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/avassert.h"
28 #include "libavutil/frame.h"
29 #include "libavutil/intreadwrite.h"
31 #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, int linesize)
263 for (i = 0; i < 256; i++) {
265 f->mv[i] = mv[i][0] + mv[i][1] * linesize / 2;
267 f->mv[i] = (i & 15) - 8 + ((i >> 4) - 8) * linesize / 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, const 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 int 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);
350 av_assert0(code >= 0 && code <= 6 && log2w >= 0);
354 if ((ret = decode_p_block(f, dst, src, log2w, log2h, stride)) < 0)
356 return decode_p_block(f, dst + (stride << log2h),
357 src + (stride << log2h),
358 log2w, log2h, stride);
359 } else if (code == 2) {
361 if ((ret = decode_p_block(f, dst , src, log2w, log2h, stride)) < 0)
363 return decode_p_block(f, dst + (1 << log2w),
365 log2w, log2h, stride);
366 } else if (code == 6) {
367 if (bytestream2_get_bytes_left(&f->g2) < 4) {
368 av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
369 return AVERROR_INVALIDDATA;
372 dst[0] = bytestream2_get_le16u(&f->g2);
373 dst[1] = bytestream2_get_le16u(&f->g2);
375 dst[0] = bytestream2_get_le16u(&f->g2);
376 dst[stride] = bytestream2_get_le16u(&f->g2);
381 if ((code&3)==0 && bytestream2_get_bytes_left(&f->g) < 1) {
382 av_log(f->avctx, AV_LOG_ERROR, "bytestream overread\n");
383 return AVERROR_INVALIDDATA;
387 src += f->mv[bytestream2_get_byte(&f->g)];
388 } else if (code == 3 && f->version >= 2) {
390 } else if (code == 4) {
391 src += f->mv[bytestream2_get_byte(&f->g)];
392 if (bytestream2_get_bytes_left(&f->g2) < 2){
393 av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
394 return AVERROR_INVALIDDATA;
396 dc = bytestream2_get_le16(&f->g2);
397 } else if (code == 5) {
398 if (bytestream2_get_bytes_left(&f->g2) < 2){
399 av_log(f->avctx, AV_LOG_ERROR, "wordstream overread\n");
400 return AVERROR_INVALIDDATA;
402 av_assert0(start <= src && src <= end);
404 dc = bytestream2_get_le16(&f->g2);
407 if (start > src || src > end) {
408 av_log(f->avctx, AV_LOG_ERROR, "mv out of pic\n");
409 return AVERROR_INVALIDDATA;
412 mcdc(dst, src, log2w, h, stride, scale, dc);
417 static int decode_p_frame(FourXContext *f, AVFrame *frame,
418 const uint8_t *buf, int length)
421 const int width = f->avctx->width;
422 const int height = f->avctx->height;
423 uint16_t *dst = (uint16_t *)frame->data[0];
424 const int stride = frame->linesize[0] >> 1;
426 unsigned int bitstream_size, bytestream_size, wordstream_size, extra,
427 bytestream_offset, wordstream_offset;
430 if (!f->last_picture->data[0]) {
431 if ((ret = ff_get_buffer(f->avctx, f->last_picture,
432 AV_GET_BUFFER_FLAG_REF)) < 0) {
435 for (y=0; y<f->avctx->height; y++)
436 memset(f->last_picture->data[0] + y*f->last_picture->linesize[0], 0, 2*f->avctx->width);
439 src = (uint16_t *)f->last_picture->data[0];
441 if (f->version > 1) {
444 return AVERROR_INVALIDDATA;
445 bitstream_size = AV_RL32(buf + 8);
446 wordstream_size = AV_RL32(buf + 12);
447 bytestream_size = AV_RL32(buf + 16);
450 bitstream_size = AV_RL16(buf - 4);
451 wordstream_size = AV_RL16(buf - 2);
452 bytestream_size = FFMAX(length - bitstream_size - wordstream_size, 0);
