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/*
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 * Westwood Studios VQA Video Decoder
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 * Copyright (C) 2003 the ffmpeg project
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 *
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 * This library is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This library is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with this library; if not, write to the Free Software
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 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
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 *
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 */
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/**
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 * @file vqavideo.c
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 * VQA Video Decoder by Mike Melanson (melanson@pcisys.net)
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 * For more information about the RPZA format, visit:
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 *   http://www.pcisys.net/~melanson/codecs/
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 *
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 * The VQA video decoder outputs PAL8 or RGB555 colorspace data, depending
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 * on the type of data in the file.
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 *
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 * This decoder needs the 42-byte VQHD header from the beginning
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 * of the VQA file passed through the extradata field. The VQHD header
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 * is laid out as:
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 *
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 *   bytes 0-3   chunk fourcc: 'VQHD'
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 *   bytes 4-7   chunk size in big-endian format, should be 0x0000002A
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 *   bytes 8-49  VQHD chunk data
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 *
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 * Bytes 8-49 are what this decoder expects to see.
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 *
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 * Briefly, VQA is a vector quantized animation format that operates in a
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 * VGA palettized colorspace. It operates on pixel vectors (blocks)
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 * of either 4x2 or 4x4 in size. Compressed VQA chunks can contain vector
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 * codebooks, palette information, and code maps for rendering vectors onto
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 * frames. Any of these components can also be compressed with a run-length
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 * encoding (RLE) algorithm commonly referred to as "format80".
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 *
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 * VQA takes a novel approach to rate control. Each group of n frames
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 * (usually, n = 8) relies on a different vector codebook. Rather than
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 * transporting an entire codebook every 8th frame, the new codebook is
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 * broken up into 8 pieces and sent along with the compressed video chunks
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 * for each of the 8 frames preceding the 8 frames which require the
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 * codebook. A full codebook is also sent on the very first frame of a
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 * file. This is an interesting technique, although it makes random file
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 * seeking difficult despite the fact that the frames are all intracoded.
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 *
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 * V1,2 VQA uses 12-bit codebook indices. If the 12-bit indices were
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 * packed into bytes and then RLE compressed, bytewise, the results would
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 * be poor. That is why the coding method divides each index into 2 parts,
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 * the top 4 bits and the bottom 8 bits, then RL encodes the 4-bit pieces
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 * together and the 8-bit pieces together. If most of the vectors are
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 * clustered into one group of 256 vectors, most of the 4-bit index pieces
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 * should be the same.
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 */
64

    
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#include <stdio.h>
66
#include <stdlib.h>
67
#include <string.h>
68
#include <unistd.h>
69

    
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#include "common.h"
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#include "avcodec.h"
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#include "dsputil.h"
73

    
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#define PALETTE_COUNT 256
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#define VQA_HEADER_SIZE 0x2A
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#define CHUNK_PREAMBLE_SIZE 8
77

    
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/* allocate the maximum vector space, regardless of the file version:
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 * (0xFF00 codebook vectors + 0x100 solid pixel vectors) * (4x4 pixels/block) */
80
#define MAX_CODEBOOK_VECTORS 0xFF00
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#define SOLID_PIXEL_VECTORS 0x100
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#define MAX_VECTORS (MAX_CODEBOOK_VECTORS + SOLID_PIXEL_VECTORS)
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#define MAX_CODEBOOK_SIZE (MAX_VECTORS * 4 * 4)
84

    
85
#define CBF0_TAG MKBETAG('C', 'B', 'F', '0')
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#define CBFZ_TAG MKBETAG('C', 'B', 'F', 'Z')
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#define CBP0_TAG MKBETAG('C', 'B', 'P', '0')
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#define CBPZ_TAG MKBETAG('C', 'B', 'P', 'Z')
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#define CPL0_TAG MKBETAG('C', 'P', 'L', '0')
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#define CPLZ_TAG MKBETAG('C', 'P', 'L', 'Z')
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#define VPTZ_TAG MKBETAG('V', 'P', 'T', 'Z')
92

    
93
#define VQA_DEBUG 0
94

    
95
#if VQA_DEBUG
96
#define vqa_debug printf
97
#else
98
static inline void vqa_debug(const char *format, ...) { }
99
#endif
100

    
101
typedef struct VqaContext {
102

    
103
    AVCodecContext *avctx;
104
    DSPContext dsp;
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    AVFrame frame;
106

    
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    unsigned char *buf;
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    int size;
109

    
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    unsigned int palette[PALETTE_COUNT];
111

    
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    int width;   /* width of a frame */
113
    int height;   /* height of a frame */
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    int vector_width;  /* width of individual vector */
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    int vector_height;  /* height of individual vector */
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    int vqa_version;  /* this should be either 1, 2 or 3 */
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118
    unsigned char *codebook;         /* the current codebook */
119
    int codebook_size;
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    unsigned char *next_codebook_buffer;  /* accumulator for next codebook */
121
    int next_codebook_buffer_index;
122

    
123
    unsigned char *decode_buffer;
124
    int decode_buffer_size;
125

    
126
    /* number of frames to go before replacing codebook */
127
    int partial_countdown;
128
    int partial_count;
129

    
130
} VqaContext;
131

    
132
static int vqa_decode_init(AVCodecContext *avctx)
133
{
134
    VqaContext *s = (VqaContext *)avctx->priv_data;
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    unsigned char *vqa_header;
136
    int i, j, codebook_index;;
137

    
138
    s->avctx = avctx;
139
    avctx->pix_fmt = PIX_FMT_PAL8;
140
    avctx->has_b_frames = 0;
141
    dsputil_init(&s->dsp, avctx);
142

    
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);
146
        return -1;
147
    }
148

    
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
    s->vector_width = vqa_header[10];
155
    s->vector_height = vqa_header[11];
156
    s->partial_count = s->partial_countdown = vqa_header[13];
157

    
158
    /* the vector dimensions have to meet very stringent requirements */
159
    if ((s->vector_width != 4) ||
160
        ((s->vector_height != 2) && (s->vector_height != 4))) {
161
        /* return without further initialization */
162
        return -1;
163
    }
164

    
165
    /* allocate codebooks */
166
    s->codebook_size = MAX_CODEBOOK_SIZE;
167
    s->codebook = av_malloc(s->codebook_size);
168
    s->next_codebook_buffer = av_malloc(s->codebook_size);
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170
    /* initialize the solid-color vectors */
171
    if (s->vector_height == 4) {
172
        codebook_index = 0xFF00 * 16;
173
        for (i = 0; i < 256; i++)
174
            for (j = 0; j < 16; j++)
175
                s->codebook[codebook_index++] = i;
176
    } else {
177
        codebook_index = 0xF00 * 8;
178
        for (i = 0; i < 256; i++)
179
            for (j = 0; j < 8; j++)
180
                s->codebook[codebook_index++] = i;
181
    }
182
    s->next_codebook_buffer_index = 0;
183

    
184
    /* allocate decode buffer */
185
    s->decode_buffer_size = (s->width / s->vector_width) *
186
        (s->height / s->vector_height) * 2;
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    s->decode_buffer = av_malloc(s->decode_buffer_size);
188

    
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    s->frame.data[0] = NULL;
190

    
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    return 0;
192
}
193

    
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#define CHECK_COUNT() \
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    if (dest_index + count > dest_size) { \
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        av_log(NULL, AV_LOG_ERROR, "  VQA video: decode_format80 problem: next op would overflow dest_index\n"); \
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        av_log(NULL, AV_LOG_ERROR, "  VQA video: current dest_index = %d, count = %d, dest_size = %d\n", \
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            dest_index, count, dest_size); \
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        return; \
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    }
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static void decode_format80(unsigned char *src, int src_size,
203
    unsigned char *dest, int dest_size, int check_size) {
204

    
205
    int src_index = 0;
206
    int dest_index = 0;
207
    int count;
208
    int src_pos;
209
    unsigned char color;
210
    int i;
211

    
212
    while (src_index < src_size) {
213

    
214
        vqa_debug("      opcode %02X: ", src[src_index]);
215

    
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        /* 0x80 means that frame is finished */
217
        if (src[src_index] == 0x80)
218
            return;
219

    
220
        if (dest_index >= dest_size) {
221
            av_log(NULL, AV_LOG_ERROR, "  VQA video: decode_format80 problem: dest_index (%d) exceeded dest_size (%d)\n",
222
                dest_index, dest_size);
223
            return;
224
        }
225

    
226
        if (src[src_index] == 0xFF) {
227

    
228
            src_index++;
229
            count = LE_16(&src[src_index]);
230
            src_index += 2;
231
            src_pos = LE_16(&src[src_index]);
232
            src_index += 2;
233
            vqa_debug("(1) copy %X bytes from absolute pos %X\n", count, src_pos);
234
            CHECK_COUNT();
235
            for (i = 0; i < count; i++)
236
                dest[dest_index + i] = dest[src_pos + i];
237
            dest_index += count;
238

    
239
        } else if (src[src_index] == 0xFE) {
240

    
241
            src_index++;
242
            count = LE_16(&src[src_index]);
243
            src_index += 2;
244
            color = src[src_index++];
245
            vqa_debug("(2) set %X bytes to %02X\n", count, color);
246
            CHECK_COUNT();
247
            memset(&dest[dest_index], color, count);
248
            dest_index += count;
249

    
250
        } else if ((src[src_index] & 0xC0) == 0xC0) {
251

    
252
            count = (src[src_index++] & 0x3F) + 3;
253
            src_pos = LE_16(&src[src_index]);
254
            src_index += 2;
255
            vqa_debug("(3) copy %X bytes from absolute pos %X\n", count, src_pos);
256
            CHECK_COUNT();
257
            for (i = 0; i < count; i++)
258
                dest[dest_index + i] = dest[src_pos + i];
259
            dest_index += count;
260

    
261
        } else if (src[src_index] > 0x80) {
262

    
263
            count = src[src_index++] & 0x3F;
264
            vqa_debug("(4) copy %X bytes from source to dest\n", count);
265
            CHECK_COUNT();
266
            memcpy(&dest[dest_index], &src[src_index], count);
267
            src_index += count;
268
            dest_index += count;
269

    
270
        } else {
271

    
272
            count = ((src[src_index] & 0x70) >> 4) + 3;
273
            src_pos = BE_16(&src[src_index]) & 0x0FFF;
274
            src_index += 2;
275
            vqa_debug("(5) copy %X bytes from relpos %X\n", count, src_pos);
276
            CHECK_COUNT();
277
            for (i = 0; i < count; i++)
278
                dest[dest_index + i] = dest[dest_index - src_pos + i];
279
            dest_index += count;
280
        }
281
    }
282

    
283
    /* validate that the entire destination buffer was filled; this is
284
     * important for decoding frame maps since each vector needs to have a
285
     * codebook entry; it is not important for compressed codebooks because
286
     * not every entry needs to be filled */
287
    if (check_size)
288
        if (dest_index < dest_size)
289
            av_log(NULL, AV_LOG_ERROR, "  VQA video: decode_format80 problem: decode finished with dest_index (%d) < dest_size (%d)\n",
290
                dest_index, dest_size);
291
}
292

    
293
static void vqa_decode_chunk(VqaContext *s)
294
{
295
    unsigned int chunk_type;
296
    unsigned int chunk_size;
297
    int byte_skip;
298
    unsigned int index = 0;
299
    int i;
300
    unsigned char r, g, b;
301
    int index_shift;
302

    
303
    int cbf0_chunk = -1;
304
    int cbfz_chunk = -1;
305
    int cbp0_chunk = -1;
306
    int cbpz_chunk = -1;
307
    int cpl0_chunk = -1;
308
    int cplz_chunk = -1;
309
    int vptz_chunk = -1;
310

    
311
    int x, y;
312
    int lines = 0;
313
    int pixel_ptr;
314
    int vector_index = 0;
315
    int lobyte = 0;
316
    int hibyte = 0;
317
    int lobytes = 0;
318
    int hibytes = s->decode_buffer_size / 2;
319

    
320
    /* first, traverse through the frame and find the subchunks */
321
    while (index < s->size) {
322

    
323
        chunk_type = BE_32(&s->buf[index]);
324
        chunk_size = BE_32(&s->buf[index + 4]);
325

    
326
        switch (chunk_type) {
327

    
328
        case CBF0_TAG:
329
            cbf0_chunk = index;
330
            break;
331

    
332
        case CBFZ_TAG:
333
            cbfz_chunk = index;
334
            break;
335

    
336
        case CBP0_TAG:
337
            cbp0_chunk = index;
338
            break;
339

    
340
        case CBPZ_TAG:
341
            cbpz_chunk = index;
342
            break;
343

    
344
        case CPL0_TAG:
345
            cpl0_chunk = index;
346
            break;
347

    
348
        case CPLZ_TAG:
349
            cplz_chunk = index;
350
            break;
351

    
352
        case VPTZ_TAG:
353
            vptz_chunk = index;
354
            break;
355

    
356
        default:
357
            av_log(s->avctx, AV_LOG_ERROR, "  VQA video: Found unknown chunk type: %c%c%c%c (%08X)\n",
358
            (chunk_type >> 24) & 0xFF,
359
            (chunk_type >> 16) & 0xFF,
360
            (chunk_type >>  8) & 0xFF,
361
            (chunk_type >>  0) & 0xFF,
362
            chunk_type);
363
            break;
364
        }
365

    
366
        byte_skip = chunk_size & 0x01;
367
        index += (CHUNK_PREAMBLE_SIZE + chunk_size + byte_skip);
368
    }
369

    
370
    /* next, deal with the palette */
371
    if ((cpl0_chunk != -1) && (cplz_chunk != -1)) {
372

    
373
        /* a chunk should not have both chunk types */
374
        av_log(s->avctx, AV_LOG_ERROR, "  VQA video: problem: found both CPL0 and CPLZ chunks\n");
375
        return;
376
    }
377

    
378
    /* decompress the palette chunk */
379
    if (cplz_chunk != -1) {
380

    
381
/* yet to be handled */
382

    
383
    }
384

    
385
    /* convert the RGB palette into the machine's endian format */
386
    if (cpl0_chunk != -1) {
387

    
388
        chunk_size = BE_32(&s->buf[cpl0_chunk + 4]);
389
        /* sanity check the palette size */
390
        if (chunk_size / 3 > 256) {
391
            av_log(s->avctx, AV_LOG_ERROR, "  VQA video: problem: found a palette chunk with %d colors\n",
392
                chunk_size / 3);
393
            return;
394
        }
395
        cpl0_chunk += CHUNK_PREAMBLE_SIZE;
396
        for (i = 0; i < chunk_size / 3; i++) {
397
            /* scale by 4 to transform 6-bit palette -> 8-bit */
398
            r = s->buf[cpl0_chunk++] * 4;
399
            g = s->buf[cpl0_chunk++] * 4;
400
            b = s->buf[cpl0_chunk++] * 4;
401
            s->palette[i] = (r << 16) | (g << 8) | (b);
402
        }
403
    }
404

    
405
    /* next, look for a full codebook */
406
    if ((cbf0_chunk != -1) && (cbfz_chunk != -1)) {
407

    
408
        /* a chunk should not have both chunk types */
409
        av_log(s->avctx, AV_LOG_ERROR, "  VQA video: problem: found both CBF0 and CBFZ chunks\n");
410
        return;
411
    }
412

    
413
    /* decompress the full codebook chunk */
414
    if (cbfz_chunk != -1) {
415

    
416
        chunk_size = BE_32(&s->buf[cbfz_chunk + 4]);
417
        cbfz_chunk += CHUNK_PREAMBLE_SIZE;
418
        decode_format80(&s->buf[cbfz_chunk], chunk_size,
419
            s->codebook, s->codebook_size, 0);
420
    }
421

    
422
    /* copy a full codebook */
423
    if (cbf0_chunk != -1) {
424

    
425
        chunk_size = BE_32(&s->buf[cbf0_chunk + 4]);
426
        /* sanity check the full codebook size */
427
        if (chunk_size > MAX_CODEBOOK_SIZE) {
428
            av_log(s->avctx, AV_LOG_ERROR, "  VQA video: problem: CBF0 chunk too large (0x%X bytes)\n",
429
                chunk_size);
430
            return;
431
        }
432
        cbf0_chunk += CHUNK_PREAMBLE_SIZE;
433

    
434
        memcpy(s->codebook, &s->buf[cbf0_chunk], chunk_size);
435
    }
436

    
437
    /* decode the frame */
438
    if (vptz_chunk == -1) {
439

    
440
        /* something is wrong if there is no VPTZ chunk */
441
        av_log(s->avctx, AV_LOG_ERROR, "  VQA video: problem: no VPTZ chunk found\n");
442
        return;
443
    }
444

    
445
    chunk_size = BE_32(&s->buf[vptz_chunk + 4]);
446
    vptz_chunk += CHUNK_PREAMBLE_SIZE;
447
    decode_format80(&s->buf[vptz_chunk], chunk_size,
448
        s->decode_buffer, s->decode_buffer_size, 1);
449

    
450
    /* render the final PAL8 frame */
451
    if (s->vector_height == 4)
452
        index_shift = 4;
453
    else
454
        index_shift = 3;
455
    for (y = 0; y < s->frame.linesize[0] * s->height; 
456
        y += s->frame.linesize[0] * s->vector_height) {
457

    
458
        for (x = y; x < y + s->width; x += 4, lobytes++, hibytes++) {
459
            pixel_ptr = x;
460

    
461
            /* get the vector index, the method for which varies according to
462
             * VQA file version */
463
            switch (s->vqa_version) {
464

    
465
            case 1:
466
/* still need sample media for this case (only one game, "Legend of 
467
 * Kyrandia III : Malcolm's Revenge", is known to use this version) */
468
                lines = 0;
469
                break;
470

    
471
            case 2:
472
                lobyte = s->decode_buffer[lobytes];
473
                hibyte = s->decode_buffer[hibytes];
474
                vector_index = (hibyte << 8) | lobyte;
475
                vector_index <<= index_shift;
476
                lines = s->vector_height;
477
                break;
478

    
479
            case 3:
480
/* not implemented yet */
481
                lines = 0;
482
                break;
483
            }
484

    
485
            while (lines--) {
486
                s->frame.data[0][pixel_ptr + 0] = s->codebook[vector_index++];
487
                s->frame.data[0][pixel_ptr + 1] = s->codebook[vector_index++];
488
                s->frame.data[0][pixel_ptr + 2] = s->codebook[vector_index++];
489
                s->frame.data[0][pixel_ptr + 3] = s->codebook[vector_index++];
490
                pixel_ptr += s->frame.linesize[0];
491
            }
492
        }
493
    }
494

    
495
    /* handle partial codebook */
496
    if ((cbp0_chunk != -1) && (cbpz_chunk != -1)) {
497
        /* a chunk should not have both chunk types */
498
        av_log(s->avctx, AV_LOG_ERROR, "  VQA video: problem: found both CBP0 and CBPZ chunks\n");
499
        return;
500
    }
501

    
502
    if (cbp0_chunk != -1) {
503

    
504
        chunk_size = BE_32(&s->buf[cbp0_chunk + 4]);
505
        cbp0_chunk += CHUNK_PREAMBLE_SIZE;
506

    
507
        /* accumulate partial codebook */
508
        memcpy(&s->next_codebook_buffer[s->next_codebook_buffer_index],
509
            &s->buf[cbp0_chunk], chunk_size);
510
        s->next_codebook_buffer_index += chunk_size;
511

    
512
        s->partial_countdown--;
513
        if (s->partial_countdown == 0) {
514

    
515
            /* time to replace codebook */
516
            memcpy(s->codebook, s->next_codebook_buffer, 
517
                s->next_codebook_buffer_index);
518

    
519
            /* reset accounting */
520
            s->next_codebook_buffer_index = 0;
521
            s->partial_countdown = s->partial_count;
522
        }
523
    }
524

    
525
    if (cbpz_chunk != -1) {
526

    
527
        chunk_size = BE_32(&s->buf[cbpz_chunk + 4]);
528
        cbpz_chunk += CHUNK_PREAMBLE_SIZE;
529

    
530
        /* accumulate partial codebook */
531
        memcpy(&s->next_codebook_buffer[s->next_codebook_buffer_index],
532
            &s->buf[cbpz_chunk], chunk_size);
533
        s->next_codebook_buffer_index += chunk_size;
534

    
535
        s->partial_countdown--;
536
        if (s->partial_countdown == 0) {
537

    
538
            /* decompress codebook */
539
            decode_format80(s->next_codebook_buffer, 
540
                s->next_codebook_buffer_index, 
541
                s->codebook, s->codebook_size, 0);
542

    
543
            /* reset accounting */
544
            s->next_codebook_buffer_index = 0;
545
            s->partial_countdown = s->partial_count;
546
        }
547
    }
548
}
549

    
550
static int vqa_decode_frame(AVCodecContext *avctx,
551
                            void *data, int *data_size,
552
                            uint8_t *buf, int buf_size)
553
{
554
    VqaContext *s = (VqaContext *)avctx->priv_data;
555

    
556
    s->buf = buf;
557
    s->size = buf_size;
558

    
559
    if (s->frame.data[0])
560
        avctx->release_buffer(avctx, &s->frame);
561

    
562
    if (avctx->get_buffer(avctx, &s->frame)) {
563
        av_log(s->avctx, AV_LOG_ERROR, "  VQA Video: get_buffer() failed\n");
564
        return -1;
565
    }
566

    
567
    vqa_decode_chunk(s);
568

    
569
    /* make the palette available on the way out */
570
    memcpy(s->frame.data[1], s->palette, PALETTE_COUNT * 4);
571
    s->frame.palette_has_changed = 1;
572

    
573
    *data_size = sizeof(AVFrame);
574
    *(AVFrame*)data = s->frame;
575

    
576
    /* report that the buffer was completely consumed */
577
    return buf_size;
578
}
579

    
580
static int vqa_decode_end(AVCodecContext *avctx)
581
{
582
    VqaContext *s = (VqaContext *)avctx->priv_data;
583

    
584
    av_free(s->codebook);
585
    av_free(s->next_codebook_buffer);
586
    av_free(s->decode_buffer);
587

    
588
    if (s->frame.data[0])
589
        avctx->release_buffer(avctx, &s->frame);
590

    
591
    return 0;
592
}
593

    
594
AVCodec vqa_decoder = {
595
    "vqavideo",
596
    CODEC_TYPE_VIDEO,
597
    CODEC_ID_WS_VQA,
598
    sizeof(VqaContext),
599
    vqa_decode_init,
600
    NULL,
601
    vqa_decode_end,
602
    vqa_decode_frame,
603
    CODEC_CAP_DR1,
604
};