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 */
63 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
65 QtrleEncContext *s = avctx->priv_data;
67 av_frame_free(&avctx->coded_frame);
69 avpicture_free(&s->previous_frame);
70 av_free(s->rlecode_table);
71 av_free(s->length_table);
72 av_free(s->skip_table);
76 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
78 QtrleEncContext *s = avctx->priv_data;
81 if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
82 return AVERROR(EINVAL);
85 s->logical_width=avctx->width;
87 switch (avctx->pix_fmt) {
88 case AV_PIX_FMT_GRAY8:
89 s->logical_width = avctx->width / 4;
92 case AV_PIX_FMT_RGB555BE:
95 case AV_PIX_FMT_RGB24:
102 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
105 avctx->bits_per_coded_sample = avctx->pix_fmt == AV_PIX_FMT_GRAY8 ? 40 : s->pixel_size*8;
107 s->rlecode_table = av_mallocz(s->logical_width);
108 s->skip_table = av_mallocz(s->logical_width);
109 s->length_table = av_mallocz_array(s->logical_width + 1, sizeof(int));
110 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
111 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
112 return AVERROR(ENOMEM);
114 if ((ret = avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height)) < 0) {
115 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
119 s->max_buf_size = s->logical_width*s->avctx->height*s->pixel_size*2 /* image base material */
120 + 15 /* header + footer */
121 + s->avctx->height*2 /* skip code+rle end */
122 + s->logical_width/MAX_RLE_BULK + 1 /* rle codes */;
124 avctx->coded_frame = av_frame_alloc();
125 if (!avctx->coded_frame) {
126 qtrle_encode_end(avctx);
127 return AVERROR(ENOMEM);
134 * Compute the best RLE sequence for a line
136 static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
138 int width=s->logical_width;
142 /* This will be the number of pixels equal to the preivous frame one's
143 * starting from the ith pixel */
144 unsigned int skipcount;
145 /* This will be the number of consecutive equal pixels in the current
146 * frame, starting from the ith one also */
147 unsigned int av_uninit(repeatcount);
149 /* The cost of the three different possibilities */
151 int total_repeat_cost;
154 int lowest_bulk_cost;
155 int lowest_bulk_cost_index;
156 int sec_lowest_bulk_cost;
157 int sec_lowest_bulk_cost_index;
159 uint8_t *this_line = p-> data[0] + line*p-> linesize[0] +
160 (width - 1)*s->pixel_size;
161 uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] +
162 (width - 1)*s->pixel_size;
164 s->length_table[width] = 0;
168 lowest_bulk_cost = INT_MAX / 2;
169 lowest_bulk_cost_index = width;
170 sec_lowest_bulk_cost = INT_MAX / 2;
171 sec_lowest_bulk_cost_index = width;
173 base_bulk_cost = 1 + s->pixel_size;
175 for (i = width - 1; i >= 0; i--) {
179 /* If our lowest bulk cost index is too far away, replace it
180 * with the next lowest bulk cost */
181 if (FFMIN(width, i + MAX_RLE_BULK) < lowest_bulk_cost_index) {
182 lowest_bulk_cost = sec_lowest_bulk_cost;
183 lowest_bulk_cost_index = sec_lowest_bulk_cost_index;
185 sec_lowest_bulk_cost = INT_MAX / 2;
186 sec_lowest_bulk_cost_index = width;
189 /* Deal with the first pixel's bulk cost */
193 sec_lowest_bulk_cost++;
196 /* Look at the bulk cost of the previous loop and see if it is
197 * a new lower bulk cost */
198 prev_bulk_cost = s->length_table[i + 1] + base_bulk_cost;
199 if (prev_bulk_cost <= sec_lowest_bulk_cost) {
200 /* If it's lower than the 2nd lowest, then it may be lower
202 if (prev_bulk_cost <= lowest_bulk_cost) {
204 /* If we have found a new lowest bulk cost,
205 * then the 2nd lowest bulk cost is now farther than the
206 * lowest bulk cost, and will never be used */
207 sec_lowest_bulk_cost = INT_MAX / 2;
209 lowest_bulk_cost = prev_bulk_cost;
210 lowest_bulk_cost_index = i + 1;
212 /* Then it must be the 2nd lowest bulk cost */
213 sec_lowest_bulk_cost = prev_bulk_cost;
214 sec_lowest_bulk_cost_index = i + 1;
218 if (!s->avctx->coded_frame->key_frame && !memcmp(this_line, prev_line, s->pixel_size))
219 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
223 total_skip_cost = s->length_table[i + skipcount] + 2;
224 s->skip_table[i] = skipcount;
227 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
228 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
232 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
234 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
235 * so let's make it aware */
