1 | /********** |
2 | This library is free software; you can redistribute it and/or modify it under |
3 | the terms of the GNU Lesser General Public License as published by the |
4 | Free Software Foundation; either version 3 of the License, or (at your |
5 | option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.) |
6 | |
7 | This library is distributed in the hope that it will be useful, but WITHOUT |
8 | ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS |
9 | FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for |
10 | more details. |
11 | |
12 | You should have received a copy of the GNU Lesser General Public License |
13 | along with this library; if not, write to the Free Software Foundation, Inc., |
14 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
15 | **********/ |
16 | // "liveMedia" |
17 | // Copyright (c) 1996-2020 Live Networks, Inc. All rights reserved. |
18 | // JPEG Video (RFC 2435) RTP Sources |
19 | // Implementation |
20 | |
21 | #include "JPEGVideoRTPSource.hh" |
22 | |
23 | ////////// JPEGBufferedPacket and JPEGBufferedPacketFactory ////////// |
24 | |
25 | class JPEGBufferedPacket: public BufferedPacket { |
26 | public: |
27 | Boolean completesFrame; |
28 | |
29 | private: |
30 | // Redefined virtual functions: |
31 | virtual void reset(); |
32 | virtual unsigned nextEnclosedFrameSize(unsigned char*& framePtr, |
33 | unsigned dataSize); |
34 | }; |
35 | |
36 | class JPEGBufferedPacketFactory: public BufferedPacketFactory { |
37 | private: // redefined virtual functions |
38 | virtual BufferedPacket* createNewPacket(MultiFramedRTPSource* ourSource); |
39 | }; |
40 | |
41 | |
42 | ////////// JPEGVideoRTPSource implementation ////////// |
43 | |
44 | #define BYTE unsigned char |
45 | #define WORD unsigned |
46 | #define DWORD unsigned long |
47 | |
48 | JPEGVideoRTPSource* |
49 | JPEGVideoRTPSource::createNew(UsageEnvironment& env, Groupsock* RTPgs, |
50 | unsigned char rtpPayloadFormat, |
51 | unsigned rtpTimestampFrequency, |
52 | unsigned defaultWidth, unsigned defaultHeight) { |
53 | return new JPEGVideoRTPSource(env, RTPgs, rtpPayloadFormat, |
54 | rtpTimestampFrequency, defaultWidth, defaultHeight); |
55 | } |
56 | |
57 | JPEGVideoRTPSource::JPEGVideoRTPSource(UsageEnvironment& env, |
58 | Groupsock* RTPgs, |
59 | unsigned char rtpPayloadFormat, |
60 | unsigned rtpTimestampFrequency, |
61 | unsigned defaultWidth, unsigned defaultHeight) |
62 | : MultiFramedRTPSource(env, RTPgs, |
63 | rtpPayloadFormat, rtpTimestampFrequency, |
64 | new JPEGBufferedPacketFactory), |
65 | fDefaultWidth(defaultWidth), fDefaultHeight(defaultHeight) { |
66 | } |
67 | |
68 | JPEGVideoRTPSource::~JPEGVideoRTPSource() { |
69 | } |
70 | |
71 | enum { |
72 | MARKER_SOF0 = 0xc0, // start-of-frame, baseline scan |
73 | MARKER_SOI = 0xd8, // start of image |
74 | MARKER_EOI = 0xd9, // end of image |
75 | MARKER_SOS = 0xda, // start of scan |
76 | MARKER_DRI = 0xdd, // restart interval |
77 | MARKER_DQT = 0xdb, // define quantization tables |
78 | MARKER_DHT = 0xc4, // huffman tables |
79 | MARKER_APP_FIRST = 0xe0, |
80 | MARKER_APP_LAST = 0xef, |
81 | = 0xfe, |
82 | }; |
83 | |
