2 * Quicktime Graphics (SMC) Video Decoder
3 * Copyright (C) 2003 the ffmpeg project
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 * QT SMC Video Decoder by Mike Melanson (melanson@pcisys.net)
24 * For more information about the SMC format, visit:
25 * http://www.pcisys.net/~melanson/codecs/
27 * The SMC decoder outputs PAL8 colorspace data.
43 #define COLORS_PER_TABLE 256
45 typedef struct SmcContext
{
47 AVCodecContext
*avctx
;
54 /* SMC color tables */
55 unsigned char color_pairs
[COLORS_PER_TABLE
* CPAIR
];
56 unsigned char color_quads
[COLORS_PER_TABLE
* CQUAD
];
57 unsigned char color_octets
[COLORS_PER_TABLE
* COCTET
];
61 #define GET_BLOCK_COUNT() \
62 (opcode & 0x10) ? (1 + s->buf[stream_ptr++]) : 1 + (opcode & 0x0F);
64 #define ADVANCE_BLOCK() \
67 if (pixel_ptr >= width) \
70 row_ptr += stride * 4; \
73 if (total_blocks < 0) \
75 av_log(s->avctx, AV_LOG_INFO, "warning: block counter just went negative (this should not happen)\n"); \
80 static void smc_decode_stream(SmcContext
*s
)
82 int width
= s
->avctx
->width
;
83 int height
= s
->avctx
->height
;
84 int stride
= s
->frame
.linesize
[0];
90 unsigned int color_flags
;
91 unsigned int color_flags_a
;
92 unsigned int color_flags_b
;
93 unsigned int flag_mask
;
95 unsigned char *pixels
= s
->frame
.data
[0];
97 int image_size
= height
* s
->frame
.linesize
[0];
100 int pixel_x
, pixel_y
;
101 int row_inc
= stride
- 4;
104 int prev_block_ptr1
, prev_block_ptr2
;
107 int color_table_index
; /* indexes to color pair, quad, or octet tables */
110 int color_pair_index
= 0;
111 int color_quad_index
= 0;
112 int color_octet_index
= 0;
114 /* make the palette available */
115 memcpy(s
->frame
.data
[1], s
->avctx
->palctrl
->palette
, AVPALETTE_SIZE
);
116 if (s
->avctx
->palctrl
->palette_changed
) {
117 s
->frame
.palette_has_changed
= 1;
118 s
->avctx
->palctrl
->palette_changed
= 0;
121 chunk_size
= BE_32(&s
->buf
[stream_ptr
]) & 0x00FFFFFF;
123 if (chunk_size
!= s
->size
)
124 av_log(s
->avctx
, AV_LOG_INFO
, "warning: MOV chunk size != encoded chunk size (%d != %d); using MOV chunk size\n",
125 chunk_size
, s
->size
);
127 chunk_size
= s
->size
;
128 total_blocks
= ((s
->avctx
->width
+ 3) / 4) * ((s
->avctx
->height
+ 3) / 4);
130 /* traverse through the blocks */
131 while (total_blocks
) {
133 /* make sure stream ptr hasn't gone out of bounds */
134 if (stream_ptr
> chunk_size
) {
135 av_log(s
->avctx
, AV_LOG_INFO
, "SMC decoder just went out of bounds (stream ptr = %d, chunk size = %d)\n",
136 stream_ptr
, chunk_size
);
139 /* make sure the row pointer hasn't gone wild */
140 if (row_ptr
>= image_size
) {
141 av_log(s
->avctx
, AV_LOG_INFO
, "SMC decoder just went out of bounds (row ptr = %d, height = %d)\n",
142 row_ptr
, image_size
);
146 opcode
= s
->buf
[stream_ptr
++];
147 switch (opcode
& 0xF0) {
151 n_blocks
= GET_BLOCK_COUNT();
157 /* repeat last block n times */
160 n_blocks
= GET_BLOCK_COUNT();
163 if ((row_ptr
== 0) && (pixel_ptr
== 0)) {
164 av_log(s
->avctx
, AV_LOG_INFO
, "encountered repeat block opcode (%02X) but no blocks rendered yet\n",
169 /* figure out where the previous block started */
172 (row_ptr
- s
->avctx
->width
* 4) + s
->avctx
->width
- 4;
174 prev_block_ptr1
= row_ptr
+ pixel_ptr
- 4;
177 block_ptr
= row_ptr
+ pixel_ptr
;
178 prev_block_ptr
= prev_block_ptr1
;
179 for (pixel_y
= 0; pixel_y
< 4; pixel_y
++) {
180 for (pixel_x
= 0; pixel_x
< 4; pixel_x
++) {
181 pixels
[block_ptr
++] = pixels
