2
* Westwood Studios VQA 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23
* VQA Video Decoder by Mike Melanson (melanson@pcisys.net)
24
* For more information about the RPZA format, visit:
25
* http://www.pcisys.net/~melanson/codecs/
27
* The VQA video decoder outputs PAL8 or RGB555 colorspace data, depending
28
* on the type of data in the file.
30
* This decoder needs the 42-byte VQHD header from the beginning
31
* of the VQA file passed through the extradata field. The VQHD header
34
* bytes 0-3 chunk fourcc: 'VQHD'
35
* bytes 4-7 chunk size in big-endian format, should be 0x0000002A
36
* bytes 8-49 VQHD chunk data
38
* Bytes 8-49 are what this decoder expects to see.
40
* Briefly, VQA is a vector quantized animation format that operates in a
41
* VGA palettized colorspace. It operates on pixel vectors (blocks)
42
* of either 4x2 or 4x4 in size. Compressed VQA chunks can contain vector
43
* codebooks, palette information, and code maps for rendering vectors onto
44
* frames. Any of these components can also be compressed with a run-length
45
* encoding (RLE) algorithm commonly referred to as "format80".
47
* VQA takes a novel approach to rate control. Each group of n frames
48
* (usually, n = 8) relies on a different vector codebook. Rather than
49
* transporting an entire codebook every 8th frame, the new codebook is
50
* broken up into 8 pieces and sent along with the compressed video chunks
51
* for each of the 8 frames preceding the 8 frames which require the
52
* codebook. A full codebook is also sent on the very first frame of a
53
* file. This is an interesting technique, although it makes random file
54
* seeking difficult despite the fact that the frames are all intracoded.
56
* V1,2 VQA uses 12-bit codebook indices. If the 12-bit indices were
57
* packed into bytes and then RLE compressed, bytewise, the results would
58
* be poor. That is why the coding method divides each index into 2 parts,
59
* the top 4 bits and the bottom 8 bits, then RL encodes the 4-bit pieces
60
* together and the 8-bit pieces together. If most of the vectors are
61
* clustered into one group of 256 vectors, most of the 4-bit index pieces
74
#define PALETTE_COUNT 256
75
#define VQA_HEADER_SIZE 0x2A
76
#define CHUNK_PREAMBLE_SIZE 8
78
/* allocate the maximum vector space, regardless of the file version:
79
* (0xFF00 codebook vectors + 0x100 solid pixel vectors) * (4x4 pixels/block) */
80
#define MAX_CODEBOOK_VECTORS 0xFF00
81
#define SOLID_PIXEL_VECTORS 0x100
82
#define MAX_VECTORS (MAX_CODEBOOK_VECTORS + SOLID_PIXEL_VECTORS)
83
#define MAX_CODEBOOK_SIZE (MAX_VECTORS * 4 * 4)
85
#define CBF0_TAG MKBETAG('C', 'B', 'F', '0')
86
#define CBFZ_TAG MKBETAG('C', 'B', 'F', 'Z')
87
#define CBP0_TAG MKBETAG('C', 'B', 'P', '0')
88
#define CBPZ_TAG MKBETAG('C', 'B', 'P', 'Z')
89
#define CPL0_TAG MKBETAG('C', 'P', 'L', '0')
90
#define CPLZ_TAG MKBETAG('C', 'P', 'L', 'Z')
91
#define VPTZ_TAG MKBETAG('V', 'P', 'T', 'Z')
96
#define vqa_debug printf
98
static inline void vqa_debug(const char *format, ...) { }
101
typedef struct VqaContext {
103
AVCodecContext *avctx;
110
unsigned int palette[PALETTE_COUNT];
112
int width; /* width of a frame */
113
int height; /* height of a frame */
114
int vector_width; /* width of individual vector */
115
int vector_height; /* height of individual vector */
116
int vqa_version; /* this should be either 1, 2 or 3 */
118
unsigned char *codebook; /* the current codebook */
120
unsigned char *next_codebook_buffer; /* accumulator for next codebook */
121
int next_codebook_buffer_index;
123
unsigned char *decode_buffer;
124
