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;
41 AVPicture previous_frame;
42 unsigned int max_buf_size;
45 * This array will contain at ith position the value of the best RLE code
46 * if the line started at pixel i
47 * There can be 3 values :
48 * skip (0) : skip as much as possible pixels because they are equal to the
50 * repeat (<-1) : repeat that pixel -rle_code times, still as much as
52 * copy (>0) : copy the raw next rle_code pixels */
53 signed char *rlecode_table;
55 * This array will contain the length of the best rle encoding of the line
56 * starting at ith pixel */
59 * Will contain at ith position the number of consecutive pixels equal to the previous
60 * frame starting from pixel i */
64 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
66 QtrleEncContext *s = avctx->priv_data;
69 if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
70 return AVERROR(EINVAL);
73 s->logical_width=avctx->width;
75 switch (avctx->pix_fmt) {
76 case AV_PIX_FMT_GRAY8:
77 s->logical_width = avctx->width / 4;
80 case AV_PIX_FMT_RGB555BE:
83 case AV_PIX_FMT_RGB24:
90 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
93 avctx->bits_per_coded_sample = avctx->pix_fmt == AV_PIX_FMT_GRAY8 ? 40 : s->pixel_size*8;
95 s->rlecode_table = av_mallocz(s->logical_width);
96 s->skip_table = av_mallocz(s->logical_width);
97 s->length_table = av_mallocz((s->logical_width + 1)*sizeof(int));
98 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
99 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
100 return AVERROR(ENOMEM);
102 if ((ret = avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height)) < 0) {
103 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
107 s->max_buf_size = s->logical_width*s->avctx->height*s->pixel_size*2 /* image base material */
108 + 15 /* header + footer */
109 + s->avctx->height*2 /* skip code+rle end */
110 + s->logical_width/MAX_RLE_BULK + 1 /* rle codes */;
111 avctx->coded_frame = &s->frame;
116 * Compute the best RLE sequence for a line
118 static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
120 int width=s->logical_width;
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 */
133 int total_repeat_cost;
136 int lowest_bulk_cost;
137 int lowest_bulk_cost_index;
138 int sec_lowest_bulk_cost;
139 int sec_lowest_bulk_cost_index;
141 uint8_t *this_line = p-> data[0] + line*p-> linesize[0] +
142 (width - 1)*s->pixel_size;
143 uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] +
144 (width - 1)*s->pixel_size;
146 s->length_table[width] = 0;
150 lowest_bulk_cost = INT_MAX / 2;
151 lowest_bulk_cost_index = width;
152 sec_lowest_bulk_cost = INT_MAX / 2;
153 sec_lowest_bulk_cost_index = width;
155 base_bulk_cost = 1 + s->pixel_size;
157 for (i = width - 1; i >= 0; i--) {
161 /* If our lowest bulk cost index is too far away, replace it
162 * with the next lowest bulk cost */
163 if (FFMIN(width, i + MAX_RLE_BULK) < lowest_bulk_cost_index) {
164 lowest_bulk_cost = sec_lowest_bulk_cost;
165 lowest_bulk_cost_index = sec_lowest_bulk_cost_index;
167 sec_lowest_bulk_cost = INT_MAX / 2;
168 sec_lowest_bulk_cost_index = width;
171 /* Deal with the first pixel's bulk cost */
175 sec_lowest_bulk_cost++;
178 /* Look at the bulk cost of the previous loop and see if it is
179 * a new lower bulk cost */
180 prev_bulk_cost = s->length_table[i + 1] + base_bulk_cost;
181 if (prev_bulk_cost <= sec_lowest_bulk_cost) {
182 /* If it's lower than the 2nd lowest, then it may be lower
184 if (prev_bulk_cost <= lowest_bulk_cost) {
186 /* If we have found a new lowest bulk cost,
187 * then the 2nd lowest bulk cost is now farther than the
188 * lowest bulk cost, and will never be used */
189 sec_lowest_bulk_cost = INT_MAX / 2;
191 lowest_bulk_cost = prev_bulk_cost;
192 lowest_bulk_cost_index = i + 1;
194 /* Then it must be the 2nd lowest bulk cost */
195 sec_lowest_bulk_cost = prev_bulk_cost;
196 sec_lowest_bulk_cost_index = i + 1;
200 if (!s->frame.key_frame && !memcmp(this_line, prev_line, s->pixel_size))
201 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
205 total_skip_cost = s->length_table[i + skipcount] + 2;
206 s->skip_table[i] = skipcount;
209 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
210 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
214 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
216 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
217 * so let's make it aware */
223 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
224 /* repeat is the best */
225 s->length_table[i] = total_repeat_cost;
