3 * Copyright (c) 2006 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
25 * Karl Morton's Video Codec decoder
34 #define KMVC_KEYFRAME 0x80
35 #define KMVC_PALETTE 0x40
36 #define KMVC_METHOD 0x0F
41 typedef struct KmvcContext {
42 AVCodecContext *avctx;
52 typedef struct BitBuf {
57 #define BLK(data, x, y) data[(x) + (y) * 320]
59 #define kmvc_init_getbits(bb, src) bb.bits = 7; bb.bitbuf = *src++;
61 #define kmvc_getbit(bb, src, res) {\
63 if (bb.bitbuf & (1 << bb.bits)) res = 1; \
71 static void kmvc_decode_intra_8x8(KmvcContext * ctx, uint8_t * src, int w, int h)
77 int l0x, l1x, l0y, l1y;
80 kmvc_init_getbits(bb, src);
82 for (by = 0; by < h; by += 8)
83 for (bx = 0; bx < w; bx += 8) {
84 kmvc_getbit(bb, src, res);
85 if (!res) { // fill whole 8x8 block
87 for (i = 0; i < 64; i++)
88 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
89 } else { // handle four 4x4 subblocks
90 for (i = 0; i < 4; i++) {
91 l0x = bx + (i & 1) * 4;
92 l0y = by + (i & 2) * 2;
93 kmvc_getbit(bb, src, res);
95 kmvc_getbit(bb, src, res);
96 if (!res) { // fill whole 4x4 block
98 for (j = 0; j < 16; j++)
99 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
100 } else { // copy block from already decoded place
104 for (j = 0; j < 16; j++)
105 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
106 BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
108 } else { // descend to 2x2 sub-sub-blocks
109 for (j = 0; j < 4; j++) {
110 l1x = l0x + (j & 1) * 2;
112 kmvc_getbit(bb, src, res);
114 kmvc_getbit(bb, src, res);
115 if (!res) { // fill whole 2x2 block
117 BLK(ctx->cur, l1x, l1y) = val;
118 BLK(ctx->cur, l1x + 1, l1y) = val;
119 BLK(ctx->cur, l1x, l1y + 1) = val;
120 BLK(ctx->cur, l1x + 1, l1y + 1) = val;
121 } else { // copy block from already decoded place
125 BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
126 BLK(ctx->cur, l1x + 1, l1y) =
127 BLK(ctx->cur, l1x + 1 - mx, l1y - my);
128 BLK(ctx->cur, l1x, l1y + 1) =
129 BLK(ctx->cur, l1x - mx, l1y + 1 - my);
130 BLK(ctx->cur, l1x + 1, l1y + 1) =
131 BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
133 } else { // read values for block
134 BLK(ctx->cur, l1x, l1y) = *src++;
135 BLK(ctx->cur, l1x + 1, l1y) = *src++;
136 BLK(ctx->cur, l1x, l1y + 1) = *src++;
137 BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
146 static void kmvc_decode_inter_8x8(KmvcContext * ctx, uint8_t * src, int w, int h)
152 int l0x, l1x, l0y, l1y;
155 kmvc_init_getbits(bb, src);
157 for (by = 0; by < h; by += 8)
158 for (bx = 0; bx < w; bx += 8) {
159 kmvc_getbit(bb, src, res);
161 kmvc_getbit(bb, src, res);
162 if (!res) { // fill whole 8x8 block
164 for (i = 0; i < 64; i++)
165 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
166 } else { // copy block from previous frame
167 for (i = 0; i < 64; i++)
168 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
169 BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
171 } else { // handle four 4x4 subblocks
172 for (i = 0; i < 4; i++) {
173 l0x = bx + (i & 1) * 4;
174 l0y = by + (i & 2) * 2;
175 kmvc_getbit(bb, src, res);
177 kmvc_getbit(bb, src, res);
178 if (!res) { // fill whole 4x4 block
180 for (j = 0; j < 16; j++)
181 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
182 } else { // copy block
184 mx = (val & 0xF) - 8;
186 for (j = 0; j < 16; j++)
187 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
188 BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
190 } else { // descend to 2x2 sub-sub-blocks
191 for (j = 0; j < 4; j++) {
192 l1x = l0x + (j & 1) * 2;
194 kmvc_getbit(bb, src, res);
196 kmvc_getbit(bb, src, res);
197 if (!res) { // fill whole 2x2 block
199 BLK(ctx->cur, l1x, l1y) = val;
200 BLK(ctx->cur, l1x + 1, l1y) = val;
201 BLK(ctx->cur, l1x, l1y + 1) = val;
202 BLK(ctx->cur, l1x + 1, l1y + 1) = val;
203 } else { // copy block