int decode_buffer_size;
126
/* number of frames to go before replacing codebook */
127
int partial_countdown;
132
static int vqa_decode_init(AVCodecContext *avctx)
134
VqaContext *s = (VqaContext *)avctx->priv_data;
135
unsigned char *vqa_header;
136
int i, j, codebook_index;;
139
avctx->pix_fmt = PIX_FMT_PAL8;
140
avctx->has_b_frames = 0;
141
dsputil_init(&s->dsp, avctx);
143
/* make sure the extradata made it */
144
if (s->avctx->extradata_size != VQA_HEADER_SIZE) {
145
av_log(s->avctx, AV_LOG_ERROR, " VQA video: expected extradata size of %d\n", VQA_HEADER_SIZE);
149
/* load up the VQA parameters from the header */
150
vqa_header = (unsigned char *)s->avctx->extradata;
151
s->vqa_version = vqa_header[0];
152
s->width = LE_16(&vqa_header[6]);
153
s->height = LE_16(&vqa_header[8]);
154
if(avcodec_check_dimensions(avctx, s->width, s->height)){
155
s->width= s->height= 0;
158
s->vector_width = vqa_header[10];
159
s->vector_height = vqa_header[11];
160
s->partial_count = s->partial_countdown = vqa_header[13];
162
/* the vector dimensions have to meet very stringent requirements */
163
if ((s->vector_width != 4) ||
164
((s->vector_height != 2) && (s->vector_height != 4))) {
165
/* return without further initialization */
169
/* allocate codebooks */
170
s->codebook_size = MAX_CODEBOOK_SIZE;
171
s->codebook = av_malloc(s->codebook_size);
172
s->next_codebook_buffer = av_malloc(s->codebook_size);
174
/* initialize the solid-color vectors */
175
if (s->vector_height == 4) {
176
codebook_index = 0xFF00 * 16;
177
for (i = 0; i < 256; i++)
178
for (j = 0; j < 16; j++)
179
s->codebook[codebook_index++] = i;
181
codebook_index = 0xF00 * 8;
182
for (i = 0; i < 256; i++)
183
for (j = 0; j < 8; j++)
184
s->codebook[codebook_index++] = i;
186
s->next_codebook_buffer_index = 0;
188
/* allocate decode buffer */
189
s->decode_buffer_size = (s->width / s->vector_width) *
190
(s->height / s->vector_height) * 2;
191
s->decode_buffer = av_malloc(s->decode_buffer_size);
193
s->frame.data[0] = NULL;
198
#define CHECK_COUNT() \
199
if (dest_index + count > dest_size) { \
200
av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: next op would overflow dest_index\n"); \
201
av_log(NULL, AV_LOG_ERROR, " VQA video: current dest_index = %d, count = %d, dest_size = %d\n", \
202
dest_index, count, dest_size); \
206
static void decode_format80(unsigned char *src, int src_size,
207
unsigned char *dest, int dest_size, int check_size) {
216
while (src_index < src_size) {
218
vqa_debug(" opcode %02X: ", src[src_index]);
220
/* 0x80 means that frame is finished */
221
if (src[src_index] == 0x80)
224
if (dest_index >= dest_size) {
225
av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: dest_index (%d) exceeded dest_size (%d)\n",
226
dest_index, dest_size);
230
if (src[src_index] == 0xFF) {
233
count = LE_16(&src[src_index]);
235
src_pos = LE_16(&src[src_index]);
237
vqa_debug("(1) copy %X bytes from absolute pos %X\n", count, src_pos);
239
for (i = 0; i < count; i++)
240
dest[dest_index + i] = dest[src_pos + i];
243
} else if (src[src_index] == 0xFE) {
246
count = LE_16(&src[src_index]);
248
color = src[src_index++];
249
vqa_debug("(2) set %X bytes to %02X\n", count, color);
251
memset(&dest[dest_index], color, count);
254
} else if ((src[src_index] & 0xC0) == 0xC0) {
256
count = (src[src_index++] & 0x3F) + 3;
257
src_pos = LE_16(&src[src_index]);
259
vqa_debug("(3) copy %X bytes from absolute pos %X\n", count, src_pos);
261
for (i = 0; i < count; i++)
262
dest[dest_index + i] = dest[src_pos + i];
265
} else if (src[src_index] > 0x80) {
267
count = src[src_index++] & 0x3F;
