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)
52 return AVERROR_INVALIDDATA;
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)
69 return AVERROR_INVALIDDATA;
72 if (bytestream2_get_bytes_left(gb) < 2)
73 return AVERROR_INVALIDDATA;
74 if (mask == 0x10000) {
75 bitbuf = bytestream2_get_le16u(gb);
78 if (frame_end - frame < 2)
79 return AVERROR_INVALIDDATA;
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)
85 return AVERROR_INVALIDDATA;
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)
108 return AVERROR_INVALIDDATA;
109 if (mask == 0x10000) {
110 bitbuf = bytestream2_get_le16u(gb);
113 if (frame_end - frame < 2)
114 return AVERROR_INVALIDDATA;
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)
120 return AVERROR_INVALIDDATA;
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)
147 return AVERROR_INVALIDDATA;
148 if (mask == 0x10000) {
149 bitbuf = bytestream2_get_le16u(gb);
152 if (frame_end - frame < width + 2)
153 return AVERROR_INVALIDDATA;
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)
159 return AVERROR_INVALIDDATA;
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 if (frame_end - frame < width + 2)
170 return AVERROR_INVALIDDATA;
171 frame[0] = frame[1] =
172 frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
174 frame[0] = frame[1] =
175 frame[width] = frame[width + 1] = bytestream2_get_byte(gb);
184 static int decode_bdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
187 int count, lines, segments;
189 count = bytestream2_get_le16(gb);
191 return AVERROR_INVALIDDATA;
192 frame += width * count;
193 lines = bytestream2_get_le16(gb);
194 if (count + lines > height)
195 return AVERROR_INVALIDDATA;
198 if (bytestream2_get_bytes_left(gb) < 1)
199 return AVERROR_INVALIDDATA;
202 segments = bytestream2_get_byteu(gb);
204 if (frame - line_ptr <= bytestream2_peek_byte(gb))
205 return AVERROR_INVALIDDATA;
206 line_ptr += bytestream2_get_byte(gb);
207 count = (int8_t)bytestream2_get_byte(gb);
209 if (frame - line_ptr < count)
210 return AVERROR_INVALIDDATA;
211 if (bytestream2_get_buffer(gb, line_ptr, count) != count)
212 return AVERROR_INVALIDDATA;
215 if (frame - line_ptr < count)
216 return AVERROR_INVALIDDATA;
217 memset(line_ptr, bytestream2_get_byte(gb), count);
226 static int decode_wdlt(GetByteContext *gb, uint8_t *frame, int width, int height)
228 const uint8_t *frame_end = frame + width * height;
230 int count, i, v, lines, segments;
233 lines = bytestream2_get_le16(gb);
235 return AVERROR_INVALIDDATA;
238 if (bytestream2_get_bytes_left(gb) < 2)
239 return AVERROR_INVALIDDATA;
240 segments = bytestream2_get_le16u(gb);
241 while ((segments & 0xC000) == 0xC000) {
242 unsigned skip_lines = -(int16_t)segments;
243 unsigned delta = -((int16_t)segments * width);
244 if (frame_end - frame <= delta || y + lines + skip_lines > height)
245 return AVERROR_INVALIDDATA;
248 segments = bytestream2_get_le16(gb);
250 if (frame_end <= frame)
252 if (segments & 0x8000) {
253 frame[width - 1] = segments & 0xFF;
254 segments = bytestream2_get_le16(gb);
260 if (frame - line_ptr <= bytestream2_peek_byte(gb))
261 return AVERROR_INVALIDDATA;
262 line_ptr += bytestream2_get_byte(gb);
263 count = (int8_t)bytestream2_get_byte(gb);
265 if (frame - line_ptr < count * 2)
266 return AVERROR_INVALIDDATA;
267 if (bytestream2_get_buffer(gb, line_ptr, count * 2) != count * 2)
268 return AVERROR_INVALIDDATA;
269 line_ptr += count * 2;
272 if (frame - line_ptr < count * 2)
273 return AVERROR_INVALIDDATA;
274 v = bytestream2_get_le16(gb);
275 for (i = 0; i < count; i++)
276 bytestream_put_le16(&line_ptr, v);
284 static int decode_unk6(GetByteContext *gb, uint8_t *frame, int width, int height)
286 return AVERROR_PATCHWELCOME;
289 static int decode_blck(GetByteContext *gb, uint8_t *frame, int width, int height)
291 memset(frame, 0, width * height);
296 typedef int (*chunk_decoder)(GetByteContext *gb, uint8_t *frame, int width, int height);
298 static const chunk_decoder decoder[8] = {
299 decode_copy, decode_tsw1, decode_bdlt, decode_wdlt,
300 decode_unk6, decode_dsw1, decode_blck, decode_dds1,
303 static const char* chunk_name[8] = {
304 "COPY", "TSW1", "BDLT", "WDLT", "????", "DSW1", "BLCK", "DDS1"
307 static int dfa_decode_frame(AVCodecContext *avctx,
308 void *data, int *data_size,
311 DfaContext *s = avctx->priv_data;
313 const uint8_t *buf = avpkt->data;
314 uint32_t chunk_type, chunk_size;
320 avctx->release_buffer(avctx, &s->pic);
322 if ((ret = avctx->get_buffer(avctx, &s->pic))) {
323 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
327 bytestream2_init(&gb, avpkt->data, avpkt->size);
328 while (bytestream2_get_bytes_left(&gb) > 0) {
329 bytestream2_skip(&gb, 4);
330 chunk_size = bytestream2_get_le32(&gb);
331 chunk_type = bytestream2_get_le32(&gb);
334 if (chunk_type == 1) {
335 pal_elems = FFMIN(chunk_size / 3, 256);
336 for (i = 0; i < pal_elems; i++) {
337 s->pal[i] = bytestream2_get_be24(&gb) << 2;
338 s->pal[i] |= 0xFF << 24 | (s->pal[i] >> 6) & 0x30303;
340 s->pic.palette_has_changed = 1;
341 } else if (chunk_type <= 9) {
342 if (decoder[chunk_type - 2](&gb, s->frame_buf, avctx->width, avctx->height)) {
343 av_log(avctx, AV_LOG_ERROR, "Error decoding %s chunk\n",
344 chunk_name[chunk_type - 2]);
345 return AVERROR_INVALIDDATA;
348 av_log(avctx, AV_LOG_WARNING, "Ignoring unknown chunk type %d\n",
355 dst = s->pic.data[0];
356 for (i = 0; i < avctx->height; i++) {
357 memcpy(dst, buf, avctx->width);
358 dst += s->pic.linesize[0];
361 memcpy(s->pic.data[1], s->pal, sizeof(s->pal));
363 *data_size = sizeof(AVFrame);
364 *(AVFrame*)data = s->pic;
369 static av_cold int dfa_decode_end(AVCodecContext *avctx)
371 DfaContext *s = avctx->priv_data;
374 avctx->release_buffer(avctx, &s->pic);
376 av_freep(&s->frame_buf);
381 AVCodec ff_dfa_decoder = {
383 .type = AVMEDIA_TYPE_VIDEO,
385 .priv_data_size = sizeof(DfaContext),
386 .init = dfa_decode_init,
387 .close = dfa_decode_end,
388 .decode = dfa_decode_frame,
389 .capabilities = CODEC_CAP_DR1,
390 .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),