1 /*
2 * RTP JPEG-compressed video Packetizer, 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
22 #include "libavcodec/bytestream.h"
23 #include "libavcodec/mjpeg.h"
24 #include "libavcodec/jpegtables.h"
25 #include "libavutil/intreadwrite.h"
26 #include "rtpenc.h"
27
ff_rtp_send_jpeg(AVFormatContext * s1,const uint8_t * buf,int size)28 void ff_rtp_send_jpeg(AVFormatContext *s1, const uint8_t *buf, int size)
29 {
30 RTPMuxContext *s = s1->priv_data;
31 const uint8_t *qtables[4] = { NULL };
32 int nb_qtables = 0;
33 uint8_t type;
34 uint8_t w, h;
35 uint8_t *p;
36 int off = 0; /* fragment offset of the current JPEG frame */
37 int len;
38 int i;
39 int default_huffman_tables = 0;
40
41 s->buf_ptr = s->buf;
42 s->timestamp = s->cur_timestamp;
43
44 /* convert video pixel dimensions from pixels to blocks */
45 w = AV_CEIL_RSHIFT(s1->streams[0]->codecpar->width, 3);
46 h = AV_CEIL_RSHIFT(s1->streams[0]->codecpar->height, 3);
47
48 /* get the pixel format type or fail */
49 if (s1->streams[0]->codecpar->format == AV_PIX_FMT_YUVJ422P ||
50 (s1->streams[0]->codecpar->color_range == AVCOL_RANGE_JPEG &&
51 s1->streams[0]->codecpar->format == AV_PIX_FMT_YUV422P)) {
52 type = 0;
53 } else if (s1->streams[0]->codecpar->format == AV_PIX_FMT_YUVJ420P ||
54 (s1->streams[0]->codecpar->color_range == AVCOL_RANGE_JPEG &&
55 s1->streams[0]->codecpar->format == AV_PIX_FMT_YUV420P)) {
56 type = 1;
57 } else {
58 av_log(s1, AV_LOG_ERROR, "Unsupported pixel format\n");
59 return;
60 }
61
62 /* preparse the header for getting some info */
63 for (i = 0; i < size; i++) {
64 if (buf[i] != 0xff)
65 continue;
66
67 if (buf[i + 1] == DQT) {
68 int tables, j;
69 if (buf[i + 4] & 0xF0)
70 av_log(s1, AV_LOG_WARNING,
71 "Only 8-bit precision is supported.\n");
72
73 /* a quantization table is 64 bytes long */
74 tables = AV_RB16(&buf[i + 2]) / 65;
75 if (i + 5 + tables * 65 > size) {
76 av_log(s1, AV_LOG_ERROR, "Too short JPEG header. Aborted!\n");
77 return;
78 }
79 if (nb_qtables + tables > 4) {
80 av_log(s1, AV_LOG_ERROR, "Invalid number of quantisation tables\n");
81 return;
82 }
83
84 for (j = 0; j < tables; j++)
85 qtables[nb_qtables + j] = buf + i + 5 + j * 65;
86 nb_qtables += tables;
87 } else if (buf[i + 1] == SOF0) {
88 if (buf[i + 14] != 17 || buf[i + 17] != 17) {
89 av_log(s1, AV_LOG_ERROR,
90 "Only 1x1 chroma blocks are supported. Aborted!\n");
91 return;
92 }
93 } else if (buf[i + 1] == DHT) {
94 int dht_size = AV_RB16(&buf[i + 2]);
95 default_huffman_tables |= 1 << 4;
96 i += 3;
97 dht_size -= 2;
98 if (i + dht_size >= size)
99 continue;
100 while (dht_size > 0)
101 switch (buf[i + 1]) {
102 case 0x00:
103 if ( dht_size >= 29
104 && !memcmp(buf + i + 2, avpriv_mjpeg_bits_dc_luminance + 1, 16)
105 && !memcmp(buf + i + 18, avpriv_mjpeg_val_dc, 12)) {
106 default_huffman_tables |= 1;
107 i += 29;
108 dht_size -= 29;
