2 * Chronomaster DFA Video Decoder
3 * Copyright (c) 2011 Konstantin Shishkov
4 * based on work by Vladimir "VAG" Gneushev
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 #include "bytestream.h"
25 #include "libavutil/lzo.h" // for av_memcpy_backptr
27 typedef struct DfaContext {
34 static av_cold int dfa_decode_init(AVCodecContext *avctx)
36 DfaContext *s = avctx->priv_data;
38 avctx->pix_fmt = PIX_FMT_PAL8;
40 s->frame_buf = av_mallocz(avctx->width * avctx->height + AV_LZO_OUTPUT_PADDING);
42 return AVERROR(ENOMEM);
47 static int decode_copy(GetByteContext *gb, uint8_t *frame, int width, int height)
49 const int size = width * height;
51 if (bytestream2_get_buffer(gb, frame, size) != size)
56 static int decode_tsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
58 const uint8_t *frame_start = frame;
59 const uint8_t *frame_end = frame + width * height;
60 int mask = 0x10000, bitbuf = 0;
61 int v, count, segments;
64 segments = bytestream2_get_le32(gb);
65 offset = bytestream2_get_le32(gb);
66 if (segments == 0 && offset == frame_end - frame)
67 return 0; // skip frame
68 if (frame_end - frame <= offset)
72 if (bytestream2_get_bytes_left(gb) < 2)
74 if (mask == 0x10000) {
75 bitbuf = bytestream2_get_le16u(gb);
78 if (frame_end - frame < 2)
81 v = bytestream2_get_le16(gb);
82 offset = (v & 0x1FFF) << 1;
83 count = ((v >> 13) + 2) << 1;
84 if (frame - frame_start < offset || frame_end - frame < count)
86 av_memcpy_backptr(frame, offset, count);
89 *frame++ = bytestream2_get_byte(gb);
90 *frame++ = bytestream2_get_byte(gb);
98 static int decode_dsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
100 const uint8_t *frame_start = frame;
101 const uint8_t *frame_end = frame + width * height;
102 int mask = 0x10000, bitbuf = 0;
103 int v, offset, count, segments;
105 segments = bytestream2_get_le16(gb);
107 if (bytestream2_get_bytes_left(gb) < 2)
109 if (mask == 0x10000) {
110 bitbuf = bytestream2_get_le16u(gb);
113 if (frame_end - frame < 2)
116 v = bytestream2_get_le16(gb);
117 offset = (v & 0x1FFF) << 1;
118 count = ((v >> 13) + 2) << 1;
119 if (frame - frame_start < offset || frame_end - frame < count)
121 // can't use av_memcpy_backptr() since it can overwrite following pixels
122 for (v = 0; v < count; v++)
123 frame[v] = frame[v - offset];
125 } else if (bitbuf & (mask << 1)) {
126 frame += bytestream2_get_le16(gb);
128 *frame++ = bytestream2_get_byte(gb);
129 *frame++ = bytestream2_get_byte(gb);
137 static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height)
139 const uint8_t *frame_start = frame;
140 const uint8_t *frame_end = frame + width * height;
141 int mask = 0x10000, bitbuf = 0;
142 int i, v, offset, count, segments;
144 segments = bytestream2_get_le16(gb);
146 if (bytestream2_get_bytes_left(gb) < 2)
148 if (mask == 0x10000) {
149 bitbuf = bytestream2_get_le16u(gb);
152 if (frame_end - frame < width + 2)
155 v = bytestream2_get_le16(gb);
156 offset = (v & 0x1FFF) << 2;
157 count = ((v >> 13) + 2) << 1;
158 if (frame - frame_start < offset || frame_end - frame < count*2 + width)
160 for (i = 0; i < count; i++) {
161 frame[0] = frame[1] =
162 frame[width] = frame[width + 1] = frame[-offset];
166 } else if (bitbuf & (mask << 1)) {
167 frame += bytestream2_get_le16(gb) * 2;
169 frame[0] = frame[1] =
170 frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
172 frame[0] = frame[1] =
173 frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
182 static int decode_bdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
185 int count, lines, segments;
187 count = bytestream2_get_le16(gb);
190 frame += width * count;
191 lines = bytestream2_get_le16(gb);
192 if (count + lines > height)
196 if (bytestream2_get_bytes_left(gb) < 1)
200 segments = bytestream2_get_byteu(gb);
