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1/*
2 * QPEG codec
3 * Copyright (c) 2004 Konstantin Shishkov
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22/**
23 * @file
24 * QPEG codec.
25 */
26
27#include "avcodec.h"
28#include "bytestream.h"
29#include "internal.h"
30
31typedef struct QpegContext{
32 AVCodecContext *avctx;
33 AVFrame *pic, *ref;
34 uint32_t pal[256];
35 GetByteContext buffer;
36} QpegContext;
37
38static void qpeg_decode_intra(QpegContext *qctx, uint8_t *dst,
39 int stride, int width, int height)
40{
41 int i;
42 int code;
43 int c0, c1;
44 int run, copy;
45 int filled = 0;
46 int rows_to_go;
47
48 rows_to_go = height;
49 height--;
50 dst = dst + height * stride;
51
52 while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (rows_to_go > 0)) {
53 code = bytestream2_get_byte(&qctx->buffer);
54 run = copy = 0;
55 if(code == 0xFC) /* end-of-picture code */
56 break;
57 if(code >= 0xF8) { /* very long run */
58 c0 = bytestream2_get_byte(&qctx->buffer);
59 c1 = bytestream2_get_byte(&qctx->buffer);
60 run = ((code & 0x7) << 16) + (c0 << 8) + c1 + 2;
61 } else if (code >= 0xF0) { /* long run */
62 c0 = bytestream2_get_byte(&qctx->buffer);
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 */
67 c0 = bytestream2_get_byte(&qctx->buffer);
68 c1 = bytestream2_get_byte(&qctx->buffer);
69 copy = ((code & 0x3F) << 16) + (c0 << 8) + c1 + 1;
70 } else if (code >= 0x80) { /* long copy */
71 c0 = bytestream2_get_byte(&qctx->buffer);
72 copy = ((code & 0x7F) << 8) + c0 + 1;
73 } else { /* short copy */
74 copy = code + 1;
75 }
76
77 /* perform actual run or copy */
78 if(run) {
79 int p;
80
81 p = bytestream2_get_byte(&qctx->buffer);
82 for(i = 0; i < run; i++) {
83 dst[filled++] = p;
84 if (filled >= width) {
85 filled = 0;
86 dst -= stride;
87 rows_to_go--;
88 if(rows_to_go <= 0)
89 break;
90 }
91 }
92 } else {
93 for(i = 0; i < copy; i++) {
94 dst[filled++] = bytestream2_get_byte(&qctx->buffer);
95 if (filled >= width) {
96 filled = 0;
97 dst -= stride;
98 rows_to_go--;
99 if(rows_to_go <= 0)
100 break;
101 }
102 }
103 }
104 }
105}
106
107static const int qpeg_table_h[16] =
108 { 0x00, 0x20, 0x20, 0x20, 0x18, 0x10, 0x10, 0x20, 0x10, 0x08, 0x18, 0x08, 0x08, 0x18, 0x10, 0x04};
109static const int qpeg_table_w[16] =
110 { 0x00, 0x20, 0x18, 0x08, 0x18, 0x10, 0x20, 0x10, 0x08, 0x10, 0x20, 0x20, 0x08, 0x10, 0x18, 0x04};
111
112/* Decodes delta frames */
113static void av_noinline qpeg_decode_inter(QpegContext *qctx, uint8_t *dst,
114 int stride, int width, int height,
115 int delta, const uint8_t *ctable,
116 uint8_t *refdata)
117{
118 int i, j;
119 int code;
120 int filled = 0;
121 int orig_height;
122
123 if (refdata) {
124 /* copy prev frame */
125 for (i = 0; i < height; i++)
126 memcpy(dst + (i * stride), refdata + (i * stride), width);
127 } else {
128 refdata = dst;
129 }
130
131 orig_height = height;
132 height--;
133 dst = dst + height * stride;
134
135 while ((bytestream2_get_bytes_left(&qctx->buffer) > 0) && (height >= 0)) {
136 code = bytestream2_get_byte(&qctx->buffer);
137
138 if(delta) {
139 /* motion compensation */
140 while(bytestream2_get_bytes_left(&qctx->buffer) > 0 && (code & 0xF0) == 0xF0) {
141 if(delta == 1) {
142 int me_idx;
143 int me_w, me_h, me_x, me_y;
144 uint8_t *me_plane;
145 int corr, val;
146
147 /* get block size by index */
148 me_idx = code & 0xF;
149 me_w = qpeg_table_w[me_idx];
150 me_h = qpeg_table_h[me_idx];
151
152 /* extract motion vector */
153 corr = bytestream2_get_byte(&qctx->buffer);
154
155 val = corr >> 4;
156 if(val > 7)
157 val -= 16;
158 me_x = val;
159
160 val = corr & 0xF;
161 if(val > 7)
162 val -= 16;
163 me_y = val;
164
165 /* check motion vector */
166 if ((me_x + filled < 0) || (me_x + me_w + filled > width) ||
167 (height - me_y - me_h < 0) || (height - me_y >= orig_height) ||
168 (filled + me_w > width) || (height - me_h < 0))
169 av_log(qctx->avctx, AV_LOG_ERROR, "Bogus motion vector (%i,%i), block size %ix%i at %i,%i\n",
170 me_x, me_y, me_w, me_h, filled, height);
171 else {
172 /* do motion compensation */
173 me_plane = refdata + (filled + me_x) + (height - me_y) * stride;
174 for(j = 0; j < me_h; j++) {
175 for(i = 0; i < me_w; i++)
176 dst[filled + i - (j * stride)] = me_plane[i - (j * stride)];
177 }
178 }
179 }
180 code = bytestream2_get_byte(&qctx->buffer);
181 }
182 }
183
184 if(code == 0xE0) /* end-of-picture code */
