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 "codec_internal.h"
30 #include "encode.h"
31 #include "libavutil/avassert.h"
32
33 typedef struct XFaceContext {
34 AVClass *class;
35 uint8_t bitmap[XFACE_PIXELS]; ///< image used internally for decoding
36 int max_line_len; ///< max line length for compressed data
37 int set_header; ///< set X-Face header in the output
38 } XFaceContext;
39
all_same(char * bitmap,int w,int h)40 static int all_same(char *bitmap, int w, int h)
41 {
42 char val, *row;
43 int x;
44
45 val = *bitmap;
46 while (h--) {
47 row = bitmap;
48 x = w;
49 while (x--)
50 if (*(row++) != val)
51 return 0;
52 bitmap += XFACE_WIDTH;
53 }
54 return 1;
55 }
56
all_black(char * bitmap,int w,int h)57 static int all_black(char *bitmap, int w, int h)
58 {
59 if (w > 3) {
60 w /= 2;
61 h /= 2;
62 return (all_black(bitmap, w, h) && all_black(bitmap + w, w, h) &&
63 all_black(bitmap + XFACE_WIDTH * h, w, h) &&
64 all_black(bitmap + XFACE_WIDTH * h + w, w, h));
65 } else {
66 /* at least one pixel in the 2x2 grid is non-zero */
67 return *bitmap || *(bitmap + 1) ||
68 *(bitmap + XFACE_WIDTH) || *(bitmap + XFACE_WIDTH + 1);
69 }
70 }
71
all_white(char * bitmap,int w,int h)72 static int all_white(char *bitmap, int w, int h)
73 {
74 return *bitmap == 0 && all_same(bitmap, w, h);
75 }
76
77 typedef struct {
78 ProbRange prob_ranges[XFACE_PIXELS*2];
79 int prob_ranges_idx;
80 } ProbRangesQueue;
81
pq_push(ProbRangesQueue * pq,const ProbRange * p)82 static inline int pq_push(ProbRangesQueue *pq, const ProbRange *p)
83 {
84 if (pq->prob_ranges_idx >= XFACE_PIXELS * 2 - 1)
85 return -1;
86 pq->prob_ranges[pq->prob_ranges_idx++] = *p;
87 return 0;
88 }
89
push_greys(ProbRangesQueue * pq,char * bitmap,int w,int h)90 static void push_greys(ProbRangesQueue *pq, char *bitmap, int w, int h)
91 {
92 if (w > 3) {
93 w /= 2;
94 h /= 2;
95 push_greys(pq, bitmap, w, h);
96 push_greys(pq, bitmap + w, w, h);
97 push_greys(pq, bitmap + XFACE_WIDTH * h, w, h);
98 push_greys(pq, bitmap + XFACE_WIDTH * h + w, w, h);
99 } else {
100 const ProbRange *p = ff_xface_probranges_2x2 +
101 *bitmap +
102 2 * *(bitmap + 1) +
103 4 * *(bitmap + XFACE_WIDTH) +
104 8 * *(bitmap + XFACE_WIDTH + 1);
105 pq_push(pq, p);
106 }
107 }
108
encode_block(char * bitmap,int w,int h,int level,ProbRangesQueue * pq)109 static void encode_block(char *bitmap, int w, int h, int level, ProbRangesQueue *pq)
110 {
111 if (all_white(bitmap, w, h)) {
112 pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_WHITE]);
113 } else if (all_black(bitmap, w, h)) {
114 pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_BLACK]);
115 push_greys(pq, bitmap, w, h);
116 } else {
117 pq_push(pq, &ff_xface_probranges_per_level[level][XFACE_COLOR_GREY]);
118 w /= 2;
119 h /= 2;
120 level++;
121 encode_block(bitmap, w, h, level, pq);
122 encode_block(bitmap + w, w, h, level, pq);
123 encode_block(bitmap + h * XFACE_WIDTH, w, h, level, pq);
124 encode_block(bitmap + w + h * XFACE_WIDTH, w, h, level, pq);
125 }
126 }
127
push_integer(BigInt * b,const ProbRange * prange)128 static void push_integer(BigInt *b, const ProbRange *prange)
