3 * Copyright (c) 2003 Michael Niedermayer
5 * This file is part of FFmpeg.
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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"
34 #include "libavutil/avassert.h"
36 #define BLOCK_TYPE_VLC_BITS 5
37 #define ACDC_VLC_BITS 9
39 #define CFRAME_BUFFER_COUNT 100
41 static const uint8_t block_type_tab[2][4][8][2] = {
43 { // { 8, 4, 2 } x { 8, 4, 2}
44 { 0, 1 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 30, 5 }, { 31, 5 }, { 0, 0 }
46 { 0, 1 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }
48 { 0, 1 }, { 2, 2 }, { 0, 0 }, { 6, 3 }, { 14, 4 }, { 15, 4 }, { 0, 0 }
50 { 0, 1 }, { 0, 0 }, { 0, 0 }, { 2, 2 }, { 6, 3 }, { 14, 4 }, { 15, 4 }
53 { // { 8, 4, 2 } x { 8, 4, 2}
54 { 1, 2 }, { 4, 3 }, { 5, 3 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }
56 { 1, 2 }, { 0, 0 }, { 2, 2 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }
58 { 1, 2 }, { 2, 2 }, { 0, 0 }, { 0, 2 }, { 6, 3 }, { 7, 3 }, { 0, 0 }
60 { 1, 2 }, { 0, 0 }, { 0, 0 }, { 0, 2 }, { 2, 2 }, { 6, 3 }, { 7, 3 }
65 static const uint8_t size2index[4][4] = {
72 static const int8_t mv[256][2] = {
73 { 0, 0 }, { 0, -1 }, { -1, 0 }, { 1, 0 }, { 0, 1 }, { -1, -1 }, { 1, -1 }, { -1, 1 },
74 { 1, 1 }, { 0, -2 }, { -2, 0 }, { 2, 0 }, { 0, 2 }, { -1, -2 }, { 1, -2 }, { -2, -1 },
75 { 2, -1 }, { -2, 1 }, { 2, 1 }, { -1, 2 }, { 1, 2 }, { -2, -2 }, { 2, -2 }, { -2, 2 },
76 { 2, 2 }, { 0, -3 }, { -3, 0 }, { 3, 0 }, { 0, 3 }, { -1, -3 }, { 1, -3 }, { -3, -1 },
77 { 3, -1 }, { -3, 1 }, { 3, 1 }, { -1, 3 }, { 1, 3 }, { -2, -3 }, { 2, -3 }, { -3, -2 },
78 { 3, -2 }, { -3, 2 }, { 3, 2 }, { -2, 3 }, { 2, 3 }, { 0, -4 }, { -4, 0 }, { 4, 0 },
79 { 0, 4 }, { -1, -4 }, { 1, -4 }, { -4, -1 }, { 4, -1 }, { 4, 1 }, { -1, 4 }, { 1, 4 },
80 { -3, -3 }, { -3, 3 }, { 3, 3 }, { -2, -4 }, { -4, -2 }, { 4, -2 }, { -4, 2 }, { -2, 4 },
81 { 2, 4 }, { -3, -4 }, { 3, -4 }, { 4, -3 }, { -5, 0 }, { -4, 3 }, { -3, 4 }, { 3, 4 },
82 { -1, -5 }, { -5, -1 }, { -5, 1 }, { -1, 5 }, { -2, -5 }, { 2, -5 }, { 5, -2 }, { 5, 2 },
83 { -4, -4 }, { -4, 4 }, { -3, -5 }, { -5, -3 }, { -5, 3 }, { 3, 5 }, { -6, 0 }, { 0, 6 },
84 { -6, -1 }, { -6, 1 }, { 1, 6 }, { 2, -6 }, { -6, 2 }, { 2, 6 }, { -5, -4 }, { 5, 4 },
85 { 4, 5 }, { -6, -3 }, { 6, 3 }, { -7, 0 }, { -1, -7 }, { 5, -5 }, { -7, 1 }, { -1, 7 },
86 { 4, -6 }, { 6, 4 }, { -2, -7 }, { -7, 2 }, { -3, -7 }, { 7, -3 }, { 3, 7 }, { 6, -5 },
87 { 0, -8 }, { -1, -8 }, { -7, -4 }, { -8, 1 }, { 4, 7 }, { 2, -8 }, { -2, 8 }, { 6, 6 },
88 { -8, 3 }, { 5, -7 }, { -5, 7 }, { 8, -4 }, { 0, -9 }, { -9, -1 }, { 1, 9 }, { 7, -6 },
89 { -7, 6 }, { -5, -8 }, { -5, 8 }, { -9, 3 }, { 9, -4 }, { 7, -7 }, { 8, -6 }, { 6, 8 },
90 { 10, 1 }, { -10, 2 }, { 9, -5 }, { 10, -3 }, { -8, -7 }, { -10, -4 }, { 6, -9 }, { -11, 0 },
91 { 11, 1 }, { -11, -2 }, { -2, 11 }, { 7, -9 }, { -7, 9 }, { 10, 6 }, { -4, 11 }, { 8, -9 },
92 { 8, 9 }, { 5, 11 }, { 7, -10 }, { 12, -3 }, { 11, 6 }, { -9, -9 }, { 8, 10 }, { 5, 12 },
