cleanup gif, use BISTREAM_WRITER_LE
[libav.git] / libavcodec / gif.c
1 /*
2 * GIF encoder.
3 * Copyright (c) 2000 Fabrice Bellard.
4 * Copyright (c) 2002 Francois Revol.
5 * Copyright (c) 2006 Baptiste Coudurier.
6 *
7 * This file is part of FFmpeg.
8 *
9 * FFmpeg is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * FFmpeg is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with FFmpeg; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 */
23
24 /*
25 * First version by Francois Revol revol@free.fr
26 *
27 * Features and limitations:
28 * - currently no compression is performed,
29 * in fact the size of the data is 9/8 the size of the image in 8bpp
30 * - uses only a global standard palette
31 * - tested with IE 5.0, Opera for BeOS, NetPositive (BeOS), and Mozilla (BeOS).
32 *
33 * Reference documents:
34 * http://www.goice.co.jp/member/mo/formats/gif.html
35 * http://astronomy.swin.edu.au/pbourke/dataformats/gif/
36 * http://www.dcs.ed.ac.uk/home/mxr/gfx/2d/GIF89a.txt
37 *
38 * this url claims to have an LZW algorithm not covered by Unisys patent:
39 * http://www.msg.net/utility/whirlgif/gifencod.html
40 * could help reduce the size of the files _a lot_...
41 * some sites mentions an RLE type compression also.
42 */
43
44 #include "avcodec.h"
45 #include "bytestream.h"
46
47 /* The GIF format uses reversed order for bitstreams... */
48 /* at least they don't use PDP_ENDIAN :) */
49 #define BITSTREAM_WRITER_LE
50
51 #include "bitstream.h"
52
53 /* bitstream minipacket size */
54 #define GIF_CHUNKS 100
55
56 /* slows down the decoding (and some browsers don't like it) */
57 /* update on the 'some browsers don't like it issue from above: this was probably due to missing 'Data Sub-block Terminator' (byte 19) in the app_header */
58 #define GIF_ADD_APP_HEADER // required to enable looping of animated gif
59
60 typedef struct {
61 unsigned char r;
62 unsigned char g;
63 unsigned char b;
64 } rgb_triplet;
65
66 /* we use the standard 216 color palette */
67
68 /* this script was used to create the palette:
69 * for r in 00 33 66 99 cc ff; do for g in 00 33 66 99 cc ff; do echo -n " "; for b in 00 33 66 99 cc ff; do
70 * echo -n "{ 0x$r, 0x$g, 0x$b }, "; done; echo ""; done; done
71 */
72
73 static const rgb_triplet gif_clut[216] = {
74 { 0x00, 0x00, 0x00 }, { 0x00, 0x00, 0x33 }, { 0x00, 0x00, 0x66 }, { 0x00, 0x00, 0x99 }, { 0x00, 0x00, 0xcc }, { 0x00, 0x00, 0xff },
75 { 0x00, 0x33, 0x00 }, { 0x00, 0x33, 0x33 }, { 0x00, 0x33, 0x66 }, { 0x00, 0x33, 0x99 }, { 0x00, 0x33, 0xcc }, { 0x00, 0x33, 0xff },
76 { 0x00, 0x66, 0x00 }, { 0x00, 0x66, 0x33 }, { 0x00, 0x66, 0x66 }, { 0x00, 0x66, 0x99 }, { 0x00, 0x66, 0xcc }, { 0x00, 0x66, 0xff },
