added automatic GIF/animated GIF probing - added GIF as an image format too - added...
[libav.git] / libavformat / gif.c
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1/*
2 * Animated GIF encoder
19720f15 3 * Copyright (c) 2000 Fabrice Bellard.
6cea494e 4 *
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5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
6cea494e 9 *
19720f15 10 * This library is distributed in the hope that it will be useful,
6cea494e 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
6cea494e 14 *
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15 * You should have received a copy of the GNU Lesser General Public
16 * License along with this library; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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18 */
19
20/*
21 * First version by Francois Revol revol@free.fr
22 *
23 * Features and limitations:
24 * - currently no compression is performed,
25 * in fact the size of the data is 9/8 the size of the image in 8bpp
26 * - uses only a global standard palette
27 * - tested with IE 5.0, Opera for BeOS, NetPositive (BeOS), and Mozilla (BeOS).
28 *
29 * Reference documents:
30 * http://www.goice.co.jp/member/mo/formats/gif.html
31 * http://astronomy.swin.edu.au/pbourke/dataformats/gif/
32 * http://www.dcs.ed.ac.uk/home/mxr/gfx/2d/GIF89a.txt
33 *
34 * this url claims to have an LZW algorithm not covered by Unisys patent:
35 * http://www.msg.net/utility/whirlgif/gifencod.html
36 * could help reduce the size of the files _a lot_...
37 * some sites mentions an RLE type compression also.
38 */
39
40#include "avformat.h"
41
42/* bitstream minipacket size */
43#define GIF_CHUNKS 100
44
45/* slows down the decoding (and some browsers doesn't like it) */
46/* #define GIF_ADD_APP_HEADER */
47
48typedef struct {
49 unsigned char r;
50 unsigned char g;
51 unsigned char b;
52} rgb_triplet;
53
54/* we use the standard 216 color palette */
55
56/* this script was used to create the palette:
57 * 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
58 * echo -n "{ 0x$r, 0x$g, 0x$b }, "; done; echo ""; done; done
59 */
60
84082497 61static const rgb_triplet gif_clut[216] = {
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62 { 0x00, 0x00, 0x00 }, { 0x00, 0x00, 0x33 }, { 0x00, 0x00, 0x66 }, { 0x00, 0x00, 0x99 }, { 0x00, 0x00, 0xcc }, { 0x00, 0x00, 0xff },
63 { 0x00, 0x33, 0x00 }, { 0x00, 0x33, 0x33 }, { 0x00, 0x33, 0x66 }, { 0x00, 0x33, 0x99 }, { 0x00, 0x33, 0xcc }, { 0x00, 0x33, 0xff },
64 { 0x00, 0x66, 0x00 }, { 0x00, 0x66, 0x33 }, { 0x00, 0x66, 0x66 }, { 0x00, 0x66, 0x99 }, { 0x00, 0x66, 0xcc }, { 0x00, 0x66, 0xff },
65 { 0x00, 0x99, 0x00 }, { 0x00, 0x99, 0x33 }, { 0x00, 0x99, 0x66 }, { 0x00, 0x99, 0x99 }, { 0x00, 0x99, 0xcc }, { 0x00, 0x99, 0xff },