455 if (bitstream_size > length || bitstream_size >= INT_MAX/8 ||
456 bytestream_size > length - bitstream_size ||
457 wordstream_size > length - bytestream_size - bitstream_size ||
458 extra > length - bytestream_size - bitstream_size - wordstream_size) {
459 av_log(f->avctx, AV_LOG_ERROR, "lengths %d %d %d %d\n", bitstream_size, bytestream_size, wordstream_size,
460 bitstream_size+ bytestream_size+ wordstream_size - length);
461 return AVERROR_INVALIDDATA;
464 av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,
465 bitstream_size + FF_INPUT_BUFFER_PADDING_SIZE);
466 if (!f->bitstream_buffer)
467 return AVERROR(ENOMEM);
468 f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)(buf + extra),
470 memset((uint8_t*)f->bitstream_buffer + bitstream_size,
471 0, FF_INPUT_BUFFER_PADDING_SIZE);
472 init_get_bits(&f->gb, f->bitstream_buffer, 8 * bitstream_size);
474 wordstream_offset = extra + bitstream_size;
475 bytestream_offset = extra + bitstream_size + wordstream_size;
476 bytestream2_init(&f->g2, buf + wordstream_offset,
477 length - wordstream_offset);
478 bytestream2_init(&f->g, buf + bytestream_offset,
479 length - bytestream_offset);
481 init_mv(f, frame->linesize[0]);
483 for (y = 0; y < height; y += 8) {
484 for (x = 0; x < width; x += 8)
485 if ((ret = decode_p_block(f, dst + x, src + x, 3, 3, stride)) < 0)
495 * decode block and dequantize.
496 * Note this is almost identical to MJPEG.
498 static int decode_i_block(FourXContext *f, int16_t *block)
500 int code, i, j, level, val;
502 if (get_bits_left(&f->gb) < 2){
503 av_log(f->avctx, AV_LOG_ERROR, "%d bits left before decode_i_block()\n", get_bits_left(&f->gb));
508 val = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
510 av_log(f->avctx, AV_LOG_ERROR, "error dc run != 0\n");
513 val = get_xbits(&f->gb, val);
515 val = val * dequant_table[0] + f->last_dc;
516 f->last_dc = block[0] = val;
520 code = get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3);
528 level = get_xbits(&f->gb, code & 0xf);
531 av_log(f->avctx, AV_LOG_ERROR, "run %d oveflow\n", i);
535 j = ff_zigzag_direct[i];
536 block[j] = level * dequant_table[j];
546 static inline void idct_put(FourXContext *f, AVFrame *frame, int x, int y)
548 int16_t (*block)[64] = f->block;
549 int stride = frame->linesize[0] >> 1;
551 uint16_t *dst = ((uint16_t*)frame->data[0]) + y * stride + x;
553 for (i = 0; i < 4; i++) {
554 block[i][0] += 0x80 * 8 * 8;
558 if (!(f->avctx->flags & CODEC_FLAG_GRAY)) {
559 for (i = 4; i < 6; i++)
563 /* Note transform is:
564 * y = ( 1b + 4g + 2r) / 14
565 * cb = ( 3b - 2g - 1r) / 14
566 * cr = (-1b - 4g + 5r) / 14 */
567 for (y = 0; y < 8; y++) {
568 for (x = 0; x < 8; x++) {
569 int16_t *temp = block[(x >> 2) + 2 * (y >> 2)] +
570 2 * (x & 3) + 2 * 8 * (y & 3); // FIXME optimize
571 int cb = block[4][x + 8 * y];
572 int cr = block[5][x + 8 * y];
573 int cg = (cb + cr) >> 1;
579 dst[0] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
581 dst[1] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
583 dst[stride] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
585 dst[1 + stride] = ((y + cb) >> 3) + (((y - cg) & 0xFC) << 3) + (((y + cr) & 0xF8) << 8);
588 dst += 2 * stride - 2 * 8;
592 static int decode_i_mb(FourXContext *f)
597 f->dsp.clear_blocks(f->block[0]);