77 { 0x00, 0x99, 0x00 }, { 0x00, 0x99, 0x33 }, { 0x00, 0x99, 0x66 }, { 0x00, 0x99, 0x99 }, { 0x00, 0x99, 0xcc }, { 0x00, 0x99, 0xff },
78 { 0x00, 0xcc, 0x00 }, { 0x00, 0xcc, 0x33 }, { 0x00, 0xcc, 0x66 }, { 0x00, 0xcc, 0x99 }, { 0x00, 0xcc, 0xcc }, { 0x00, 0xcc, 0xff },
79 { 0x00, 0xff, 0x00 }, { 0x00, 0xff, 0x33 }, { 0x00, 0xff, 0x66 }, { 0x00, 0xff, 0x99 }, { 0x00, 0xff, 0xcc }, { 0x00, 0xff, 0xff },
80 { 0x33, 0x00, 0x00 }, { 0x33, 0x00, 0x33 }, { 0x33, 0x00, 0x66 }, { 0x33, 0x00, 0x99 }, { 0x33, 0x00, 0xcc }, { 0x33, 0x00, 0xff },
81 { 0x33, 0x33, 0x00 }, { 0x33, 0x33, 0x33 }, { 0x33, 0x33, 0x66 }, { 0x33, 0x33, 0x99 }, { 0x33, 0x33, 0xcc }, { 0x33, 0x33, 0xff },
82 { 0x33, 0x66, 0x00 }, { 0x33, 0x66, 0x33 }, { 0x33, 0x66, 0x66 }, { 0x33, 0x66, 0x99 }, { 0x33, 0x66, 0xcc }, { 0x33, 0x66, 0xff },
83 { 0x33, 0x99, 0x00 }, { 0x33, 0x99, 0x33 }, { 0x33, 0x99, 0x66 }, { 0x33, 0x99, 0x99 }, { 0x33, 0x99, 0xcc }, { 0x33, 0x99, 0xff },
84 { 0x33, 0xcc, 0x00 }, { 0x33, 0xcc, 0x33 }, { 0x33, 0xcc, 0x66 }, { 0x33, 0xcc, 0x99 }, { 0x33, 0xcc, 0xcc }, { 0x33, 0xcc, 0xff },
85 { 0x33, 0xff, 0x00 }, { 0x33, 0xff, 0x33 }, { 0x33, 0xff, 0x66 }, { 0x33, 0xff, 0x99 }, { 0x33, 0xff, 0xcc }, { 0x33, 0xff, 0xff },
86 { 0x66, 0x00, 0x00 }, { 0x66, 0x00, 0x33 }, { 0x66, 0x00, 0x66 }, { 0x66, 0x00, 0x99 }, { 0x66, 0x00, 0xcc }, { 0x66, 0x00, 0xff },
87 { 0x66, 0x33, 0x00 }, { 0x66, 0x33, 0x33 }, { 0x66, 0x33, 0x66 }, { 0x66, 0x33, 0x99 }, { 0x66, 0x33, 0xcc }, { 0x66, 0x33, 0xff },
88 { 0x66, 0x66, 0x00 }, { 0x66, 0x66, 0x33 }, { 0x66, 0x66, 0x66 }, { 0x66, 0x66, 0x99 }, { 0x66, 0x66, 0xcc }, { 0x66, 0x66, 0xff },
89 { 0x66, 0x99, 0x00 }, { 0x66, 0x99, 0x33 }, { 0x66, 0x99, 0x66 }, { 0x66, 0x99, 0x99 }, { 0x66, 0x99, 0xcc }, { 0x66, 0x99, 0xff },
90 { 0x66, 0xcc, 0x00 }, { 0x66, 0xcc, 0x33 }, { 0x66, 0xcc, 0x66 }, { 0x66, 0xcc, 0x99 }, { 0x66, 0xcc, 0xcc }, { 0x66, 0xcc, 0xff },
91 { 0x66, 0xff, 0x00 }, { 0x66, 0xff, 0x33 }, { 0x66, 0xff, 0x66 }, { 0x66, 0xff, 0x99 }, { 0x66, 0xff, 0xcc }, { 0x66, 0xff, 0xff },
92 { 0x99, 0x00, 0x00 }, { 0x99, 0x00, 0x33 }, { 0x99, 0x00, 0x66 }, { 0x99, 0x00, 0x99 }, { 0x99, 0x00, 0xcc }, { 0x99, 0x00, 0xff },
93 { 0x99, 0x33, 0x00 }, { 0x99, 0x33, 0x33 }, { 0x99, 0x33, 0x66 }, { 0x99, 0x33, 0x99 }, { 0x99, 0x33, 0xcc }, { 0x99, 0x33, 0xff },
94 { 0x99, 0x66, 0x00 }, { 0x99, 0x66, 0x33 }, { 0x99, 0x66, 0x66 }, { 0x99, 0x66, 0x99 }, { 0x99, 0x66, 0xcc }, { 0x99, 0x66, 0xff },
95 { 0x99, 0x99, 0x00 }, { 0x99, 0x99, 0x33 }, { 0x99, 0x99, 0x66 }, { 0x99, 0x99, 0x99 }, { 0x99, 0x99, 0xcc }, { 0x99, 0x99, 0xff },