205 mx = (val & 0xF) - 8;
207 BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
208 BLK(ctx->cur, l1x + 1, l1y) =
209 BLK(ctx->prev, l1x + 1 + mx, l1y + my);
210 BLK(ctx->cur, l1x, l1y + 1) =
211 BLK(ctx->prev, l1x + mx, l1y + 1 + my);
212 BLK(ctx->cur, l1x + 1, l1y + 1) =
213 BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
215 } else { // read values for block
216 BLK(ctx->cur, l1x, l1y) = *src++;
217 BLK(ctx->cur, l1x + 1, l1y) = *src++;
218 BLK(ctx->cur, l1x, l1y + 1) = *src++;
219 BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
228 static int decode_frame(AVCodecContext * avctx, void *data, int *data_size, uint8_t * buf,
231 KmvcContext *const ctx = (KmvcContext *) avctx->priv_data;
237 if (ctx->pic.data[0])
238 avctx->release_buffer(avctx, &ctx->pic);
240 ctx->pic.reference = 1;
241 ctx->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
242 if (avctx->get_buffer(avctx, &ctx->pic) < 0) {
243 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
249 /* blocksize 127 is really palette change event */
252 for (i = 0; i < 127; i++) {
253 ctx->pal[i + (header & 0x81)] = (buf[0] << 16) | (buf[1] << 8) | buf[2];
259 if (header & KMVC_KEYFRAME) {
260 ctx->pic.key_frame = 1;
261 ctx->pic.pict_type = FF_I_TYPE;
263 ctx->pic.key_frame = 0;
264 ctx->pic.pict_type = FF_P_TYPE;
267 /* if palette has been changed, copy it from palctrl */
268 if (ctx->avctx->palctrl && ctx->avctx->palctrl->palette_changed) {
269 memcpy(ctx->pal, ctx->avctx->palctrl->palette, AVPALETTE_SIZE);
271 ctx->avctx->palctrl->palette_changed = 0;
274 if (header & KMVC_PALETTE) {
275 ctx->pic.palette_has_changed = 1;
276 // palette starts from index 1 and has 127 entries
277 for (i = 1; i <= ctx->palsize; i++) {
278 ctx->pal[i] = (buf[0] << 16) | (buf[1] << 8) | buf[2];
285 ctx->pic.palette_has_changed = 1;
288 /* make the palette available on the way out */
289 memcpy(ctx->pic.data[1], ctx->pal, 1024);
293 if (blocksize != 8 && blocksize != 127) {
294 av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
297 memset(ctx->cur, 0, 320 * 200);
298 switch (header & KMVC_METHOD) {
300 case 1: // used in palette changed event
301 memcpy(ctx->cur, ctx->prev, 320 * 200);
304 kmvc_decode_intra_8x8(ctx, buf, avctx->width, avctx->height);
307 kmvc_decode_inter_8x8(ctx, buf, avctx->width, avctx->height);
310 av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
314 out = ctx->pic.data[0];
316 for (i = 0; i < avctx->height; i++) {
317 memcpy(out, src, avctx->width);
319 out += ctx->pic.linesize[0];
323 if (ctx->cur == ctx->frm0) {
324 ctx->cur = ctx->frm1;
325 ctx->prev = ctx->frm0;
327 ctx->cur = ctx->frm0;
328 ctx->prev = ctx->frm1;
331 *data_size = sizeof(AVFrame);
332 *(AVFrame *) data = ctx->pic;
334 /* always report that the buffer was completely consumed */
343 static int decode_init(AVCodecContext * avctx)
345 KmvcContext *const c = (KmvcContext *) avctx->priv_data;
350 c->pic.data[0] = NULL;
352 if (avctx->width > 320 || avctx->height > 200) {
353 av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
357 c->frm0 = av_mallocz(320 * 200);
358 c->frm1 = av_mallocz(320 * 200);
362 for (i = 0; i < 256; i++) {
363 c->pal[i] = i * 0x10101;
366 if (avctx->extradata_size < 12) {
367 av_log(NULL, 0, "Extradata missing, decoding may not work properly...\n");
370 c->palsize = AV_RL16(avctx->extradata + 10);
373 if (avctx->extradata_size == 1036) { // palette in extradata
374 uint8_t *src = avctx->extradata + 12;
375 for (i = 0; i < 256; i++) {
376 c->pal[i] = AV_RL32(src);
380 if (c->avctx->palctrl) {
381 c->avctx->palctrl->palette_changed = 0;
385 avctx->pix_fmt = PIX_FMT_PAL8;
393 * Uninit kmvc decoder
395 static int decode_end(AVCodecContext * avctx)
397 KmvcContext *const c = (KmvcContext *) avctx->priv_data;
402 avctx->release_buffer(avctx, &c->pic);
407 AVCodec kmvc_decoder = {