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, DCTELEM, 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(DCTELEM 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);
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, DCTELEM *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 DCTELEM (*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 DCTELEM *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)
547 f->dsp.clear_blocks(f->block[0]);
549 for (i = 0; i < 6; i++)
550 if (decode_i_block(f, f->block[i]) < 0)
556 static const uint8_t *read_huffman_tables(FourXContext *f,
557 const uint8_t * const buf)
559 int frequency[512] = { 0 };
562 uint8_t len_tab[257];
565 const uint8_t *ptr = buf;
568 memset(up, -1, sizeof(up));
575 for (i = start; i <= end; i++)
576 frequency[i] = *ptr++;
585 while ((ptr - buf) & 3)
586 ptr++; // 4byte align
588 for (j = 257; j < 512; j++) {
589 int min_freq[2] = { 256 * 256, 256 * 256 };
590 int smallest[2] = { 0, 0 };
592 for (i = 0; i < j; i++) {
593 if (frequency[i] == 0)
595 if (frequency[i] < min_freq[1]) {
596 if (frequency[i] < min_freq[0]) {
597 min_freq[1] = min_freq[0];
598 smallest[1] = smallest[0];
599 min_freq[0] = frequency[i];
602 min_freq[1] = frequency[i];
607 if (min_freq[1] == 256 * 256)
610 frequency[j] = min_freq[0] + min_freq[1];
611 flag[smallest[0]] = 0;
612 flag[smallest[1]] = 1;
615 frequency[smallest[0]] = frequency[smallest[1]] = 0;
618 for (j = 0; j < 257; j++) {
619 int node, len = 0, bits = 0;
621 for (node = j; up[node] != -1; node = up[node]) {
622 bits += flag[node] << len;
625 // can this happen at all ?
626 av_log(f->avctx, AV_LOG_ERROR,
627 "vlc length overflow\n");
634 if (init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257, len_tab, 1, 1,
641 static int mix(int c0, int c1)
643 int blue = 2 * (c0 & 0x001F) + (c1 & 0x001F);
644 int green = (2 * (c0 & 0x03E0) + (c1 & 0x03E0)) >> 5;
645 int red = 2 * (c0 >> 10) + (c1 >> 10);
646 return red / 3 * 1024 + green / 3 * 32 + blue / 3;
649 static int decode_i2_frame(FourXContext *f, const uint8_t *buf, int length)
652 const int width = f->avctx->width;
653 const int height = f->avctx->height;
654 const int mbs = (FFALIGN(width, 16) >> 4) * (FFALIGN(height, 16) >> 4);
655 uint16_t *dst = (uint16_t*)f->current_picture.data[0];
656 const int stride = f->current_picture.linesize[0]>>1;
659 if (length < mbs * 8) {
660 av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
661 return AVERROR_INVALIDDATA;
663 bytestream2_init(&g3, buf, length);
665 for (y = 0; y < height; y += 16) {
666 for (x = 0; x < width; x += 16) {
667 unsigned int color[4] = { 0 }, bits;
668 // warning following is purely guessed ...
669 color[0] = bytestream2_get_le16u(&g3);
670 color[1] = bytestream2_get_le16u(&g3);
672 if (color[0] & 0x8000)
673 av_log(NULL, AV_LOG_ERROR, "unk bit 1\n");
674 if (color[1] & 0x8000)
675 av_log(NULL, AV_LOG_ERROR, "unk bit 2\n");
677 color[2] = mix(color[0], color[1]);
678 color[3] = mix(color[1], color[0]);
680 bits = bytestream2_get_le32u(&g3);
681 for (y2 = 0; y2 < 16; y2++) {
682 for (x2 = 0; x2 < 16; x2++) {
683 int index = 2 * (x2 >> 2) + 8 * (y2 >> 2);
684 dst[y2 * stride + x2] = color[(bits >> index) & 3];
689 dst += 16 * stride - x;
695 static int decode_i_frame(FourXContext *f, const uint8_t *buf, int length)
698 const int width = f->avctx->width;
699 const int height = f->avctx->height;
700 const unsigned int bitstream_size = AV_RL32(buf);
701 int token_count av_unused;
702 unsigned int prestream_size;
703 const uint8_t *prestream;
705 if (length < bitstream_size + 12) {
706 av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
707 return AVERROR_INVALIDDATA;
710 token_count = AV_RL32(buf + bitstream_size + 8);
711 prestream_size = 4 * AV_RL32(buf + bitstream_size + 4);
712 prestream = buf + bitstream_size + 12;
714 if (prestream_size + bitstream_size + 12 != length
715 || bitstream_size > (1 << 26)
716 || prestream_size > (1 << 26)) {
717 av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d %d\n",
718 prestream_size, bitstream_size, length);
722 prestream = read_huffman_tables(f, prestream);
724 init_get_bits(&f->gb, buf + 4, 8 * bitstream_size);
726 prestream_size = length + buf - prestream;
728 av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,
729 prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);
730 if (!f->bitstream_buffer)
731 return AVERROR(ENOMEM);
732 f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)prestream,
734 memset((uint8_t*)f->bitstream_buffer + prestream_size,
