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 encoder, based on libcompface, by James Ashton.
25 */
26
27 #include "xface.h"
28 #include "avcodec.h"
29 #include "internal.h"
30 #include "libavutil/avassert.h"
31
32 typedef struct XFaceContext {
33 AVClass *class;
34 uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding
35 int max_line_len; ///< max line length for compressed data
36 int set_header; ///< set X-Face header in the output
37 } XFaceContext;
38
all_same(char * bitmap,int w,int h)39 static int all_same(char *bitmap, int w, int h)
40 {
41 char val, *row;
42 int x;
43
44 val = *bitmap;
45 while (h--) {
46 row = bitmap;
47 x = w;
48 while (x--)
49 if (*(row++) != val)
50 return 0;
51 bitmap += XFACE_WIDTH;
52 }
53 return 1;
54 }
55
all_black(char * bitmap,int w,int h)56 static int all_black(char *bitmap, int w, int h)
57 {
58 if (w > 3) {
59 w /= 2;
60 h /= 2;
61 return (all_black(bitmap, w, h) && all_black(bitmap + w, w, h) &&
62 all_black(bitmap + XFACE_WIDTH * h, w, h) &&
63 all_black(bitmap + XFACE_WIDTH * h + w, w, h));
64 } else {
65 /* at least one pixel in the 2x2 grid is non-zero */
66 return *bitmap || *(bitmap + 1) ||
67 *(bitmap + XFACE_WIDTH) || *(bitmap + XFACE_WIDTH + 1);
68 }
69 }
70
all_white(char * bitmap,int w,int h)71 static int all_white(char *bitmap, int w, int h)
72 {
73 return *bitmap == 0 && all_same(bitmap, w, h);
74 }
75
76 typedef struct {
77 ProbRange prob_ranges[XFACE_PIXELS*2];
78 int prob_ranges_idx;
79 } ProbRangesQueue;
80
pq_push(ProbRangesQueue * pq,const ProbRange * p)81 static inline int pq_push(ProbRangesQueue *pq, const ProbRange *p)
82 {
83 if (pq->prob_ranges_idx >= XFACE_PIXELS * 2 - 1)
84 return -1;
85 pq->prob_ranges[pq->prob_ranges_idx++] = *p;
86 return 0;
87 }
88
push_greys(ProbRangesQueue * pq,char * bitmap,int w,int h)89 static void push_greys(ProbRangesQueue *pq, char *bitmap, int w, int h)
90 {
91 if (w > 3) {
92 w /= 2;
93 h /= 2;
94 push_greys(pq, bitmap, w, h);
95 push_greys(pq, bitmap + w, w, h);
96 push_greys(pq, bitmap + XFACE_WIDTH * h, w, h);
97 push_greys(pq, bitmap + XFACE_WIDTH * h + w, w, h);
98 } else {
99 const ProbRange *p = ff_xface_probranges_2x2 +
100 *bitmap +
101 2 * *(bitmap + 1) +
102 4 * *(bitmap + XFACE_WIDTH) +
103 8 * *(bitmap + XFACE_WIDTH + 1);
104 pq_push(pq, p);
105 }
106 }
107
encode_block(char * bitmap,int w,int h,int level,ProbRangesQueue * pq)108 static void encode_block(char *bitmap, int w, int h, int level, ProbRangesQueue *pq)
109 {
110 if (all_white(bitmap, w, h)) {
111 pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_WHITE]);
112 } else if (all_black(bitmap, w, h)) {
113 pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_BLACK]);
114 push_greys(pq, bitmap, w, h);
115 } else {
116 pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_GREY]);
117 w /= 2;
118 h /= 2;
119 level++;
120 encode_block(bitmap, w, h, level, pq);
121 encode_block(bitmap + w, w, h, level, pq);
122 encode_block(bitmap + h * XFACE_WIDTH, w, h, level, pq);
123 encode_block(bitmap + w + h * XFACE_WIDTH, w, h, level, pq);
124 }
125 }
126