66 { 0x00, 0xcc, 0x00 }, { 0x00, 0xcc, 0x33 }, { 0x00, 0xcc, 0x66 }, { 0x00, 0xcc, 0x99 }, { 0x00, 0xcc, 0xcc }, { 0x00, 0xcc, 0xff },
67 { 0x00, 0xff, 0x00 }, { 0x00, 0xff, 0x33 }, { 0x00, 0xff, 0x66 }, { 0x00, 0xff, 0x99 }, { 0x00, 0xff, 0xcc }, { 0x00, 0xff, 0xff },
68 { 0x33, 0x00, 0x00 }, { 0x33, 0x00, 0x33 }, { 0x33, 0x00, 0x66 }, { 0x33, 0x00, 0x99 }, { 0x33, 0x00, 0xcc }, { 0x33, 0x00, 0xff },
69 { 0x33, 0x33, 0x00 }, { 0x33, 0x33, 0x33 }, { 0x33, 0x33, 0x66 }, { 0x33, 0x33, 0x99 }, { 0x33, 0x33, 0xcc }, { 0x33, 0x33, 0xff },
70 { 0x33, 0x66, 0x00 }, { 0x33, 0x66, 0x33 }, { 0x33, 0x66, 0x66 }, { 0x33, 0x66, 0x99 }, { 0x33, 0x66, 0xcc }, { 0x33, 0x66, 0xff },
71 { 0x33, 0x99, 0x00 }, { 0x33, 0x99, 0x33 }, { 0x33, 0x99, 0x66 }, { 0x33, 0x99, 0x99 }, { 0x33, 0x99, 0xcc }, { 0x33, 0x99, 0xff },
72 { 0x33, 0xcc, 0x00 }, { 0x33, 0xcc, 0x33 }, { 0x33, 0xcc, 0x66 }, { 0x33, 0xcc, 0x99 }, { 0x33, 0xcc, 0xcc }, { 0x33, 0xcc, 0xff },
73 { 0x33, 0xff, 0x00 }, { 0x33, 0xff, 0x33 }, { 0x33, 0xff, 0x66 }, { 0x33, 0xff, 0x99 }, { 0x33, 0xff, 0xcc }, { 0x33, 0xff, 0xff },
74 { 0x66, 0x00, 0x00 }, { 0x66, 0x00, 0x33 }, { 0x66, 0x00, 0x66 }, { 0x66, 0x00, 0x99 }, { 0x66, 0x00, 0xcc }, { 0x66, 0x00, 0xff },
75 { 0x66, 0x33, 0x00 }, { 0x66, 0x33, 0x33 }, { 0x66, 0x33, 0x66 }, { 0x66, 0x33, 0x99 }, { 0x66, 0x33, 0xcc }, { 0x66, 0x33, 0xff },
76 { 0x66, 0x66, 0x00 }, { 0x66, 0x66, 0x33 }, { 0x66, 0x66, 0x66 }, { 0x66, 0x66, 0x99 }, { 0x66, 0x66, 0xcc }, { 0x66, 0x66, 0xff },
77 { 0x66, 0x99, 0x00 }, { 0x66, 0x99, 0x33 }, { 0x66, 0x99, 0x66 }, { 0x66, 0x99, 0x99 }, { 0x66, 0x99, 0xcc }, { 0x66, 0x99, 0xff },
78 { 0x66, 0xcc, 0x00 }, { 0x66, 0xcc, 0x33 }, { 0x66, 0xcc, 0x66 }, { 0x66, 0xcc, 0x99 }, { 0x66, 0xcc, 0xcc }, { 0x66, 0xcc, 0xff },
79 { 0x66, 0xff, 0x00 }, { 0x66, 0xff, 0x33 }, { 0x66, 0xff, 0x66 }, { 0x66, 0xff, 0x99 }, { 0x66, 0xff, 0xcc }, { 0x66, 0xff, 0xff },
80 { 0x99, 0x00, 0x00 }, { 0x99, 0x00, 0x33 }, { 0x99, 0x00, 0x66 }, { 0x99, 0x00, 0x99 }, { 0x99, 0x00, 0xcc }, { 0x99, 0x00, 0xff },
81 { 0x99, 0x33, 0x00 }, { 0x99, 0x33, 0x33 }, { 0x99, 0x33, 0x66 }, { 0x99, 0x33, 0x99 }, { 0x99, 0x33, 0xcc }, { 0x99, 0x33, 0xff },
82 { 0x99, 0x66, 0x00 }, { 0x99, 0x66, 0x33 }, { 0x99, 0x66, 0x66 }, { 0x99, 0x66, 0x99 }, { 0x99, 0x66, 0xcc }, { 0x99, 0x66, 0xff },
83 { 0x99, 0x99, 0x00 }, { 0x99, 0x99, 0x33 }, { 0x99, 0x99, 0x66 }, { 0x99, 0x99, 0x99 }, { 0x99, 0x99, 0xcc }, { 0x99, 0x99, 0xff },
84 { 0x99, 0xcc, 0x00 }, { 0x99, 0xcc, 0x33 }, { 0x99, 0xcc, 0x66 }, { 0x99, 0xcc, 0x99 }, { 0x99, 0xcc, 0xcc }, { 0x99, 0xcc, 0xff },
85 { 0x99, 0xff, 0x00 }, { 0x99, 0xff, 0x33 }, { 0x99, 0xff, 0x66 }, { 0x99, 0xff, 0x99 }, { 0x99, 0xff, 0xcc }, { 0x99, 0xff, 0xff },
86 { 0xcc, 0x00, 0x00 }, { 0xcc, 0x00, 0x33 }, { 0xcc, 0x00, 0x66 }, { 0xcc, 0x00, 0x99 }, { 0xcc, 0x00, 0xcc }, { 0xcc, 0x00, 0xff },