93 { -11, 7 }, { 13, 2 }, { 6, -12 }, { 10, 9 }, { -11, 8 }, { -7, 12 }, { 0, 14 }, { 14, -2 },
94 { -9, 11 }, { -6, 13 }, { -14, -4 }, { -5, -14 }, { 5, 14 }, { -15, -1 }, { -14, -6 }, { 3, -15 },
95 { 11, -11 }, { -7, 14 }, { -5, 15 }, { 8, -14 }, { 15, 6 }, { 3, 16 }, { 7, -15 }, { -16, 5 },
96 { 0, 17 }, { -16, -6 }, { -10, 14 }, { -16, 7 }, { 12, 13 }, { -16, 8 }, { -17, 6 }, { -18, 3 },
97 { -7, 17 }, { 15, 11 }, { 16, 10 }, { 2, -19 }, { 3, -19 }, { -11, -16 }, { -18, 8 }, { -19, -6 },
98 { 2, -20 }, { -17, -11 }, { -10, -18 }, { 8, 19 }, { -21, -1 }, { -20, 7 }, { -4, 21 }, { 21, 5 },
99 { 15, 16 }, { 2, -22 }, { -10, -20 }, { -22, 5 }, { 20, -11 }, { -7, -22 }, { -12, 20 }, { 23, -5 },
100 { 13, -20 }, { 24, -2 }, { -15, 19 }, { -11, 22 }, { 16, 19 }, { 23, -10 }, { -18, -18 }, { -9, -24 },
101 { 24, -10 }, { -3, 26 }, { -23, 13 }, { -18, -20 }, { 17, 21 }, { -4, 27 }, { 27, 6 }, { 1, -28 },
102 { -11, 26 }, { -17, -23 }, { 7, 28 }, { 11, -27 }, { 29, 5 }, { -23, -19 }, { -28, -11 }, { -21, 22 },
103 { -30, 7 }, { -17, 26 }, { -27, 16 }, { 13, 29 }, { 19, -26 }, { 10, -31 }, { -14, -30 }, { 20, -27 },
104 { -29, 18 }, { -16, -31 }, { -28, -22 }, { 21, -30 }, { -25, 28 }, { 26, -29 }, { 25, -32 }, { -32, -32 }
107 /* This is simply the scaled down elementwise product of the standard JPEG
108 * quantizer table and the AAN premul table. */
109 static const uint8_t dequant_table[64] = {
110 16, 15, 13, 19, 24, 31, 28, 17,
111 17, 23, 25, 31, 36, 63, 45, 21,
112 18, 24, 27, 37, 52, 59, 49, 20,
113 16, 28, 34, 40, 60, 80, 51, 20,
114 18, 31, 48, 66, 68, 86, 56, 21,
115 19, 38, 56, 59, 64, 64, 48, 20,
116 27, 48, 55, 55, 56, 51, 35, 15,
117 20, 35, 34, 32, 31, 22, 15, 8,
120 static VLC block_type_vlc[2][4];
123 typedef struct CFrameBuffer {
124 unsigned int allocated_size;
130 typedef struct FourXContext {
131 AVCodecContext *avctx;
133 AVFrame *current_picture, *last_picture;
134 GetBitContext pre_gb; ///< ac/dc prefix
141 DECLARE_ALIGNED(16, DCTELEM, block)[6][64];
142 void *bitstream_buffer;
143 unsigned int bitstream_buffer_size;
145 CFrameBuffer cfrm[CFRAME_BUFFER_COUNT];
149 #define FIX_1_082392200 70936
150 #define FIX_1_414213562 92682
151 #define FIX_1_847759065 121095
152 #define FIX_2_613125930 171254
154 #define MULTIPLY(var, const) (((var) * (const)) >> 16)
156 static void idct(DCTELEM block[64])
158 int tmp0, tmp1, tmp2, tmp3, tmp4, tmp5, tmp6, tmp7;
159 int tmp10, tmp11, tmp12, tmp13;
160 int z5, z10, z11, z12, z13;
164 for (i = 0; i < 8; i++) {
165 tmp10 = block[8 * 0 + i] + block[8 * 4 + i];
166 tmp11 = block[8 * 0 + i] - block[8 * 4 + i];
168 tmp13 = block[8 * 2 + i] + block[8 * 6 + i];
169 tmp12 = MULTIPLY(block[8 * 2 + i] - block[8 * 6 + i], FIX_1_414213562) - tmp13;
171 tmp0 = tmp10 + tmp13;
172 tmp3 = tmp10 - tmp13;
173 tmp1 = tmp11 + tmp12;
174 tmp2 = tmp11 - tmp12;
176 z13 = block[8 * 5 + i] + block[8 * 3 + i];
177 z10 = block[8 * 5 + i] - block[8 * 3 + i];
