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"
34 #define KMVC_KEYFRAME 0x80
35 #define KMVC_PALETTE 0x40
36 #define KMVC_METHOD 0x0F
37 #define MAX_PALSIZE 256
42 typedef struct KmvcContext {
43 AVCodecContext *avctx;
47 uint32_t pal[MAX_PALSIZE];
53 typedef struct BitBuf {
58 #define BLK(data, x, y) data[(x) + (y) * 320]
60 #define kmvc_init_getbits(bb, g) bb.bits = 7; bb.bitbuf = bytestream2_get_byte(g);
62 #define kmvc_getbit(bb, g, res) {\
64 if (bb.bitbuf & (1 << bb.bits)) res = 1; \
67 bb.bitbuf = bytestream2_get_byte(g); \
72 static int kmvc_decode_intra_8x8(KmvcContext * ctx, int w, int h)
78 int l0x, l1x, l0y, l1y;
81 kmvc_init_getbits(bb, &ctx->g);
83 for (by = 0; by < h; by += 8)
84 for (bx = 0; bx < w; bx += 8) {
85 if (!bytestream2_get_bytes_left(&ctx->g)) {
86 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
87 return AVERROR_INVALIDDATA;
89 kmvc_getbit(bb, &ctx->g, res);
90 if (!res) { // fill whole 8x8 block
91 val = bytestream2_get_byte(&ctx->g);
92 for (i = 0; i < 64; i++)
93 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
94 } else { // handle four 4x4 subblocks
95 for (i = 0; i < 4; i++) {
96 l0x = bx + (i & 1) * 4;
97 l0y = by + (i & 2) * 2;
98 kmvc_getbit(bb, &ctx->g, res);
100 kmvc_getbit(bb, &ctx->g, res);
101 if (!res) { // fill whole 4x4 block
102 val = bytestream2_get_byte(&ctx->g);
103 for (j = 0; j < 16; j++)
104 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
105 } else { // copy block from already decoded place
106 val = bytestream2_get_byte(&ctx->g);
109 if ((l0x-mx) + 320*(l0y-my) < 0 || (l0x-mx) + 320*(l0y-my) > 316*196) {
110 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
111 return AVERROR_INVALIDDATA;
113 for (j = 0; j < 16; j++)
114 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
115 BLK(ctx->cur, l0x + (j & 3) - mx, l0y + (j >> 2) - my);
117 } else { // descend to 2x2 sub-sub-blocks
118 for (j = 0; j < 4; j++) {
119 l1x = l0x + (j & 1) * 2;
121 kmvc_getbit(bb, &ctx->g, res);
123 kmvc_getbit(bb, &ctx->g, res);
124 if (!res) { // fill whole 2x2 block
125 val = bytestream2_get_byte(&ctx->g);
126 BLK(ctx->cur, l1x, l1y) = val;
127 BLK(ctx->cur, l1x + 1, l1y) = val;
128 BLK(ctx->cur, l1x, l1y + 1) = val;
129 BLK(ctx->cur, l1x + 1, l1y + 1) = val;
130 } else { // copy block from already decoded place
131 val = bytestream2_get_byte(&ctx->g);
134 if ((l1x-mx) + 320*(l1y-my) < 0 || (l1x-mx) + 320*(l1y-my) > 318*198) {
135 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
136 return AVERROR_INVALIDDATA;
138 BLK(ctx->cur, l1x, l1y) = BLK(ctx->cur, l1x - mx, l1y - my);
139 BLK(ctx->cur, l1x + 1, l1y) =
140 BLK(ctx->cur, l1x + 1 - mx, l1y - my);
141 BLK(ctx->cur, l1x, l1y + 1) =
142 BLK(ctx->cur, l1x - mx, l1y + 1 - my);
143 BLK(ctx->cur, l1x + 1, l1y + 1) =
144 BLK(ctx->cur, l1x + 1 - mx, l1y + 1 - my);
146 } else { // read values for block
147 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
148 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
149 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
150 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
161 static int kmvc_decode_inter_8x8(KmvcContext * ctx, int w, int h)
167 int l0x, l1x, l0y, l1y;
170 kmvc_init_getbits(bb, &ctx->g);