87 { 0xcc, 0x33, 0x00 }, { 0xcc, 0x33, 0x33 }, { 0xcc, 0x33, 0x66 }, { 0xcc, 0x33, 0x99 }, { 0xcc, 0x33, 0xcc }, { 0xcc, 0x33, 0xff },
88 { 0xcc, 0x66, 0x00 }, { 0xcc, 0x66, 0x33 }, { 0xcc, 0x66, 0x66 }, { 0xcc, 0x66, 0x99 }, { 0xcc, 0x66, 0xcc }, { 0xcc, 0x66, 0xff },
89 { 0xcc, 0x99, 0x00 }, { 0xcc, 0x99, 0x33 }, { 0xcc, 0x99, 0x66 }, { 0xcc, 0x99, 0x99 }, { 0xcc, 0x99, 0xcc }, { 0xcc, 0x99, 0xff },
90 { 0xcc, 0xcc, 0x00 }, { 0xcc, 0xcc, 0x33 }, { 0xcc, 0xcc, 0x66 }, { 0xcc, 0xcc, 0x99 }, { 0xcc, 0xcc, 0xcc }, { 0xcc, 0xcc, 0xff },
91 { 0xcc, 0xff, 0x00 }, { 0xcc, 0xff, 0x33 }, { 0xcc, 0xff, 0x66 }, { 0xcc, 0xff, 0x99 }, { 0xcc, 0xff, 0xcc }, { 0xcc, 0xff, 0xff },
92 { 0xff, 0x00, 0x00 }, { 0xff, 0x00, 0x33 }, { 0xff, 0x00, 0x66 }, { 0xff, 0x00, 0x99 }, { 0xff, 0x00, 0xcc }, { 0xff, 0x00, 0xff },
93 { 0xff, 0x33, 0x00 }, { 0xff, 0x33, 0x33 }, { 0xff, 0x33, 0x66 }, { 0xff, 0x33, 0x99 }, { 0xff, 0x33, 0xcc }, { 0xff, 0x33, 0xff },
94 { 0xff, 0x66, 0x00 }, { 0xff, 0x66, 0x33 }, { 0xff, 0x66, 0x66 }, { 0xff, 0x66, 0x99 }, { 0xff, 0x66, 0xcc }, { 0xff, 0x66, 0xff },
95 { 0xff, 0x99, 0x00 }, { 0xff, 0x99, 0x33 }, { 0xff, 0x99, 0x66 }, { 0xff, 0x99, 0x99 }, { 0xff, 0x99, 0xcc }, { 0xff, 0x99, 0xff },
96 { 0xff, 0xcc, 0x00 }, { 0xff, 0xcc, 0x33 }, { 0xff, 0xcc, 0x66 }, { 0xff, 0xcc, 0x99 }, { 0xff, 0xcc, 0xcc }, { 0xff, 0xcc, 0xff },
97 { 0xff, 0xff, 0x00 }, { 0xff, 0xff, 0x33 }, { 0xff, 0xff, 0x66 }, { 0xff, 0xff, 0x99 }, { 0xff, 0xff, 0xcc }, { 0xff, 0xff, 0xff },
98};
99
100/* The GIF format uses reversed order for bitstreams... */
101/* at least they don't use PDP_ENDIAN :) */
102/* so we 'extend' PutBitContext. hmmm, OOP :) */
103/* seems this thing changed slightly since I wrote it... */
104
105#ifdef ALT_BITSTREAM_WRITER
106# error no ALT_BITSTREAM_WRITER support for now
107#endif
108
84082497 109static void gif_put_bits_rev(PutBitContext *s, int n, unsigned int value)
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110{
111 unsigned int bit_buf;
112 int bit_cnt;
113
114#ifdef STATS
115 st_out_bit_counts[st_current_index] += n;
116#endif
117 // printf("put_bits=%d %x\n", n, value);
118 assert(n == 32 || value < (1U << n));
119
120 bit_buf = s->bit_buf;
121 bit_cnt = 32 - s->bit_left; /* XXX:lazyness... was = s->bit_cnt; */
122
123 // printf("n=%d value=%x cnt=%d buf=%x\n", n, value, bit_cnt, bit_buf);
124 /* XXX: optimize */
125 if (n < (32-bit_cnt)) {
126 bit_buf |= value << (bit_cnt);
127 bit_cnt+=n;
128 } else {
129 bit_buf |= value << (bit_cnt);
130
131 *s->buf_ptr = bit_buf & 0xff;
132 s->buf_ptr[1] = (bit_buf >> 8) & 0xff;
133 s->buf_ptr[2] = (bit_buf >> 16) & 0xff;
134 s->buf_ptr[3] = (bit_buf >> 24) & 0xff;
135
136 //printf("bitbuf = %08x\n", bit_buf);
137 s->buf_ptr+=4;
138 if (s->buf_ptr >= s->buf_end)
139 puts("bit buffer overflow !!"); // should never happen ! who got rid of the callback ???