129 {
130 uint8_t r;
131
132 ff_big_div(b, prange->range, &r);
133 ff_big_mul(b, 0);
134 ff_big_add(b, r + prange->offset);
135 }
136
xface_encode_frame(AVCodecContext * avctx,AVPacket * pkt,const AVFrame * frame,int * got_packet)137 static int xface_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
138 const AVFrame *frame, int *got_packet)
139 {
140 XFaceContext *xface = avctx->priv_data;
141 ProbRangesQueue pq = {{{ 0 }}, 0};
142 uint8_t bitmap_copy[XFACE_PIXELS];
143 BigInt b = {0};
144 int i, j, k, ret = 0;
145 const uint8_t *buf;
146 uint8_t *p;
147 char intbuf[XFACE_MAX_DIGITS];
148
149 if (avctx->width || avctx->height) {
150 if (avctx->width != XFACE_WIDTH || avctx->height != XFACE_HEIGHT) {
151 av_log(avctx, AV_LOG_ERROR,
152 "Size value %dx%d not supported, only accepts a size of %dx%d\n",
153 avctx->width, avctx->height, XFACE_WIDTH, XFACE_HEIGHT);
154 return AVERROR(EINVAL);
155 }
156 }
157 avctx->width = XFACE_WIDTH;
158 avctx->height = XFACE_HEIGHT;
159
160 /* convert image from MONOWHITE to 1=black 0=white bitmap */
161 buf = frame->data[0];
162 i = j = 0;
163 do {
164 for (k = 0; k < 8; k++)
165 xface->bitmap[i++] = (buf[j]>>(7-k))&1;
166 if (++j == XFACE_WIDTH/8) {
167 buf += frame->linesize[0];
168 j = 0;
169 }
170 } while (i < XFACE_PIXELS);
171
172 /* create a copy of bitmap */
173 memcpy(bitmap_copy, xface->bitmap, XFACE_PIXELS);
174 ff_xface_generate_face(xface->bitmap, bitmap_copy);
175
176 encode_block(xface->bitmap, 16, 16, 0, &pq);
177 encode_block(xface->bitmap + 16, 16, 16, 0, &pq);
178 encode_block(xface->bitmap + 32, 16, 16, 0, &pq);
179 encode_block(xface->bitmap + XFACE_WIDTH * 16, 16, 16, 0, &pq);
180 encode_block(xface->bitmap + XFACE_WIDTH * 16 + 16, 16, 16, 0, &pq);
181 encode_block(xface->bitmap + XFACE_WIDTH * 16 + 32, 16, 16, 0, &pq);
182 encode_block(xface->bitmap + XFACE_WIDTH * 32, 16, 16, 0, &pq);
183 encode_block(xface->bitmap + XFACE_WIDTH * 32 + 16, 16, 16, 0, &pq);
184 encode_block(xface->bitmap + XFACE_WIDTH * 32 + 32, 16, 16, 0, &pq);
185
186 while (pq.prob_ranges_idx > 0)
187 push_integer(&b, &pq.prob_ranges[--pq.prob_ranges_idx]);
188
189 /* write the inverted big integer in b to intbuf */
190 i = 0;
191 av_assert0(b.nb_words < XFACE_MAX_WORDS);
192 while (b.nb_words) {
193 uint8_t r;
194 ff_big_div(&b, XFACE_PRINTS, &r);
195 av_assert0(i < sizeof(intbuf));
196 intbuf[i++] = r + XFACE_FIRST_PRINT;
197 }
198
199 if ((ret = ff_get_encode_buffer(avctx, pkt, i + 2, 0)) < 0)
200 return ret;
201
202 /* revert the number, and close the buffer */
203 p = pkt->data;
204 while (--i >= 0)
205 *(p++) = intbuf[i];
206 *(p++) = '\n';
207 *(p++) = 0;
208
209 *got_packet = 1;
210
211 return 0;
212 }
213
214 const FFCodec ff_xface_encoder = {
215 .p.name = "xface",
216 .p.long_name = NULL_IF_CONFIG_SMALL("X-face image"),
217 .p.type = AVMEDIA_TYPE_VIDEO,
218 .p.id = AV_CODEC_ID_XFACE,
219 .p.capabilities = AV_CODEC_CAP_DR1,
220 .p.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_MONOWHITE, AV_PIX_FMT_NONE },
221 .priv_data_size = sizeof(XFaceContext),
222 FF_CODEC_ENCODE_CB(xface_encode_frame),
223 };
224