178 z11 = block[8 * 1 + i] + block[8 * 7 + i];
179 z12 = block[8 * 1 + i] - block[8 * 7 + i];
182 tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);
184 z5 = MULTIPLY(z10 + z12, FIX_1_847759065);
185 tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5;
186 tmp12 = MULTIPLY(z10, -FIX_2_613125930) + z5;
192 temp[8 * 0 + i] = tmp0 + tmp7;
193 temp[8 * 7 + i] = tmp0 - tmp7;
194 temp[8 * 1 + i] = tmp1 + tmp6;
195 temp[8 * 6 + i] = tmp1 - tmp6;
196 temp[8 * 2 + i] = tmp2 + tmp5;
197 temp[8 * 5 + i] = tmp2 - tmp5;
198 temp[8 * 4 + i] = tmp3 + tmp4;
199 temp[8 * 3 + i] = tmp3 - tmp4;
202 for (i = 0; i < 8 * 8; i += 8) {
203 tmp10 = temp[0 + i] + temp[4 + i];
204 tmp11 = temp[0 + i] - temp[4 + i];
206 tmp13 = temp[2 + i] + temp[6 + i];
207 tmp12 = MULTIPLY(temp[2 + i] - temp[6 + i], FIX_1_414213562) - tmp13;
209 tmp0 = tmp10 + tmp13;
210 tmp3 = tmp10 - tmp13;
211 tmp1 = tmp11 + tmp12;
212 tmp2 = tmp11 - tmp12;
214 z13 = temp[5 + i] + temp[3 + i];
215 z10 = temp[5 + i] - temp[3 + i];
216 z11 = temp[1 + i] + temp[7 + i];
217 z12 = temp[1 + i] - temp[7 + i];
220 tmp11 = MULTIPLY(z11 - z13, FIX_1_414213562);
222 z5 = MULTIPLY(z10 + z12, FIX_1_847759065);
223 tmp10 = MULTIPLY(z12, FIX_1_082392200) - z5;
224 tmp12 = MULTIPLY(z10, -FIX_2_613125930) + z5;
230 block[0 + i] = (tmp0 + tmp7) >> 6;
231 block[7 + i] = (tmp0 - tmp7) >> 6;
232 block[1 + i] = (tmp1 + tmp6) >> 6;
233 block[6 + i] = (tmp1 - tmp6) >> 6;
234 block[2 + i] = (tmp2 + tmp5) >> 6;
235 block[5 + i] = (tmp2 - tmp5) >> 6;
236 block[4 + i] = (tmp3 + tmp4) >> 6;
237 block[3 + i] = (tmp3 - tmp4) >> 6;
241 static av_cold void init_vlcs(FourXContext *f)
243 static VLC_TYPE table[2][4][32][2];
246 for (i = 0; i < 2; i++) {
247 for (j = 0; j < 4; j++) {
248 block_type_vlc[i][j].table = table[i][j];
249 block_type_vlc[i][j].table_allocated = 32;
250 init_vlc(&block_type_vlc[i][j], BLOCK_TYPE_VLC_BITS, 7,
251 &block_type_tab[i][j][0][1], 2, 1,
252 &block_type_tab[i][j][0][0], 2, 1,
253 INIT_VLC_USE_NEW_STATIC);
258 static void init_mv(FourXContext *f)
262 for (i = 0; i < 256; i++) {
264 f->mv[i] = mv[i][0] + mv[i][1] * f->current_picture->linesize[0] / 2;
266 f->mv[i] = (i & 15) - 8 + ((i >> 4) - 8) * f->current_picture->linesize[0] / 2;
271 #define LE_CENTRIC_MUL(dst, src, scale, dc) \
273 unsigned tmpval = AV_RN32(src); \
274 tmpval = (tmpval << 16) | (tmpval >> 16); \
275 tmpval = tmpval * (scale) + (dc); \
276 tmpval = (tmpval << 16) | (tmpval >> 16); \
277 AV_WN32A(dst, tmpval); \
280 #define LE_CENTRIC_MUL(dst, src, scale, dc) \
282 unsigned tmpval = AV_RN32(src) * (scale) + (dc); \
283 AV_WN32A(dst, tmpval); \
287 static inline void mcdc(uint16_t *dst, const uint16_t *src, int log2w,
288 int h, int stride, int scale, unsigned dc)
295 for (i = 0; i < h; i++) {
296 dst[0] = scale * src[0] + dc;
303 for (i = 0; i < h; i++) {
304 LE_CENTRIC_MUL(dst, src, scale, dc);
311 for (i = 0; i < h; i++) {
312 LE_CENTRIC_MUL(dst, src, scale, dc);