599 for (i = 0; i < 6; i++)
600 if ((ret = decode_i_block(f, f->block[i])) < 0)
606 static const uint8_t *read_huffman_tables(FourXContext *f,
607 const uint8_t * const buf,
610 int frequency[512] = { 0 };
613 uint8_t len_tab[257];
616 const uint8_t *ptr = buf;
617 const uint8_t *ptr_end = buf + buf_size;
620 memset(up, -1, sizeof(up));
627 if (ptr_end - ptr < FFMAX(end - start + 1, 0) + 1) {
628 av_log(f->avctx, AV_LOG_ERROR, "invalid data in read_huffman_tables\n");
632 for (i = start; i <= end; i++)
633 frequency[i] = *ptr++;
642 while ((ptr - buf) & 3)
643 ptr++; // 4byte align
646 av_log(f->avctx, AV_LOG_ERROR, "ptr overflow in read_huffman_tables\n");
650 for (j = 257; j < 512; j++) {
651 int min_freq[2] = { 256 * 256, 256 * 256 };
652 int smallest[2] = { 0, 0 };
654 for (i = 0; i < j; i++) {
655 if (frequency[i] == 0)
657 if (frequency[i] < min_freq[1]) {
658 if (frequency[i] < min_freq[0]) {
659 min_freq[1] = min_freq[0];
660 smallest[1] = smallest[0];
661 min_freq[0] = frequency[i];
664 min_freq[1] = frequency[i];
669 if (min_freq[1] == 256 * 256)
672 frequency[j] = min_freq[0] + min_freq[1];
673 flag[smallest[0]] = 0;
674 flag[smallest[1]] = 1;
677 frequency[smallest[0]] = frequency[smallest[1]] = 0;
680 for (j = 0; j < 257; j++) {
681 int node, len = 0, bits = 0;
683 for (node = j; up[node] != -1; node = up[node]) {
684 bits += flag[node] << len;
687 // can this happen at all ?
688 av_log(f->avctx, AV_LOG_ERROR,
689 "vlc length overflow\n");
696 if (init_vlc(&f->pre_vlc, ACDC_VLC_BITS, 257, len_tab, 1, 1,
703 static int mix(int c0, int c1)
705 int blue = 2 * (c0 & 0x001F) + (c1 & 0x001F);
706 int green = (2 * (c0 & 0x03E0) + (c1 & 0x03E0)) >> 5;
707 int red = 2 * (c0 >> 10) + (c1 >> 10);
708 return red / 3 * 1024 + green / 3 * 32 + blue / 3;
711 static int decode_i2_frame(FourXContext *f, AVFrame *frame, const uint8_t *buf, int length)
714 const int width = f->avctx->width;
715 const int height = f->avctx->height;
716 const int mbs = (FFALIGN(width, 16) >> 4) * (FFALIGN(height, 16) >> 4);
717 uint16_t *dst = (uint16_t*)frame->data[0];
718 const int stride = frame->linesize[0]>>1;
719 const uint8_t *buf_end = buf + length;
722 if (length < mbs * 8) {
723 av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
724 return AVERROR_INVALIDDATA;
726 bytestream2_init(&g3, buf, length);
728 for (y = 0; y < height; y += 16) {
729 for (x = 0; x < width; x += 16) {
730 unsigned int color[4] = { 0 }, bits;
731 if (buf_end - buf < 8)
733 // warning following is purely guessed ...
734 color[0] = bytestream2_get_le16u(&g3);
735 color[1] = bytestream2_get_le16u(&g3);
737 if (color[0] & 0x8000)
738 av_log(f->avctx, AV_LOG_ERROR, "unk bit 1\n");
739 if (color[1] & 0x8000)
740 av_log(f->avctx, AV_LOG_ERROR, "unk bit 2\n");
742 color[2] = mix(color[0], color[1]);
743 color[3] = mix(color[1], color[0]);
745 bits = bytestream2_get_le32u(&g3);
746 for (y2 = 0; y2 < 16; y2++) {
747 for (x2 = 0; x2 < 16; x2++) {
748 int index = 2 * (x2 >> 2) + 8 * (y2 >> 2);
749 dst[y2 * stride + x2] = color[(bits >> index) & 3];
754 dst += 16 * stride - x;
760 static int decode_i_frame(FourXContext *f, AVFrame *frame, const uint8_t *buf, int length)
763 const int width = f->avctx->width;
764 const int height = f->avctx->height;