96 { 0x99, 0xcc, 0x00 }, { 0x99, 0xcc, 0x33 }, { 0x99, 0xcc, 0x66 }, { 0x99, 0xcc, 0x99 }, { 0x99, 0xcc, 0xcc }, { 0x99, 0xcc, 0xff },
97 { 0x99, 0xff, 0x00 }, { 0x99, 0xff, 0x33 }, { 0x99, 0xff, 0x66 }, { 0x99, 0xff, 0x99 }, { 0x99, 0xff, 0xcc }, { 0x99, 0xff, 0xff },
98 { 0xcc, 0x00, 0x00 }, { 0xcc, 0x00, 0x33 }, { 0xcc, 0x00, 0x66 }, { 0xcc, 0x00, 0x99 }, { 0xcc, 0x00, 0xcc }, { 0xcc, 0x00, 0xff },
99 { 0xcc, 0x33, 0x00 }, { 0xcc, 0x33, 0x33 }, { 0xcc, 0x33, 0x66 }, { 0xcc, 0x33, 0x99 }, { 0xcc, 0x33, 0xcc }, { 0xcc, 0x33, 0xff },
100 { 0xcc, 0x66, 0x00 }, { 0xcc, 0x66, 0x33 }, { 0xcc, 0x66, 0x66 }, { 0xcc, 0x66, 0x99 }, { 0xcc, 0x66, 0xcc }, { 0xcc, 0x66, 0xff },
101 { 0xcc, 0x99, 0x00 }, { 0xcc, 0x99, 0x33 }, { 0xcc, 0x99, 0x66 }, { 0xcc, 0x99, 0x99 }, { 0xcc, 0x99, 0xcc }, { 0xcc, 0x99, 0xff },
102 { 0xcc, 0xcc, 0x00 }, { 0xcc, 0xcc, 0x33 }, { 0xcc, 0xcc, 0x66 }, { 0xcc, 0xcc, 0x99 }, { 0xcc, 0xcc, 0xcc }, { 0xcc, 0xcc, 0xff },
103 { 0xcc, 0xff, 0x00 }, { 0xcc, 0xff, 0x33 }, { 0xcc, 0xff, 0x66 }, { 0xcc, 0xff, 0x99 }, { 0xcc, 0xff, 0xcc }, { 0xcc, 0xff, 0xff },
104 { 0xff, 0x00, 0x00 }, { 0xff, 0x00, 0x33 }, { 0xff, 0x00, 0x66 }, { 0xff, 0x00, 0x99 }, { 0xff, 0x00, 0xcc }, { 0xff, 0x00, 0xff },
105 { 0xff, 0x33, 0x00 }, { 0xff, 0x33, 0x33 }, { 0xff, 0x33, 0x66 }, { 0xff, 0x33, 0x99 }, { 0xff, 0x33, 0xcc }, { 0xff, 0x33, 0xff },
106 { 0xff, 0x66, 0x00 }, { 0xff, 0x66, 0x33 }, { 0xff, 0x66, 0x66 }, { 0xff, 0x66, 0x99 }, { 0xff, 0x66, 0xcc }, { 0xff, 0x66, 0xff },
107 { 0xff, 0x99, 0x00 }, { 0xff, 0x99, 0x33 }, { 0xff, 0x99, 0x66 }, { 0xff, 0x99, 0x99 }, { 0xff, 0x99, 0xcc }, { 0xff, 0x99, 0xff },
108 { 0xff, 0xcc, 0x00 }, { 0xff, 0xcc, 0x33 }, { 0xff, 0xcc, 0x66 }, { 0xff, 0xcc, 0x99 }, { 0xff, 0xcc, 0xcc }, { 0xff, 0xcc, 0xff },
109 { 0xff, 0xff, 0x00 }, { 0xff, 0xff, 0x33 }, { 0xff, 0xff, 0x66 }, { 0xff, 0xff, 0x99 }, { 0xff, 0xff, 0xcc }, { 0xff, 0xff, 0xff },
110 };
111
112 /* GIF header */
113 static int gif_image_write_header(uint8_t **bytestream,
114 int width, int height, int loop_count,
115 uint32_t *palette)
116 {
117 int i;
118 unsigned int v;
119
120 bytestream_put_buffer(bytestream, "GIF", 3);
121 bytestream_put_buffer(bytestream, "89a", 3);
122 bytestream_put_le16(bytestream, width);
123 bytestream_put_le16(bytestream, height);
124
125 bytestream_put_byte(bytestream, 0xf7); /* flags: global clut, 256 entries */
126 bytestream_put_byte(bytestream, 0x1f); /* background color index */
127 bytestream_put_byte(bytestream, 0); /* aspect ratio */
128
129 /* the global palette */
130 if (!palette) {
131 bytestream_put_buffer(bytestream, (const unsigned char *)gif_clut, 216*3);