140// flush_buffer_rev(s);
141 bit_cnt=bit_cnt + n - 32;
142 if (bit_cnt == 0) {
143 bit_buf = 0;
144 } else {
145 bit_buf = value >> (n - bit_cnt);
146 }
147 }
148
149 s->bit_buf = bit_buf;
150 s->bit_left = 32 - bit_cnt;
151}
152
6cea494e 153/* pad the end of the output stream with zeros */
84082497 154static void gif_flush_put_bits_rev(PutBitContext *s)
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155{
156 while (s->bit_left < 32) {
157 /* XXX: should test end of buffer */
158 *s->buf_ptr++=s->bit_buf & 0xff;
159 s->bit_buf>>=8;
160 s->bit_left+=8;
161 }
162// flush_buffer_rev(s);
163 s->bit_left=32;
164 s->bit_buf=0;
165}
166
167/* !RevPutBitContext */
168
169typedef struct {
170 UINT8 buffer[100]; /* data chunks */
171 INT64 time, file_time;
172} GIFContext;
173
174static int gif_write_header(AVFormatContext *s)
175{
c9a65ca8 176 GIFContext *gif = s->priv_data;
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177 ByteIOContext *pb = &s->pb;
178 AVCodecContext *enc, *video_enc;
179 int i, width, height, rate;
180
181/* XXX: do we reject audio streams or just ignore them ?
182 if(s->nb_streams > 1)
183 return -1;
184*/
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185 gif->time = 0;
186 gif->file_time = 0;
187
188 video_enc = NULL;
189 for(i=0;i<s->nb_streams;i++) {
190 enc = &s->streams[i]->codec;
191 if (enc->codec_type != CODEC_TYPE_AUDIO)
192 video_enc = enc;
193 }
194
195 if (!video_enc) {
1ea4f593 196 av_free(gif);
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197 return -1;
198 } else {
199 width = video_enc->width;
200 height = video_enc->height;
201 rate = video_enc->frame_rate;
202 }
203
204 /* XXX: is it allowed ? seems to work so far... */
205 video_enc->pix_fmt = PIX_FMT_RGB24;
206
207 /* GIF header */
208
209 put_tag(pb, "GIF");
210 put_tag(pb, "89a");
211 put_le16(pb, width);
212 put_le16(pb, height);
213
214 put_byte(pb, 0xf7); /* flags: global clut, 256 entries */
215 put_byte(pb, 0x1f); /* background color index */
216 put_byte(pb, 0); /* aspect ratio */
217
218 /* the global palette */
219
220 put_buffer(pb, (unsigned char *)gif_clut, 216*3);
221 for(i=0;i<((256-216)*3);i++)
222 put_byte(pb, 0);
223
224 /* application extension header */
225 /* XXX: not really sure what to put in here... */
226#ifdef GIF_ADD_APP_HEADER
227 put_byte(pb, 0x21);
228 put_byte(pb, 0xff);
229 put_byte(pb, 0x0b);
230 put_tag(pb, "NETSCAPE2.0");
231 put_byte(pb, 0x03);
232 put_byte(pb, 0x01);
233 put_byte(pb, 0x00);
234 put_byte(pb, 0x00);
235#endif
236
237 put_flush_packet(&s->pb);
238 return 0;
239}
240
241/* this is maybe slow, but allows for extensions */
242static inline unsigned char gif_clut_index(rgb_triplet *clut, UINT8 r, UINT8 g, UINT8 b)
243{
244 return ((((r)/47)%6)*6*6+(((g)/47)%6)*6+(((b)/47)%6));
245}
246
247/* chunk writer callback */
248/* !!! XXX:deprecated
249static void gif_put_chunk(void *pbctx, UINT8 *buffer, int count)
250{
251 ByteIOContext *pb = (ByteIOContext *)pbctx;
252 put_byte(pb, (UINT8)count);
253 put_buffer(pb, buffer, count);
254}
255*/
256
257static int gif_write_video(AVFormatContext *s,
258 AVCodecContext *enc, UINT8 *buf, int size)
259{
260 ByteIOContext *pb = &s->pb;
261 GIFContext *gif = s->priv_data;
262 int i, left, jiffies;
263 INT64 delay;
264 PutBitContext p;
265 UINT8 buffer[200]; /* 100 * 9 / 8 = 113 */
266
267
268 /* graphic control extension block */
269 put_byte(pb, 0x21);
270 put_byte(pb, 0xf9);
271 put_byte(pb, 0x04); /* block size */
272 put_byte(pb, 0x04); /* flags */
273
274 /* 1 jiffy is 1/70 s */
275 /* the delay_time field indicates the number of jiffies - 1 */
276 delay = gif->file_time - gif->time;
277
278 /* XXX: should use delay, in order to be more accurate */
279 /* instead of using the same rounded value each time */
280 /* XXX: don't even remember if I really use it for now */
281 jiffies = (70*FRAME_RATE_BASE/enc->frame_rate) - 1;
282
283 put_le16(pb, jiffies);
284
285 put_byte(pb, 0x1f); /* transparent color index */
286 put_byte(pb, 0x00);
287
288 /* image block */
289
290 put_byte(pb, 0x2c);
291 put_le16(pb, 0);
292 put_le16(pb, 0);
293 put_le16(pb, enc->width);
294 put_le16(pb, enc->height);
295 put_byte(pb, 0x00); /* flags */
296 /* no local clut */
297
298 put_byte(pb, 0x08);
299
300 left=size/3;
301
84082497 302 init_put_bits(&p, buffer, 130, NULL, NULL);
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303
304/*
305 * the thing here is the bitstream is written as little packets, with a size byte before
306 * but it's still the same bitstream between packets (no flush !)
307 */
308
309 while(left>0) {
310
84082497 311 gif_put_bits_rev(&p, 9, 0x0100); /* clear code */
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312
313 for(i=0;i<GIF_CHUNKS;i++) {
84082497 314 gif_put_bits_rev(&p, 9, gif_clut_index(NULL, *buf, buf[1], buf[2]));
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315 buf+=3;
316 }
317
318 if(left<=GIF_CHUNKS) {
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319 gif_put_bits_rev(&p, 9, 0x101); /* end of stream */
320 gif_flush_put_bits_rev(&p);
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321 }
322 if(pbBufPtr(&p) - p.buf > 0) {
323 put_byte(pb, pbBufPtr(&p) - p.buf); /* byte count of the packet */
324 put_buffer(pb, p.buf, pbBufPtr(&p) - p.buf); /* the actual buffer */
325 p.data_out_size += pbBufPtr(&p) - p.buf;
326 p.buf_ptr = p.buf; /* dequeue the bytes off the bitstream */
327 }
328 if(left<=GIF_CHUNKS) {
329 put_byte(pb, 0x00); /* end of image block */
330 }
331
332 left-=GIF_CHUNKS;
333 }
334
335 put_flush_packet(&s->pb);
336 return 0;
337}
338
339static int gif_write_packet(AVFormatContext *s, int stream_index,
a266644f 340 UINT8 *buf, int size, int force_pts)
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341{
342 AVCodecContext *codec = &s->streams[stream_index]->codec;
343 if (codec->codec_type == CODEC_TYPE_AUDIO)
344 return 0; /* just ignore audio */
345 else
346 return gif_write_video(s, codec, buf, size);
347}
348
349static int gif_write_trailer(AVFormatContext *s)
350{
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351 ByteIOContext *pb = &s->pb;
352
353 put_byte(pb, 0x3b);
354 put_flush_packet(&s->pb);
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355 return 0;
356}
357
c9a65ca8 358static AVOutputFormat gif_oformat = {
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359 "gif",
360 "GIF Animation",
361 "image/gif",
362 "gif",
c9a65ca8 363 sizeof(GIFContext),
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364 CODEC_ID_NONE,
365 CODEC_ID_RAWVIDEO,
366 gif_write_header,
367 gif_write_packet,
368 gif_write_trailer,
6cea494e 369};
12b64a22 370extern AVInputFormat gif_iformat;
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371
372int gif_init(void)
373{
374 av_register_output_format(&gif_oformat);
12b64a22 375 av_register_input_format(&gif_iformat);
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376 return 0;
377}