3 * Copyright (c) 2003 Michael Niedermayer
5 * This file is part of Libav.
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 #include "libavutil/intreadwrite.h"
29 #include "bytestream.h"
37 #define BLOCK_TYPE_VLC_BITS 5
38 #define ACDC_VLC_BITS 9
40 #define CFRAME_BUFFER_COUNT 100
42 static const uint8_t block_type_tab[2][4][8][2] = {
44 { // { 8, 4, 2 } x { 8, 4, 2}
45 { 0, 1 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 30, 5 }, { 31, 5 }, { 0, 0 }
47 { 0, 1 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }
49 { 0, 1 }, { 2, 2 }, { 0, 0 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }
51 { 0, 1 }, { 0, 0 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }
54 { // { 8, 4, 2 } x { 8, 4, 2}
55 { 1, 2 }, { 4, 3 }, { 5, 3 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }
57 { 1, 2 }, { 0, 0 }, { 2, 2 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }
59 { 1, 2 }, { 2, 2 }, { 0, 0 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }
61 { 1, 2 }, { 0, 0 }, { 0, 0 }, { 0, 2 }, { 2, 2 }, { 6, 3 }, { 7, 3 }
66 static const uint8_t size2index[4][4] = {
73 static const int8_t mv[256][2] = {
74 { 0, 0 }, { 0, -1 }, { -1, 0 }, { 1, 0 }, { 0, 1 }, { -1, -1 }, { 1, -1 }, { -1, 1 },
75 { 1, 1 }, { 0, -2 }, { -2, 0 }, { 2, 0 }, { 0, 2 }, { -1, -2 }, { 1, -2 }, { -2, -1 },
76 { 2, -1 }, { -2, 1 }, { 2, 1 }, { -1, 2 }, { 1, 2 }, { -2, -2 }, { 2, -2 }, { -2, 2 },
77 { 2, 2 }, { 0, -3 }, { -3, 0 }, { 3, 0 }, { 0, 3 }, { -1, -3 }, { 1, -3 }, { -3, -1 },
78 { 3, -1 }, { -3, 1 }, { 3, 1 }, { -1, 3 }, { 1, 3 }, { -2, -3 }, { 2, -3 }, { -3, -2 },
79 { 3, -2 }, { -3, 2 }, { 3, 2 }, { -2, 3 }, { 2, 3 }, { 0, -4 }, { -4, 0 }, { 4, 0 },
80 { 0, 4 }, { -1, -4 }, { 1, -4 }, { -4, -1 }, { 4, -1 }, { 4, 1 }, { -1, 4 }, { 1, 4 },
81 { -3, -3 }, { -3, 3 }, { 3, 3 }, { -2, -4 }, { -4, -2 }, { 4, -2 }, { -4, 2 }, { -2, 4 },
82 { 2, 4 }, { -3, -4 }, { 3, -4 }, { 4, -3 }, { -5, 0 }, { -4, 3 }, { -3, 4 }, { 3, 4 },
83 { -1, -5 }, { -5, -1 }, { -5, 1 }, { -1, 5 }, { -2, -5 }, { 2, -5 }, { 5, -2 }, { 5, 2 },
84 { -4, -4 }, { -4, 4 }, { -3, -5 }, { -5, -3 }, { -5, 3 }, { 3, 5 }, { -6, 0 }, { 0, 6 },
85 { -6, -1 }, { -6, 1 }, { 1, 6 }, { 2, -6 }, { -6, 2 }, { 2, 6 }, { -5, -4 }, { 5, 4 },
86 { 4, 5 }, { -6, -3 }, { 6, 3 }, { -7, 0 }, { -1, -7 }, { 5, -5 }, { -7, 1 }, { -1, 7 },
87 { 4, -6 }, { 6, 4 }, { -2, -7 }, { -7, 2 }, { -3, -7 }, { 7, -3 }, { 3, 7 }, { 6, -5 },
88 { 0, -8 }, { -1, -8 }, { -7, -4 }, { -8, 1 }, { 4, 7 }, { 2, -8 }, { -2, 8 }, { 6, 6 },
89 { -8, 3 }, { 5, -7 }, { -5, 7 }, { 8, -4 }, { 0, -9 }, { -9, -1 }, { 1, 9 }, { 7, -6 },
90 { -7, 6 }, { -5, -8 }, { -5, 8 }, { -9, 3 }, { 9, -4 }, { 7, -7 }, { 8, -6 }, { 6, 8 },
91 { 10, 1 }, { -10, 2 }, { 9, -5 }, { 10, -3 }, { -8, -7 }, { -10, -4 }, { 6, -9 }, { -11, 0 },