[prev_block_ptr
++];
183 block_ptr
+= row_inc
;
184 prev_block_ptr
+= row_inc
;
190 /* repeat previous pair of blocks n times */
193 n_blocks
= GET_BLOCK_COUNT();
197 if ((row_ptr
== 0) && (pixel_ptr
< 2 * 4)) {
198 av_log(s
->avctx
, AV_LOG_INFO
, "encountered repeat block opcode (%02X) but not enough blocks rendered yet\n",
203 /* figure out where the previous 2 blocks started */
205 prev_block_ptr1
= (row_ptr
- s
->avctx
->width
* 4) +
206 s
->avctx
->width
- 4 * 2;
207 else if (pixel_ptr
== 4)
208 prev_block_ptr1
= (row_ptr
- s
->avctx
->width
* 4) + row_inc
;
210 prev_block_ptr1
= row_ptr
+ pixel_ptr
- 4 * 2;
213 prev_block_ptr2
= (row_ptr
- s
->avctx
->width
* 4) + row_inc
;
215 prev_block_ptr2
= row_ptr
+ pixel_ptr
- 4;
219 block_ptr
= row_ptr
+ pixel_ptr
;
221 prev_block_ptr
= prev_block_ptr2
;
223 prev_block_ptr
= prev_block_ptr1
;
224 prev_block_flag
= !prev_block_flag
;
226 for (pixel_y
= 0; pixel_y
< 4; pixel_y
++) {
227 for (pixel_x
= 0; pixel_x
< 4; pixel_x
++) {
228 pixels
[block_ptr
++] = pixels
[prev_block_ptr
++];
230 block_ptr
+= row_inc
;
231 prev_block_ptr
+= row_inc
;
237 /* 1-color block encoding */
240 n_blocks
= GET_BLOCK_COUNT();
241 pixel
= s
->buf
[stream_ptr
++];
244 block_ptr
= row_ptr
+ pixel_ptr
;
245 for (pixel_y
= 0; pixel_y
< 4; pixel_y
++) {
246 for (pixel_x
= 0; pixel_x
< 4; pixel_x
++) {
247 pixels
[block_ptr
++] = pixel
;
249 block_ptr
+= row_inc
;
255 /* 2-color block encoding */
258 n_blocks
= (opcode
& 0x0F) + 1;
260 /* figure out which color pair to use to paint the 2-color block */
261 if ((opcode
& 0xF0) == 0x80) {
262 /* fetch the next 2 colors from bytestream and store in next
263 * available entry in the color pair table */
264 for (i
= 0; i
< CPAIR
; i
++) {
265 pixel
= s
->buf
[stream_ptr
++];
266 color_table_index
= CPAIR
* color_pair_index
+ i
;
267 s
->color_pairs
[color_table_index
] = pixel
;
269 /* this is the base index to use for this block */
270 color_table_index
= CPAIR
* color_pair_index
;
273 if (color_pair_index
== COLORS_PER_TABLE
)
274 color_pair_index
= 0;
276 color_table_index
= CPAIR
* s
->buf
[stream_ptr
++];
279 color_flags
= BE_16(&s
->buf
[stream_ptr
]);
282 block_ptr
= row_ptr
+ pixel_ptr
;
283 for (pixel_y
= 0; pixel_y
< 4; pixel_y
++) {
284 for (pixel_x
= 0; pixel_x
< 4; pixel_x
++) {
285 if (color_flags
& flag_mask
)
286 pixel
= color_table_index
+ 1;
288 pixel
= color_table_index
;
290 pixels
[block_ptr
++] = s
->color_pairs
[pixel
];
292 block_ptr
+= row_inc
;
298 /* 4-color block encoding */
301 n_blocks
= (opcode
& 0x0F) + 1;
303 /* figure out which color quad to use to paint the 4-color block */
304 if ((opcode
& 0xF0) == 0xA0) {
305 /* fetch the next 4 colors from bytestream and store in next
306 * available entry in the color quad table */
307 for (i
= 0; i
< CQUAD
; i
++) {
308 pixel
= s
->buf
[stream_ptr
++];
309 color_table_index
= CQUAD
* color_quad_index
+ i
;
310 s
->color_quads
[color_table_index
] = pixel
;
312 /* this is the base index to use for this block */
313 color_table_index
= CQUAD
* color_quad_index
;
316 if (color_quad_index
== COLORS_PER_TABLE
)
317 color_quad_index
= 0;
319 color_table_index
= CQUAD
* s
->buf
[stream_ptr
++];
322 color_flags
= BE_32(&s
->buf
[stream_ptr
]);
324 /* flag mask actually acts as a bit shift count here */
326 block_ptr
= row_ptr
+ pixel_ptr
;
327 for (pixel_y
= 0; pixel_y
< 4; pixel_y
++) {
328 for (pixel_x
= 0; pixel_x
< 4; pixel_x
++) {
329 pixel
= color_table_index
