cleanup gif, use BISTREAM_WRITER_LE
[libav.git] / libavformat / gif.c
1 /*
2 * Animated GIF muxer
3 * Copyright (c) 2000 Fabrice Bellard.
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 * First version by Francois Revol revol@free.fr
24 *
25 * Features and limitations:
26 * - currently no compression is performed,
27 * in fact the size of the data is 9/8 the size of the image in 8bpp
28 * - uses only a global standard palette
29 * - tested with IE 5.0, Opera for BeOS, NetPositive (BeOS), and Mozilla (BeOS).
30 *
31 * Reference documents:
32 * http://www.goice.co.jp/member/mo/formats/gif.html
33 * http://astronomy.swin.edu.au/pbourke/dataformats/gif/
34 * http://www.dcs.ed.ac.uk/home/mxr/gfx/2d/GIF89a.txt
35 *
36 * this url claims to have an LZW algorithm not covered by Unisys patent:
37 * http://www.msg.net/utility/whirlgif/gifencod.html
38 * could help reduce the size of the files _a lot_...
39 * some sites mentions an RLE type compression also.
40 */
41
42 #include "avformat.h"
43
44 /* The GIF format uses reversed order for bitstreams... */
45 /* at least they don't use PDP_ENDIAN :) */
46 #define BITSTREAM_WRITER_LE
47
48 #include "libavcodec/bitstream.h"
49
50 /* bitstream minipacket size */
51 #define GIF_CHUNKS 100
52
53 /* slows down the decoding (and some browsers don't like it) */
54 /* 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 */
55 #define GIF_ADD_APP_HEADER // required to enable looping of animated gif
56
57 typedef struct {
58 unsigned char r;
59 unsigned char g;
60 unsigned char b;
61 } rgb_triplet;
62
63 /* we use the standard 216 color palette */
64
65 /* this script was used to create the palette:
66 * 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
67 * echo -n "{ 0x$r, 0x$g, 0x$b }, "; done; echo ""; done; done
68 */
69
70 static const rgb_triplet gif_clut[216] = {
71 { 0x00, 0x00, 0x00 }, { 0x00, 0x00, 0x33 }, { 0x00, 0x00, 0x66 }, { 0x00, 0x00, 0x99 }, { 0x00, 0x00, 0xcc }, { 0x00, 0x00, 0xff },
72 { 0x00, 0x33, 0x00 }, { 0x00, 0x33, 0x33 }, { 0x00, 0x33, 0x66 }, { 0x00, 0x33, 0x99 }, { 0x00, 0x33, 0xcc }, { 0x00, 0x33, 0xff },
73 { 0x00, 0x66, 0x00 }, { 0x00, 0x66, 0x33 }, { 0x00, 0x66, 0x66 }, { 0x00, 0x66, 0x99 }, { 0x00, 0x66, 0xcc }, { 0x00, 0x66, 0xff },
74 { 0x00, 0x99, 0x00 }, { 0x00, 0x99, 0x33 }, { 0x00, 0x99, 0x66 }, { 0x00, 0x99, 0x99 }, { 0x00, 0x99, 0xcc }, { 0x00, 0x99, 0xff },