313 LE_CENTRIC_MUL(dst + 2, src + 2, scale, dc);
320 for (i = 0; i < h; i++) {
321 LE_CENTRIC_MUL(dst, src, scale, dc);
322 LE_CENTRIC_MUL(dst + 2, src + 2, scale, dc);
323 LE_CENTRIC_MUL(dst + 4, src + 4, scale, dc);
324 LE_CENTRIC_MUL(dst + 6, src + 6, scale, dc);
335 static void decode_p_block(FourXContext *f, uint16_t *dst, uint16_t *src,
336 int log2w, int log2h, int stride)
338 const int index = size2index[log2h][log2w];
339 const int h = 1 << log2h;
340 int code = get_vlc2(&f->gb,
341 block_type_vlc[1 - (f->version > 1)][index].table,
342 BLOCK_TYPE_VLC_BITS, 1);
343 uint16_t *start = (uint16_t *)f->last_picture->data[0];
344 uint16_t *end = start + stride * (f->avctx->height - h + 1) - (1 << log2w);
346 av_assert2(code >= 0 && code <= 6);
349 if (bytestream2_get_bytes_left(&f->g) < 1) {
350 av_log(f->avctx, AV_LOG_ERROR, "bytestream overread\n");
353 src += f->mv[bytestream2_get_byteu(&f->g)];
354 if (start > src || src > end) {
355 av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
358 mcdc(dst, src, log2w, h, stride, 1, 0);
359 } else if (code == 1) {
361 decode_p_block(f, dst, src, log2w, log2h, stride);
362 decode_p_block(f, dst + (stride << log2h),
363 src + (stride << log2h), log2w, log2h, stride);
364 } else if (code == 2) {
366 decode_p_block(f, dst , src, log2w, log2h, stride);
367 decode_p_block(f, dst + (1 << log2w),
368 src + (1 << log2w), log2w, log2h, stride);
369 } else if (code == 3 && f->version < 2) {
370 mcdc(dst, src, log2w, h, stride, 1, 0);
371 } else if (code == 4) {
372 if (bytestream2_get_bytes_left(&f->g) < 1) {
373 av_log(f->avctx, AV_LOG_ERROR, "bytestream overread\n");
376 src += f->mv[bytestream2_get_byteu(&f->g)];
377 if (start > src || src > end) {
378 av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
381 if (bytestream2_get_bytes_left(&f->g2) < 2){
382 av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
385 mcdc(dst, src, log2w, h, stride, 1, bytestream2_get_le16u(&f->g2));
386 } else if (code == 5) {
387 if (bytestream2_get_bytes_left(&f->g2) < 2) {
388 av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
391 mcdc(dst, src, log2w, h, stride, 0, bytestream2_get_le16u(&f->g2));
392 } else if (code == 6) {
393 if (bytestream2_get_bytes_left(&f->g2) < 4) {
394 av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
398 dst[0] = bytestream2_get_le16u(&f->g2);
399 dst[1] = bytestream2_get_le16u(&f->g2);
401 dst[0] = bytestream2_get_le16u(&f->g2);
402 dst[stride] = bytestream2_get_le16u(&f->g2);
407 static int decode_p_frame(FourXContext *f, const uint8_t *buf, int length)
410 const int width = f->avctx->width;
411 const int height = f->avctx->height;
412 uint16_t *src = (uint16_t *)f->last_picture->data[0];
413 uint16_t *dst = (uint16_t *)f->current_picture->data[0];
414 const int stride = f->current_picture->linesize[0] >> 1;
415 unsigned int bitstream_size, bytestream_size, wordstream_size, extra,
416 bytestream_offset, wordstream_offset;
418 if (f->version > 1) {