268
vqa_debug("(4) copy %X bytes from source to dest\n", count);
270
memcpy(&dest[dest_index], &src[src_index], count);
276
count = ((src[src_index] & 0x70) >> 4) + 3;
277
src_pos = BE_16(&src[src_index]) & 0x0FFF;
279
vqa_debug("(5) copy %X bytes from relpos %X\n", count, src_pos);
281
for (i = 0; i < count; i++)
282
dest[dest_index + i] = dest[dest_index - src_pos + i];
287
/* validate that the entire destination buffer was filled; this is
288
* important for decoding frame maps since each vector needs to have a
289
* codebook entry; it is not important for compressed codebooks because
290
* not every entry needs to be filled */
292
if (dest_index < dest_size)
293
av_log(NULL, AV_LOG_ERROR, " VQA video: decode_format80 problem: decode finished with dest_index (%d) < dest_size (%d)\n",
294
dest_index, dest_size);
297
static void vqa_decode_chunk(VqaContext *s)
299
unsigned int chunk_type;
300
unsigned int chunk_size;
302
unsigned int index = 0;
304
unsigned char r, g, b;
318
int vector_index = 0;
322
int hibytes = s->decode_buffer_size / 2;
324
/* first, traverse through the frame and find the subchunks */
325
while (index < s->size) {
327
chunk_type = BE_32(&s->buf[index]);
328
chunk_size = BE_32(&s->buf[index + 4]);
330
switch (chunk_type) {
361
av_log(s->avctx, AV_LOG_ERROR, " VQA video: Found unknown chunk type: %c%c%c%c (%08X)\n",
362
(chunk_type >> 24) & 0xFF,
363
(chunk_type >> 16) & 0xFF,
364
(chunk_type >> 8) & 0xFF,
365
(chunk_type >> 0) & 0xFF,
370
byte_skip = chunk_size & 0x01;
371
index += (CHUNK_PREAMBLE_SIZE + chunk_size + byte_skip);
374
/* next, deal with the palette */
375
if ((cpl0_chunk != -1) && (cplz_chunk != -1)) {
377
/* a chunk should not have both chunk types */
378
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CPL0 and CPLZ chunks\n");
382
/* decompress the palette chunk */
383
if (cplz_chunk != -1) {
385
/* yet to be handled */
389
/* convert the RGB palette into the machine's endian format */
390
if (cpl0_chunk != -1) {
392
chunk_size = BE_32(&s->buf[cpl0_chunk + 4]);
393
/* sanity check the palette size */
394
if (chunk_size / 3 > 256) {
395
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found a palette chunk with %d colors\n",
399
cpl0_chunk += CHUNK_PREAMBLE_SIZE;
400
for (i = 0; i < chunk_size / 3; i++) {
401
/* scale by 4 to transform 6-bit palette -> 8-bit */
402
r = s->buf[cpl0_chunk++] * 4;
403
g = s->buf[cpl0_chunk++] * 4;
404
b = s->buf[cpl0_chunk++] * 4;
405
s->palette[i] = (r << 16) | (g << 8) | (b);
409
/* next, look for a full codebook */
410
if ((cbf0_chunk != -1) && (cbfz_chunk != -1)) {
412
/* a chunk should not have both chunk types */
413
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CBF0 and CBFZ chunks\n");
417
/* decompress the full codebook chunk */
418
if (cbfz_chunk != -1) {
420
chunk_size = BE_32(&s->buf[cbfz_chunk + 4]);
421
cbfz_chunk += CHUNK_PREAMBLE_SIZE;
422
decode_format80(&s->buf[cbfz_chunk], chunk_size,
423
s->codebook, s->codebook_size, 0);
426
/* copy a full codebook */
427
if (cbf0_chunk != -1) {
429
chunk_size = BE_32(&s->buf[cbf0_chunk + 4]);
430
/* sanity check the full codebook size */
431
if (chunk_size > MAX_CODEBOOK_SIZE) {
432
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: CBF0 chunk too large (0x%X bytes)\n",
436
cbf0_chunk += CHUNK_PREAMBLE_SIZE;
438
memcpy(s->codebook, &s->buf[cbf0_chunk], chunk_size);
441
/* decode the frame */
442
if (vptz_chunk == -1) {
444
/* something is wrong if there is no VPTZ chunk */
445
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: no VPTZ chunk found\n");
449
chunk_size = BE_32(&s->buf[vptz_chunk + 4]);
450
vptz_chunk += CHUNK_PREAMBLE_SIZE;
451
decode_format80(&s->buf[vptz_chunk], chunk_size,
452
s->decode_buffer, s->decode_buffer_size, 1);
454
/* render the final PAL8 frame */
455
if (s->vector_height == 4)
459
for (y = 0; y < s->frame.linesize[0] * s->height;
460
y += s->frame.linesize[0] * s->vector_height) {
462
for (x = y; x < y + s->width; x += 4, lobytes++, hibytes++) {
465
/* get the vector index, the method for which varies according to
466
* VQA file version */
467
switch (s->vqa_version) {
470
/* still need sample media for this case (only one game, "Legend of
471
* Kyrandia III : Malcolm's Revenge", is known to use this version) */
476
lobyte = s->decode_buffer[lobytes];
477
hibyte = s->decode_buffer[hibytes];
478
vector_index = (hibyte << 8) | lobyte;
479
vector_index <<= index_shift;
480
lines = s->vector_height;
484
/* not implemented yet */
490
s->frame.data[0][pixel_ptr + 0] = s->codebook[vector_index++];
491
s->frame.data[0][pixel_ptr + 1] = s->codebook[vector_index++];
492
s->frame.data[0][pixel_ptr + 2] = s->codebook[vector_index++];
493
s->frame.data[0][pixel_ptr + 3] = s->codebook[vector_index++];
494
pixel_ptr += s->frame.linesize[0];
499
/* handle partial codebook */
500
if ((cbp0_chunk != -1) && (cbpz_chunk != -1)) {
501
/* a chunk should not have both chunk types */
502
av_log(s->avctx, AV_LOG_ERROR, " VQA video: problem: found both CBP0 and CBPZ chunks\n");
506
if (cbp0_chunk != -1) {
508
chunk_size = BE_32(&s->buf[cbp0_chunk + 4]);
509
cbp0_chunk += CHUNK_PREAMBLE_SIZE;
511
/* accumulate partial codebook */
512
memcpy(&s->next_codebook_buffer[s->next_codebook_buffer_index],
513
&s->buf[cbp0_chunk], chunk_size);
514
s->next_codebook_buffer_index += chunk_size;
516
s->partial_countdown--;
517
if (s->partial_countdown == 0) {
519
/* time to replace codebook */
520
memcpy(s->codebook, s->next_codebook_buffer,
521
s->next_codebook_buffer_index);
523
/* reset accounting */
524
s->next_codebook_buffer_index = 0;
525
s->partial_countdown = s->partial_count;
529
if (cbpz_chunk != -1) {
531
chunk_size = BE_32(&s->buf[cbpz_chunk + 4]);
532
cbpz_chunk += CHUNK_PREAMBLE_SIZE;
534
/* accumulate partial codebook */
535
memcpy(&s->next_codebook_buffer[s->next_codebook_buffer_index],
536
&s->buf[cbpz_chunk], chunk_size);
537
s->next_codebook_buffer_index += chunk_size;
539
s->partial_countdown--;
540
if (s->partial_countdown == 0) {
542
/* decompress codebook */
543
decode_format80(s->next_codebook_buffer,
544
s->next_codebook_buffer_index,
545
s->codebook, s->codebook_size, 0);
547
/* reset accounting */
548
s->next_codebook_buffer_index = 0;
549
s->partial_countdown = s->partial_count;
554
static int vqa_decode_frame(AVCodecContext *avctx,
555
void *data, int *data_size,
556
uint8_t *buf, int buf_size)
558
VqaContext *s = (VqaContext *)avctx->priv_data;
563
if (s->frame.data[0])
564
avctx->release_buffer(avctx, &s->frame);
566
if (avctx->get_buffer(avctx, &s->frame)) {
567
av_log(s->avctx, AV_LOG_ERROR, " VQA Video: get_buffer() failed\n");
573
/* make the palette available on the way out */
574
memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);
575
s->frame.palette_has_changed = 1;
577
*data_size = sizeof(AVFrame);
578
*(AVFrame*)data = s->frame;
580
/* report that the buffer was completely consumed */
584
static int vqa_decode_end(AVCodecContext *avctx)
586
VqaContext *s = (VqaContext *)avctx->priv_data;
588
av_free(s->codebook);
589
av_free(s->next_codebook_buffer);
590
av_free(s->decode_buffer);
592
if (s->frame.data[0])
593
avctx->release_buffer(avctx, &s->frame);
598
AVCodec vqa_decoder = {