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
24 * Karl Morton's Video Codec decoder
31 #include "bytestream.h"
33 #define KMVC_KEYFRAME 0x80
34 #define KMVC_PALETTE 0x40
35 #define KMVC_METHOD 0x0F
40 typedef struct KmvcContext {
41 AVCodecContext *avctx;
51 typedef struct BitBuf {
56 #define BLK(data, x, y) data[(x) + (y) * 320]
58 #define kmvc_init_getbits(bb, src) bb.bits = 7; bb.bitbuf = *src++;
60 #define kmvc_getbit(bb, src, res) {\
62 if (bb.bitbuf & (1 << bb.bits)) res = 1; \
70 static void kmvc_decode_intra_8x8(KmvcContext * ctx, const uint8_t * src, int w, int h)
76 int l0x, l1x, l0y, l1y;
79 kmvc_init_getbits(bb, src);
81 for (by = 0; by < h; by += 8)
82 for (bx = 0; bx < w; bx += 8) {
83 kmvc_getbit(bb, src, res);
84 if (!res) { // fill whole 8x8 block
86 for (i = 0; i < 64; i++)
87 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
88 } else { // handle four 4x4 subblocks
89 for (i = 0; i < 4; i++) {
90 l0x = bx + (i & 1) * 4;
91 l0y = by + (i & 2) * 2;
92 kmvc_getbit(bb, src, res);
94 kmvc_getbit(bb, src, res);
95 if (!res) { // fill whole 4x4 block
97 for (j = 0; j < 16; j++)
98 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
99 } else { // copy block from already decoded place
103 for (j = 0; j < 16; j++)
104 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
105 BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
107 } else { // descend to 2x2 sub-sub-blocks
108 for (j = 0; j < 4; j++) {
109 l1x = l0x + (j & 1) * 2;
111 kmvc_getbit(bb, src, res);
113 kmvc_getbit(bb, src, res);
114 if (!res) { // fill whole 2x2 block
116 BLK(ctx->cur, l1x, l1y) = val;
117 BLK(ctx->cur, l1x + 1, l1y) = val;
118 BLK(ctx->cur, l1x, l1y + 1) = val;
119 BLK(ctx->cur, l1x + 1, l1y + 1) = val;
120 } else { // copy block from already decoded place
124 BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
125 BLK(ctx->cur, l1x + 1, l1y) =
126 BLK(ctx->cur, l1x + 1 - mx, l1y - my);
127 BLK(ctx->cur, l1x, l1y + 1) =
128 BLK(ctx->cur, l1x - mx, l1y + 1 - my);
129 BLK(ctx->cur, l1x + 1, l1y + 1) =
130 BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
132 } else { // read values for block
133 BLK(ctx->cur, l1x, l1y) = *src++;
134 BLK(ctx->cur, l1x + 1, l1y) = *src++;
135 BLK(ctx->cur, l1x, l1y + 1) = *src++;
136 BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
145 static void kmvc_decode_inter_8x8(KmvcContext * ctx, const uint8_t * src, int w, int h)
151 int l0x, l1x, l0y, l1y;
154 kmvc_init_getbits(bb, src);
156 for (by = 0; by < h; by += 8)
157 for (bx = 0; bx < w; bx += 8) {
158 kmvc_getbit(bb, src, res);
160 kmvc_getbit(bb, src, res);
161 if (!res) { // fill whole 8x8 block
163 for (i = 0; i < 64; i++)
164 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
165 } else { // copy block from previous frame
166 for (i = 0; i < 64; i++)
167 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
168 BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
170 } else { // handle four 4x4 subblocks
171 for (i = 0; i < 4; i++) {
172 l0x = bx + (i & 1) * 4;
173 l0y = by + (i & 2) * 2;
174 kmvc_getbit(bb, src, res);
176 kmvc_getbit(bb, src, res);
177 if (!res) { // fill whole 4x4 block
179 for (j = 0; j < 16; j++)
180 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
181 } else { // copy block
183 mx = (val & 0xF) - 8;
185 for (j = 0; j < 16; j++)
186 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
187 BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
189 } else { // descend to 2x2 sub-sub-blocks
190 for (j = 0; j < 4; j++) {
191 l1x = l0x + (j & 1) * 2;
193 kmvc_getbit(bb, src, res);
195 kmvc_getbit(bb, src, res);
196 if (!res) { // fill whole 2x2 block
198 BLK(ctx->cur, l1x, l1y) = val;
199 BLK(ctx->cur, l1x + 1, l1y) = val;
200 BLK(ctx->cur, l1x, l1y + 1) = val;
201 BLK(ctx->cur, l1x + 1, l1y + 1) = val;
202 } else { // copy block