202 if (frame - line_ptr <= bytestream2_peek_byte(gb))
204 line_ptr += bytestream2_get_byte(gb);
205 count = (int8_t)bytestream2_get_byte(gb);
207 if (frame - line_ptr < count)
209 if (bytestream2_get_buffer(gb, line_ptr, count) != count)
213 if (frame - line_ptr < count)
215 memset(line_ptr, bytestream2_get_byte(gb), count);
224 static int decode_wdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
226 const uint8_t *frame_end = frame + width * height;
228 int count, i, v, lines, segments;
230 lines = bytestream2_get_le16(gb);
235 if (bytestream2_get_bytes_left(gb) < 2)
237 segments = bytestream2_get_le16u(gb);
238 while ((segments & 0xC000) == 0xC000) {
239 unsigned delta = -((int16_t)segments * width);
240 if (frame_end - frame <= delta)
243 segments = bytestream2_get_le16(gb);
245 if (frame_end <= frame)
247 if (segments & 0x8000) {
248 frame[width - 1] = segments & 0xFF;
249 segments = bytestream2_get_le16(gb);
254 if (frame - line_ptr <= bytestream2_peek_byte(gb))
256 line_ptr += bytestream2_get_byte(gb);
257 count = (int8_t)bytestream2_get_byte(gb);
259 if (frame - line_ptr < count * 2)
261 if (bytestream2_get_buffer(gb, line_ptr, count * 2) != count * 2)
263 line_ptr += count * 2;
266 if (frame - line_ptr < count * 2)
268 v = bytestream2_get_le16(gb);
269 for (i = 0; i < count; i++)
270 bytestream_put_le16(&line_ptr, v);
278 static int decode_unk6(GetByteContext *gb, uint8_t *frame, int width, int height)
283 static int decode_blck(GetByteContext *gb, uint8_t *frame, int width, int height)
285 memset(frame, 0, width * height);
290 typedef int (*chunk_decoder)(GetByteContext *gb, uint8_t *frame, int width, int height);
292 static const chunk_decoder decoder[8] = {
293 decode_copy, decode_tsw1, decode_bdlt, decode_wdlt,
294 decode_unk6, decode_dsw1, decode_blck, decode_dds1,
297 static const char* chunk_name[8] = {
298 "COPY", "TSW1", "BDLT", "WDLT", "????", "DSW1", "BLCK", "DDS1"
301 static int dfa_decode_frame(AVCodecContext *avctx,
302 void *data, int *data_size,
305 DfaContext *s = avctx->priv_data;
307 const uint8_t *buf = avpkt->data;
308 uint32_t chunk_type, chunk_size;
314 avctx->release_buffer(avctx, &s->pic);
316 if ((ret = avctx->get_buffer(avctx, &s->pic))) {
317 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
321 bytestream2_init(&gb, avpkt->data, avpkt->size);
322 while (bytestream2_get_bytes_left(&gb) > 0) {
323 bytestream2_skip(&gb, 4);
324 chunk_size = bytestream2_get_le32(&gb);
325 chunk_type = bytestream2_get_le32(&gb);
328 if (chunk_type == 1) {
329 pal_elems = FFMIN(chunk_size / 3, 256);
330 for (i = 0; i < pal_elems; i++) {
331 s->pal[i] = bytestream2_get_be24(&gb) << 2;
332 s->pal[i] |= 0xFF << 24 | (s->pal[i] >> 6) & 0x30303;
334 s->pic.palette_has_changed = 1;
335 } else if (chunk_type <= 9) {
336 if (decoder[chunk_type - 2](&gb, s->frame_buf, avctx->width, avctx->height)) {
337 av_log(avctx, AV_LOG_ERROR, "Error decoding %s chunk\n",
338 chunk_name[chunk_type - 2]);
342 av_log(avctx, AV_LOG_WARNING, "Ignoring unknown chunk type %d\n",
349 dst = s->pic.data[0];
350 for (i = 0; i < avctx->height; i++) {
351 memcpy(dst, buf, avctx->width);
352 dst += s->pic.linesize[0];
355 memcpy(s->pic.data[1], s->pal, sizeof(s->pal));
357 *data_size = sizeof(AVFrame);
358 *(AVFrame*)data = s->pic;
363 static av_cold int dfa_decode_end(AVCodecContext *avctx)
365 DfaContext *s = avctx->priv_data;
368 avctx->release_buffer(avctx, &s->pic);
370 av_freep(&s->frame_buf);
375 AVCodec ff_dfa_decoder = {
377 .type = AVMEDIA_TYPE_VIDEO,
379 .priv_data_size = sizeof(DfaContext),
380 .init = dfa_decode_init,
381 .close = dfa_decode_end,
382 .decode = dfa_decode_frame,
383 .capabilities = CODEC_CAP_DR1,
384 .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),