75 { 0x00, 0xcc, 0x00 }, { 0x00, 0xcc, 0x33 }, { 0x00, 0xcc, 0x66 }, { 0x00, 0xcc, 0x99 }, { 0x00, 0xcc, 0xcc }, { 0x00, 0xcc, 0xff },
76 { 0x00, 0xff, 0x00 }, { 0x00, 0xff, 0x33 }, { 0x00, 0xff, 0x66 }, { 0x00, 0xff, 0x99 }, { 0x00, 0xff, 0xcc }, { 0x00, 0xff, 0xff },
77 { 0x33, 0x00, 0x00 }, { 0x33, 0x00, 0x33 }, { 0x33, 0x00, 0x66 }, { 0x33, 0x00, 0x99 }, { 0x33, 0x00, 0xcc }, { 0x33, 0x00, 0xff },
78 { 0x33, 0x33, 0x00 }, { 0x33, 0x33, 0x33 }, { 0x33, 0x33, 0x66 }, { 0x33, 0x33, 0x99 }, { 0x33, 0x33, 0xcc }, { 0x33, 0x33, 0xff },
79 { 0x33, 0x66, 0x00 }, { 0x33, 0x66, 0x33 }, { 0x33, 0x66, 0x66 }, { 0x33, 0x66, 0x99 }, { 0x33, 0x66, 0xcc }, { 0x33, 0x66, 0xff },
80 { 0x33, 0x99, 0x00 }, { 0x33, 0x99, 0x33 }, { 0x33, 0x99, 0x66 }, { 0x33, 0x99, 0x99 }, { 0x33, 0x99, 0xcc }, { 0x33, 0x99, 0xff },
81 { 0x33, 0xcc, 0x00 }, { 0x33, 0xcc, 0x33 }, { 0x33, 0xcc, 0x66 }, { 0x33, 0xcc, 0x99 }, { 0x33, 0xcc, 0xcc }, { 0x33, 0xcc, 0xff },
82 { 0x33, 0xff, 0x00 }, { 0x33, 0xff, 0x33 }, { 0x33, 0xff, 0x66 }, { 0x33, 0xff, 0x99 }, { 0x33, 0xff, 0xcc }, { 0x33, 0xff, 0xff },
83 { 0x66, 0x00, 0x00 }, { 0x66, 0x00, 0x33 }, { 0x66, 0x00, 0x66 }, { 0x66, 0x00, 0x99 }, { 0x66, 0x00, 0xcc }, { 0x66, 0x00, 0xff },
84 { 0x66, 0x33, 0x00 }, { 0x66, 0x33, 0x33 }, { 0x66, 0x33, 0x66 }, { 0x66, 0x33, 0x99 }, { 0x66, 0x33, 0xcc }, { 0x66, 0x33, 0xff },
85 { 0x66, 0x66, 0x00 }, { 0x66, 0x66, 0x33 }, { 0x66, 0x66, 0x66 }, { 0x66, 0x66, 0x99 }, { 0x66, 0x66, 0xcc }, { 0x66, 0x66, 0xff },
86 { 0x66, 0x99, 0x00 }, { 0x66, 0x99, 0x33 }, { 0x66, 0x99, 0x66 }, { 0x66, 0x99, 0x99 }, { 0x66, 0x99, 0xcc }, { 0x66, 0x99, 0xff },
87 { 0x66, 0xcc, 0x00 }, { 0x66, 0xcc, 0x33 }, { 0x66, 0xcc, 0x66 }, { 0x66, 0xcc, 0x99 }, { 0x66, 0xcc, 0xcc }, { 0x66, 0xcc, 0xff },
88 { 0x66, 0xff, 0x00 }, { 0x66, 0xff, 0x33 }, { 0x66, 0xff, 0x66 }, { 0x66, 0xff, 0x99 }, { 0x66, 0xff, 0xcc }, { 0x66, 0xff, 0xff },
89 { 0x99, 0x00, 0x00 }, { 0x99, 0x00, 0x33 }, { 0x99, 0x00, 0x66 }, { 0x99, 0x00, 0x99 }, { 0x99, 0x00, 0xcc }, { 0x99, 0x00, 0xff },
90 { 0x99, 0x33, 0x00 }, { 0x99, 0x33, 0x33 }, { 0x99, 0x33, 0x66 }, { 0x99, 0x33, 0x99 }, { 0x99, 0x33, 0xcc }, { 0x99, 0x33, 0xff },
91 { 0x99, 0x66, 0x00 }, { 0x99, 0x66, 0x33 }, { 0x99, 0x66, 0x66 }, { 0x99, 0x66, 0x99 }, { 0x99, 0x66, 0xcc }, { 0x99, 0x66, 0xff },
92 { 0x99, 0x99, 0x00 }, { 0x99, 0x99, 0x33 }, { 0x99, 0x99, 0x66 }, { 0x99, 0x99, 0x99 }, { 0x99, 0x99, 0xcc }, { 0x99, 0x99, 0xff },