132 for(i=0;i<((256-216)*3);i++)
133 bytestream_put_byte(bytestream, 0);
134 } else {
135 for(i=0;i<256;i++) {
136 v = palette[i];
137 bytestream_put_be24(bytestream, v);
138 }
139 }
140
141 /* update: this is the 'NETSCAPE EXTENSION' that allows for looped animated gif
142 see http://members.aol.com/royalef/gifabout.htm#net-extension
143
144 byte 1 : 33 (hex 0x21) GIF Extension code
145 byte 2 : 255 (hex 0xFF) Application Extension Label
146 byte 3 : 11 (hex (0x0B) Length of Application Block
147 (eleven bytes of data to follow)
148 bytes 4 to 11 : "NETSCAPE"
149 bytes 12 to 14 : "2.0"
150 byte 15 : 3 (hex 0x03) Length of Data Sub-Block
151 (three bytes of data to follow)
152 byte 16 : 1 (hex 0x01)
153 bytes 17 to 18 : 0 to 65535, an unsigned integer in
154 lo-hi byte format. This indicate the
155 number of iterations the loop should
156 be executed.
157 bytes 19 : 0 (hex 0x00) a Data Sub-block Terminator
158 */
159
160 /* application extension header */
161 #ifdef GIF_ADD_APP_HEADER
162 if (loop_count >= 0 && loop_count <= 65535) {
163 bytestream_put_byte(bytestream, 0x21);
164 bytestream_put_byte(bytestream, 0xff);
165 bytestream_put_byte(bytestream, 0x0b);
166 bytestream_put_buffer(bytestream, "NETSCAPE2.0", 11); // bytes 4 to 14
167 bytestream_put_byte(bytestream, 0x03); // byte 15
168 bytestream_put_byte(bytestream, 0x01); // byte 16
169 bytestream_put_le16(bytestream, (uint16_t)loop_count);
170 bytestream_put_byte(bytestream, 0x00); // byte 19
171 }
172 #endif
173 return 0;
174 }
175
176 /* this is maybe slow, but allows for extensions */
177 static inline unsigned char gif_clut_index(uint8_t r, uint8_t g, uint8_t b)
178 {
179 return ((((r)/47)%6)*6*6+(((g)/47)%6)*6+(((b)/47)%6));
180 }
181
182
183 static int gif_image_write_image(uint8_t **bytestream,
184 int x1, int y1, int width, int height,
185 const uint8_t *buf, int linesize, int pix_fmt)
186 {
187 PutBitContext p;
188 uint8_t buffer[200]; /* 100 * 9 / 8 = 113 */
189 int i, left, w, v;
190 const uint8_t *ptr;
191 /* image block */
192
193 bytestream_put_byte(bytestream, 0x2c);
194 bytestream_put_le16(bytestream, x1);
195 bytestream_put_le16(bytestream, y1);
196 bytestream_put_le16(bytestream, width);
197 bytestream_put_le16(bytestream, height);
198 bytestream_put_byte(bytestream, 0x00); /* flags */
199 /* no local clut */
200
201 bytestream_put_byte(bytestream, 0x08);
202
203 left= width * height;
204
205 init_put_bits(&p, buffer, 130);
206
207 /*
208 * the thing here is the bitstream is written as little packets, with a size byte before
209 * but it's still the same bitstream between packets (no flush !)