92 { 11, 1 }, { -11, -2 }, { -2, 11 }, { 7, -9 }, { -7, 9 }, { 10, 6 }, { -4, 11 }, { 8, -9 },
93 { 8, 9 }, { 5, 11 }, { 7, -10 }, { 12, -3 }, { 11, 6 }, { -9, -9 }, { 8, 10 }, { 5, 12 },
94 { -11, 7 }, { 13, 2 }, { 6, -12 }, { 10, 9 }, { -11, 8 }, { -7, 12 }, { 0, 14 }, { 14, -2 },
95 { -9, 11 }, { -6, 13 }, { -14, -4 }, { -5, -14 }, { 5, 14 }, { -15, -1 }, { -14, -6 }, { 3, -15 },
96 { 11, -11 }, { -7, 14 }, { -5, 15 }, { 8, -14 }, { 15, 6 }, { 3, 16 }, { 7, -15 }, { -16, 5 },
97 { 0, 17 }, { -16, -6 }, { -10, 14 }, { -16, 7 }, { 12, 13 }, { -16, 8 }, { -17, 6 }, { -18, 3 },
98 { -7, 17 }, { 15, 11 }, { 16, 10 }, { 2, -19 }, { 3, -19 }, { -11, -16 }, { -18, 8 }, { -19, -6 },
99 { 2, -20 }, { -17, -11 }, { -10, -18 }, { 8, 19 }, { -21, -1 }, { -20, 7 }, { -4, 21 }, { 21, 5 },
100 { 15, 16 }, { 2, -22 }, { -10, -20 }, { -22, 5 }, { 20, -11 }, { -7, -22 }, { -12, 20 }, { 23, -5 },
101 { 13, -20 }, { 24, -2 }, { -15, 19 }, { -11, 22 }, { 16, 19 }, { 23, -10 }, { -18, -18 }, { -9, -24 },
102 { 24, -10 }, { -3, 26 }, { -23, 13 }, { -18, -20 }, { 17, 21 }, { -4, 27 }, { 27, 6 }, { 1, -28 },
103 { -11, 26 }, { -17, -23 }, { 7, 28 }, { 11, -27 }, { 29, 5 }, { -23, -19 }, { -28, -11 }, { -21, 22 },
104 { -30, 7 }, { -17, 26 }, { -27, 16 }, { 13, 29 }, { 19, -26 }, { 10, -31 }, { -14, -30 }, { 20, -27 },
105 { -29, 18 }, { -16, -31 }, { -28, -22 }, { 21, -30 }, { -25, 28 }, { 26, -29 }, { 25, -32 }, { -32, -32 }
108 /* This is simply the scaled down elementwise product of the standard JPEG
109 * quantizer table and the AAN premul table. */
110 static const uint8_t dequant_table[64] = {
111 16, 15, 13, 19, 24, 31, 28, 17,
112 17, 23, 25, 31, 36, 63, 45, 21,
113 18, 24, 27, 37, 52, 59, 49, 20,
114 16, 28, 34, 40, 60, 80, 51, 20,
115 18, 31, 48, 66, 68, 86, 56, 21,
116 19, 38, 56, 59, 64, 64, 48, 20,
117 27, 48, 55, 55, 56, 51, 35, 15,
118 20, 35, 34, 32, 31, 22, 15, 8,
121 static VLC block_type_vlc[2][4];
124 typedef struct CFrameBuffer {
125 unsigned int allocated_size;
131 typedef struct FourXContext {
132 AVCodecContext *avctx;
134 AVFrame *current_picture, *last_picture;
135 GetBitContext pre_gb; ///< ac/dc prefix
142 DECLARE_ALIGNED(16, int16_t, block)[6][64];
143 void *bitstream_buffer;
144 unsigned int bitstream_buffer_size;
146 CFrameBuffer cfrm[CFRAME_BUFFER_COUNT];
150 #define FIX_1_082392200 70936
151 #define FIX_1_414213562 92682
152 #define FIX_1_847759065 121095
153 #define FIX_2_613125930 171254
155 #define MULTIPLY(var, const) (((var) * (const)) >> 16)
157 static void idct(int16_t block[64])
159 int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
160 int tmp10, tmp11, tmp12, tmp13;
161 int z5, z10, z11, z12, z13;
165 for (i = 0; i < 8; i++) {
166 tmp10 = block[8 * 0 + i] + block[8 * 4 + i];
167 tmp11 = block[8 * 0 + i] - block[8 * 4 + i];