765 const unsigned int bitstream_size = AV_RL32(buf);
766 unsigned int prestream_size;
767 const uint8_t *prestream;
769 if (bitstream_size > (1<<26) || length < bitstream_size + 12) {
770 av_log(f->avctx, AV_LOG_ERROR, "packet size too small\n");
771 return AVERROR_INVALIDDATA;
774 prestream_size = 4 * AV_RL32(buf + bitstream_size + 4);
775 prestream = buf + bitstream_size + 12;
777 if (prestream_size + bitstream_size + 12 != length
778 || bitstream_size > (1 << 26)
779 || prestream_size > (1 << 26)) {
780 av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d %d\n",
781 prestream_size, bitstream_size, length);
782 return AVERROR_INVALIDDATA;
785 prestream = read_huffman_tables(f, prestream, prestream_size);
787 av_log(f->avctx, AV_LOG_ERROR, "Error reading Huffman tables.\n");
788 return AVERROR_INVALIDDATA;
791 av_assert0(prestream <= buf + length);
793 init_get_bits(&f->gb, buf + 4, 8 * bitstream_size);
795 prestream_size = length + buf - prestream;
797 av_fast_malloc(&f->bitstream_buffer, &f->bitstream_buffer_size,
798 prestream_size + FF_INPUT_BUFFER_PADDING_SIZE);
799 if (!f->bitstream_buffer)
800 return AVERROR(ENOMEM);
801 f->dsp.bswap_buf(f->bitstream_buffer, (const uint32_t*)prestream,
803 memset((uint8_t*)f->bitstream_buffer + prestream_size,
804 0, FF_INPUT_BUFFER_PADDING_SIZE);
805 init_get_bits(&f->pre_gb, f->bitstream_buffer, 8 * prestream_size);
807 f->last_dc = 0 * 128 * 8 * 8;
809 for (y = 0; y < height; y += 16) {
810 for (x = 0; x < width; x += 16) {
811 if ((ret = decode_i_mb(f)) < 0)
814 idct_put(f, frame, x, y);
818 if (get_vlc2(&f->pre_gb, f->pre_vlc.table, ACDC_VLC_BITS, 3) != 256)
819 av_log(f->avctx, AV_LOG_ERROR, "end mismatch\n");
824 static int decode_frame(AVCodecContext *avctx, void *data,
825 int *got_frame, AVPacket *avpkt)
827 const uint8_t *buf = avpkt->data;
828 int buf_size = avpkt->size;
829 FourXContext *const f = avctx->priv_data;
830 AVFrame *picture = data;
831 int i, frame_4cc, frame_size, ret;
834 return AVERROR_INVALIDDATA;
836 if (buf_size < AV_RL32(buf + 4) + 8) {
837 av_log(f->avctx, AV_LOG_ERROR, "size mismatch %d %d\n",
838 buf_size, AV_RL32(buf + 4));
839 return AVERROR_INVALIDDATA;
842 frame_4cc = AV_RL32(buf);
844 if (frame_4cc == AV_RL32("cfrm")) {
847 const int data_size = buf_size - 20;
850 if (f->version <= 1) {
851 av_log(f->avctx, AV_LOG_ERROR, "cfrm in version %d\n", f->version);
852 return AVERROR_INVALIDDATA;
855 id = AV_RL32(buf + 12);
856 whole_size = AV_RL32(buf + 16);
858 if (data_size < 0 || whole_size < 0) {
859 av_log(f->avctx, AV_LOG_ERROR, "sizes invalid\n");
860 return AVERROR_INVALIDDATA;
863 for (i = 0; i < CFRAME_BUFFER_COUNT; i++)
864 if (f->cfrm[i].id && f->cfrm[i].id < avctx->frame_number)
865 av_log(f->avctx, AV_LOG_ERROR, "lost c frame %d\n",
868 for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {
869 if (f->cfrm[i].id == id)
871 if (f->cfrm[i].size == 0)
875 if (i >= CFRAME_BUFFER_COUNT) {
881 if (data_size > UINT_MAX - cfrm->size - FF_INPUT_BUFFER_PADDING_SIZE)
882 return AVERROR_INVALIDDATA;
884 cfrm->data = av_fast_realloc(cfrm->data, &cfrm->allocated_size,
885 cfrm->size + data_size + FF_INPUT_BUFFER_PADDING_SIZE);
886 // explicit check needed as memcpy below might not catch a NULL