185 break;
186 if(code > 0xE0) { /* run code: 0xE1..0xFF */
187 int p;
188
189 code &= 0x1F;
190 p = bytestream2_get_byte(&qctx->buffer);
191 for(i = 0; i <= code; i++) {
192 dst[filled++] = p;
193 if(filled >= width) {
194 filled = 0;
195 dst -= stride;
196 height--;
197 if (height < 0)
198 break;
199 }
200 }
201 } else if(code >= 0xC0) { /* copy code: 0xC0..0xDF */
202 code &= 0x1F;
203
204 if(code + 1 > bytestream2_get_bytes_left(&qctx->buffer))
205 break;
206
207 for(i = 0; i <= code; i++) {
208 dst[filled++] = bytestream2_get_byte(&qctx->buffer);
209 if(filled >= width) {
210 filled = 0;
211 dst -= stride;
212 height--;
213 if (height < 0)
214 break;
215 }
216 }
217 } else if(code >= 0x80) { /* skip code: 0x80..0xBF */
218 int skip;
219
220 code &= 0x3F;
221 /* codes 0x80 and 0x81 are actually escape codes,
222 skip value minus constant is in the next byte */
223 if(!code)
224 skip = bytestream2_get_byte(&qctx->buffer) + 64;
225 else if(code == 1)
226 skip = bytestream2_get_byte(&qctx->buffer) + 320;
227 else
228 skip = code;
229 filled += skip;
230 while( filled >= width) {
231 filled -= width;
232 dst -= stride;
233 height--;
234 if(height < 0)
235 break;
236 }
237 } else {
238 /* zero code treated as one-pixel skip */
239 if(code) {
240 dst[filled++] = ctable[code & 0x7F];
241 }
242 else
243 filled++;
244 if(filled >= width) {
245 filled = 0;
246 dst -= stride;
247 height--;
248 }
249 }
250 }
251}
252
253static int decode_frame(AVCodecContext *avctx,
254 void *data, int *got_frame,
255 AVPacket *avpkt)
256{
257 uint8_t ctable[128];
258 QpegContext * const a = avctx->priv_data;
259 AVFrame * const p = a->pic;
260 AVFrame * const ref = a->ref;
261 uint8_t* outdata;
262 int delta, ret;
263 int pal_size;
264 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, &pal_size);
265
266 if (avpkt->size < 0x86) {
267 av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
268 return AVERROR_INVALIDDATA;
269 }
270
271 bytestream2_init(&a->buffer, avpkt->data, avpkt->size);
272
273 av_frame_unref(ref);
274 av_frame_move_ref(ref, p);
275
276 if ((ret = ff_get_buffer(avctx, p, AV_GET_BUFFER_FLAG_REF)) < 0)
277 return ret;
278 outdata = p->data[0];
279 bytestream2_skip(&a->buffer, 4);
280 bytestream2_get_buffer(&a->buffer, ctable, 128);
281 bytestream2_skip(&a->buffer, 1);
282
283 delta = bytestream2_get_byte(&a->buffer);
284 if(delta == 0x10) {
285 qpeg_decode_intra(a, outdata, p->linesize[0], avctx->width, avctx->height);
286 } else {
287 qpeg_decode_inter(a, outdata, p->linesize[0], avctx->width, avctx->height, delta, ctable, ref->data[0]);
288 }
289
290 /* make the palette available on the way out */
291 if (pal && pal_size == AVPALETTE_SIZE) {
292 p->palette_has_changed = 1;
293 memcpy(a->pal, pal, AVPALETTE_SIZE);
294 } else if (pal) {
295 av_log(avctx, AV_LOG_ERROR, "Palette size %d is wrong\n", pal_size);
296 }
297 memcpy(p->data[1], a->pal, AVPALETTE_SIZE);
298
299 if ((ret = av_frame_ref(data, p)) < 0)
300 return ret;
301
302 *got_frame = 1;
303
304 return avpkt->size;
305}
306
307static void decode_flush(AVCodecContext *avctx){
308 QpegContext * const a = avctx->priv_data;
309 int i, pal_size;
310 const uint8_t *pal_src;
311
312 pal_size = FFMIN(1024U, avctx->extradata_size);
313 pal_src = avctx->extradata + avctx->extradata_size - pal_size;
314
315 for (i=0; i<pal_size/4; i++)
316 a->pal[i] = 0xFFU<<24 | AV_RL32(pal_src+4*i);
317}
318
319static av_cold int decode_end(AVCodecContext *avctx)
320{
321 QpegContext * const a = avctx->priv_data;
322
323 av_frame_free(&a->pic);
324 av_frame_free(&a->ref);
325
326 return 0;
327}
328
329static av_cold int decode_init(AVCodecContext *avctx){
330 QpegContext * const a = avctx->priv_data;
331
332 a->avctx = avctx;
333 avctx->pix_fmt= AV_PIX_FMT_PAL8;
334
335 decode_flush(avctx);
336
337 a->pic = av_frame_alloc();
338 a->ref = av_frame_alloc();
339 if (!a->pic || !a->ref) {
340 decode_end(avctx);
341 return AVERROR(ENOMEM);
342 }
343
344 return 0;
345}
346
347AVCodec ff_qpeg_decoder = {
348 .name = "qpeg",
349 .long_name = NULL_IF_CONFIG_SMALL("Q-team QPEG"),
350 .type = AVMEDIA_TYPE_VIDEO,
351 .id = AV_CODEC_ID_QPEG,
352 .priv_data_size = sizeof(QpegContext),
353 .init = decode_init,
354 .close = decode_end,
355 .decode = decode_frame,
356 .flush = decode_flush,
357 .capabilities = AV_CODEC_CAP_DR1,
358};
359
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