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 Libav.
8 * Libav 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 * Libav 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 Libav; 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 (frame_end - frame <= offset)
67 return AVERROR_INVALIDDATA;
70 if (bytestream2_get_bytes_left(gb) < 2)
71 return AVERROR_INVALIDDATA;
72 if (mask == 0x10000) {
73 bitbuf = bytestream2_get_le16u(gb);
76 if (frame_end - frame < 2)
77 return AVERROR_INVALIDDATA;
79 v = bytestream2_get_le16(gb);
80 offset = (v & 0x1FFF) << 1;
81 count = ((v >> 13) + 2) << 1;
82 if (frame - frame_start < offset || frame_end - frame < count)
83 return AVERROR_INVALIDDATA;
84 av_memcpy_backptr(frame, offset, count);
87 *frame++ = bytestream2_get_byte(gb);
88 *frame++ = bytestream2_get_byte(gb);
96 static int decode_dsw1(GetByteContext *gb, uint8_t *frame, int width, int height)
98 const uint8_t *frame_start = frame;
99 const uint8_t *frame_end = frame + width * height;
100 int mask = 0x10000, bitbuf = 0;
101 int v, offset, count, segments;
103 segments = bytestream2_get_le16(gb);
105 if (bytestream2_get_bytes_left(gb) < 2)
106 return AVERROR_INVALIDDATA;
107 if (mask == 0x10000) {
108 bitbuf = bytestream2_get_le16u(gb);
111 if (frame_end - frame < 2)
112 return AVERROR_INVALIDDATA;
114 v = bytestream2_get_le16(gb);
115 offset = (v & 0x1FFF) << 1;
116 count = ((v >> 13) + 2) << 1;
117 if (frame - frame_start < offset || frame_end - frame < count)
118 return AVERROR_INVALIDDATA;
119 // can't use av_memcpy_backptr() since it can overwrite following pixels
120 for (v = 0; v < count; v++)
121 frame[v] = frame[v - offset];
123 } else if (bitbuf & (mask << 1)) {
124 frame += bytestream2_get_le16(gb);
126 *frame++ = bytestream2_get_byte(gb);
127 *frame++ = bytestream2_get_byte(gb);
135 static int decode_dds1(GetByteContext *gb, uint8_t *frame, int width, int height)
137 const uint8_t *frame_start = frame;
138 const uint8_t *frame_end = frame + width * height;
139 int mask = 0x10000, bitbuf = 0;
140 int i, v, offset, count, segments;
142 segments = bytestream2_get_le16(gb);
144 if (bytestream2_get_bytes_left(gb) < 2)
145 return AVERROR_INVALIDDATA;
146 if (mask == 0x10000) {
147 bitbuf = bytestream2_get_le16u(gb);
150 if (frame_end - frame < 2)
151 return AVERROR_INVALIDDATA;
153 v = bytestream2_get_le16(gb);
154 offset = (v & 0x1FFF) << 2;
155 count = ((v >> 13) + 2) << 1;
156 if (frame - frame_start < offset || frame_end - frame < count*2 + width)
157 return AVERROR_INVALIDDATA;
158 for (i = 0; i < count; i++) {
159 frame[0] = frame[1] =
160 frame[width] = frame[width + 1] = frame[-offset];
164 } else if (bitbuf & (mask << 1)) {
165 frame += bytestream2_get_le16(gb) * 2;
167 if (frame_end - frame < width + 2)
168 return AVERROR_INVALIDDATA;
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);
189 return AVERROR_INVALIDDATA;
190 frame += width * count;
191 lines = bytestream2_get_le16(gb);
192 if (count + lines > height)
193 return AVERROR_INVALIDDATA;
196 if (bytestream2_get_bytes_left(gb) < 1)
197 return AVERROR_INVALIDDATA;
200 segments = bytestream2_get_byteu(gb);
202 if (frame - line_ptr <= bytestream2_peek_byte(gb))
203 return AVERROR_INVALIDDATA;
204 line_ptr += bytestream2_get_byte(gb);
205 count = (int8_t)bytestream2_get_byte(gb);
207 if (frame - line_ptr < count)
208 return AVERROR_INVALIDDATA;
209 if (bytestream2_get_buffer(gb, line_ptr, count) != count)
210 return AVERROR_INVALIDDATA;
213 if (frame - line_ptr < count)
214 return AVERROR_INVALIDDATA;
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;
