3 * Copyright (c) 2004 Konstantin Shishkov
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
29 typedef struct QpegContext{
30 AVCodecContext *avctx;
35 static void qpeg_decode_intra(const uint8_t *src, uint8_t *dst, int size,
36 int stride, int width, int height)
47 dst = dst + height * stride;
49 while((size > 0) && (rows_to_go > 0)) {
53 if(code == 0xFC) /* end-of-picture code */
55 if(code >= 0xF8) { /* very long run */
59 run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2;
60 } else if (code >= 0xF0) { /* long run */
63 run = ((code & 0xF) << 8) + c0 + 2;
64 } else if (code >= 0xE0) { /* short run */
65 run = (code & 0x1F) + 2;
66 } else if (code >= 0xC0) { /* very long copy */
70 copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1;
71 } else if (code >= 0x80) { /* long copy */
74 copy = ((code & 0x7F) << 8) + c0 + 1;
75 } else { /* short copy */
79 /* perform actual run or copy */
85 for(i = 0; i < run; i++) {
87 if (filled >= width) {
97 for(i = 0; i < copy; i++) {
98 dst[filled++] = *src++;
99 if (filled >= width) {
111 static const int qpeg_table_h[16] =
112 { 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04};
113 static const int qpeg_table_w[16] =
114 { 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04};
116 /* Decodes delta frames */
117 static void qpeg_decode_inter(const uint8_t *src, uint8_t *dst, int size,
118 int stride, int width, int height,
119 int delta, const uint8_t *ctable, uint8_t *refdata)
129 /* copy prev frame */
130 for(i = 0; i < height; i++)
131 memcpy(dst + (i * stride), refdata + (i * stride), width);
133 orig_height = height;
135 dst = dst + height * stride;
137 while((size > 0) && (height >= 0)) {
142 /* motion compensation */
143 while((code & 0xF0) == 0xF0) {
146 int me_w, me_h, me_x, me_y;
150 /* get block size by index */
152 me_w = qpeg_table_w[me_idx];
153 me_h = qpeg_table_h[me_idx];
155 /* extract motion vector */
169 /* check motion vector */
170 if ((me_x + filled < 0) || (me_x + me_w + filled > width) ||
171 (height - me_y - me_h < 0) || (height - me_y > orig_height) ||
172 (filled + me_w > width) || (height - me_h < 0))
173 av_log(NULL, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n",
174 me_x, me_y, me_w, me_h, filled, height);
176 /* do motion compensation */
177 me_plane = refdata + (filled + me_x) + (height - me_y) * stride;
178 for(j = 0; j < me_h; j++) {
179 for(i = 0; i < me_w; i++)
180 dst[filled + i - (j * stride)] = me_plane[i - (j * stride)];
189 if(code == 0xE0) /* end-of-picture code */
191 if(code > 0xE0) { /* run code: 0xE1..0xFF */
197 for(i = 0; i <= code; i++) {
199 if(filled >= width) {
205 } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */
208 for(i = 0; i <= code; i++) {
209 dst[filled++] = *src++;
210 if(filled >= width) {
217 } else if(code >= 0x80) { /* skip code: 0x80..0xBF */
221 /* codes 0x80 and 0x81 are actually escape codes,
222 skip value minus constant is in the next byte */
224 skip = (*src++) + 64;
226 skip = (*src++) + 320;
230 while( filled >= width) {
238 /* zero code treated as one-pixel skip */
240 dst[filled++] = ctable[code & 0x7F];
243 if(filled >= width) {
252 static int decode_frame(AVCodecContext *avctx,
253 void *data, int *data_size,
256 const uint8_t *buf = avpkt->data;
257 int buf_size = avpkt->size;
258 QpegContext * const a = avctx->priv_data;
259 AVFrame * p= (AVFrame*)&a->pic;
260 AVFrame * ref= (AVFrame*)&a->ref;
263 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
266 avctx->release_buffer(avctx, ref);
267 FFSWAP(AVFrame, *ref, *p);
270 if(avctx->get_buffer(avctx, p) < 0){
271 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
274 outdata = a->pic.data[0];
275 if(buf[0x85] == 0x10) {
276 qpeg_decode_intra(buf+0x86, outdata, buf_size - 0x86, a->pic.linesize[0], avctx->width, avctx->height);
279 qpeg_decode_inter(buf+0x86, outdata, buf_size - 0x86, a->pic.linesize[0], avctx->width, avctx->height, delta, buf + 4, a->ref.data[0]);
282 /* make the palette available on the way out */
284 a->pic.palette_has_changed = 1;
285 memcpy(a->pal, pal, AVPALETTE_SIZE);
287 memcpy(a->pic.data[1], a->pal, AVPALETTE_SIZE);
289 *data_size = sizeof(AVFrame);
290 *(AVFrame*)data = a->pic;
295 static av_cold int decode_init(AVCodecContext *avctx){
296 QpegContext * const a = avctx->priv_data;
298 avcodec_get_frame_defaults(&a->pic);
299 avcodec_get_frame_defaults(&a->ref);
301 avctx->pix_fmt= PIX_FMT_PAL8;
306 static av_cold int decode_end(AVCodecContext *avctx){
307 QpegContext * const a = avctx->priv_data;
308 AVFrame * const p= (AVFrame*)&a->pic;
309 AVFrame * const ref= (AVFrame*)&a->ref;
312 avctx->release_buffer(avctx, p);
314 avctx->release_buffer(avctx, ref);
319 AVCodec ff_qpeg_decoder = {
321 .type = AVMEDIA_TYPE_VIDEO,
323 .priv_data_size = sizeof(QpegContext),
326 .decode = decode_frame,
327 .capabilities = CODEC_CAP_DR1,
328 .long_name = NULL_IF_CONFIG_SMALL("Q-team QPEG"),