422 bitstream_size = AV_RL32(buf + 8);
423 wordstream_size = AV_RL32(buf + 12);
424 bytestream_size = AV_RL32(buf + 16);
427 bitstream_size = AV_RL16(buf - 4);
428 wordstream_size = AV_RL16(buf - 2);
429 bytestream_size = FFMAX(length - bitstream_size - wordstream_size, 0);
432 if (bitstream_size > length || bitstream_size >= INT_MAX/8 ||
433 bytestream_size > length - bitstream_size ||
434 wordstream_size > length - bytestream_size - bitstream_size ||
435 extra > length - bytestream_size - bitstream_size - wordstream_size) {
436 av_log(f->avctx, AV_LOG_ERROR, "lengths %d %d %d %d\n", bitstream_size, bytestream_size, wordstream_size,
437 bitstream_size+ bytestream_size+ wordstream_size - length);
438 return AVERROR_INVALIDDATA;
441 av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,
442 bitstream_size + FF_INPUT_BUFFER_PADDING_SIZE);
443 if (!f->bitstream_buffer)
444 return AVERROR(ENOMEM);
445 f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)(buf + extra),
447 memset((uint8_t*)f->bitstream_buffer + bitstream_size,
448 0, FF_INPUT_BUFFER_PADDING_SIZE);
449 init_get_bits(&f->gb, f->bitstream_buffer, 8 * bitstream_size);
451 wordstream_offset = extra + bitstream_size;
452 bytestream_offset = extra + bitstream_size + wordstream_size;
453 bytestream2_init(&f->g2, buf + wordstream_offset,
454 length - wordstream_offset);
455 bytestream2_init(&f->g, buf + bytestream_offset,
456 length - bytestream_offset);
460 for (y = 0; y < height; y += 8) {
461 for (x = 0; x < width; x += 8)
462 decode_p_block(f, dst + x, src + x, 3, 3, stride);
471 * decode block and dequantize.
472 * Note this is almost identical to MJPEG.
474 static int decode_i_block(FourXContext *f, DCTELEM *block)
476 int code, i, j, level, val;
478 if (get_bits_left(&f->gb) < 2){
479 av_log(f->avctx, AV_LOG_ERROR, "%d bits left before decode_i_block()\n", get_bits_left(&f->gb));
484 val = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
486 av_log(f->avctx, AV_LOG_ERROR, "error dc run != 0\n");
489 val = get_xbits(&f->gb, val);
491 val = val * dequant_table[0] + f->last_dc;
492 f->last_dc = block[0] = val;
496 code = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
504 level = get_xbits(&f->gb, code & 0xf);
507 av_log(f->avctx, AV_LOG_ERROR, "run %d oveflow\n", i);
511 j = ff_zigzag_direct[i];
512 block[j] = level * dequant_table[j];
522 static inline void idct_put(FourXContext *f, int x, int y)
524 DCTELEM (*block)[64] = f->block;
525 int stride = f->current_picture->linesize[0] >> 1;
527 uint16_t *dst = ((uint16_t*)f->current_picture->data[0]) + y * stride + x;
529 for (i = 0; i < 4; i++) {
530 block[i][0] += 0x80 * 8 * 8;
534 if (!(f->avctx->flags & CODEC_FLAG_GRAY)) {
535 for (i = 4; i < 6; i++)
539 /* Note transform is:
540 * y = ( 1b + 4g + 2r) / 14
541 * cb = ( 3b - 2g - 1r) / 14
542 * cr = (-1b - 4g + 5r) / 14 */
543 for (y = 0; y < 8; y++) {
544 for (x = 0; x < 8; x++) {
545 DCTELEM *temp = block[(x >> 2) + 2 * (y >> 2)] +
