1 /*
2 * RTP JPEG-compressed Video Depacketizer, RFC 2435
3 * Copyright (c) 2012 Samuel Pitoiset
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
30
31 /**
32 * RTP/JPEG specific private data.
33 */
36 uint32_t
timestamp;
///< current frame timestamp
37 int hdr_size;
///< size of the current frame header
40 };
41
43 /* luma table */
44 16, 11, 12, 14, 12, 10, 16, 14,
45 13, 14, 18, 17, 16, 19, 24, 40,
46 26, 24, 22, 22, 24, 49, 35, 37,
47 29, 40, 58, 51, 61, 60, 57, 51,
48 56, 55, 64, 72, 92, 78, 64, 68,
49 87, 69, 55, 56, 80, 109, 81, 87,
50 95, 98, 103, 104, 103, 62, 77, 113,
51 121, 112, 100, 120, 92, 101, 103, 99,
52
53 /* chroma table */
54 17, 18, 18, 24, 21, 24, 47, 26,
55 26, 47, 99, 66, 56, 66, 99, 99,
56 99, 99, 99, 99, 99, 99, 99, 99,
57 99, 99, 99, 99, 99, 99, 99, 99,
58 99, 99, 99, 99, 99, 99, 99, 99,
59 99, 99, 99, 99, 99, 99, 99, 99,
60 99, 99, 99, 99, 99, 99, 99, 99,
61 99, 99, 99, 99, 99, 99, 99, 99
62 };
63
65 {
67 }
68
70 int table_id, const uint8_t *bits_table,
71 const uint8_t *value_table)
72 {
74
75 bytestream2_put_byte(p, table_class << 4 | table_id);
76
77 for (
i = 1;
i <= 16;
i++) {
79 bytestream2_put_byte(p, bits_table[
i]);
80 }
81
82 for (
i = 0;
i < n;
i++) {
83 bytestream2_put_byte(p, value_table[
i]);
84 }
85 return n + 17;
86 }
87
89 {
90 bytestream2_put_byte(pbc, 0xff);
91 bytestream2_put_byte(pbc,
code);
92 }
93
95 uint32_t
h,
const uint8_t *qtable,
int nb_qtable,
96 int dri)
97 {
99 uint8_t *dht_size_ptr;
101
103
104 /* Convert from blocks to pixels. */
107
108 /* SOI */
110
111 /* JFIF header */
113 bytestream2_put_be16(&pbc, 16);
115 bytestream2_put_be16(&pbc, 0x0102);
116 bytestream2_put_byte(&pbc, 0);
117 bytestream2_put_be16(&pbc, 1);
118 bytestream2_put_be16(&pbc, 1);
119 bytestream2_put_byte(&pbc, 0);
120 bytestream2_put_byte(&pbc, 0);
121
122 if (dri) {
124 bytestream2_put_be16(&pbc, 4);
125 bytestream2_put_be16(&pbc, dri);
126 }
127
128 /* DQT */
130 bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
131
132 for (
i = 0;
i < nb_qtable;
i++) {
133 bytestream2_put_byte(&pbc,
i);
134
135 /* Each table is an array of 64 values given in zig-zag
136 * order, identical to the format used in a JFIF DQT
137 * marker segment. */
139 }
140
141 /* DHT */
143 dht_size_ptr = pbc.