169 tmp13 = block[8 * 2 + i] + block[8 * 6 + i];
170 tmp12 = MULTIPLY(block[8 * 2 + i] - block[8 * 6 + i], FIX_1_414213562) - tmp13;
172 tmp0 = tmp10 + tmp13;
173 tmp3 = tmp10 - tmp13;
174 tmp1 = tmp11 + tmp12;
175 tmp2 = tmp11 - tmp12;
177 z13 = block[8 * 5 + i] + block[8 * 3 + i];
178 z10 = block[8 * 5 + i] - block[8 * 3 + i];
179 z11 = block[8 * 1 + i] + block[8 * 7 + i];
180 z12 = block[8 * 1 + i] - block[8 * 7 + i];
183 tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);
185 z5 = MULTIPLY(z10 + z12, FIX_1_847759065);
186 tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5;
187 tmp12 = MULTIPLY(z10, -FIX_2_613125930) + z5;
193 temp[8 * 0 + i] = tmp0 + tmp7;
194 temp[8 * 7 + i] = tmp0 - tmp7;
195 temp[8 * 1 + i] = tmp1 + tmp6;
196 temp[8 * 6 + i] = tmp1 - tmp6;
197 temp[8 * 2 + i] = tmp2 + tmp5;
198 temp[8 * 5 + i] = tmp2 - tmp5;
199 temp[8 * 4 + i] = tmp3 + tmp4;
200 temp[8 * 3 + i] = tmp3 - tmp4;
203 for (i = 0; i < 8 * 8; i += 8) {
204 tmp10 = temp[0 + i] + temp[4 + i];
205 tmp11 = temp[0 + i] - temp[4 + i];
207 tmp13 = temp[2 + i] + temp[6 + i];
208 tmp12 = MULTIPLY(temp[2 + i] - temp[6 + i], FIX_1_414213562) - tmp13;
210 tmp0 = tmp10 + tmp13;
211 tmp3 = tmp10 - tmp13;
212 tmp1 = tmp11 + tmp12;
213 tmp2 = tmp11 - tmp12;
215 z13 = temp[5 + i] + temp[3 + i];
216 z10 = temp[5 + i] - temp[3 + i];
217 z11 = temp[1 + i] + temp[7 + i];
218 z12 = temp[1 + i] - temp[7 + i];
221 tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);
223 z5 = MULTIPLY(z10 + z12, FIX_1_847759065);
224 tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5;
225 tmp12 = MULTIPLY(z10, -FIX_2_613125930) + z5;
231 block[0 + i] = (tmp0 + tmp7) >> 6;
232 block[7 + i] = (tmp0 - tmp7) >> 6;
233 block[1 + i] = (tmp1 + tmp6) >> 6;
234 block[6 + i] = (tmp1 - tmp6) >> 6;
235 block[2 + i] = (tmp2 + tmp5) >> 6;
236 block[5 + i] = (tmp2 - tmp5) >> 6;
237 block[4 + i] = (tmp3 + tmp4) >> 6;
238 block[3 + i] = (tmp3 - tmp4) >> 6;
242 static av_cold void init_vlcs(FourXContext *f)
244 static VLC_TYPE table[2][4][32][2];
247 for (i = 0; i < 2; i++) {
248 for (j = 0; j < 4; j++) {
249 block_type_vlc[i][j].table = table[i][j];
250 block_type_vlc[i][j].table_allocated = 32;
251 init_vlc(&block_type_vlc[i][j], BLOCK_TYPE_VLC_BITS, 7,
252 &block_type_tab[i][j][0][1], 2, 1,
253 &block_type_tab[i][j][0][0], 2, 1,
254 INIT_VLC_USE_NEW_STATIC);
259 static void init_mv(FourXContext *f)
263 for (i = 0; i < 256; i++) {
265 f->mv[i] = mv[i][0] + mv[i][1] * f->current_picture->linesize[0] / 2;
267 f->mv[i] = (i & 15) - 8 + ((i >> 4) - 8) * f->current_picture->linesize[0] / 2;
272 #define LE_CENTRIC_MUL(dst, src, scale, dc) \
274 unsigned tmpval = AV_RN32(src); \
275 tmpval = (tmpval << 16) | (tmpval >> 16); \
276 tmpval = tmpval * (scale) + (dc); \
277 tmpval = (tmpval << 16) | (tmpval >> 16); \
278 AV_WN32A(dst, tmpval); \