546 2 * (x & 3) + 2 * 8 * (y & 3); // FIXME optimize
547 int cb = block[4][x + 8 * y];
548 int cr = block[5][x + 8 * y];
549 int cg = (cb + cr) >> 1;
555 dst[0] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
557 dst[1] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
559 dst[stride] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
561 dst[1 + stride] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
564 dst += 2 * stride - 2 * 8;
568 static int decode_i_mb(FourXContext *f)
573 f->dsp.clear_blocks(f->block[0]);
575 for (i = 0; i < 6; i++)
576 if ((ret = decode_i_block(f, f->block[i])) < 0)
582 static const uint8_t *read_huffman_tables(FourXContext *f,
583 const uint8_t * const buf, int buf_size)
585 int frequency[512] = { 0 };
588 uint8_t len_tab[257];
591 const uint8_t *ptr = buf;
592 const uint8_t *ptr_end = buf + buf_size;
595 memset(up, -1, sizeof(up));
602 if (start <= end && ptr_end - ptr < end - start + 1 + 1)
604 for (i = start; i <= end; i++)
605 frequency[i] = *ptr++;
614 while ((ptr - buf) & 3)
615 ptr++; // 4byte align
617 for (j = 257; j < 512; j++) {
618 int min_freq[2] = { 256 * 256, 256 * 256 };
619 int smallest[2] = { 0, 0 };
621 for (i = 0; i < j; i++) {
622 if (frequency[i] == 0)
624 if (frequency[i] < min_freq[1]) {
625 if (frequency[i] < min_freq[0]) {
626 min_freq[1] = min_freq[0];
627 smallest[1] = smallest[0];
628 min_freq[0] = frequency[i];
631 min_freq[1] = frequency[i];
636 if (min_freq[1] == 256 * 256)
639 frequency[j] = min_freq[0] + min_freq[1];
640 flag[smallest[0]] = 0;
641 flag[smallest[1]] = 1;
644 frequency[smallest[0]] = frequency[smallest[1]] = 0;
647 for (j = 0; j < 257; j++) {
648 int node, len = 0, bits = 0;
650 for (node = j; up[node] != -1; node = up[node]) {
651 bits += flag[node] << len;
654 // can this happen at all ?
655 av_log(f->avctx, AV_LOG_ERROR,
656 "vlc length overflow\n");
663 if (init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257, len_tab, 1, 1,
670 static int mix(int c0, int c1)
672 int blue = 2 * (c0 & 0x001F) + (c1 & 0x001F);
673 int green = (2 * (c0 & 0x03E0) + (c1 & 0x03E0)) >> 5;
674 int red = 2 * (c0 >> 10) + (c1 >> 10);
675 return red / 3 * 1024 + green / 3 * 32 + blue / 3;
678 static int decode_i2_frame(FourXContext *f, const uint8_t *buf, int length)
681 const int width = f->avctx->width;
682 const int height = f->avctx->height;
683 const int mbs = (FFALIGN(width, 16) >> 4) * (FFALIGN(height, 16) >> 4);
684 uint16_t *dst = (uint16_t*)f->current_picture->data[0];
685 const int stride = f->current_picture->linesize[0]>>1;
686 const uint8_t *buf_end = buf + length;
689 if (length < mbs * 8) {
690 av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
691 return AVERROR_INVALIDDATA;
693 bytestream2_init(&g3, buf, length);
695 for (y = 0; y < height; y += 16) {
696 for (x = 0; x < width; x += 16) {
697 unsigned int color[4] = { 0 }, bits;
698 if (buf_end - buf < 8)
700 // warning following is purely guessed ...