204 mx = (val & 0xF) - 8;
206 BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
207 BLK(ctx->cur, l1x + 1, l1y) =
208 BLK(ctx->prev, l1x + 1 + mx, l1y + my);
209 BLK(ctx->cur, l1x, l1y + 1) =
210 BLK(ctx->prev, l1x + mx, l1y + 1 + my);
211 BLK(ctx->cur, l1x + 1, l1y + 1) =
212 BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
214 } else { // read values for block
215 BLK(ctx->cur, l1x, l1y) = *src++;
216 BLK(ctx->cur, l1x + 1, l1y) = *src++;
217 BLK(ctx->cur, l1x, l1y + 1) = *src++;
218 BLK(ctx->cur, l1x + 1, l1y + 1) = *src++;
227 static int decode_frame(AVCodecContext * avctx, void *data, int *data_size, const uint8_t * buf,
230 KmvcContext *const ctx = avctx->priv_data;
236 if (ctx->pic.data[0])
237 avctx->release_buffer(avctx, &ctx->pic);
239 ctx->pic.reference = 1;
240 ctx->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
241 if (avctx->get_buffer(avctx, &ctx->pic) < 0) {
242 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
248 /* blocksize 127 is really palette change event */
251 for (i = 0; i < 127; i++) {
252 ctx->pal[i + (header & 0x81)] = AV_RB24(buf);
258 if (header & KMVC_KEYFRAME) {
259 ctx->pic.key_frame = 1;
260 ctx->pic.pict_type = FF_I_TYPE;
262 ctx->pic.key_frame = 0;
263 ctx->pic.pict_type = FF_P_TYPE;
266 /* if palette has been changed, copy it from palctrl */
267 if (ctx->avctx->palctrl && ctx->avctx->palctrl->palette_changed) {
268 memcpy(ctx->pal, ctx->avctx->palctrl->palette, AVPALETTE_SIZE);
270 ctx->avctx->palctrl->palette_changed = 0;
273 if (header & KMVC_PALETTE) {
274 ctx->pic.palette_has_changed = 1;
275 // palette starts from index 1 and has 127 entries
276 for (i = 1; i <= ctx->palsize; i++) {
277 ctx->pal[i] = bytestream_get_be24(&buf);
283 ctx->pic.palette_has_changed = 1;
286 /* make the palette available on the way out */
287 memcpy(ctx->pic.data[1], ctx->pal, 1024);
291 if (blocksize != 8 && blocksize != 127) {
292 av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
295 memset(ctx->cur, 0, 320 * 200);
296 switch (header & KMVC_METHOD) {
298 case 1: // used in palette changed event
299 memcpy(ctx->cur, ctx->prev, 320 * 200);
302 kmvc_decode_intra_8x8(ctx, buf, avctx->width, avctx->height);
305 kmvc_decode_inter_8x8(ctx, buf, avctx->width, avctx->height);
308 av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
312 out = ctx->pic.data[0];
314 for (i = 0; i < avctx->height; i++) {
315 memcpy(out, src, avctx->width);
317 out += ctx->pic.linesize[0];
321 if (ctx->cur == ctx->frm0) {
322 ctx->cur = ctx->frm1;
323 ctx->prev = ctx->frm0;
325 ctx->cur = ctx->frm0;
326 ctx->prev = ctx->frm1;
329 *data_size = sizeof(AVFrame);
330 *(AVFrame *) data = ctx->pic;
332 /* always report that the buffer was completely consumed */
341 static av_cold int decode_init(AVCodecContext * avctx)
343 KmvcContext *const c = avctx->priv_data;
348 c->pic.data[0] = NULL;
350 if (avctx->width > 320 || avctx->height > 200) {
351 av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
355 c->frm0 = av_mallocz(320 * 200);
356 c->frm1 = av_mallocz(320 * 200);
360 for (i = 0; i < 256; i++) {
361 c->pal[i] = i * 0x10101;
364 if (avctx->extradata_size < 12) {
365 av_log(NULL, 0, "Extradata missing, decoding may not work properly...\n");
368 c->palsize = AV_RL16(avctx->extradata + 10);
371 if (avctx->extradata_size == 1036) { // palette in extradata
372 uint8_t *src = avctx->extradata + 12;
373 for (i = 0; i < 256; i++) {
374 c->pal[i] = AV_RL32(src);
378 if (c->avctx->palctrl) {
379 c->avctx->palctrl->palette_changed = 0;
383 avctx->pix_fmt = PIX_FMT_PAL8;
391 * Uninit kmvc decoder
393 static av_cold int decode_end(AVCodecContext * avctx)
395 KmvcContext *const c = avctx->priv_data;
400 avctx->release_buffer(avctx, &c->pic);
405 AVCodec kmvc_decoder = {
414 .long_name = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),