172 for (by = 0; by < h; by += 8)
173 for (bx = 0; bx < w; bx += 8) {
174 kmvc_getbit(bb, &ctx->g, res);
176 kmvc_getbit(bb, &ctx->g, res);
177 if (!res) { // fill whole 8x8 block
178 if (!bytestream2_get_bytes_left(&ctx->g)) {
179 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
180 return AVERROR_INVALIDDATA;
182 val = bytestream2_get_byte(&ctx->g);
183 for (i = 0; i < 64; i++)
184 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) = val;
185 } else { // copy block from previous frame
186 for (i = 0; i < 64; i++)
187 BLK(ctx->cur, bx + (i & 0x7), by + (i >> 3)) =
188 BLK(ctx->prev, bx + (i & 0x7), by + (i >> 3));
190 } else { // handle four 4x4 subblocks
191 if (!bytestream2_get_bytes_left(&ctx->g)) {
192 av_log(ctx->avctx, AV_LOG_ERROR, "Data overrun\n");
193 return AVERROR_INVALIDDATA;
195 for (i = 0; i < 4; i++) {
196 l0x = bx + (i & 1) * 4;
197 l0y = by + (i & 2) * 2;
198 kmvc_getbit(bb, &ctx->g, res);
200 kmvc_getbit(bb, &ctx->g, res);
201 if (!res) { // fill whole 4x4 block
202 val = bytestream2_get_byte(&ctx->g);
203 for (j = 0; j < 16; j++)
204 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) = val;
205 } else { // copy block
206 val = bytestream2_get_byte(&ctx->g);
207 mx = (val & 0xF) - 8;
209 if ((l0x+mx) + 320*(l0y+my) < 0 || (l0x+mx) + 320*(l0y+my) > 318*198) {
210 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
211 return AVERROR_INVALIDDATA;
213 for (j = 0; j < 16; j++)
214 BLK(ctx->cur, l0x + (j & 3), l0y + (j >> 2)) =
215 BLK(ctx->prev, l0x + (j & 3) + mx, l0y + (j >> 2) + my);
217 } else { // descend to 2x2 sub-sub-blocks
218 for (j = 0; j < 4; j++) {
219 l1x = l0x + (j & 1) * 2;
221 kmvc_getbit(bb, &ctx->g, res);
223 kmvc_getbit(bb, &ctx->g, res);
224 if (!res) { // fill whole 2x2 block
225 val = bytestream2_get_byte(&ctx->g);
226 BLK(ctx->cur, l1x, l1y) = val;
227 BLK(ctx->cur, l1x + 1, l1y) = val;
228 BLK(ctx->cur, l1x, l1y + 1) = val;
229 BLK(ctx->cur, l1x + 1, l1y + 1) = val;
230 } else { // copy block
231 val = bytestream2_get_byte(&ctx->g);
232 mx = (val & 0xF) - 8;
234 if ((l1x+mx) + 320*(l1y+my) < 0 || (l1x+mx) + 320*(l1y+my) > 318*198) {
235 av_log(ctx->avctx, AV_LOG_ERROR, "Invalid MV\n");
236 return AVERROR_INVALIDDATA;
238 BLK(ctx->cur, l1x, l1y) = BLK(ctx->prev, l1x + mx, l1y + my);
239 BLK(ctx->cur, l1x + 1, l1y) =
240 BLK(ctx->prev, l1x + 1 + mx, l1y + my);
241 BLK(ctx->cur, l1x, l1y + 1) =
242 BLK(ctx->prev, l1x + mx, l1y + 1 + my);
243 BLK(ctx->cur, l1x + 1, l1y + 1) =
244 BLK(ctx->prev, l1x + 1 + mx, l1y + 1 + my);
246 } else { // read values for block
247 BLK(ctx->cur, l1x, l1y) = bytestream2_get_byte(&ctx->g);
248 BLK(ctx->cur, l1x + 1, l1y) = bytestream2_get_byte(&ctx->g);
249 BLK(ctx->cur, l1x, l1y + 1) = bytestream2_get_byte(&ctx->g);
250 BLK(ctx->cur, l1x + 1, l1y + 1) = bytestream2_get_byte(&ctx->g);
261 static int decode_frame(AVCodecContext * avctx, void *data, int *got_frame,
264 KmvcContext *const ctx = avctx->priv_data;
265 AVFrame *frame = data;
270 const uint8_t *pal = av_packet_get_side_data(avpkt, AV_PKT_DATA_PALETTE, NULL);
272 bytestream2_init(&ctx->g, avpkt->data, avpkt->size);
274 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
277 header = bytestream2_get_byte(&ctx->g);