93 { 0x99, 0xcc, 0x00 }, { 0x99, 0xcc, 0x33 }, { 0x99, 0xcc, 0x66 }, { 0x99, 0xcc, 0x99 }, { 0x99, 0xcc, 0xcc }, { 0x99, 0xcc, 0xff },
94 { 0x99, 0xff, 0x00 }, { 0x99, 0xff, 0x33 }, { 0x99, 0xff, 0x66 }, { 0x99, 0xff, 0x99 }, { 0x99, 0xff, 0xcc }, { 0x99, 0xff, 0xff },
95 { 0xcc, 0x00, 0x00 }, { 0xcc, 0x00, 0x33 }, { 0xcc, 0x00, 0x66 }, { 0xcc, 0x00, 0x99 }, { 0xcc, 0x00, 0xcc }, { 0xcc, 0x00, 0xff },
96 { 0xcc, 0x33, 0x00 }, { 0xcc, 0x33, 0x33 }, { 0xcc, 0x33, 0x66 }, { 0xcc, 0x33, 0x99 }, { 0xcc, 0x33, 0xcc }, { 0xcc, 0x33, 0xff },
97 { 0xcc, 0x66, 0x00 }, { 0xcc, 0x66, 0x33 }, { 0xcc, 0x66, 0x66 }, { 0xcc, 0x66, 0x99 }, { 0xcc, 0x66, 0xcc }, { 0xcc, 0x66, 0xff },
98 { 0xcc, 0x99, 0x00 }, { 0xcc, 0x99, 0x33 }, { 0xcc, 0x99, 0x66 }, { 0xcc, 0x99, 0x99 }, { 0xcc, 0x99, 0xcc }, { 0xcc, 0x99, 0xff },
99 { 0xcc, 0xcc, 0x00 }, { 0xcc, 0xcc, 0x33 }, { 0xcc, 0xcc, 0x66 }, { 0xcc, 0xcc, 0x99 }, { 0xcc, 0xcc, 0xcc }, { 0xcc, 0xcc, 0xff },
100 { 0xcc, 0xff, 0x00 }, { 0xcc, 0xff, 0x33 }, { 0xcc, 0xff, 0x66 }, { 0xcc, 0xff, 0x99 }, { 0xcc, 0xff, 0xcc }, { 0xcc, 0xff, 0xff },
101 { 0xff, 0x00, 0x00 }, { 0xff, 0x00, 0x33 }, { 0xff, 0x00, 0x66 }, { 0xff, 0x00, 0x99 }, { 0xff, 0x00, 0xcc }, { 0xff, 0x00, 0xff },
102 { 0xff, 0x33, 0x00 }, { 0xff, 0x33, 0x33 }, { 0xff, 0x33, 0x66 }, { 0xff, 0x33, 0x99 }, { 0xff, 0x33, 0xcc }, { 0xff, 0x33, 0xff },
103 { 0xff, 0x66, 0x00 }, { 0xff, 0x66, 0x33 }, { 0xff, 0x66, 0x66 }, { 0xff, 0x66, 0x99 }, { 0xff, 0x66, 0xcc }, { 0xff, 0x66, 0xff },
104 { 0xff, 0x99, 0x00 }, { 0xff, 0x99, 0x33 }, { 0xff, 0x99, 0x66 }, { 0xff, 0x99, 0x99 }, { 0xff, 0x99, 0xcc }, { 0xff, 0x99, 0xff },
105 { 0xff, 0xcc, 0x00 }, { 0xff, 0xcc, 0x33 }, { 0xff, 0xcc, 0x66 }, { 0xff, 0xcc, 0x99 }, { 0xff, 0xcc, 0xcc }, { 0xff, 0xcc, 0xff },
106 { 0xff, 0xff, 0x00 }, { 0xff, 0xff, 0x33 }, { 0xff, 0xff, 0x66 }, { 0xff, 0xff, 0x99 }, { 0xff, 0xff, 0xcc }, { 0xff, 0xff, 0xff },
107 };
108
109 /* GIF header */
110 static int gif_image_write_header(ByteIOContext *pb,
111 int width, int height, int loop_count,
112 uint32_t *palette)
113 {
114 int i;
115 unsigned int v;
116
117 put_tag(pb, "GIF");
118 put_tag(pb, "89a");
119 put_le16(pb, width);
120 put_le16(pb, height);
121
122 put_byte(pb, 0xf7); /* flags: global clut, 256 entries */
123 put_byte(pb, 0x1f); /* background color index */
124 put_byte(pb, 0); /* aspect ratio */
125
126 /* the global palette */
127 if (!palette) {