888 av_log(f->avctx, AV_LOG_ERROR, "realloc failure\n");
889 return AVERROR(ENOMEM);
892 memcpy(cfrm->data + cfrm->size, buf + 20, data_size);
893 cfrm->size += data_size;
895 if (cfrm->size >= whole_size) {
897 frame_size = cfrm->size;
899 if (id != avctx->frame_number)
900 av_log(f->avctx, AV_LOG_ERROR, "cframe id mismatch %d %d\n",
901 id, avctx->frame_number);
904 return AVERROR_INVALIDDATA;
906 cfrm->size = cfrm->id = 0;
907 frame_4cc = AV_RL32("pfrm");
912 frame_size = buf_size - 12;
915 FFSWAP(AVFrame*, f->current_picture, f->last_picture);
917 // alternatively we would have to use our own buffer management
918 avctx->flags |= CODEC_FLAG_EMU_EDGE;
920 if ((ret = ff_reget_buffer(avctx, f->current_picture)) < 0)
923 if (frame_4cc == AV_RL32("ifr2")) {
924 f->current_picture->pict_type = AV_PICTURE_TYPE_I;
925 if ((ret = decode_i2_frame(f, f->current_picture, buf - 4, frame_size + 4)) < 0) {
926 av_log(f->avctx, AV_LOG_ERROR, "decode i2 frame failed\n");
929 } else if (frame_4cc == AV_RL32("ifrm")) {
930 f->current_picture->pict_type = AV_PICTURE_TYPE_I;
931 if ((ret = decode_i_frame(f, f->current_picture, buf, frame_size)) < 0) {
932 av_log(f->avctx, AV_LOG_ERROR, "decode i frame failed\n");
935 } else if (frame_4cc == AV_RL32("pfrm") || frame_4cc == AV_RL32("pfr2")) {
936 f->current_picture->pict_type = AV_PICTURE_TYPE_P;
937 if ((ret = decode_p_frame(f, f->current_picture, buf, frame_size)) < 0) {
938 av_log(f->avctx, AV_LOG_ERROR, "decode p frame failed\n");
941 } else if (frame_4cc == AV_RL32("snd_")) {
942 av_log(avctx, AV_LOG_ERROR, "ignoring snd_ chunk length:%d\n",
945 av_log(avctx, AV_LOG_ERROR, "ignoring unknown chunk length:%d\n",
949 f->current_picture->key_frame = f->current_picture->pict_type == AV_PICTURE_TYPE_I;
951 if ((ret = av_frame_ref(picture, f->current_picture)) < 0)
960 static av_cold int decode_init(AVCodecContext *avctx)
962 FourXContext * const f = avctx->priv_data;
964 if (avctx->extradata_size != 4 || !avctx->extradata) {
965 av_log(avctx, AV_LOG_ERROR, "extradata wrong or missing\n");
966 return AVERROR_INVALIDDATA;
968 if((avctx->width % 16) || (avctx->height % 16)) {
969 av_log(avctx, AV_LOG_ERROR, "unsupported width/height\n");
970 return AVERROR_INVALIDDATA;
973 f->version = AV_RL32(avctx->extradata) >> 16;
974 ff_dsputil_init(&f->dsp, avctx);
979 avctx->pix_fmt = AV_PIX_FMT_RGB565;
981 avctx->pix_fmt = AV_PIX_FMT_BGR555;
983 f->current_picture = av_frame_alloc();
984 f->last_picture = av_frame_alloc();
985 if (!f->current_picture || !f->last_picture)
986 return AVERROR(ENOMEM);
992 static av_cold int decode_end(AVCodecContext *avctx)
994 FourXContext * const f = avctx->priv_data;
997 av_freep(&f->bitstream_buffer);
998 f->bitstream_buffer_size = 0;
999 for (i = 0; i < CFRAME_BUFFER_COUNT; i++) {
1000 av_freep(&f->cfrm[i].data);
1001 f->cfrm[i].allocated_size = 0;
1003 ff_free_vlc(&f->pre_vlc);
1004 av_frame_free(&f->current_picture);
1005 av_frame_free(&f->last_picture);
1010 AVCodec ff_fourxm_decoder = {
1012 .type = AVMEDIA_TYPE_VIDEO,
1013 .id = AV_CODEC_ID_4XM,
1014 .priv_data_size = sizeof(FourXContext),
1015 .init = decode_init,
1016 .close = decode_end,
1017 .decode = decode_frame,
1018 .capabilities = CODEC_CAP_DR1,
1019 .long_name = NULL_IF_CONFIG_SMALL("4X Movie"),