84 | static unsigned char const lum_dc_codelens[] = { |
85 | 0, 1, 5, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, |
86 | }; |
87 | |
88 | static unsigned char const lum_dc_symbols[] = { |
89 | 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, |
90 | }; |
91 | |
92 | static unsigned char const lum_ac_codelens[] = { |
93 | 0, 2, 1, 3, 3, 2, 4, 3, 5, 5, 4, 4, 0, 0, 1, 0x7d, |
94 | }; |
95 | |
96 | static unsigned char const lum_ac_symbols[] = { |
97 | 0x01, 0x02, 0x03, 0x00, 0x04, 0x11, 0x05, 0x12, |
98 | 0x21, 0x31, 0x41, 0x06, 0x13, 0x51, 0x61, 0x07, |
99 | 0x22, 0x71, 0x14, 0x32, 0x81, 0x91, 0xa1, 0x08, |
100 | 0x23, 0x42, 0xb1, 0xc1, 0x15, 0x52, 0xd1, 0xf0, |
101 | 0x24, 0x33, 0x62, 0x72, 0x82, 0x09, 0x0a, 0x16, |
102 | 0x17, 0x18, 0x19, 0x1a, 0x25, 0x26, 0x27, 0x28, |
103 | 0x29, 0x2a, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, |
104 | 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, |
105 | 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, |
106 | 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, |
107 | 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, |
108 | 0x7a, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89, |
109 | 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, |
110 | 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, |
111 | 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, |
112 | 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, 0xc4, 0xc5, |
113 | 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, 0xd3, 0xd4, |
114 | 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, 0xe1, 0xe2, |
115 | 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, 0xea, |
116 | 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, |
117 | 0xf9, 0xfa, |
118 | }; |
119 | |
120 | static unsigned char const chm_dc_codelens[] = { |
121 | 0, 3, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, |
122 | }; |
123 | |
124 | static unsigned char const chm_dc_symbols[] = { |
125 | 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, |
126 | }; |
127 | |
128 | static unsigned char const chm_ac_codelens[] = { |
129 | 0, 2, 1, 2, 4, 4, 3, 4, 7, 5, 4, 4, 0, 1, 2, 0x77, |
130 | }; |
131 | |
132 | static unsigned char const chm_ac_symbols[] = { |
133 | 0x00, 0x01, 0x02, 0x03, 0x11, 0x04, 0x05, 0x21, |
134 | 0x31, 0x06, 0x12, 0x41, 0x51, 0x07, 0x61, 0x71, |
135 | 0x13, 0x22, 0x32, 0x81, 0x08, 0x14, 0x42, 0x91, |
136 | 0xa1, 0xb1, 0xc1, 0x09, 0x23, 0x33, 0x52, 0xf0, |
137 | 0x15, 0x62, 0x72, 0xd1, 0x0a, 0x16, 0x24, 0x34, |
138 | 0xe1, 0x25, 0xf1, 0x17, 0x18, 0x19, 0x1a, 0x26, |
139 | 0x27, 0x28, 0x29, 0x2a, 0x35, 0x36, 0x37, 0x38, |
140 | 0x39, 0x3a, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, |
141 | 0x49, 0x4a, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, |
142 | 0x59, 0x5a, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, |
143 | 0x69, 0x6a, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, |
144 | 0x79, 0x7a, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, |
145 | 0x88, 0x89, 0x8a, 0x92, 0x93, 0x94, 0x95, 0x96, |
146 | 0x97, 0x98, 0x99, 0x9a, 0xa2, 0xa3, 0xa4, 0xa5, |
147 | 0xa6, 0xa7, 0xa8, 0xa9, 0xaa, 0xb2, 0xb3, 0xb4, |