128 put_buffer(pb, (const unsigned char *)gif_clut, 216*3);
129 for(i=0;i<((256-216)*3);i++)
130 put_byte(pb, 0);
131 } else {
132 for(i=0;i<256;i++) {
133 v = palette[i];
134 put_byte(pb, (v >> 16) & 0xff);
135 put_byte(pb, (v >> 8) & 0xff);
136 put_byte(pb, (v) & 0xff);
137 }
138 }
139
140 /* update: this is the 'NETSCAPE EXTENSION' that allows for looped animated gif
141 see http://members.aol.com/royalef/gifabout.htm#net-extension
142
143 byte 1 : 33 (hex 0x21) GIF Extension code
144 byte 2 : 255 (hex 0xFF) Application Extension Label
145 byte 3 : 11 (hex (0x0B) Length of Application Block
146 (eleven bytes of data to follow)
147 bytes 4 to 11 : "NETSCAPE"
148 bytes 12 to 14 : "2.0"
149 byte 15 : 3 (hex 0x03) Length of Data Sub-Block
150 (three bytes of data to follow)
151 byte 16 : 1 (hex 0x01)
152 bytes 17 to 18 : 0 to 65535, an unsigned integer in
153 lo-hi byte format. This indicate the
154 number of iterations the loop should
155 be executed.
156 bytes 19 : 0 (hex 0x00) a Data Sub-block Terminator
157 */
158
159 /* application extension header */
160 #ifdef GIF_ADD_APP_HEADER
161 if (loop_count >= 0 && loop_count <= 65535) {
162 put_byte(pb, 0x21);
163 put_byte(pb, 0xff);
164 put_byte(pb, 0x0b);
165 put_tag(pb, "NETSCAPE2.0"); // bytes 4 to 14
166 put_byte(pb, 0x03); // byte 15
167 put_byte(pb, 0x01); // byte 16
168 put_le16(pb, (uint16_t)loop_count);
169 put_byte(pb, 0x00); // byte 19
170 }
171 #endif
172 return 0;
173 }
174
175 /* this is maybe slow, but allows for extensions */
176 static inline unsigned char gif_clut_index(uint8_t r, uint8_t g, uint8_t b)
177 {
178 return (((r) / 47) % 6) * 6 * 6 + (((g) / 47) % 6) * 6 + (((b) / 47) % 6);
179 }
180
181
182 static int gif_image_write_image(ByteIOContext *pb,
183 int x1, int y1, int width, int height,
184 const uint8_t *buf, int linesize, int pix_fmt)
185 {
186 PutBitContext p;
187 uint8_t buffer[200]; /* 100 * 9 / 8 = 113 */
188 int i, left, w, v;
189 const uint8_t *ptr;
190 /* image block */
191
192 put_byte(pb, 0x2c);
193 put_le16(pb, x1);
194 put_le16(pb, y1);
195 put_le16(pb, width);
196 put_le16(pb, height);
197 put_byte(pb, 0x00); /* flags */
198 /* no local clut */
199
200 put_byte(pb, 0x08);
201
202 left= width * height;
203
204 init_put_bits(&p, buffer, 130);
205
206 /*
207 * the thing here is the bitstream is written as little packets, with a size byte before
208 * but it's still the same bitstream between packets (no flush !)
209 */
210 ptr = buf;
211 w = width;
212 while(left>0) {
213
214 put_bits(&p, 9, 0x0100); /* clear code */
215
216 for(i=(left<GIF_CHUNKS)?left:GIF_CHUNKS;i;i--) {
217 if (pix_fmt == PIX_FMT_RGB24) {
218 v = gif_clut_index(ptr[0], ptr[1], ptr[2]);
219 ptr+=3;
220 } else {
221 v = *ptr++;
222 }
223 put_bits(&p, 9, v);
224 if (--w == 0) {
225 w = width;
226 buf += linesize;
227 ptr = buf;
228 }
229 }
230
231 if(left<=GIF_CHUNKS) {
232 put_bits(&p, 9, 0x101); /* end of stream */
233 flush_put_bits(&p);
234 }
235 if(pbBufPtr(&p) - p.buf > 0) {
236 put_byte(pb, pbBufPtr(&p) - p.buf); /* byte count of the packet */
237 put_buffer(pb, p.buf, pbBufPtr(&p) - p.buf); /* the actual buffer */
238 p.buf_ptr = p.buf; /* dequeue the bytes off the bitstream */
239 }
240 left-=GIF_CHUNKS;
241 }
242 put_byte(pb, 0x00); /* end of image block */
243
244 return 0;
245 }
246
247 typedef struct {
248 int64_t time, file_time;
249 uint8_t buffer[100]; /* data chunks */
250 } GIFContext;
251
252 static int gif_write_header(AVFormatContext *s)
253 {
254 GIFContext *gif = s->priv_data;
255 ByteIOContext *pb = s->pb;
256 AVCodecContext *enc, *video_enc;
257 int i, width, height, loop_count /*, rate*/;
258
259 /* XXX: do we reject audio streams or just ignore them ?
260 if(s->nb_streams > 1)
261 return -1;
262 */
263 gif->time = 0;
264 gif->file_time = 0;
265
266 video_enc = NULL;
267 for(i=0;i<s->nb_streams;i++) {
268 enc = s->streams[i]->codec;
269 if (enc->codec_type != CODEC_TYPE_AUDIO)
270 video_enc = enc;
271 }
272
273 if (!video_enc) {
274 av_free(gif);
275 return -1;
276 } else {
277 width = video_enc->width;
278 height = video_enc->height;
279 loop_count = s->loop_output;
280 // rate = video_enc->time_base.den;
281 }
282
283 if (video_enc->pix_fmt != PIX_FMT_RGB24) {
284 av_log(s, AV_LOG_ERROR, "ERROR: gif only handles the rgb24 pixel format. Use -pix_fmt rgb24.\n");
285 return AVERROR(EIO);
286 }
287
288 gif_image_write_header(pb, width, height, loop_count, NULL);
289
290 put_flush_packet(s->pb);
291 return 0;
292 }
293
294 static int gif_write_video(AVFormatContext *s,
295 AVCodecContext *enc, const uint8_t *buf, int size)
296 {
297 ByteIOContext *pb = s->pb;
298 GIFContext *gif = s->priv_data;
299 int jiffies;
300 int64_t delay;
301
302 /* graphic control extension block */
303 put_byte(pb, 0x21);
304 put_byte(pb, 0xf9);
305 put_byte(pb, 0x04); /* block size */
306 put_byte(pb, 0x04); /* flags */
307
308 /* 1 jiffy is 1/70 s */
309 /* the delay_time field indicates the number of jiffies - 1 */
310 delay = gif->file_time - gif->time;
311
312 /* XXX: should use delay, in order to be more accurate */
313 /* instead of using the same rounded value each time */
314 /* XXX: don't even remember if I really use it for now */
315 jiffies = (70*enc->time_base.num/enc->time_base.den) - 1;
316
317 put_le16(pb, jiffies);
318
319 put_byte(pb, 0x1f); /* transparent color index */
320 put_byte(pb, 0x00);
321
322 gif_image_write_image(pb, 0, 0, enc->width, enc->height,
323 buf, enc->width * 3, PIX_FMT_RGB24);
324
325 put_flush_packet(s->pb);
326 return 0;
327 }
328
329 static int gif_write_packet(AVFormatContext *s, AVPacket *pkt)
330 {
331 AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
332 if (codec->codec_type == CODEC_TYPE_AUDIO)
333 return 0; /* just ignore audio */
334 else
335 return gif_write_video(s, codec, pkt->data, pkt->size);
336 }
337
338 static int gif_write_trailer(AVFormatContext *s)
339 {
340 ByteIOContext *pb = s->pb;
341
342 put_byte(pb, 0x3b);
343 put_flush_packet(s->pb);
344 return 0;
345 }
346
347 AVOutputFormat gif_muxer = {
348 "gif",
349 NULL_IF_CONFIG_SMALL("GIF Animation"),
350 "image/gif",
351 "gif",
352 sizeof(GIFContext),
353 CODEC_ID_NONE,
354 CODEC_ID_RAWVIDEO,
355 gif_write_header,
356 gif_write_packet,
357 gif_write_trailer,
358 };