701 color[0] = bytestream2_get_le16u(&g3);
702 color[1] = bytestream2_get_le16u(&g3);
704 if (color[0] & 0x8000)
705 av_log(NULL, AV_LOG_ERROR, "unk bit 1\n");
706 if (color[1] & 0x8000)
707 av_log(NULL, AV_LOG_ERROR, "unk bit 2\n");
709 color[2] = mix(color[0], color[1]);
710 color[3] = mix(color[1], color[0]);
712 bits = bytestream2_get_le32u(&g3);
713 for (y2 = 0; y2 < 16; y2++) {
714 for (x2 = 0; x2 < 16; x2++) {
715 int index = 2 * (x2 >> 2) + 8 * (y2 >> 2);
716 dst[y2 * stride + x2] = color[(bits >> index) & 3];
721 dst += 16 * stride - x;
727 static int decode_i_frame(FourXContext *f, const uint8_t *buf, int length)
730 const int width = f->avctx->width;
731 const int height = f->avctx->height;
732 const unsigned int bitstream_size = AV_RL32(buf);
733 unsigned int prestream_size;
734 const uint8_t *prestream;
736 if (bitstream_size > (1<<26) || length < bitstream_size + 12) {
737 av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
738 return AVERROR_INVALIDDATA;
741 prestream_size = 4 * AV_RL32(buf + bitstream_size + 4);
742 prestream = buf + bitstream_size + 12;
744 if (prestream_size + bitstream_size + 12 != length
745 || bitstream_size > (1 << 26)
746 || prestream_size > (1 << 26)) {
747 av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d %d\n",
748 prestream_size, bitstream_size, length);
749 return AVERROR_INVALIDDATA;
752 prestream = read_huffman_tables(f, prestream, buf + length - prestream);
756 init_get_bits(&f->gb, buf + 4, 8 * bitstream_size);
758 prestream_size = length + buf - prestream;
760 av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,
761 prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);
762 if (!f->bitstream_buffer)
763 return AVERROR(ENOMEM);
764 f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)prestream,
766 memset((uint8_t*)f->bitstream_buffer + prestream_size,
767 0, FF_INPUT_BUFFER_PADDING_SIZE);
768 init_get_bits(&f->pre_gb, f->bitstream_buffer, 8 * prestream_size);
770 f->last_dc = 0 * 128 * 8 * 8;
772 for (y = 0; y < height; y += 16) {
773 for (x = 0; x < width; x += 16) {
774 if ((ret = decode_i_mb(f)) < 0)
781 if (get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3) != 256)
782 av_log(f->avctx, AV_LOG_ERROR, "end mismatch\n");
787 static int decode_frame(AVCodecContext *avctx, void *data,
788 int *got_frame, AVPacket *avpkt)
790 const uint8_t *buf = avpkt->data;
791 int buf_size = avpkt->size;
792 FourXContext *const f = avctx->priv_data;
793 AVFrame *picture = data;
795 int i, frame_4cc, frame_size, ret;
798 return AVERROR_INVALIDDATA;
799 frame_4cc = AV_RL32(buf);
800 if (buf_size != AV_RL32(buf + 4) + 8 || buf_size < 20)
801 av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d\n",
802 buf_size, AV_RL32(buf + 4));
804 if (frame_4cc == AV_RL32("cfrm")) {
806 const int data_size = buf_size - 20;
807 const int id = AV_RL32(buf + 12);
808 const int whole_size = AV_RL32(buf + 16);
811 if (data_size < 0 || whole_size < 0) {
812 av_log(f->avctx, AV_LOG_ERROR, "sizes invalid\n");
813 return AVERROR_INVALIDDATA;
816 if (f->version <= 1) {
817 av_log(f->avctx, AV_LOG_ERROR, "cfrm in version %d\n", f->version);
818 return AVERROR_INVALIDDATA;
821 for (i = 0; i < CFRAME_BUFFER_COUNT; i++)
822 if (f->cfrm[i].id && f->cfrm[i].id < avctx->frame_number)
823 av_log(f->avctx, AV_LOG_ERROR, "lost c frame %d\n",
826 for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {
827 if (f->cfrm[i].id == id)
829 if (f->cfrm[i].size == 0)
833 if (i >= CFRAME_BUFFER_COUNT) {
839 if (data_size > UINT_MAX - cfrm->size - FF_INPUT_BUFFER_PADDING_SIZE)
840 return AVERROR_INVALIDDATA;
842 cfrm->data = av_fast_realloc(cfrm->data, &cfrm->allocated_size,
843 cfrm->size + data_size + FF_INPUT_BUFFER_PADDING_SIZE);
844 // explicit check needed as memcpy below might not catch a NULL