231 lines = bytestream2_get_le16(gb);
233 return AVERROR_INVALIDDATA;
236 if (bytestream2_get_bytes_left(gb) < 2)
237 return AVERROR_INVALIDDATA;
238 segments = bytestream2_get_le16u(gb);
239 while ((segments & 0xC000) == 0xC000) {
240 unsigned skip_lines = -(int16_t)segments;
241 unsigned delta = -((int16_t)segments * width);
242 if (frame_end - frame <= delta || y + lines + skip_lines > height)
243 return AVERROR_INVALIDDATA;
246 segments = bytestream2_get_le16(gb);
248 if (segments & 0x8000) {
249 frame[width - 1] = segments & 0xFF;
250 segments = bytestream2_get_le16(gb);
256 if (frame - line_ptr <= bytestream2_peek_byte(gb))
257 return AVERROR_INVALIDDATA;
258 line_ptr += bytestream2_get_byte(gb);
259 count = (int8_t)bytestream2_get_byte(gb);
261 if (frame - line_ptr < count * 2)
262 return AVERROR_INVALIDDATA;
263 if (bytestream2_get_buffer(gb, line_ptr, count * 2) != count * 2)
264 return AVERROR_INVALIDDATA;
265 line_ptr += count * 2;
268 if (frame - line_ptr < count * 2)
269 return AVERROR_INVALIDDATA;
270 v = bytestream2_get_le16(gb);
271 for (i = 0; i < count; i++)
272 bytestream_put_le16(&line_ptr, v);
280 static int decode_unk6(GetByteContext *gb, uint8_t *frame, int width, int height)
282 return AVERROR_PATCHWELCOME;
285 static int decode_blck(GetByteContext *gb, uint8_t *frame, int width, int height)
287 memset(frame, 0, width * height);
292 typedef int (*chunk_decoder)(GetByteContext *gb, uint8_t *frame, int width, int height);
294 static const chunk_decoder decoder[8] = {
295 decode_copy, decode_tsw1, decode_bdlt, decode_wdlt,
296 decode_unk6, decode_dsw1, decode_blck, decode_dds1,
299 static const char* chunk_name[8] = {
300 "COPY", "TSW1", "BDLT", "WDLT", "????", "DSW1", "BLCK", "DDS1"
303 static int dfa_decode_frame(AVCodecContext *avctx,
304 void *data, int *data_size,
307 DfaContext *s = avctx->priv_data;
309 const uint8_t *buf = avpkt->data;
310 uint32_t chunk_type, chunk_size;
316 avctx->release_buffer(avctx, &s->pic);
318 if ((ret = avctx->get_buffer(avctx, &s->pic))) {
319 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
323 bytestream2_init(&gb, avpkt->data, avpkt->size);
324 while (bytestream2_get_bytes_left(&gb) > 0) {
325 bytestream2_skip(&gb, 4);
326 chunk_size = bytestream2_get_le32(&gb);
327 chunk_type = bytestream2_get_le32(&gb);
330 if (chunk_type == 1) {
331 pal_elems = FFMIN(chunk_size / 3, 256);
332 for (i = 0; i < pal_elems; i++) {
333 s->pal[i] = bytestream2_get_be24(&gb) << 2;
334 s->pal[i] |= (s->pal[i] >> 6) & 0x333;
336 s->pic.palette_has_changed = 1;
337 } else if (chunk_type <= 9) {
338 if (decoder[chunk_type - 2](&gb, s->frame_buf, avctx->width, avctx->height)) {
339 av_log(avctx, AV_LOG_ERROR, "Error decoding %s chunk\n",
340 chunk_name[chunk_type - 2]);
341 return AVERROR_INVALIDDATA;
344 av_log(avctx, AV_LOG_WARNING, "Ignoring unknown chunk type %d\n",
351 dst = s->pic.data[0];
352 for (i = 0; i < avctx->height; i++) {
353 memcpy(dst, buf, avctx->width);
354 dst += s->pic.linesize[0];
357 memcpy(s->pic.data[1], s->pal, sizeof(s->pal));
359 *data_size = sizeof(AVFrame);
360 *(AVFrame*)data = s->pic;
365 static av_cold int dfa_decode_end(AVCodecContext *avctx)
367 DfaContext *s = avctx->priv_data;
370 avctx->release_buffer(avctx, &s->pic);
372 av_freep(&s->frame_buf);
377 AVCodec ff_dfa_decoder = {
379 .type = AVMEDIA_TYPE_VIDEO,
381 .priv_data_size = sizeof(DfaContext),
382 .init = dfa_decode_init,
383 .close = dfa_decode_end,
384 .decode = dfa_decode_frame,
385 .capabilities = CODEC_CAP_DR1,
386 .long_name = NULL_IF_CONFIG_SMALL("Chronomaster DFA"),