148 | 0xb5, 0xb6, 0xb7, 0xb8, 0xb9, 0xba, 0xc2, 0xc3, |
149 | 0xc4, 0xc5, 0xc6, 0xc7, 0xc8, 0xc9, 0xca, 0xd2, |
150 | 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, 0xd8, 0xd9, 0xda, |
151 | 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, 0xe8, 0xe9, |
152 | 0xea, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, 0xf8, |
153 | 0xf9, 0xfa, |
154 | }; |
155 | |
156 | static void (unsigned char*& p, |
157 | unsigned char const* codelens, |
158 | int ncodes, |
159 | unsigned char const* symbols, |
160 | int nsymbols, |
161 | int tableNo, int tableClass) { |
162 | *p++ = 0xff; *p++ = MARKER_DHT; |
163 | *p++ = 0; /* length msb */ |
164 | *p++ = 3 + ncodes + nsymbols; /* length lsb */ |
165 | *p++ = (tableClass << 4) | tableNo; |
166 | memcpy(p, codelens, ncodes); |
167 | p += ncodes; |
168 | memcpy(p, symbols, nsymbols); |
169 | p += nsymbols; |
170 | } |
171 | |
172 | static unsigned (unsigned qtlen, unsigned dri) { |
173 | unsigned qtlen_half = qtlen/2; // in case qtlen is odd; shouldn't happen |
174 | qtlen = qtlen_half*2; |
175 | |
176 | unsigned numQtables = qtlen > 64 ? 2 : 1; |
177 | return 485 + numQtables*5 + qtlen + (dri > 0 ? 6 : 0); |
178 | } |
179 | |
180 | static void (unsigned char* buf, unsigned type, |
181 | unsigned w, unsigned h, |
182 | unsigned char const* qtables, unsigned qtlen, |
183 | unsigned dri) { |
184 | unsigned char *ptr = buf; |
185 | unsigned numQtables = qtlen > 64 ? 2 : 1; |
186 | |
187 | // MARKER_SOI: |
188 | *ptr++ = 0xFF; *ptr++ = MARKER_SOI; |
189 | |
190 | // MARKER_APP_FIRST: |
191 | *ptr++ = 0xFF; *ptr++ = MARKER_APP_FIRST; |
192 | *ptr++ = 0x00; *ptr++ = 0x10; // size of chunk |
193 | *ptr++ = 'J'; *ptr++ = 'F'; *ptr++ = 'I'; *ptr++ = 'F'; *ptr++ = 0x00; |
194 | *ptr++ = 0x01; *ptr++ = 0x01; // JFIF format version (1.1) |
195 | *ptr++ = 0x00; // no units |
196 | *ptr++ = 0x00; *ptr++ = 0x01; // Horizontal pixel aspect ratio |
197 | *ptr++ = 0x00; *ptr++ = 0x01; // Vertical pixel aspect ratio |
198 | *ptr++ = 0x00; *ptr++ = 0x00; // no thumbnail |
199 | |
200 | // MARKER_DRI: |
201 | if (dri > 0) { |
202 | *ptr++ = 0xFF; *ptr++ = MARKER_DRI; |
203 | *ptr++ = 0x00; *ptr++ = 0x04; // size of chunk |
204 | *ptr++ = (BYTE)(dri >> 8); *ptr++ = (BYTE)(dri); // restart interval |
205 | } |
206 | |
207 | // MARKER_DQT (luma): |
208 | unsigned tableSize = numQtables == 1 ? qtlen : qtlen/2; |
209 | *ptr++ = 0xFF; *ptr++ = MARKER_DQT; |
210 | *ptr++ = 0x00; *ptr++ = tableSize + 3; // size of chunk |
211 | *ptr++ = 0x00; // precision(0), table id(0) |
212 | memcpy(ptr, qtables, tableSize); |
213 | qtables += tableSize; |
214 | ptr += tableSize; |
215 | |
216 | if (numQtables > 1) { |
217 | unsigned tableSize = qtlen - qtlen/2; |
218 | // MARKER_DQT (chroma): |
219 | *ptr++ = 0xFF; *ptr++ = MARKER_DQT; |
220 | *ptr++ = 0x00; *ptr++ = tableSize + 3; // size of chunk |
221 | *ptr++ = 0x01; // precision(0), table id(1) |
222 | memcpy(ptr, qtables, tableSize); |
223 | qtables += tableSize; |
224 | ptr += tableSize; |
225 | } |
226 | |
227 | // MARKER_SOF0: |
228 | *ptr++ = 0xFF; *ptr++ = MARKER_SOF0; |
229 | *ptr++ = 0x00; *ptr++ = 0x11; // size of chunk |
230 | *ptr++ = 0x08; // sample precision |
231 | *ptr++ = (BYTE)(h >> 8); |
232 | *ptr++ = (BYTE)(h); // number of lines (must be a multiple of 8) |
233 | *ptr++ = (BYTE)(w >> 8); |
234 | *ptr++ = (BYTE)(w); // number of columns (must be a multiple of 8) |
235 | *ptr++ = 0x03; // number of components |
236 | *ptr++ = 0x01; // id of component |
237 | *ptr++ = type ? 0x22 : 0x21; // sampling ratio (h,v) |
238 | *ptr++ = 0x00; // quant table id |
239 | *ptr++ = 0x02; // id of component |
240 | *ptr++ = 0x11; // sampling ratio (h,v) |
241 | *ptr++ = numQtables == 1 ? 0x00 : 0x01; // quant table id |
242 | *ptr++ = 0x03; // id of component |
243 | *ptr++ = 0x11; // sampling ratio (h,v) |
244 | *ptr++ = numQtables == 1 ? 0x00 : 0x01; // quant table id |
245 | |
246 | createHuffmanHeader(ptr, lum_dc_codelens, sizeof lum_dc_codelens, |
247 | lum_dc_symbols, sizeof lum_dc_symbols, 0, 0); |
248 | createHuffmanHeader(ptr, lum_ac_codelens, sizeof lum_ac_codelens, |
249 | lum_ac_symbols, sizeof lum_ac_symbols, 0, 1); |
250 | createHuffmanHeader(ptr, chm_dc_codelens, sizeof chm_dc_codelens, |
251 | chm_dc_symbols, sizeof chm_dc_symbols, 1, 0); |
252 | createHuffmanHeader(ptr, chm_ac_codelens, sizeof chm_ac_codelens, |
253 | chm_ac_symbols, sizeof chm_ac_symbols, 1, 1); |
254 | |
255 | // MARKER_SOS: |
256 | *ptr++ = 0xFF; *ptr++ = MARKER_SOS; |
257 | *ptr++ = 0x00; *ptr++ = 0x0C; // size of chunk |
258 | *ptr++ = 0x03; // number of components |
259 | *ptr++ = 0x01; // id of component |
260 | *ptr++ = 0x00; // huffman table id (DC, AC) |
261 | *ptr++ = 0x02; // id of component |
262 | *ptr++ = 0x11; // huffman table id (DC, AC) |
263 | *ptr++ = 0x03; // id of component |
264 | *ptr++ = 0x11; // huffman table id (DC, AC) |
265 | *ptr++ = 0x00; // start of spectral |
266 | *ptr++ = 0x3F; // end of spectral |
267 | *ptr++ = 0x00; // successive approximation bit position (high, low) |
268 | } |
269 | |
270 | // The default 'luma' and 'chroma' quantizer tables, in zigzag order: |
271 | static unsigned char const defaultQuantizers[128] = { |
272 | // luma table: |
273 | 16, 11, 12, 14, 12, 10, 16, 14, |
274 | 13, 14, 18, 17, 16, 19, 24, 40, |
275 | 26, 24, 22, 22, 24, 49, 35, 37, |
276 | 29, 40, 58, 51, 61, 60, 57, 51, |
277 | 56, 55, 64, 72, 92, 78, 64, 68, |
278 | 87, 69, 55, 56, 80, 109, 81, 87, |
279 | 95, 98, 103, 104, 103, 62, 77, 113, |
280 | 121, 112, 100, 120, 92, 101, 103, 99, |
281 | // chroma table: |
282 | 17, 18, 18, 24, 21, 24, 47, 26, |
283 | 26, 47, 99, 66, 56, 66, 99, 99, |
284 | 99, 99, 99, 99, 99, 99, 99, 99, |
285 | 99, 99, 99, 99, 99, 99, 99, 99, |
286 | 99, 99, 99, 99, 99, 99, 99, 99, |
287 | 99, 99, 99, 99, 99, 99, 99, 99, |
288 | 99, 99, 99, 99, 99, 99, 99, 99, |
289 | 99, 99, 99, 99, 99, 99, 99, 99 |
290 | }; |
291 | |
292 | static void makeDefaultQtables(unsigned char* resultTables, unsigned Q) { |
293 | int factor = Q; |
294 | int q; |
295 | |
296 | if (Q < 1) factor = 1; |
297 | else if (Q > 99) factor = 99; |
298 | |
299 | if (Q < 50) { |
300 | q = 5000 / factor; |
301 | } else { |
302 | q = 200 - factor*2; |
303 | } |
304 | |
305 | for (int i = 0; i < 128; ++i) { |
306 | int newVal = (defaultQuantizers[i]*q + 50)/100; |
307 | if (newVal < 1) newVal = 1; |
308 | else if (newVal > 255) newVal = 255; |
309 | resultTables[i] = newVal; |
310 | } |
311 | } |
312 | |
313 | Boolean JPEGVideoRTPSource |
314 | ::(BufferedPacket* packet, |
315 | unsigned& ) { |
316 | unsigned char* = packet->data(); |
317 | unsigned packetSize = packet->dataSize(); |
318 | |
319 | unsigned char* qtables = NULL; |
320 | unsigned qtlen = 0; |
321 | unsigned dri = 0; |
322 | |
323 | // There's at least 8-byte video-specific header |
324 | /* |
325 | 0 1 2 3 |
326 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
327 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
328 | | Type-specific | Fragment Offset | |
329 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
330 | | Type | Q | Width | Height | |
331 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
332 | */ |
333 | if (packetSize < 8) return False; |
334 | |
335 | resultSpecialHeaderSize = 8; |
336 | |
337 | unsigned Offset = (unsigned)((DWORD)headerStart[1] << 16 | (DWORD)headerStart[2] << 8 | (DWORD)headerStart[3]); |
338 | unsigned Type = (unsigned)headerStart[4]; |
339 | unsigned type = Type & 1; |
340 | unsigned Q = (unsigned)headerStart[5]; |
341 | unsigned width = (unsigned)headerStart[6] * 8; |
342 | unsigned height = (unsigned)headerStart[7] * 8; |
343 | if ((width == 0 || height == 0) && fDefaultWidth != 0 && fDefaultHeight != 0) { |
344 | // Use the default width and height parameters instead: |
345 | width = fDefaultWidth; |
346 | height = fDefaultHeight; |
347 | } |
348 | if (width == 0) width = 256*8; // special case |
349 | if (height == 0) height = 256*8; // special case |
350 | |
351 | if (Type > 63) { |
352 | // Restart Marker header present |
353 | /* |
354 | 0 1 2 3 |
355 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
356 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
357 | | Restart Interval |F|L| Restart Count | |
358 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
359 | */ |
360 | if (packetSize < resultSpecialHeaderSize + 4) return False; |
361 | |
362 | unsigned RestartInterval = (unsigned)((WORD)headerStart[resultSpecialHeaderSize] << 8 | (WORD)headerStart[resultSpecialHeaderSize + 1]); |
363 | dri = RestartInterval; |
364 | resultSpecialHeaderSize += 4; |
365 | } |
366 | |
367 | if (Offset == 0) { |
368 | if (Q > 127) { |
369 | // Quantization Table header present |
370 | /* |
371 | 0 1 2 3 |
372 | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 |
373 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
374 | | MBZ | Precision | Length | |
375 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
376 | | Quantization Table Data | |
377 | | ... | |
378 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |
379 | */ |
380 | if (packetSize < resultSpecialHeaderSize + 4) return False; |
381 | |
382 | unsigned MBZ = (unsigned)headerStart[resultSpecialHeaderSize]; |
383 | if (MBZ == 0) { |
384 | // unsigned Precision = (unsigned)headerStart[resultSpecialHeaderSize + 1]; |
385 | unsigned Length = (unsigned)((WORD)headerStart[resultSpecialHeaderSize + 2] << 8 | (WORD)headerStart[resultSpecialHeaderSize + 3]); |
386 | |
387 | //ASSERT(Length == 128); |
388 | |
389 | resultSpecialHeaderSize += 4; |
390 | |
391 | if (packetSize < resultSpecialHeaderSize + Length) return False; |
392 | |
393 | qtlen = Length; |
394 | qtables = &headerStart[resultSpecialHeaderSize]; |
395 | |
396 | resultSpecialHeaderSize += Length; |
397 | } |
398 | } |
399 | } |
400 | |
401 | // If this is the first (or only) fragment of a JPEG frame, then we need |
402 | // to synthesize a JPEG header, and prepend it to the incoming data. |
403 | // Hack: We can do this because we allowed space for it in |
404 | // our special "JPEGBufferedPacket" subclass. We also adjust |
405 | // "resultSpecialHeaderSize" to compensate for this, by subtracting |
406 | // the size of the synthesized header. Note that this will cause |
407 | // "resultSpecialHeaderSize" to become negative, but the code that called |
408 | // us (in "MultiFramedRTPSource") will handle this properly. |
409 | if (Offset == 0) { |
410 | unsigned char newQtables[128]; |
411 | if (qtlen == 0) { |
412 | // A quantization table was not present in the RTP JPEG header, |
413 | // so use the default tables, scaled according to the "Q" factor: |
414 | makeDefaultQtables(newQtables, Q); |
415 | qtables = newQtables; |
416 | qtlen = sizeof newQtables; |
417 | } |
418 | |
419 | unsigned hdrlen = computeJPEGHeaderSize(qtlen, dri); |
420 | resultSpecialHeaderSize -= hdrlen; // goes negative |
421 | headerStart += (int)resultSpecialHeaderSize; // goes backward |
422 | createJPEGHeader(headerStart, type, width, height, qtables, qtlen, dri); |
423 | } |
424 | |
425 | fCurrentPacketBeginsFrame = (Offset == 0); |
426 | |
427 | // The RTP "M" (marker) bit indicates the last fragment of a frame: |
428 | ((JPEGBufferedPacket*)packet)->completesFrame |
429 | = fCurrentPacketCompletesFrame = packet->rtpMarkerBit(); |
430 | |
431 | return True; |
432 | } |
433 | |
434 | char const* JPEGVideoRTPSource::MIMEtype() const { |
435 | return "video/JPEG" ; |
436 | } |
437 | |
438 | ////////// JPEGBufferedPacket and JPEGBufferedPacketFactory implementation |
439 | |
440 | void JPEGBufferedPacket::reset() { |
441 | BufferedPacket::reset(); |
442 | |
443 | // Move our "fHead" and "fTail" forward, to allow space for a synthesized |
444 | // JPEG header to precede the RTP data that comes in over the network. |
445 | unsigned offset = MAX_JPEG_HEADER_SIZE; |
446 | if (offset > fPacketSize) offset = fPacketSize; // shouldn't happen |
447 | fHead = fTail = offset; |
448 | } |
449 | |
450 | unsigned JPEGBufferedPacket |
451 | ::nextEnclosedFrameSize(unsigned char*& framePtr, unsigned dataSize) { |
452 | // Normally, the enclosed frame size is just "dataSize". If, however, |
453 | // the frame does not end with the "EOI" marker, then add this now: |
454 | if (completesFrame && dataSize >= 2 && |
455 | !(framePtr[dataSize-2] == 0xFF && framePtr[dataSize-1] == MARKER_EOI)) { |
456 | framePtr[dataSize++] = 0xFF; |
457 | framePtr[dataSize++] = MARKER_EOI; |
458 | } |
459 | return dataSize; |
460 | } |
461 | |
462 | BufferedPacket* JPEGBufferedPacketFactory |
463 | ::createNewPacket(MultiFramedRTPSource* /*ourSource*/) { |
464 | return new JPEGBufferedPacket; |
465 | } |
466 | |