241 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
242 /* repeat is the best */
243 s->length_table[i] = total_repeat_cost;
244 s->rlecode_table[i] = -repeatcount;
246 else if (skipcount > 0) {
247 /* skip is the best choice here */
248 s->length_table[i] = total_skip_cost;
249 s->rlecode_table[i] = 0;
252 /* We cannot do neither skip nor repeat
253 * thus we use the best bulk copy */
255 s->length_table[i] = lowest_bulk_cost;
256 s->rlecode_table[i] = lowest_bulk_cost_index - i;
260 /* These bulk costs increase every iteration */
261 lowest_bulk_cost += s->pixel_size;
262 sec_lowest_bulk_cost += s->pixel_size;
264 this_line -= s->pixel_size;
265 prev_line -= s->pixel_size;
268 /* Good ! Now we have the best sequence for this line, let's output it */
270 /* We do a special case for the first pixel so that we avoid testing it in
274 this_line = p-> data[0] + line*p->linesize[0];
276 if (s->rlecode_table[0] == 0) {
277 bytestream_put_byte(buf, s->skip_table[0] + 1);
278 i += s->skip_table[0];
280 else bytestream_put_byte(buf, 1);
284 rlecode = s->rlecode_table[i];
285 bytestream_put_byte(buf, rlecode);
287 /* Write a skip sequence */
288 bytestream_put_byte(buf, s->skip_table[i] + 1);
289 i += s->skip_table[i];
291 else if (rlecode > 0) {
293 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
295 // QT grayscale colorspace has 0=white and 255=black, we will
296 // ignore the palette that is included in the AVFrame because
297 // AV_PIX_FMT_GRAY8 has defined color mapping
298 for (j = 0; j < rlecode*s->pixel_size; ++j)
299 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
301 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
306 /* repeat the bits */
307 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
309 // QT grayscale colorspace has 0=white and 255=black, ...
310 for (j = 0; j < s->pixel_size; ++j)
311 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
313 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
318 bytestream_put_byte(buf, -1); // end RLE line
321 /** Encode frame including header */
322 static int encode_frame(QtrleEncContext *s, const AVFrame *p, uint8_t *buf)
326 int end_line = s->avctx->height;
327 uint8_t *orig_buf = buf;
329 if (!s->avctx->coded_frame->key_frame) {
330 unsigned line_size = s->logical_width * s->pixel_size;
331 for (start_line = 0; start_line < s->avctx->height; start_line++)
332 if (memcmp(p->data[0] + start_line*p->linesize[0],
333 s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0],
337 for (end_line=s->avctx->height; end_line > start_line; end_line--)
338 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
339 s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0],
344 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
346 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
347 bytestream_put_be16(&buf, 0); // header
349 bytestream_put_be16(&buf, 8); // header
350 bytestream_put_be16(&buf, start_line); // starting line
351 bytestream_put_be16(&buf, 0); // unknown
352 bytestream_put_be16(&buf, end_line - start_line); // lines to update
353 bytestream_put_be16(&buf, 0); // unknown
355 for (i = start_line; i < end_line; i++)
356 qtrle_encode_line(s, p, i, &buf);
358 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
359 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
360 return buf - orig_buf;
363 static int qtrle_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
364 const AVFrame *pict, int *got_packet)
366 QtrleEncContext * const s = avctx->priv_data;
367 AVFrame * const p = avctx->coded_frame;
370 if ((ret = ff_alloc_packet2(avctx, pkt, s->max_buf_size)) < 0)
373 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
375 p->pict_type = AV_PICTURE_TYPE_I;
379 p->pict_type = AV_PICTURE_TYPE_P;
383 pkt->size = encode_frame(s, pict, pkt->data);
385 /* save the current frame */
386 av_picture_copy(&s->previous_frame, (const AVPicture *)pict,
387 avctx->pix_fmt, avctx->width, avctx->height);
390 pkt->flags |= AV_PKT_FLAG_KEY;
396 AVCodec ff_qtrle_encoder = {
398 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
399 .type = AVMEDIA_TYPE_VIDEO,
400 .id = AV_CODEC_ID_QTRLE,
401 .priv_data_size = sizeof(QtrleEncContext),
402 .init = qtrle_encode_init,
403 .encode2 = qtrle_encode_frame,
404 .close = qtrle_encode_end,
405 .pix_fmts = (const enum AVPixelFormat[]){
406 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGB555BE, AV_PIX_FMT_ARGB, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE