1 /*
2 * Copyright (c) 1990 James Ashton - Sydney University
3 * Copyright (c) 2012 Stefano Sabatini
4 *
5 * This file is part of FFmpeg.
6 *
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.
11 *
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.
16 *
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
20 */
21
22 /**
23 * @file
24 * X-Face decoder, based on libcompface, by James Ashton.
25 */
26
27 #include "libavutil/pixdesc.h"
28 #include "avcodec.h"
29 #include "bytestream.h"
30 #include "codec_internal.h"
31 #include "internal.h"
32 #include "xface.h"
33
pop_integer(BigInt *b, const ProbRange *pranges)34 static int pop_integer(BigInt *b, const ProbRange *pranges)
35 {
36 uint8_t r;
37 int i;
38
39 /* extract the last byte into r, and shift right b by 8 bits */
40 ff_big_div(b, 0, &r);
41
42 i = 0;
43 while (r < pranges->offset || r >= pranges->range + pranges->offset) {
44 pranges++;
45 i++;
46 }
47 ff_big_mul(b, pranges->range);
48 ff_big_add(b, r - pranges->offset);
49 return i;
50 }
51
pop_greys(BigInt *b, char *bitmap, int w, int h)52 static void pop_greys(BigInt *b, char *bitmap, int w, int h)
53 {
54 if (w > 3) {
55 w /= 2;
56 h /= 2;
57 pop_greys(b, bitmap, w, h);
58 pop_greys(b, bitmap + w, w, h);
59 pop_greys(b, bitmap + XFACE_WIDTH * h, w, h);
60 pop_greys(b, bitmap + XFACE_WIDTH * h + w, w, h);
61 } else {
62 w = pop_integer(b, ff_xface_probranges_2x2);
63 if (w & 1) bitmap[0] = 1;
64 if (w & 2) bitmap[1] = 1;
65 if (w & 4) bitmap[XFACE_WIDTH] = 1;
66 if (w & 8) bitmap[XFACE_WIDTH + 1] = 1;
67 }
68 }
69
decode_block(BigInt *b, char *bitmap, int w, int h, int level)70 static void decode_block(BigInt *b, char *bitmap, int w, int h, int level)
71 {
72 switch (pop_integer(b, &ff_xface_probranges_per_level[level][0])) {
73 case XFACE_COLOR_WHITE:
74 return;
75 case XFACE_COLOR_BLACK:
76 pop_greys(b, bitmap, w, h);
77 return;
78 default:
79 w /= 2;
80 h /= 2;
81 level++;
82 decode_block(b, bitmap, w, h, level);
83 decode_block(b, bitmap + w, w, h, level);
84 decode_block(b, bitmap + h * XFACE_WIDTH, w, h, level);
85 decode_block(b, bitmap + w + h * XFACE_WIDTH, w, h, level);
86 return;
87 }
88 }
89
90 typedef struct XFaceContext {
91 uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding
92 } XFaceContext;
93
xface_decode_init(AVCodecContext *avctx)94 static av_cold int xface_decode_init(AVCodecContext *avctx)
95 {
96 if (avctx->width || avctx->height) {
97 if (avctx->width != XFACE_WIDTH || avctx->height != XFACE_HEIGHT) {
98 av_log(avctx, AV_LOG_ERROR,
99 "Size value %dx%d not supported, only accepts a size of %dx%d\n",
100 avctx->width, avctx->height, XFACE_WIDTH, XFACE_HEIGHT);
101 return AVERROR(EINVAL);
102 }
103 }
104
105 avctx->width = XFACE_WIDTH;
106 avctx->height = XFACE_HEIGHT;
107 avctx->pix_fmt = AV_PIX_FMT_MONOWHITE;
108
109 return 0;
110 }
111
xface_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *avpkt)112 static int xface_decode_frame(AVCodecContext *avctx, AVFrame *frame,
113 int *got_frame, AVPacket *avpkt)
114 {
115 XFaceContext *xface = avctx->priv_data;
116 int ret, i, j, k;
117 uint8_t byte;
118 BigInt b = {0};
119 char *buf;
120 int64_t c;
121
122 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
123 return ret;
124
125 for (i = 0, k = 0; i < avpkt->size && avpkt->data[i]; i++) {
126 c = avpkt->data[i];
127
128 /* ignore invalid digits */
129 if (c < XFACE_FIRST_PRINT || c > XFACE_LAST_PRINT)
130 continue;
131
132 if (++k > XFACE_MAX_DIGITS) {
133 av_log(avctx, AV_LOG_WARNING,
134 "Buffer is longer than expected, truncating at byte %d\n", i);
135 break;
136 }
137 ff_big_mul(&b, XFACE_PRINTS);
138 ff_big_add(&b, c - XFACE_FIRST_PRINT);
139 }
140
141 /* decode image and put it in bitmap */
142 memset(xface->bitmap, 0, XFACE_PIXELS);
143 buf = xface->bitmap;
144 decode_block(&b, buf, 16, 16, 0);
145 decode_block(&b, buf + 16, 16, 16, 0);
146 decode_block(&b, buf + 32, 16, 16, 0);
147 decode_block(&b, buf + XFACE_WIDTH * 16, 16, 16, 0);
148 decode_block(&b, buf + XFACE_WIDTH * 16 + 16, 16, 16, 0);
149 decode_block(&b, buf + XFACE_WIDTH * 16 + 32, 16, 16, 0);
150 decode_block(&b, buf + XFACE_WIDTH * 32 , 16, 16, 0);
151 decode_block(&b, buf + XFACE_WIDTH * 32 + 16, 16, 16, 0);
152 decode_block(&b, buf + XFACE_WIDTH * 32 + 32, 16, 16, 0);
153
154 ff_xface_generate_face(xface->bitmap, xface->bitmap);
155
156 /* convert image from 1=black 0=white bitmap to MONOWHITE */
157 buf = frame->data[0];
158 for (i = 0, j = 0, k = 0, byte = 0; i < XFACE_PIXELS; i++) {
159 byte += xface->bitmap[i];
160 if (k == 7) {
161 buf[j++] = byte;
162 byte = k = 0;
163 } else {
164 k++;
165 byte <<= 1;
166 }
167 if (j == XFACE_WIDTH/8) {
168 j = 0;
169 buf += frame->linesize[0];
170 }
171 }
172
173 *got_frame = 1;
174
175 return avpkt->size;
176 }
177
178 const FFCodec ff_xface_decoder = {
179 .p.name = "xface",
180 .p.long_name = NULL_IF_CONFIG_SMALL("X-face image"),
181 .p.type = AVMEDIA_TYPE_VIDEO,
182 .p.id = AV_CODEC_ID_XFACE,
183 .p.capabilities = AV_CODEC_CAP_DR1,
184 .priv_data_size = sizeof(XFaceContext),
185 .init = xface_decode_init,
186 FF_CODEC_DECODE_CB(xface_decode_frame),
187 .p.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
188 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
189 };
190