279 /* blocksize 127 is really palette change event */
280 if (bytestream2_peek_byte(&ctx->g) == 127) {
281 bytestream2_skip(&ctx->g, 3);
282 for (i = 0; i < 127; i++) {
283 ctx->pal[i + (header & 0x81)] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
284 bytestream2_skip(&ctx->g, 1);
286 bytestream2_seek(&ctx->g, -127 * 4 - 3, SEEK_CUR);
289 if (header & KMVC_KEYFRAME) {
290 frame->key_frame = 1;
291 frame->pict_type = AV_PICTURE_TYPE_I;
293 frame->key_frame = 0;
294 frame->pict_type = AV_PICTURE_TYPE_P;
297 if (header & KMVC_PALETTE) {
298 frame->palette_has_changed = 1;
299 // palette starts from index 1 and has 127 entries
300 for (i = 1; i <= ctx->palsize; i++) {
301 ctx->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&ctx->g);
306 frame->palette_has_changed = 1;
307 memcpy(ctx->pal, pal, AVPALETTE_SIZE);
312 frame->palette_has_changed = 1;
315 /* make the palette available on the way out */
316 memcpy(frame->data[1], ctx->pal, 1024);
318 blocksize = bytestream2_get_byte(&ctx->g);
320 if (blocksize != 8 && blocksize != 127) {
321 av_log(avctx, AV_LOG_ERROR, "Block size = %i\n", blocksize);
322 return AVERROR_INVALIDDATA;
324 memset(ctx->cur, 0, 320 * 200);
325 switch (header & KMVC_METHOD) {
327 case 1: // used in palette changed event
328 memcpy(ctx->cur, ctx->prev, 320 * 200);
331 kmvc_decode_intra_8x8(ctx, avctx->width, avctx->height);
334 kmvc_decode_inter_8x8(ctx, avctx->width, avctx->height);
337 av_log(avctx, AV_LOG_ERROR, "Unknown compression method %i\n", header & KMVC_METHOD);
338 return AVERROR_INVALIDDATA;
341 out = frame->data[0];
343 for (i = 0; i < avctx->height; i++) {
344 memcpy(out, src, avctx->width);
346 out += frame->linesize[0];
350 if (ctx->cur == ctx->frm0) {
351 ctx->cur = ctx->frm1;
352 ctx->prev = ctx->frm0;
354 ctx->cur = ctx->frm0;
355 ctx->prev = ctx->frm1;
360 /* always report that the buffer was completely consumed */
369 static av_cold int decode_init(AVCodecContext * avctx)
371 KmvcContext *const c = avctx->priv_data;
376 if (avctx->width > 320 || avctx->height > 200) {
377 av_log(avctx, AV_LOG_ERROR, "KMVC supports frames <= 320x200\n");
378 return AVERROR(EINVAL);
381 c->frm0 = av_mallocz(320 * 200);
382 c->frm1 = av_mallocz(320 * 200);
386 for (i = 0; i < 256; i++) {
387 c->pal[i] = 0xFFU << 24 | i * 0x10101;
390 if (avctx->extradata_size < 12) {
391 av_log(avctx, AV_LOG_WARNING,
392 "Extradata missing, decoding may not work properly...\n");
395 c->palsize = AV_RL16(avctx->extradata + 10);
396 if (c->palsize >= (unsigned)MAX_PALSIZE) {
398 av_log(avctx, AV_LOG_ERROR, "KMVC palette too large\n");
399 return AVERROR_INVALIDDATA;
403 if (avctx->extradata_size == 1036) { // palette in extradata
404 uint8_t *src = avctx->extradata + 12;
405 for (i = 0; i < 256; i++) {
406 c->pal[i] = AV_RL32(src);
412 avctx->pix_fmt = AV_PIX_FMT_PAL8;
420 * Uninit kmvc decoder
422 static av_cold int decode_end(AVCodecContext * avctx)
424 KmvcContext *const c = avctx->priv_data;
432 AVCodec ff_kmvc_decoder = {
434 .type = AVMEDIA_TYPE_VIDEO,
435 .id = AV_CODEC_ID_KMVC,
436 .priv_data_size = sizeof(KmvcContext),
439 .decode = decode_frame,
440 .capabilities = CODEC_CAP_DR1,
441 .long_name = NULL_IF_CONFIG_SMALL("Karl Morton's video codec"),