226 s->rlecode_table[i] = -repeatcount;
228 else if (skipcount > 0) {
229 /* skip is the best choice here */
230 s->length_table[i] = total_skip_cost;
231 s->rlecode_table[i] = 0;
234 /* We cannot do neither skip nor repeat
235 * thus we use the best bulk copy */
237 s->length_table[i] = lowest_bulk_cost;
238 s->rlecode_table[i] = lowest_bulk_cost_index - i;
242 /* These bulk costs increase every iteration */
243 lowest_bulk_cost += s->pixel_size;
244 sec_lowest_bulk_cost += s->pixel_size;
246 this_line -= s->pixel_size;
247 prev_line -= s->pixel_size;
250 /* Good ! Now we have the best sequence for this line, let's output it */
252 /* We do a special case for the first pixel so that we avoid testing it in
256 this_line = p-> data[0] + line*p->linesize[0];
258 if (s->rlecode_table[0] == 0) {
259 bytestream_put_byte(buf, s->skip_table[0] + 1);
260 i += s->skip_table[0];
262 else bytestream_put_byte(buf, 1);
266 rlecode = s->rlecode_table[i];
267 bytestream_put_byte(buf, rlecode);
269 /* Write a skip sequence */
270 bytestream_put_byte(buf, s->skip_table[i] + 1);
271 i += s->skip_table[i];
273 else if (rlecode > 0) {
275 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
277 // QT grayscale colorspace has 0=white and 255=black, we will
278 // ignore the palette that is included in the AVFrame because
279 // AV_PIX_FMT_GRAY8 has defined color mapping
280 for (j = 0; j < rlecode*s->pixel_size; ++j)
281 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
283 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
288 /* repeat the bits */
289 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
291 // QT grayscale colorspace has 0=white and 255=black, ...
292 for (j = 0; j < s->pixel_size; ++j)
293 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
295 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
300 bytestream_put_byte(buf, -1); // end RLE line
303 /** Encode frame including header */
304 static int encode_frame(QtrleEncContext *s, const AVFrame *p, uint8_t *buf)
308 int end_line = s->avctx->height;
309 uint8_t *orig_buf = buf;
311 if (!s->frame.key_frame) {
312 unsigned line_size = s->logical_width * s->pixel_size;
313 for (start_line = 0; start_line < s->avctx->height; start_line++)
314 if (memcmp(p->data[0] + start_line*p->linesize[0],
315 s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0],
319 for (end_line=s->avctx->height; end_line > start_line; end_line--)
320 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
321 s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0],
326 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
328 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
329 bytestream_put_be16(&buf, 0); // header
331 bytestream_put_be16(&buf, 8); // header
332 bytestream_put_be16(&buf, start_line); // starting line
333 bytestream_put_be16(&buf, 0); // unknown
334 bytestream_put_be16(&buf, end_line - start_line); // lines to update
335 bytestream_put_be16(&buf, 0); // unknown
337 for (i = start_line; i < end_line; i++)
338 qtrle_encode_line(s, p, i, &buf);
340 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
341 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
342 return buf - orig_buf;
345 static int qtrle_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
346 const AVFrame *pict, int *got_packet)
348 QtrleEncContext * const s = avctx->priv_data;
349 AVFrame * const p = &s->frame;
354 if ((ret = ff_alloc_packet2(avctx, pkt, s->max_buf_size)) < 0)
357 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
359 p->pict_type = AV_PICTURE_TYPE_I;
363 p->pict_type = AV_PICTURE_TYPE_P;
367 pkt->size = encode_frame(s, pict, pkt->data);
369 /* save the current frame */
370 av_picture_copy(&s->previous_frame, (AVPicture *)p, avctx->pix_fmt, avctx->width, avctx->height);
373 pkt->flags |= AV_PKT_FLAG_KEY;
379 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
381 QtrleEncContext *s = avctx->priv_data;
383 avpicture_free(&s->previous_frame);
384 av_free(s->rlecode_table);
385 av_free(s->length_table);
386 av_free(s->skip_table);
390 AVCodec ff_qtrle_encoder = {
392 .type = AVMEDIA_TYPE_VIDEO,
393 .id = AV_CODEC_ID_QTRLE,
394 .priv_data_size = sizeof(QtrleEncContext),
395 .init = qtrle_encode_init,
396 .encode2 = qtrle_encode_frame,
397 .close = qtrle_encode_end,
398 .pix_fmts = (const enum AVPixelFormat[]){
399 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGB555BE, AV_PIX_FMT_ARGB, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
401 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),