281 #define LE_CENTRIC_MUL(dst, src, scale, dc) \
283 unsigned tmpval = AV_RN32(src) * (scale) + (dc); \
284 AV_WN32A(dst, tmpval); \
288 static inline void mcdc(uint16_t *dst, uint16_t *src, int log2w,
289 int h, int stride, int scale, unsigned dc)
296 for (i = 0; i < h; i++) {
297 dst[0] = scale * src[0] + dc;
304 for (i = 0; i < h; i++) {
305 LE_CENTRIC_MUL(dst, src, scale, dc);
312 for (i = 0; i < h; i++) {
313 LE_CENTRIC_MUL(dst, src, scale, dc);
314 LE_CENTRIC_MUL(dst + 2, src + 2, scale, dc);
321 for (i = 0; i < h; i++) {
322 LE_CENTRIC_MUL(dst, src, scale, dc);
323 LE_CENTRIC_MUL(dst + 2, src + 2, scale, dc);
324 LE_CENTRIC_MUL(dst + 4, src + 4, scale, dc);
325 LE_CENTRIC_MUL(dst + 6, src + 6, scale, dc);
336 static void decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src,
337 int log2w, int log2h, int stride)
339 const int index = size2index[log2h][log2w];
340 const int h = 1 << log2h;
341 int code = get_vlc2(&f->gb,
342 block_type_vlc[1 - (f->version > 1)][index].table,
343 BLOCK_TYPE_VLC_BITS, 1);
344 uint16_t *start = (uint16_t *)f->last_picture->data[0];
345 uint16_t *end = start + stride * (f->avctx->height - h + 1) - (1 << log2w);
347 assert(code >= 0 && code <= 6);
350 src += f->mv[bytestream2_get_byte(&f->g)];
351 if (start > src || src > end) {
352 av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
355 mcdc(dst, src, log2w, h, stride, 1, 0);
356 } else if (code == 1) {
358 decode_p_block(f, dst, src, log2w, log2h, stride);
359 decode_p_block(f, dst + (stride << log2h),
360 src + (stride << log2h), log2w, log2h, stride);
361 } else if (code == 2) {
363 decode_p_block(f, dst , src, log2w, log2h, stride);
364 decode_p_block(f, dst + (1 << log2w),
365 src + (1 << log2w), log2w, log2h, stride);
366 } else if (code == 3 && f->version < 2) {
367 mcdc(dst, src, log2w, h, stride, 1, 0);
368 } else if (code == 4) {
369 src += f->mv[bytestream2_get_byte(&f->g)];
370 if (start > src || src > end) {
371 av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
374 mcdc(dst, src, log2w, h, stride, 1, bytestream2_get_le16(&f->g2));
375 } else if (code == 5) {
376 mcdc(dst, src, log2w, h, stride, 0, bytestream2_get_le16(&f->g2));
377 } else if (code == 6) {
379 dst[0] = bytestream2_get_le16(&f->g2);
380 dst[1] = bytestream2_get_le16(&f->g2);
382 dst[0] = bytestream2_get_le16(&f->g2);
383 dst[stride] = bytestream2_get_le16(&f->g2);
388 static int decode_p_frame(FourXContext *f, const uint8_t *buf, int length)
391 const int width = f->avctx->width;
392 const int height = f->avctx->height;
393 uint16_t *src = (uint16_t *)f->last_picture->data[0];
394 uint16_t *dst = (uint16_t *)f->current_picture->data[0];
395 const int stride = f->current_picture->linesize[0] >> 1;
396 unsigned int bitstream_size, bytestream_size, wordstream_size, extra,