735 0, FF_INPUT_BUFFER_PADDING_SIZE);
736 init_get_bits(&f->pre_gb, f->bitstream_buffer, 8 * prestream_size);
738 f->last_dc = 0 * 128 * 8 * 8;
740 for (y = 0; y < height; y += 16) {
741 for (x = 0; x < width; x += 16) {
742 if (decode_i_mb(f) < 0)
749 if (get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3) != 256)
750 av_log(f->avctx, AV_LOG_ERROR, "end mismatch\n");
755 static int decode_frame(AVCodecContext *avctx, void *data,
756 int *got_frame, AVPacket *avpkt)
758 const uint8_t *buf = avpkt->data;
759 int buf_size = avpkt->size;
760 FourXContext *const f = avctx->priv_data;
761 AVFrame *picture = data;
763 int i, frame_4cc, frame_size;
765 frame_4cc = AV_RL32(buf);
766 if (buf_size != AV_RL32(buf + 4) + 8 || buf_size < 20)
767 av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d\n",
768 buf_size, AV_RL32(buf + 4));
770 if (frame_4cc == AV_RL32("cfrm")) {
772 const int data_size = buf_size - 20;
773 const int id = AV_RL32(buf + 12);
774 const int whole_size = AV_RL32(buf + 16);
777 for (i = 0; i < CFRAME_BUFFER_COUNT; i++)
778 if (f->cfrm[i].id && f->cfrm[i].id < avctx->frame_number)
779 av_log(f->avctx, AV_LOG_ERROR, "lost c frame %d\n",
782 for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {
783 if (f->cfrm[i].id == id)
785 if (f->cfrm[i].size == 0)
789 if (i >= CFRAME_BUFFER_COUNT) {
795 cfrm->data = av_fast_realloc(cfrm->data, &cfrm->allocated_size,
796 cfrm->size + data_size + FF_INPUT_BUFFER_PADDING_SIZE);
797 // explicit check needed as memcpy below might not catch a NULL
799 av_log(f->avctx, AV_LOG_ERROR, "realloc failure");
803 memcpy(cfrm->data + cfrm->size, buf + 20, data_size);
804 cfrm->size += data_size;
806 if (cfrm->size >= whole_size) {
808 frame_size = cfrm->size;
810 if (id != avctx->frame_number)
811 av_log(f->avctx, AV_LOG_ERROR, "cframe id mismatch %d %d\n",
812 id, avctx->frame_number);
814 cfrm->size = cfrm->id = 0;
815 frame_4cc = AV_RL32("pfrm");
820 frame_size = buf_size - 12;
823 temp = f->current_picture;
824 f->current_picture = f->last_picture;
825 f->last_picture = temp;
827 p = &f->current_picture;
828 avctx->coded_frame = p;
830 // alternatively we would have to use our own buffer management
831 avctx->flags |= CODEC_FLAG_EMU_EDGE;
834 avctx->release_buffer(avctx, p);
837 if (ff_get_buffer(avctx, p) < 0) {
838 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
842 if (frame_4cc == AV_RL32("ifr2")) {
843 p->pict_type = AV_PICTURE_TYPE_I;
844 if (decode_i2_frame(f, buf - 4, frame_size + 4) < 0)
846 } else if (frame_4cc == AV_RL32("ifrm")) {
847 p->pict_type = AV_PICTURE_TYPE_I;
848 if (decode_i_frame(f, buf, frame_size) < 0)
850 } else if (frame_4cc == AV_RL32("pfrm") || frame_4cc == AV_RL32("pfr2")) {
851 if (!f->last_picture.data[0]) {
852 f->last_picture.reference = 1;
853 if (ff_get_buffer(avctx, &f->last_picture) < 0) {
854 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
857 memset(f->last_picture.data[0], 0, avctx->height * FFABS(f->last_picture.linesize[0]));
860 p->pict_type = AV_PICTURE_TYPE_P;
861 if (decode_p_frame(f, buf, frame_size) < 0)
863 } else if (frame_4cc == AV_RL32("snd_")) {
864 av_log(avctx, AV_LOG_ERROR, "ignoring snd_ chunk length:%d\n",
867 av_log(avctx, AV_LOG_ERROR, "ignoring unknown chunk length:%d\n",
871 p->key_frame = p->pict_type == AV_PICTURE_TYPE_I;
882 static av_cold void common_init(AVCodecContext *avctx)
884 FourXContext * const f = avctx->priv_data;
886 ff_dsputil_init(&f->dsp, avctx);
891 static av_cold int decode_init(AVCodecContext *avctx)
893 FourXContext * const f = avctx->priv_data;
895 if (avctx->extradata_size != 4 || !avctx->extradata) {
896 av_log(avctx, AV_LOG_ERROR, "extradata wrong or missing\n");
900 f->version = AV_RL32(avctx->extradata) >> 16;
905 avctx->pix_fmt = AV_PIX_FMT_RGB565;
907 avctx->pix_fmt = AV_PIX_FMT_BGR555;
913 static av_cold int decode_end(AVCodecContext *avctx)
915 FourXContext * const f = avctx->priv_data;
918 av_freep(&f->bitstream_buffer);
919 f->bitstream_buffer_size = 0;
920 for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {
921 av_freep(&f->cfrm[i].data);
922 f->cfrm[i].allocated_size = 0;
924 ff_free_vlc(&f->pre_vlc);
925 if (f->current_picture.data[0])
926 avctx->release_buffer(avctx, &f->current_picture);
927 if (f->last_picture.data[0])
928 avctx->release_buffer(avctx, &f->last_picture);
933 AVCodec ff_fourxm_decoder = {
935 .type = AVMEDIA_TYPE_VIDEO,
936 .id = AV_CODEC_ID_4XM,
937 .priv_data_size = sizeof(FourXContext),
940 .decode = decode_frame,
941 .capabilities = CODEC_CAP_DR1,
942 .long_name = NULL_IF_CONFIG_SMALL("4X Movie"),