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 Libav.
10 * Libav 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 * Libav 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 Libav; 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;
43 * This array will contain at ith position the value of the best RLE code
44 * if the line started at pixel i
45 * There can be 3 values :
46 * skip (0) : skip as much as possible pixels because they are equal to the
48 * repeat (<-1) : repeat that pixel -rle_code times, still as much as
50 * copy (>0) : copy the raw next rle_code pixels */
51 signed char *rlecode_table;
53 * This array will contain the length of the best rle encoding of the line
54 * starting at ith pixel */
57 * Will contain at ith position the number of consecutive pixels equal to the previous
58 * frame starting from pixel i */
61 /** Encoded frame is a key frame */
65 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
67 QtrleEncContext *s = avctx->priv_data;
69 av_frame_free(&avctx->coded_frame);
71 avpicture_free(&s->previous_frame);
72 av_free(s->rlecode_table);
73 av_free(s->length_table);
74 av_free(s->skip_table);
78 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
80 QtrleEncContext *s = avctx->priv_data;
82 if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
87 switch (avctx->pix_fmt) {
88 case AV_PIX_FMT_RGB555BE:
91 case AV_PIX_FMT_RGB24:
98 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
101 avctx->bits_per_coded_sample = s->pixel_size*8;
103 s->rlecode_table = av_mallocz(s->avctx->width);
104 s->skip_table = av_mallocz(s->avctx->width);
105 s->length_table = av_mallocz((s->avctx->width + 1)*sizeof(int));
106 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
107 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
110 if (avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height) < 0) {
111 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
115 s->max_buf_size = s->avctx->width*s->avctx->height*s->pixel_size*2 /* image base material */
116 + 15 /* header + footer */
117 + s->avctx->height*2 /* skip code+rle end */
118 + s->avctx->width/MAX_RLE_BULK + 1 /* rle codes */;
120 avctx->coded_frame = av_frame_alloc();
121 if (!avctx->coded_frame) {
122 qtrle_encode_end(avctx);
123 return AVERROR(ENOMEM);
130 * Compute the best RLE sequence for a line
132 static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
134 int width=s->avctx->width;
138 /* We will use it to compute the best bulk copy sequence */
139 unsigned int bulkcount;
140 /* This will be the number of pixels equal to the preivous frame one's
141 * starting from the ith pixel */
142 unsigned int skipcount;
143 /* This will be the number of consecutive equal pixels in the current
144 * frame, starting from the ith one also */
145 unsigned int repeatcount;
147 /* The cost of the three different possibilities */
150 int total_repeat_cost;
155 uint8_t *this_line = p-> data[0] + line*p-> linesize[0] +
156 (width - 1)*s->pixel_size;
157 uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] +
158 (width - 1)*s->pixel_size;
160 s->length_table[width] = 0;
163 for (i = width - 1; i >= 0; i--) {
165 if (!s->key_frame && !memcmp(this_line, prev_line, s->pixel_size))
166 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
170 total_skip_cost = s->length_table[i + skipcount] + 2;
171 s->skip_table[i] = skipcount;
174 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
175 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
179 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
181 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
182 * so let's make it aware */
188 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
189 /* repeat is the best */
190 s->length_table[i] = total_repeat_cost;
191 s->rlecode_table[i] = -repeatcount;
193 else if (skipcount > 0) {
194 /* skip is the best choice here */
195 s->length_table[i] = total_skip_cost;
196 s->rlecode_table[i] = 0;
199 /* We cannot do neither skip nor repeat
200 * thus we search for the best bulk copy to do */
202 int limit = FFMIN(width - i, MAX_RLE_BULK);
204 temp_cost = 1 + s->pixel_size + !i;
205 total_bulk_cost = INT_MAX;
207 for (j = 1; j <= limit; j++) {
208 if (s->length_table[i + j] + temp_cost < total_bulk_cost) {
209 /* We have found a better bulk copy ... */
210 total_bulk_cost = s->length_table[i + j] + temp_cost;
213 temp_cost += s->pixel_size;
216 s->length_table[i] = total_bulk_cost;
217 s->rlecode_table[i] = bulkcount;
220 this_line -= s->pixel_size;
221 prev_line -= s->pixel_size;
224 /* Good ! Now we have the best sequence for this line, let's ouput it */
226 /* We do a special case for the first pixel so that we avoid testing it in
230 this_line = p-> data[0] + line*p->linesize[0];
232 if (s->rlecode_table[0] == 0) {
233 bytestream_put_byte(buf, s->skip_table[0] + 1);
234 i += s->skip_table[0];
236 else bytestream_put_byte(buf, 1);
240 rlecode = s->rlecode_table[i];
241 bytestream_put_byte(buf, rlecode);
243 /* Write a skip sequence */
244 bytestream_put_byte(buf, s->skip_table[i] + 1);
245 i += s->skip_table[i];
247 else if (rlecode > 0) {
249 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
253 /* repeat the bits */
254 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, const AVFrame *p, uint8_t *buf)
266 int end_line = s->avctx->height;
267 uint8_t *orig_buf = buf;
270 unsigned line_size = s->avctx->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, AVPacket *pkt,
304 const AVFrame *pict, int *got_packet)
306 QtrleEncContext * const s = avctx->priv_data;
307 enum AVPictureType pict_type;
310 if ((ret = ff_alloc_packet(pkt, s->max_buf_size)) < 0) {
311 /* Upper bound check for compressed data */
312 av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", s->max_buf_size);
316 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
318 pict_type = AV_PICTURE_TYPE_I;
322 pict_type = AV_PICTURE_TYPE_P;
326 pkt->size = encode_frame(s, pict, pkt->data);
328 /* save the current frame */
329 av_picture_copy(&s->previous_frame, (const AVPicture *)pict,
330 avctx->pix_fmt, avctx->width, avctx->height);
332 avctx->coded_frame->key_frame = s->key_frame;
333 avctx->coded_frame->pict_type = pict_type;
336 pkt->flags |= AV_PKT_FLAG_KEY;
342 AVCodec ff_qtrle_encoder = {
344 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
345 .type = AVMEDIA_TYPE_VIDEO,
346 .id = AV_CODEC_ID_QTRLE,
347 .priv_data_size = sizeof(QtrleEncContext),
348 .init = qtrle_encode_init,
349 .encode2 = qtrle_encode_frame,
350 .close = qtrle_encode_end,
351 .pix_fmts = (const enum AVPixelFormat[]){
352 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGB555BE, AV_PIX_FMT_ARGB, AV_PIX_FMT_NONE