846 av_log(f->avctx, AV_LOG_ERROR, "realloc failure\n");
847 return AVERROR(ENOMEM);
850 memcpy(cfrm->data + cfrm->size, buf + 20, data_size);
851 cfrm->size += data_size;
853 if (cfrm->size >= whole_size) {
855 frame_size = cfrm->size;
857 if (id != avctx->frame_number)
858 av_log(f->avctx, AV_LOG_ERROR, "cframe id mismatch %d %d\n",
859 id, avctx->frame_number);
861 cfrm->size = cfrm->id = 0;
862 frame_4cc = AV_RL32("pfrm");
867 frame_size = buf_size - 12;
870 FFSWAP(AVFrame*, f->current_picture, f->last_picture);
872 p = f->current_picture;
873 avctx->coded_frame = p;
875 // alternatively we would have to use our own buffer management
876 avctx->flags |= CODEC_FLAG_EMU_EDGE;
879 if ((ret = avctx->reget_buffer(avctx, p)) < 0) {
880 av_log(avctx, AV_LOG_ERROR, "reget_buffer() failed\n");
884 if (frame_4cc == AV_RL32("ifr2")) {
885 p->pict_type= AV_PICTURE_TYPE_I;
886 if ((ret = decode_i2_frame(f, buf - 4, frame_size + 4)) < 0) {
887 av_log(f->avctx, AV_LOG_ERROR, "decode i2 frame failed\n");
890 } else if (frame_4cc == AV_RL32("ifrm")) {
891 p->pict_type= AV_PICTURE_TYPE_I;
892 if ((ret = decode_i_frame(f, buf, frame_size)) < 0) {
893 av_log(f->avctx, AV_LOG_ERROR, "decode i frame failed\n");
896 } else if (frame_4cc == AV_RL32("pfrm") || frame_4cc == AV_RL32("pfr2")) {
897 if (!f->last_picture->data[0]) {
898 f->last_picture->reference = 3;
899 if ((ret = ff_get_buffer(avctx, f->last_picture)) < 0) {
900 av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
903 for (i=0; i<avctx->height; i++)
904 memset(f->last_picture->data[0] + i*f->last_picture->linesize[0], 0, 2*avctx->width);
907 p->pict_type = AV_PICTURE_TYPE_P;
908 if ((ret = decode_p_frame(f, buf, frame_size)) < 0) {
909 av_log(f->avctx, AV_LOG_ERROR, "decode p frame failed\n");
912 } else if (frame_4cc == AV_RL32("snd_")) {
913 av_log(avctx, AV_LOG_ERROR, "ignoring snd_ chunk length:%d\n",
916 av_log(avctx, AV_LOG_ERROR, "ignoring unknown chunk length:%d\n",
920 p->key_frame = p->pict_type == AV_PICTURE_TYPE_I;
930 static av_cold int decode_init(AVCodecContext *avctx)
932 FourXContext * const f = avctx->priv_data;
934 if (avctx->extradata_size != 4 || !avctx->extradata) {
935 av_log(avctx, AV_LOG_ERROR, "extradata wrong or missing\n");
936 return AVERROR_INVALIDDATA;
938 if((avctx->width % 16) || (avctx->height % 16)) {
939 av_log(avctx, AV_LOG_ERROR, "unsupported width/height\n");
940 return AVERROR_INVALIDDATA;
943 avcodec_get_frame_defaults(&f->current_picture);
944 avcodec_get_frame_defaults(&f->last_picture);
945 f->version = AV_RL32(avctx->extradata) >> 16;
946 ff_dsputil_init(&f->dsp, avctx);
951 avctx->pix_fmt = AV_PIX_FMT_RGB565;
953 avctx->pix_fmt = AV_PIX_FMT_BGR555;
955 f->current_picture = avcodec_alloc_frame();
956 f->last_picture = avcodec_alloc_frame();
957 if (!f->current_picture || !f->last_picture) {
958 avcodec_free_frame(&f->current_picture);
959 avcodec_free_frame(&f->last_picture);
960 return AVERROR(ENOMEM);
967 static av_cold int decode_end(AVCodecContext *avctx)
969 FourXContext * const f = avctx->priv_data;
972 av_freep(&f->bitstream_buffer);
973 f->bitstream_buffer_size = 0;
974 for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {
975 av_freep(&f->cfrm[i].data);
976 f->cfrm[i].allocated_size = 0;
978 ff_free_vlc(&f->pre_vlc);
979 if (f->current_picture->data[0])
980 avctx->release_buffer(avctx, f->current_picture);
981 if (f->last_picture->data[0])
982 avctx->release_buffer(avctx, f->last_picture);
983 avcodec_free_frame(&f->current_picture);
984 avcodec_free_frame(&f->last_picture);
989 AVCodec ff_fourxm_decoder = {
991 .type = AVMEDIA_TYPE_VIDEO,
992 .id = AV_CODEC_ID_4XM,
993 .priv_data_size = sizeof(FourXContext),
996 .decode = decode_frame,
997 .capabilities = CODEC_CAP_DR1,
998 .long_name = NULL_IF_CONFIG_SMALL("4X Movie"),