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 /* We will use it to compute the best bulk copy sequence */
125 unsigned int av_uninit(bulkcount);
126 /* This will be the number of pixels equal to the preivous frame one's
127 * starting from the ith pixel */
128 unsigned int skipcount;
129 /* This will be the number of consecutive equal pixels in the current
130 * frame, starting from the ith one also */
131 unsigned int av_uninit(repeatcount);
133 /* The cost of the three different possibilities */
136 int total_repeat_cost;
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;
149 for (i = width - 1; i >= 0; i--) {
151 if (!s->frame.key_frame && !memcmp(this_line, prev_line, s->pixel_size))
152 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
156 total_skip_cost = s->length_table[i + skipcount] + 2;
157 s->skip_table[i] = skipcount;
160 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
161 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
165 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
167 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
168 * so let's make it aware */
174 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
175 /* repeat is the best */
176 s->length_table[i] = total_repeat_cost;
177 s->rlecode_table[i] = -repeatcount;
179 else if (skipcount > 0) {
180 /* skip is the best choice here */
181 s->length_table[i] = total_skip_cost;
182 s->rlecode_table[i] = 0;
185 /* We cannot do neither skip nor repeat
186 * thus we search for the best bulk copy to do */
188 int limit = FFMIN(width - i, MAX_RLE_BULK);
190 temp_cost = 1 + s->pixel_size + !i;
191 total_bulk_cost = INT_MAX;
193 for (j = 1; j <= limit; j++) {
194 if (s->length_table[i + j] + temp_cost < total_bulk_cost) {
195 /* We have found a better bulk copy ... */
196 total_bulk_cost = s->length_table[i + j] + temp_cost;
199 temp_cost += s->pixel_size;
202 s->length_table[i] = total_bulk_cost;
203 s->rlecode_table[i] = bulkcount;
206 this_line -= s->pixel_size;
207 prev_line -= s->pixel_size;
210 /* Good ! Now we have the best sequence for this line, let's output it */
212 /* We do a special case for the first pixel so that we avoid testing it in
216 this_line = p-> data[0] + line*p->linesize[0];
218 if (s->rlecode_table[0] == 0) {
219 bytestream_put_byte(buf, s->skip_table[0] + 1);
220 i += s->skip_table[0];
222 else bytestream_put_byte(buf, 1);
226 rlecode = s->rlecode_table[i];
227 bytestream_put_byte(buf, rlecode);
229 /* Write a skip sequence */
230 bytestream_put_byte(buf, s->skip_table[i] + 1);
231 i += s->skip_table[i];
233 else if (rlecode > 0) {
235 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
237 // QT grayscale colorspace has 0=white and 255=black, we will
238 // ignore the palette that is included in the AVFrame because
239 // AV_PIX_FMT_GRAY8 has defined color mapping
240 for (j = 0; j < rlecode*s->pixel_size; ++j)
241 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
243 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
248 /* repeat the bits */
249 if (s->avctx->pix_fmt == AV_PIX_FMT_GRAY8) {
251 // QT grayscale colorspace has 0=white and 255=black, ...
252 for (j = 0; j < s->pixel_size; ++j)
253 bytestream_put_byte(buf, *(this_line + i*s->pixel_size + j) ^ 0xff);
255 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
260 bytestream_put_byte(buf, -1); // end RLE line
263 /** Encode frame including header */
264 static int encode_frame(QtrleEncContext *s, const AVFrame *p, uint8_t *buf)
268 int end_line = s->avctx->height;
269 uint8_t *orig_buf = buf;
271 if (!s->frame.key_frame) {
272 unsigned line_size = s->logical_width * s->pixel_size;
273 for (start_line = 0; start_line < s->avctx->height; start_line++)
274 if (memcmp(p->data[0] + start_line*p->linesize[0],
275 s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0],
279 for (end_line=s->avctx->height; end_line > start_line; end_line--)
280 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
281 s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0],
286 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
288 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
289 bytestream_put_be16(&buf, 0); // header
291 bytestream_put_be16(&buf, 8); // header
292 bytestream_put_be16(&buf, start_line); // starting line
293 bytestream_put_be16(&buf, 0); // unknown
294 bytestream_put_be16(&buf, end_line - start_line); // lines to update
295 bytestream_put_be16(&buf, 0); // unknown
297 for (i = start_line; i < end_line; i++)
298 qtrle_encode_line(s, p, i, &buf);
300 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
301 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
302 return buf - orig_buf;
305 static int qtrle_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
306 const AVFrame *pict, int *got_packet)
308 QtrleEncContext * const s = avctx->priv_data;
309 AVFrame * const p = &s->frame;
314 if ((ret = ff_alloc_packet2(avctx, pkt, s->max_buf_size)) < 0)
317 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
319 p->pict_type = AV_PICTURE_TYPE_I;
323 p->pict_type = AV_PICTURE_TYPE_P;
327 pkt->size = encode_frame(s, pict, pkt->data);
329 /* save the current frame */
330 av_picture_copy(&s->previous_frame, (AVPicture *)p, avctx->pix_fmt, avctx->width, avctx->height);
333 pkt->flags |= AV_PKT_FLAG_KEY;
339 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
341 QtrleEncContext *s = avctx->priv_data;
343 avpicture_free(&s->previous_frame);
344 av_free(s->rlecode_table);
345 av_free(s->length_table);
346 av_free(s->skip_table);
350 AVCodec ff_qtrle_encoder = {
352 .type = AVMEDIA_TYPE_VIDEO,
353 .id = AV_CODEC_ID_QTRLE,
354 .priv_data_size = sizeof(QtrleEncContext),
355 .init = qtrle_encode_init,
356 .encode2 = qtrle_encode_frame,
357 .close = qtrle_encode_end,
358 .pix_fmts = (const enum AVPixelFormat[]){
359 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGB555BE, AV_PIX_FMT_ARGB, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE
361 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),