397 bytestream_offset, wordstream_offset;
399 if (f->version > 1) {
401 bitstream_size = AV_RL32(buf + 8);
402 wordstream_size = AV_RL32(buf + 12);
403 bytestream_size = AV_RL32(buf + 16);
406 bitstream_size = AV_RL16(buf - 4);
407 wordstream_size = AV_RL16(buf - 2);
408 bytestream_size = FFMAX(length - bitstream_size - wordstream_size, 0);
411 if (bitstream_size + bytestream_size + wordstream_size + extra != length
412 || bitstream_size > (1 << 26)
413 || bytestream_size > (1 << 26)
414 || wordstream_size > (1 << 26)) {
415 av_log(f->avctx, AV_LOG_ERROR, "lengths %d %d %d %d\n",
416 bitstream_size, bytestream_size, wordstream_size,
417 bitstream_size + bytestream_size + wordstream_size - length);
418 return AVERROR_INVALIDDATA;
421 av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,
422 bitstream_size + FF_INPUT_BUFFER_PADDING_SIZE);
423 if (!f->bitstream_buffer)
424 return AVERROR(ENOMEM);
425 f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)(buf + extra),
427 memset((uint8_t*)f->bitstream_buffer + bitstream_size,
428 0, FF_INPUT_BUFFER_PADDING_SIZE);
429 init_get_bits(&f->gb, f->bitstream_buffer, 8 * bitstream_size);
431 wordstream_offset = extra + bitstream_size;
432 bytestream_offset = extra + bitstream_size + wordstream_size;
433 bytestream2_init(&f->g2, buf + wordstream_offset,
434 length - wordstream_offset);
435 bytestream2_init(&f->g, buf + bytestream_offset,
436 length - bytestream_offset);
440 for (y = 0; y < height; y += 8) {
441 for (x = 0; x < width; x += 8)
442 decode_p_block(f, dst + x, src + x, 3, 3, stride);
451 * decode block and dequantize.
452 * Note this is almost identical to MJPEG.
454 static int decode_i_block(FourXContext *f, int16_t *block)
456 int code, i, j, level, val;
459 val = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
461 av_log(f->avctx, AV_LOG_ERROR, "error dc run != 0\n");
464 val = get_xbits(&f->gb, val);
466 val = val * dequant_table[0] + f->last_dc;
467 f->last_dc = block[0] = val;
471 code = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
479 level = get_xbits(&f->gb, code & 0xf);
482 av_log(f->avctx, AV_LOG_ERROR, "run %d oveflow\n", i);
486 j = ff_zigzag_direct[i];
487 block[j] = level * dequant_table[j];
497 static inline void idct_put(FourXContext *f, int x, int y)
499 int16_t (*block)[64] = f->block;
500 int stride = f->current_picture->linesize[0] >> 1;
502 uint16_t *dst = ((uint16_t*)f->current_picture->data[0]) + y * stride + x;
504 for (i = 0; i < 4; i++) {
505 block[i][0] += 0x80 * 8 * 8;
509 if (!(f->avctx->flags & CODEC_FLAG_GRAY)) {
510 for (i = 4; i < 6; i++)
514 /* Note transform is:
515 * y = ( 1b + 4g + 2r) / 14
516 * cb = ( 3b - 2g - 1r) / 14
517 * cr = (-1b - 4g + 5r) / 14 */
518 for (y = 0; y < 8; y++) {
519 for (x = 0; x < 8; x++) {
520 int16_t *temp = block[(x >> 2) + 2 * (y >> 2)] +
521 2 * (x & 3) + 2 * 8 * (y & 3); // FIXME optimize
522 int cb = block[4][x + 8 * y];
523 int cr = block[5][x + 8 * y];
524 int cg = (cb + cr) >> 1;
530 dst[0] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
532 dst[1] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
534 dst[stride] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
536 dst[1 + stride] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
539 dst += 2 * stride - 2 * 8;
543 static int decode_i_mb(FourXContext *f)
548 f->dsp.clear_blocks(f->block[0]);
550 for (i = 0; i < 6; i++)
551 if ((ret = decode_i_block(f, f->block[i])) < 0)
557 static const uint8_t *read_huffman_tables(FourXContext *f,
558 const uint8_t * const buf)
560 int frequency[512] = { 0 };
563 uint8_t len_tab[257];
566 const uint8_t *ptr = buf;
569 memset(up, -1, sizeof(up));
576 for (i = start; i <= end; i++)
577 frequency[i] = *ptr++;
586 while ((ptr - buf) & 3)
587 ptr++; // 4byte align
589 for (j = 257; j < 512; j++) {
590 int min_freq[2] = { 256 * 256, 256 * 256 };
591 int smallest[2] = { 0, 0 };
593 for (i = 0; i < j; i++) {
594 if (frequency[i] == 0)
596 if (frequency[i] < min_freq[1]) {
597 if (frequency[i] < min_freq[0]) {
598 min_freq[1] = min_freq[0];
599 smallest[1] = smallest[0];
600 min_freq[0] = frequency[i];
603 min_freq[1] = frequency[i];
608 if (min_freq[1] == 256 * 256)
611 frequency[j] = min_freq[0] + min_freq[1];
612 flag[smallest[0]] = 0;
613 flag[smallest[1]] = 1;
616 frequency[smallest[0]] = frequency[smallest[1]] = 0;
619 for (j = 0; j < 257; j++) {
620 int node, len = 0, bits = 0;
622 for (node = j; up[node] != -1; node = up[node]) {
623 bits += flag[node] << len;
626 // can this happen at all ?
627 av_log(f->avctx, AV_LOG_ERROR,
628 "vlc length overflow\n");
635 if (init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257, len_tab, 1, 1,
642 static int mix(int c0, int c1)
644 int blue = 2 * (c0 & 0x001F) + (c1 & 0x001F);
645 int green = (2 * (c0 & 0x03E0) + (c1 & 0x03E0)) >> 5;
646 int red = 2 * (c0 >> 10) + (c1 >> 10);
647 return red / 3 * 1024 + green / 3 * 32 + blue / 3;
650 static int decode_i2_frame(FourXContext *f, const uint8_t *buf, int length)
653 const int width = f->avctx->width;
654 const int height = f->avctx->height;
655 const int mbs = (FFALIGN(width, 16) >> 4) * (FFALIGN(height, 16) >> 4);
656 uint16_t *dst = (uint16_t*)f->current_picture->data[0];
657 const int stride = f->current_picture->linesize[0]>>1;
660 if (length < mbs * 8) {
661 av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
662 return AVERROR_INVALIDDATA;
664 bytestream2_init(&g3, buf, length);
666 for (y = 0; y < height; y += 16) {
667 for (x = 0; x < width; x += 16) {
668 unsigned int color[4] = { 0 }, bits;
669 // warning following is purely guessed ...
670 color[0] = bytestream2_get_le16u(&g3);
671 color[1] = bytestream2_get_le16u(&g3);
673 if (color[0] & 0x8000)
674 av_log(NULL, AV_LOG_ERROR, "unk bit 1\n");
675 if (color[1] & 0x8000)
676 av_log(NULL, AV_LOG_ERROR, "unk bit 2\n");
678 color[2] = mix(color[0], color[1]);
679 color[3] = mix(color[1], color[0]);
681 bits = bytestream2_get_le32u(&g3);
682 for (y2 = 0; y2 < 16; y2++) {
683 for (x2 = 0; x2 < 16; x2++) {
684 int index = 2 * (x2 >> 2) + 8 * (y2 >> 2);
685 dst[y2 * stride + x2] = color[(bits >> index) & 3];
690 dst += 16 * stride - x;
696 static int decode_i_frame(FourXContext *f, const uint8_t *buf, int length)
699 const int width = f->avctx->width;
700 const int height = f->avctx->height;
701 const unsigned int bitstream_size = AV_RL32(buf);
702 int token_count av_unused;
703 unsigned int prestream_size;
704 const uint8_t *prestream;
706 if (length < bitstream_size + 12) {
707 av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
708 return AVERROR_INVALIDDATA;
711 token_count = AV_RL32(buf + bitstream_size + 8);
712 prestream_size = 4 * AV_RL32(buf + bitstream_size + 4);
713 prestream = buf + bitstream_size + 12;
715 if (prestream_size + bitstream_size + 12 != length
716 || bitstream_size > (1 << 26)
717 || prestream_size > (1 << 26)) {
718 av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d %d\n",
719 prestream_size, bitstream_size, length);
720 return AVERROR_INVALIDDATA;
723 prestream = read_huffman_tables(f, prestream);
725 av_log(f->avctx, AV_LOG_ERROR, "Error reading Huffman tables.\n");
726 return AVERROR_INVALIDDATA;
729 init_get_bits(&f->gb, buf + 4, 8 * bitstream_size);
731 prestream_size = length + buf - prestream;
733 av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,
734 prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);
735 if (!f->bitstream_buffer)
736 return AVERROR(ENOMEM);
737 f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)prestream,
739 memset((uint8_t*)f->bitstream_buffer + prestream_size,
740 0, FF_INPUT_BUFFER_PADDING_SIZE);
741 init_get_bits(&f->pre_gb, f->bitstream_buffer, 8 * prestream_size);
743 f->last_dc = 0 * 128 * 8 * 8;
745 for (y = 0; y < height; y += 16) {
746 for (x = 0; x < width; x += 16) {
747 if ((ret = decode_i_mb(f)) < 0)
754 if (get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3) != 256)
755 av_log(f->avctx, AV_LOG_ERROR, "end mismatch\n");
760 static int decode_frame(AVCodecContext *avctx, void *data,
761 int *got_frame, AVPacket *avpkt)
763 const uint8_t *buf = avpkt->data;
764 int buf_size = avpkt->size;
765 FourXContext *const f = avctx->priv_data;
766 AVFrame *picture = data;
768 int i, frame_4cc, frame_size, ret;
770 frame_4cc = AV_RL32(buf);
771 if (buf_size != AV_RL32(buf + 4) + 8 || buf_size < 20)
772 av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d\n",
773 buf_size, AV_RL32(buf + 4));
775 if (frame_4cc == AV_RL32("cfrm")) {
777 const int data_size = buf_size - 20;
778 const int id = AV_RL32(buf + 12);
779 const int whole_size = AV_RL32(buf + 16);
782 for (i = 0; i < CFRAME_BUFFER_COUNT; i++)
783 if (f->cfrm[i].id && f->cfrm[i].id < avctx->frame_number)
784 av_log(f->avctx, AV_LOG_ERROR, "lost c frame %d\n",
787 for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {
788 if (f->cfrm[i].id == id)
790 if (f->cfrm[i].size == 0)
794 if (i >= CFRAME_BUFFER_COUNT) {
800 cfrm->data = av_fast_realloc(cfrm->data, &cfrm->allocated_size,
801 cfrm->size + data_size + FF_INPUT_BUFFER_PADDING_SIZE);
802 // explicit check needed as memcpy below might not catch a NULL
804 av_log(f->avctx, AV_LOG_ERROR, "realloc failure");
805 return AVERROR(ENOMEM);
808 memcpy(cfrm->data + cfrm->size, buf + 20, data_size);
809 cfrm->size += data_size;
811 if (cfrm->size >= whole_size) {
813 frame_size = cfrm->size;
815 if (id != avctx->frame_number)
816 av_log(f->avctx, AV_LOG_ERROR, "cframe id mismatch %d %d\n",
817 id, avctx->frame_number);
819 cfrm->size = cfrm->id = 0;
820 frame_4cc = AV_RL32("pfrm");
825 frame_size = buf_size - 12;
828 FFSWAP(AVFrame*, f->current_picture, f->last_picture);
830 p = f->current_picture;
831 avctx->coded_frame = p;
833 // alternatively we would have to use our own buffer management
834 avctx->flags |= CODEC_FLAG_EMU_EDGE;
837 avctx->release_buffer(avctx, p);
840 if ((ret = ff_get_buffer(avctx, p)) < 0) {
841 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
845 if (frame_4cc == AV_RL32("ifr2")) {
846 p->pict_type = AV_PICTURE_TYPE_I;
847 if ((ret = decode_i2_frame(f, buf - 4, frame_size + 4)) < 0)
849 } else if (frame_4cc == AV_RL32("ifrm")) {
850 p->pict_type = AV_PICTURE_TYPE_I;
851 if ((ret = decode_i_frame(f, buf, frame_size)) < 0)
853 } else if (frame_4cc == AV_RL32("pfrm") || frame_4cc == AV_RL32("pfr2")) {
854 if (!f->last_picture->data[0]) {
855 f->last_picture->reference = 1;
856 if ((ret = ff_get_buffer(avctx, f->last_picture)) < 0) {
857 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
860 memset(f->last_picture->data[0], 0, avctx->height * FFABS(f->last_picture->linesize[0]));
863 p->pict_type = AV_PICTURE_TYPE_P;
864 if ((ret = decode_p_frame(f, buf, frame_size)) < 0)
866 } else if (frame_4cc == AV_RL32("snd_")) {
867 av_log(avctx, AV_LOG_ERROR, "ignoring snd_ chunk length:%d\n",
870 av_log(avctx, AV_LOG_ERROR, "ignoring unknown chunk length:%d\n",
874 p->key_frame = p->pict_type == AV_PICTURE_TYPE_I;
884 static av_cold int decode_init(AVCodecContext *avctx)
886 FourXContext * const f = avctx->priv_data;
888 if (avctx->extradata_size != 4 || !avctx->extradata) {
889 av_log(avctx, AV_LOG_ERROR, "extradata wrong or missing\n");
893 f->version = AV_RL32(avctx->extradata) >> 16;
894 ff_dsputil_init(&f->dsp, avctx);
899 avctx->pix_fmt = AV_PIX_FMT_RGB565;
901 avctx->pix_fmt = AV_PIX_FMT_BGR555;
903 f->current_picture = avcodec_alloc_frame();
904 f->last_picture = avcodec_alloc_frame();
905 if (!f->current_picture || !f->last_picture) {
906 avcodec_free_frame(&f->current_picture);
907 avcodec_free_frame(&f->last_picture);
908 return AVERROR(ENOMEM);
915 static av_cold int decode_end(AVCodecContext *avctx)
917 FourXContext * const f = avctx->priv_data;
920 av_freep(&f->bitstream_buffer);
921 f->bitstream_buffer_size = 0;
922 for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {
923 av_freep(&f->cfrm[i].data);
924 f->cfrm[i].allocated_size = 0;
926 ff_free_vlc(&f->pre_vlc);
927 if (f->current_picture->data[0])
928 avctx->release_buffer(avctx, f->current_picture);
929 if (f->last_picture->data[0])
930 avctx->release_buffer(avctx, f->last_picture);
931 avcodec_free_frame(&f->current_picture);
932 avcodec_free_frame(&f->last_picture);
937 AVCodec ff_fourxm_decoder = {
939 .type = AVMEDIA_TYPE_VIDEO,
940 .id = AV_CODEC_ID_4XM,
941 .priv_data_size = sizeof(FourXContext),
944 .decode = decode_frame,
945 .capabilities = CODEC_CAP_DR1,
946 .long_name = NULL_IF_CONFIG_SMALL("4X Movie"),