 uint8_t *orig_buf = buf;
337 unsigned line_size = s->logical_width * s->pixel_size;
338 for (start_line = 0; start_line < s->avctx->height; start_line++)
339 if (memcmp(p->data[0] + start_line*p->linesize[0],
340 s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0],
344 for (end_line=s->avctx->height; end_line > start_line; end_line--)
345 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
346 s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0],
351 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
353 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
354 bytestream_put_be16(&buf, 0); // header
356 bytestream_put_be16(&buf, 8); // header
357 bytestream_put_be16(&buf, start_line); // starting line
358 bytestream_put_be16(&buf, 0); // unknown
359 bytestream_put_be16(&buf, end_line - start_line); // lines to update
360 bytestream_put_be16(&buf, 0); // unknown
362 for (i = start_line; i < end_line; i++)
363 qtrle_encode_line(s, p, i, &buf);
365 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
366 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
367 return buf - orig_buf;
370 static int qtrle_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
371 const AVFrame *pict, int *got_packet)
373 QtrleEncContext * const s = avctx->priv_data;
374 enum AVPictureType pict_type;
377 if ((ret = ff_alloc_packet2(avctx, pkt, s->max_buf_size)) < 0)
380 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
382 pict_type = AV_PICTURE_TYPE_I;
386 pict_type = AV_PICTURE_TYPE_P;
390 pkt->size = encode_frame(s, pict, pkt->data);
392 /* save the current frame */
393 av_picture_copy(&s->previous_frame, (const AVPicture *)pict,
394 avctx->pix_fmt, avctx->width, avctx->height);
396 avctx->coded_frame->key_frame = s->key_frame;
397 avctx->coded_frame->pict_type = pict_type;
400 pkt->flags |= AV_PKT_FLAG_KEY;
406 AVCodec ff_qtrle_encoder = {
408 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
409 .type = AVMEDIA_TYPE_VIDEO,
410 .id = AV_CODEC_ID_QTRLE,
411 .priv_data_size = sizeof(QtrleEncContext),
412 .init = qtrle_encode_init,
413 .encode2 = qtrle_encode_frame,
414 .close = qtrle_encode_end,
415 .pix_fmts = (const enum AVPixelFormat[]){
416 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGB555BE, AV_PIX_FMT_ARGB, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE