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 */
62 static av_cold int qtrle_encode_end(AVCodecContext *avctx)
64 QtrleEncContext *s = avctx->priv_data;
66 av_frame_free(&avctx->coded_frame);
68 avpicture_free(&s->previous_frame);
69 av_free(s->rlecode_table);
70 av_free(s->length_table);
71 av_free(s->skip_table);
75 static av_cold int qtrle_encode_init(AVCodecContext *avctx)
77 QtrleEncContext *s = avctx->priv_data;
79 if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
84 switch (avctx->pix_fmt) {
85 case AV_PIX_FMT_RGB555BE:
88 case AV_PIX_FMT_RGB24:
95 av_log(avctx, AV_LOG_ERROR, "Unsupported colorspace.\n");
98 avctx->bits_per_coded_sample = s->pixel_size*8;
100 s->rlecode_table = av_mallocz(s->avctx->width);
101 s->skip_table = av_mallocz(s->avctx->width);
102 s->length_table = av_mallocz((s->avctx->width + 1)*sizeof(int));
103 if (!s->skip_table || !s->length_table || !s->rlecode_table) {
104 av_log(avctx, AV_LOG_ERROR, "Error allocating memory.\n");
107 if (avpicture_alloc(&s->previous_frame, avctx->pix_fmt, avctx->width, avctx->height) < 0) {
108 av_log(avctx, AV_LOG_ERROR, "Error allocating picture\n");
112 s->max_buf_size = s->avctx->width*s->avctx->height*s->pixel_size*2 /* image base material */
113 + 15 /* header + footer */
114 + s->avctx->height*2 /* skip code+rle end */
115 + s->avctx->width/MAX_RLE_BULK + 1 /* rle codes */;
117 avctx->coded_frame = av_frame_alloc();
118 if (!avctx->coded_frame) {
119 qtrle_encode_end(avctx);
120 return AVERROR(ENOMEM);
127 * Compute the best RLE sequence for a line
129 static void qtrle_encode_line(QtrleEncContext *s, const AVFrame *p, int line, uint8_t **buf)
131 int width=s->avctx->width;
135 /* We will use it to compute the best bulk copy sequence */
136 unsigned int bulkcount;
137 /* This will be the number of pixels equal to the preivous frame one's
138 * starting from the ith pixel */
139 unsigned int skipcount;
140 /* This will be the number of consecutive equal pixels in the current
141 * frame, starting from the ith one also */
142 unsigned int repeatcount;
144 /* The cost of the three different possibilities */
147 int total_repeat_cost;
152 uint8_t *this_line = p-> data[0] + line*p-> linesize[0] +
153 (width - 1)*s->pixel_size;
154 uint8_t *prev_line = s->previous_frame.data[0] + line*s->previous_frame.linesize[0] +
155 (width - 1)*s->pixel_size;
157 s->length_table[width] = 0;
160 for (i = width - 1; i >= 0; i--) {
162 if (!s->avctx->coded_frame->key_frame && !memcmp(this_line, prev_line, s->pixel_size))
163 skipcount = FFMIN(skipcount + 1, MAX_RLE_SKIP);
167 total_skip_cost = s->length_table[i + skipcount] + 2;
168 s->skip_table[i] = skipcount;
171 if (i < width - 1 && !memcmp(this_line, this_line + s->pixel_size, s->pixel_size))
172 repeatcount = FFMIN(repeatcount + 1, MAX_RLE_REPEAT);
176 total_repeat_cost = s->length_table[i + repeatcount] + 1 + s->pixel_size;
178 /* skip code is free for the first pixel, it costs one byte for repeat and bulk copy
179 * so let's make it aware */
185 if (repeatcount > 1 && (skipcount == 0 || total_repeat_cost < total_skip_cost)) {
186 /* repeat is the best */
187 s->length_table[i] = total_repeat_cost;
188 s->rlecode_table[i] = -repeatcount;
190 else if (skipcount > 0) {
191 /* skip is the best choice here */
192 s->length_table[i] = total_skip_cost;
193 s->rlecode_table[i] = 0;
196 /* We cannot do neither skip nor repeat
197 * thus we search for the best bulk copy to do */
199 int limit = FFMIN(width - i, MAX_RLE_BULK);
201 temp_cost = 1 + s->pixel_size + !i;
202 total_bulk_cost = INT_MAX;
204 for (j = 1; j <= limit; j++) {
205 if (s->length_table[i + j] + temp_cost < total_bulk_cost) {
206 /* We have found a better bulk copy ... */
207 total_bulk_cost = s->length_table[i + j] + temp_cost;
210 temp_cost += s->pixel_size;
213 s->length_table[i] = total_bulk_cost;
214 s->rlecode_table[i] = bulkcount;
217 this_line -= s->pixel_size;
218 prev_line -= s->pixel_size;
221 /* Good ! Now we have the best sequence for this line, let's ouput it */
223 /* We do a special case for the first pixel so that we avoid testing it in
227 this_line = p-> data[0] + line*p->linesize[0];
229 if (s->rlecode_table[0] == 0) {
230 bytestream_put_byte(buf, s->skip_table[0] + 1);
231 i += s->skip_table[0];
233 else bytestream_put_byte(buf, 1);
237 rlecode = s->rlecode_table[i];
238 bytestream_put_byte(buf, rlecode);
240 /* Write a skip sequence */
241 bytestream_put_byte(buf, s->skip_table[i] + 1);
242 i += s->skip_table[i];
244 else if (rlecode > 0) {
246 bytestream_put_buffer(buf, this_line + i*s->pixel_size, rlecode*s->pixel_size);
250 /* repeat the bits */
251 bytestream_put_buffer(buf, this_line + i*s->pixel_size, s->pixel_size);
255 bytestream_put_byte(buf, -1); // end RLE line
258 /** Encode frame including header */
259 static int encode_frame(QtrleEncContext *s, const AVFrame *p, uint8_t *buf)
263 int end_line = s->avctx->height;
264 uint8_t *orig_buf = buf;
266 if (!s->avctx->coded_frame->key_frame) {
267 unsigned line_size = s->avctx->width * s->pixel_size;
268 for (start_line = 0; start_line < s->avctx->height; start_line++)
269 if (memcmp(p->data[0] + start_line*p->linesize[0],
270 s->previous_frame.data[0] + start_line*s->previous_frame.linesize[0],
274 for (end_line=s->avctx->height; end_line > start_line; end_line--)
275 if (memcmp(p->data[0] + (end_line - 1)*p->linesize[0],
276 s->previous_frame.data[0] + (end_line - 1)*s->previous_frame.linesize[0],
281 bytestream_put_be32(&buf, 0); // CHUNK SIZE, patched later
283 if ((start_line == 0 && end_line == s->avctx->height) || start_line == s->avctx->height)
284 bytestream_put_be16(&buf, 0); // header
286 bytestream_put_be16(&buf, 8); // header
287 bytestream_put_be16(&buf, start_line); // starting line
288 bytestream_put_be16(&buf, 0); // unknown
289 bytestream_put_be16(&buf, end_line - start_line); // lines to update
290 bytestream_put_be16(&buf, 0); // unknown
292 for (i = start_line; i < end_line; i++)
293 qtrle_encode_line(s, p, i, &buf);
295 bytestream_put_byte(&buf, 0); // zero skip code = frame finished
296 AV_WB32(orig_buf, buf - orig_buf); // patch the chunk size
297 return buf - orig_buf;
300 static int qtrle_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
301 const AVFrame *pict, int *got_packet)
303 QtrleEncContext * const s = avctx->priv_data;
304 AVFrame * const p = avctx->coded_frame;
307 if ((ret = ff_alloc_packet(pkt, s->max_buf_size)) < 0) {
308 /* Upper bound check for compressed data */
309 av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", s->max_buf_size);
313 if (avctx->gop_size == 0 || (s->avctx->frame_number % avctx->gop_size) == 0) {
315 p->pict_type = AV_PICTURE_TYPE_I;
319 p->pict_type = AV_PICTURE_TYPE_P;
323 pkt->size = encode_frame(s, pict, pkt->data);
325 /* save the current frame */
326 av_picture_copy(&s->previous_frame, (const AVPicture *)pict,
327 avctx->pix_fmt, avctx->width, avctx->height);
330 pkt->flags |= AV_PKT_FLAG_KEY;
336 AVCodec ff_qtrle_encoder = {
338 .long_name = NULL_IF_CONFIG_SMALL("QuickTime Animation (RLE) video"),
339 .type = AVMEDIA_TYPE_VIDEO,
340 .id = AV_CODEC_ID_QTRLE,
341 .priv_data_size = sizeof(QtrleEncContext),
342 .init = qtrle_encode_init,
343 .encode2 = qtrle_encode_frame,
344 .close = qtrle_encode_end,
345 .pix_fmts = (const enum AVPixelFormat[]){
346 AV_PIX_FMT_RGB24, AV_PIX_FMT_RGB555BE, AV_PIX_FMT_ARGB, AV_PIX_FMT_NONE