push_integer(BigInt * b,const ProbRange * prange)127 static void push_integer(BigInt *b, const ProbRange *prange)
128 {
129 uint8_t r;
130
131 ff_big_div(b, prange->range, &r);
132 ff_big_mul(b, 0);
133 ff_big_add(b, r + prange->offset);
134 }
135
xface_encode_frame(AVCodecContext * avctx,AVPacket * pkt,const AVFrame * frame,int * got_packet)136 static int xface_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
137 const AVFrame *frame, int *got_packet)
138 {
139 XFaceContext *xface = avctx->priv_data;
140 ProbRangesQueue pq = {{{ 0 }}, 0};
141 uint8_t bitmap_copy[XFACE_PIXELS];
142 BigInt b = {0};
143 int i, j, k, ret = 0;
144 const uint8_t *buf;
145 uint8_t *p;
146 char intbuf[XFACE_MAX_DIGITS];
147
148 if (avctx->width || avctx->height) {
149 if (avctx->width != XFACE_WIDTH || avctx->height != XFACE_HEIGHT) {
150 av_log(avctx, AV_LOG_ERROR,
151 "Size value %dx%d not supported, only accepts a size of %dx%d\n",
152 avctx->width, avctx->height, XFACE_WIDTH, XFACE_HEIGHT);
153 return AVERROR(EINVAL);
154 }
155 }
156 avctx->width = XFACE_WIDTH;
157 avctx->height = XFACE_HEIGHT;
158
159 /* convert image from MONOWHITE to 1=black 0=white bitmap */
160 buf = frame->data[0];
161 i = j = 0;
162 do {
163 for (k = 0; k < 8; k++)
164 xface->bitmap[i++] = (buf[j]>>(7-k))&1;
165 if (++j == XFACE_WIDTH/8) {
166 buf += frame->linesize[0];
167 j = 0;
168 }
169 } while (i < XFACE_PIXELS);
170
171 /* create a copy of bitmap */
172 memcpy(bitmap_copy, xface->bitmap, XFACE_PIXELS);
173 ff_xface_generate_face(xface->bitmap, bitmap_copy);
174
175 encode_block(xface->bitmap, 16, 16, 0, &pq);
176 encode_block(xface->bitmap + 16, 16, 16, 0, &pq);
177 encode_block(xface->bitmap + 32, 16, 16, 0, &pq);
178 encode_block(xface->bitmap + XFACE_WIDTH * 16, 16, 16, 0, &pq);
179 encode_block(xface->bitmap + XFACE_WIDTH * 16 + 16, 16, 16, 0, &pq);
180 encode_block(xface->bitmap + XFACE_WIDTH * 16 + 32, 16, 16, 0, &pq);
181 encode_block(xface->bitmap + XFACE_WIDTH * 32, 16, 16, 0, &pq);
182 encode_block(xface->bitmap + XFACE_WIDTH * 32 + 16, 16, 16, 0, &pq);
183 encode_block(xface->bitmap + XFACE_WIDTH * 32 + 32, 16, 16, 0, &pq);
184
185 while (pq.prob_ranges_idx > 0)
186 push_integer(&b, &pq.prob_ranges[--pq.prob_ranges_idx]);
187
188 /* write the inverted big integer in b to intbuf */
189 i = 0;
190 av_assert0(b.nb_words < XFACE_MAX_WORDS);
191 while (b.nb_words) {
192 uint8_t r;
193 ff_big_div(&b, XFACE_PRINTS, &r);
194 av_assert0(i < sizeof(intbuf));
195 intbuf[i++] = r + XFACE_FIRST_PRINT;
196 }
197
198 if ((ret = ff_alloc_packet2(avctx, pkt, i+2, 0)) < 0)
199 return ret;
200
201 /* revert the number, and close the buffer */
202 p = pkt->data;
203 while (--i >= 0)
204 *(p++) = intbuf[i];
205 *(p++) = '\n';
206 *(p++) = 0;
207
208 pkt->flags |= AV_PKT_FLAG_KEY;
209 *got_packet = 1;
210
211 return 0;
212 }
213
214 AVCodec ff_xface_encoder = {
215 .name = "xface",
216 .long_name = NULL_IF_CONFIG_SMALL("X-face image"),
217 .type = AVMEDIA_TYPE_VIDEO,
218 .id = AV_CODEC_ID_XFACE,
219 .priv_data_size = sizeof(XFaceContext),
220 .encode2 = xface_encode_frame,
221 .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
222 };
223