buffer;
144 bytestream2_put_be16(&pbc, 0);
145
146 dht_size = 2;
155 AV_WB16(dht_size_ptr, dht_size);
156
157 /* SOF0 */
159 bytestream2_put_be16(&pbc, 17); /* size */
160 bytestream2_put_byte(&pbc, 8); /* bits per component */
161 bytestream2_put_be16(&pbc,
h);
162 bytestream2_put_be16(&pbc,
w);
163 bytestream2_put_byte(&pbc, 3); /* number of components */
164 bytestream2_put_byte(&pbc, 1); /* component number */
165 bytestream2_put_byte(&pbc, (2 << 4) | (
type ? 2 : 1));
/* hsample/vsample */
166 bytestream2_put_byte(&pbc, 0); /* matrix number */
167 bytestream2_put_byte(&pbc, 2); /* component number */
168 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
169 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
170 bytestream2_put_byte(&pbc, 3); /* component number */
171 bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
172 bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
173
174 /* SOS */
176 bytestream2_put_be16(&pbc, 12);
177 bytestream2_put_byte(&pbc, 3);
178 bytestream2_put_byte(&pbc, 1);
179 bytestream2_put_byte(&pbc, 0);
180 bytestream2_put_byte(&pbc, 2);
181 bytestream2_put_byte(&pbc, 17);
182 bytestream2_put_byte(&pbc, 3);
183 bytestream2_put_byte(&pbc, 17);
184 bytestream2_put_byte(&pbc, 0);
185 bytestream2_put_byte(&pbc, 63);
186 bytestream2_put_byte(&pbc, 0);
187
188 /* Return the length in bytes of the JPEG header. */
190 }
191
193 {
197
199
200 if (q < 50)
202 else
204
205 for (
i = 0;
i < 128;
i++) {
207
208 /* Limit the quantizers to 1 <= q <= 255. */
211 }
212 }
213
216 const uint8_t *buf,
int len, uint16_t seq,
218 {
220 const uint8_t *qtables =
NULL;
221 uint16_t qtable_len;
222 uint32_t off;
224
228 }
229
230 /* Parse the main JPEG header. */
231 off =
AV_RB24(buf + 1);
/* fragment byte offset */
232 type =
AV_RB8(buf + 4);
/* id of jpeg decoder params */
233 q =
AV_RB8(buf + 5);
/* quantization factor (or table id) */
234 width =
AV_RB8(buf + 6);
/* frame width in 8 pixel blocks */
235 height =
AV_RB8(buf + 7);
/* frame height in 8 pixel blocks */
236 buf += 8;
238
243 }
245 buf += 4;
248 }
252 }
253
254 /* Parse the quantization table header. */
255 if (off == 0) {
256 /* Start of JPEG data packet. */
257 uint8_t new_qtables[128];
258 uint8_t hdr[1024];
259
260 if (q > 127) {
261 uint8_t precision;
265 }
266
267 /* The first byte is reserved for future use. */
268 precision =
AV_RB8(buf + 1);
/* size of coefficients */
269 qtable_len =
AV_RB16(buf + 2);
/* length in bytes */
270 buf += 4;
272
273 if (precision)
275
276 if (qtable_len > 0) {
277 if (
len < qtable_len) {
280 }
281 qtables = buf;
282 buf += qtable_len;
284 if (q < 255) {
287 memcmp(qtables, &jpeg->
qtables[q - 128][0], qtable_len))) {
289 "Quantization tables for q=%d changed\n", q);
290 }
else if (!jpeg->
qtables_len[q - 128] && qtable_len <= 128) {
291 memcpy(&jpeg->
qtables[q - 128][0], qtables,
292 qtable_len);
294 }
295 }
296 } else {
297 if (q == 255) {
299 "Invalid RTP/JPEG packet. Quantization tables not found.\n");
301 }
304 "No quantization tables known for q=%d yet.\n", q);
306 }
307 qtables = &jpeg->
qtables[q - 128][0];
309 }
310 } else { /* q <= 127 */
311 if (q == 0 || q > 99) {
314 }
316 qtables = new_qtables;
317 qtable_len = sizeof(new_qtables);
318 }
319
320 /* Skip the current frame in case of the end packet
321 * has been lost somewhere. */
323
327
328 /* Generate a frame and scan headers that can be prepended to the
329 * RTP/JPEG data payload to produce a JPEG compressed image in
330 * interchange format. */
333 qtable_len / 64, dri);
334
335 /* Copy JPEG header to frame buffer. */
337 }
338
341 "Received packet without a start chunk; dropping frame.\n");
343 }
344
346 /* Skip the current frame if timestamp is incorrect.
347 * A start packet has been lost somewhere. */
351 }
352
355 "Missing packets; dropping frame.\n");
357 }
358
359 /* Copy data to frame buffer. */
361
363 /* End of JPEG data packet. */
364 uint8_t buf[2] = { 0xff,
EOI };
365
366 /* Put EOI marker. */
368
369 /* Prepare the JPEG packet. */
372 "Error occurred when getting frame buffer.\n");
374 }
375
376 return 0;
377 }
378
380 }
381
389 .static_payload_id = 26,
390 };