210 */
211 ptr = buf;
212 w = width;
213 while(left>0) {
214
215 put_bits(&p, 9, 0x0100); /* clear code */
216
217 for(i=(left<GIF_CHUNKS)?left:GIF_CHUNKS;i;i--) {
218 if (pix_fmt == PIX_FMT_RGB24) {
219 v = gif_clut_index(ptr[0], ptr[1], ptr[2]);
220 ptr+=3;
221 } else {
222 v = *ptr++;
223 }
224 put_bits(&p, 9, v);
225 if (--w == 0) {
226 w = width;
227 buf += linesize;
228 ptr = buf;
229 }
230 }
231
232 if(left<=GIF_CHUNKS) {
233 put_bits(&p, 9, 0x101); /* end of stream */
234 flush_put_bits(&p);
235 }
236 if(pbBufPtr(&p) - p.buf > 0) {
237 bytestream_put_byte(bytestream, pbBufPtr(&p) - p.buf); /* byte count of the packet */
238 bytestream_put_buffer(bytestream, p.buf, pbBufPtr(&p) - p.buf); /* the actual buffer */
239 p.buf_ptr = p.buf; /* dequeue the bytes off the bitstream */
240 }
241 left-=GIF_CHUNKS;
242 }
243 bytestream_put_byte(bytestream, 0x00); /* end of image block */
244 bytestream_put_byte(bytestream, 0x3b);
245 return 0;
246 }
247
248 typedef struct {
249 int64_t time, file_time;
250 uint8_t buffer[100]; /* data chunks */
251 AVFrame picture;
252 } GIFContext;
253
254 static av_cold int gif_encode_init(AVCodecContext *avctx)
255 {
256 GIFContext *s = avctx->priv_data;
257
258 avctx->coded_frame = &s->picture;
259 return 0;
260 }
261
262 /* better than nothing gif encoder */
263 static int gif_encode_frame(AVCodecContext *avctx, unsigned char *outbuf, int buf_size, void *data)
264 {
265 GIFContext *s = avctx->priv_data;
266 AVFrame *pict = data;
267 AVFrame *const p = (AVFrame *)&s->picture;
268 uint8_t *outbuf_ptr = outbuf;
269
270 *p = *pict;
271 p->pict_type = FF_I_TYPE;
272 p->key_frame = 1;
273 gif_image_write_header(&outbuf_ptr, avctx->width, avctx->height, -1, (uint32_t *)pict->data[1]);
274 gif_image_write_image(&outbuf_ptr, 0, 0, avctx->width, avctx->height, pict->data[0], pict->linesize[0], PIX_FMT_PAL8);
275 return outbuf_ptr - outbuf;
276 }
277
278 AVCodec gif_encoder = {
279 "gif",
280 CODEC_TYPE_VIDEO,
281 CODEC_ID_GIF,
282 sizeof(GIFContext),
283 gif_encode_init,
284 gif_encode_frame,
285 NULL, //encode_end,
286 .pix_fmts= (enum PixelFormat[]){PIX_FMT_PAL8, PIX_FMT_NONE},
287 .long_name= NULL_IF_CONFIG_SMALL("GIF (Graphics Interchange Format)"),
288 };