109 } else {
110 i += dht_size;
111 dht_size = 0;
112 }
113 break;
114 case 0x01:
115 if ( dht_size >= 29
116 && !memcmp(buf + i + 2, avpriv_mjpeg_bits_dc_chrominance + 1, 16)
117 && !memcmp(buf + i + 18, avpriv_mjpeg_val_dc, 12)) {
118 default_huffman_tables |= 1 << 1;
119 i += 29;
120 dht_size -= 29;
121 } else {
122 i += dht_size;
123 dht_size = 0;
124 }
125 break;
126 case 0x10:
127 if ( dht_size >= 179
128 && !memcmp(buf + i + 2, avpriv_mjpeg_bits_ac_luminance + 1, 16)
129 && !memcmp(buf + i + 18, avpriv_mjpeg_val_ac_luminance, 162)) {
130 default_huffman_tables |= 1 << 2;
131 i += 179;
132 dht_size -= 179;
133 } else {
134 i += dht_size;
135 dht_size = 0;
136 }
137 break;
138 case 0x11:
139 if ( dht_size >= 179
140 && !memcmp(buf + i + 2, avpriv_mjpeg_bits_ac_chrominance + 1, 16)
141 && !memcmp(buf + i + 18, avpriv_mjpeg_val_ac_chrominance, 162)) {
142 default_huffman_tables |= 1 << 3;
143 i += 179;
144 dht_size -= 179;
145 } else {
146 i += dht_size;
147 dht_size = 0;
148 }
149 break;
150 default:
151 i += dht_size;
152 dht_size = 0;
153 continue;
154 }
155 } else if (buf[i + 1] == SOS) {
156 /* SOS is last marker in the header */
157 i += AV_RB16(&buf[i + 2]) + 2;
158 if (i > size) {
159 av_log(s1, AV_LOG_ERROR,
160 "Insufficient data. Aborted!\n");
161 return;
162 }
163 break;
164 }
165 }
166 if (default_huffman_tables && default_huffman_tables != 31) {
167 av_log(s1, AV_LOG_ERROR,
168 "RFC 2435 requires standard Huffman tables for jpeg\n");
169 return;
170 }
171 if (nb_qtables && nb_qtables != 2)
172 av_log(s1, AV_LOG_WARNING,
173 "RFC 2435 suggests two quantization tables, %d provided\n",
174 nb_qtables);
175
176 /* skip JPEG header */
177 buf += i;
178 size -= i;
179
180 for (i = size - 2; i >= 0; i--) {
181 if (buf[i] == 0xff && buf[i + 1] == EOI) {
182 /* Remove the EOI marker */
183 size = i;
184 break;
185 }
186 }
187
188 p = s->buf_ptr;
189 while (size > 0) {
190 int hdr_size = 8;
191
192 if (off == 0 && nb_qtables)
193 hdr_size += 4 + 64 * nb_qtables;
194
195 /* payload max in one packet */
196 len = FFMIN(size, s->max_payload_size - hdr_size);
197
198 /* set main header */
199 bytestream_put_byte(&p, 0);
200 bytestream_put_be24(&p, off);
201 bytestream_put_byte(&p, type);
202 bytestream_put_byte(&p, 255);
203 bytestream_put_byte(&p, w);
204 bytestream_put_byte(&p, h);
205
206 if (off == 0 && nb_qtables) {
207 /* set quantization tables header */
208 bytestream_put_byte(&p, 0);
209 bytestream_put_byte(&p, 0);
210 bytestream_put_be16(&p, 64 * nb_qtables);
211
212 for (i = 0; i < nb_qtables; i++)
213 bytestream_put_buffer(&p, qtables[i], 64);
214 }
215
216 /* copy payload data */
217 memcpy(p, buf, len);
218
219 /* marker bit is last packet in frame */
220 ff_rtp_send_data(s1, s->buf, len + hdr_size, size == len);
221
222 buf += len;
223 size -= len;
224 off += len;
225 p = s->buf;
226 }
227 }
228