+
330 ((color_flags
>> flag_mask
) & 0x03);
332 pixels
[block_ptr
++] = s
->color_quads
[pixel
];
334 block_ptr
+= row_inc
;
340 /* 8-color block encoding */
343 n_blocks
= (opcode
& 0x0F) + 1;
345 /* figure out which color octet to use to paint the 8-color block */
346 if ((opcode
& 0xF0) == 0xC0) {
347 /* fetch the next 8 colors from bytestream and store in next
348 * available entry in the color octet table */
349 for (i
= 0; i
< COCTET
; i
++) {
350 pixel
= s
->buf
[stream_ptr
++];
351 color_table_index
= COCTET
* color_octet_index
+ i
;
352 s
->color_octets
[color_table_index
] = pixel
;
354 /* this is the base index to use for this block */
355 color_table_index
= COCTET
* color_octet_index
;
358 if (color_octet_index
== COLORS_PER_TABLE
)
359 color_octet_index
= 0;
361 color_table_index
= COCTET
* s
->buf
[stream_ptr
++];
365 For this input of 6 hex bytes:
367 Mangle it to this output:
368 flags_a = xx012456, flags_b = xx89A37B
370 /* build the color flags */
371 color_flags_a
= color_flags_b
= 0;
373 (s
->buf
[stream_ptr
+ 0] << 16) |
374 ((s
->buf
[stream_ptr
+ 1] & 0xF0) << 8) |
375 ((s
->buf
[stream_ptr
+ 2] & 0xF0) << 4) |
376 ((s
->buf
[stream_ptr
+ 2] & 0x0F) << 4) |
377 ((s
->buf
[stream_ptr
+ 3] & 0xF0) >> 4);
379 (s
->buf
[stream_ptr
+ 4] << 16) |
380 ((s
->buf
[stream_ptr
+ 5] & 0xF0) << 8) |
381 ((s
->buf
[stream_ptr
+ 1] & 0x0F) << 8) |
382 ((s
->buf
[stream_ptr
+ 3] & 0x0F) << 4) |
383 (s
->buf
[stream_ptr
+ 5] & 0x0F);
386 color_flags
= color_flags_a
;
387 /* flag mask actually acts as a bit shift count here */
389 block_ptr
= row_ptr
+ pixel_ptr
;
390 for (pixel_y
= 0; pixel_y
< 4; pixel_y
++) {
391 /* reload flags at third row (iteration pixel_y == 2) */
393 color_flags
= color_flags_b
;
396 for (pixel_x
= 0; pixel_x
< 4; pixel_x
++) {
397 pixel
= color_table_index
+
398 ((color_flags
>> flag_mask
) & 0x07);
400 pixels
[block_ptr
++] = s
->color_octets
[pixel
];
402 block_ptr
+= row_inc
;
408 /* 16-color block encoding (every pixel is a different color) */
410 n_blocks
= (opcode
& 0x0F) + 1;
413 block_ptr
= row_ptr
+ pixel_ptr
;
414 for (pixel_y
= 0; pixel_y
< 4; pixel_y
++) {
415 for (pixel_x
= 0; pixel_x
< 4; pixel_x
++) {
416 pixels
[block_ptr
++] = s
->buf
[stream_ptr
++];
418 block_ptr
+= row_inc
;
425 av_log(s
->avctx
, AV_LOG_INFO
, "0xF0 opcode seen in SMC chunk (contact the developers)\n");
431 static int smc_decode_init(AVCodecContext
*avctx
)
433 SmcContext
*s
= (SmcContext
*)avctx
->priv_data
;
436 avctx
->pix_fmt
= PIX_FMT_PAL8
;
437 avctx
->has_b_frames
= 0;
438 dsputil_init(&s
->dsp
, avctx
);
440 s
->frame
.data
[0] = NULL
;
445 static int smc_decode_frame(AVCodecContext
*avctx
,
446 void *data
, int *data_size
,
447 uint8_t *buf
, int buf_size
)
449 SmcContext
*s
= (SmcContext
*)avctx
->priv_data
;
454 s
->frame
.reference
= 1;
455 s
->frame
.buffer_hints
= FF_BUFFER_HINTS_VALID
| FF_BUFFER_HINTS_PRESERVE
|
456 FF_BUFFER_HINTS_REUSABLE
| FF_BUFFER_HINTS_READABLE
;
457 if (avctx
->reget_buffer(avctx
, &s
->frame
)) {
458 av_log(s
->avctx
, AV_LOG_ERROR
, "reget_buffer() failed\n");
462 smc_decode_stream(s
);
464 *data_size
= sizeof(AVFrame
);
465 *(AVFrame
*)data
= s
->frame
;
467 /* always report that the buffer was completely consumed */
471 static int smc_decode_end(AVCodecContext
*avctx
)
473 SmcContext
*s
= (SmcContext
*)avctx
->priv_data
;
475 if (s
->frame
.data
[0])
476 avctx
->release_buffer(avctx
, &s
->frame
);
481 AVCodec smc_decoder
= {