2 * RTP JPEG-compressed video Packetizer, RFC 2435
3 * Copyright (c) 2012 Samuel Pitoiset
5 * This file is part of FFmpeg.
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.
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.
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
22 #include "libavcodec/bytestream.h"
23 #include "libavcodec/mjpeg.h"
24 #include "libavcodec/jpegtables.h"
25 #include "libavutil/intreadwrite.h"
28 void ff_rtp_send_jpeg(AVFormatContext *s1, const uint8_t *buf, int size)
30 RTPMuxContext *s = s1->priv_data;
31 const uint8_t *qtables[4] = { NULL };
36 int off = 0; /* fragment offset of the current JPEG frame */
41 s->timestamp = s->cur_timestamp;
43 /* convert video pixel dimensions from pixels to blocks */
44 w = FF_CEIL_RSHIFT(s1->streams[0]->codec->width, 3);
45 h = FF_CEIL_RSHIFT(s1->streams[0]->codec->height, 3);
47 /* get the pixel format type or fail */
48 if (s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUVJ422P ||
49 (s1->streams[0]->codec->color_range == AVCOL_RANGE_JPEG &&
50 s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUV422P)) {
52 } else if (s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUVJ420P ||
53 (s1->streams[0]->codec->color_range == AVCOL_RANGE_JPEG &&
54 s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUV420P)) {
57 av_log(s1, AV_LOG_ERROR, "Unsupported pixel format\n");
61 /* preparse the header for getting some infos */
62 for (i = 0; i < size; i++) {
66 if (buf[i + 1] == DQT) {
68 if (buf[i + 4] & 0xF0)
69 av_log(s1, AV_LOG_WARNING,
70 "Only 8-bit precision is supported.\n");
72 /* a quantization table is 64 bytes long */
73 tables = AV_RB16(&buf[i + 2]) / 65;
74 if (i + 5 + tables * 65 > size) {
75 av_log(s1, AV_LOG_ERROR, "Too short JPEG header. Aborted!\n");
78 if (nb_qtables + tables > 4) {
79 av_log(s1, AV_LOG_ERROR, "Invalid number of quantisation tables\n");
83 for (j = 0; j < tables; j++)
84 qtables[nb_qtables + j] = buf + i + 5 + j * 65;
86 } else if (buf[i + 1] == SOF0) {
87 if (buf[i + 14] != 17 || buf[i + 17] != 17) {
88 av_log(s1, AV_LOG_ERROR,
89 "Only 1x1 chroma blocks are supported. Aborted!\n");
92 } else if (buf[i + 1] == DHT) {
93 if ( AV_RB16(&buf[i + 2]) < 418
96 || buf[i + 33] != 0x01
97 || buf[i + 62] != 0x10
98 || buf[i + 241] != 0x11
99 || memcmp(buf + i + 5, avpriv_mjpeg_bits_dc_luminance + 1, 16)
100 || memcmp(buf + i + 21, avpriv_mjpeg_val_dc, 12)
101 || memcmp(buf + i + 34, avpriv_mjpeg_bits_dc_chrominance + 1, 16)
102 || memcmp(buf + i + 50, avpriv_mjpeg_val_dc, 12)
103 || memcmp(buf + i + 63, avpriv_mjpeg_bits_ac_luminance + 1, 16)
104 || memcmp(buf + i + 79, avpriv_mjpeg_val_ac_luminance, 162)
105 || memcmp(buf + i + 242, avpriv_mjpeg_bits_ac_chrominance + 1, 16)
106 || memcmp(buf + i + 258, avpriv_mjpeg_val_ac_chrominance, 162)) {
107 av_log(s1, AV_LOG_ERROR,
108 "RFC 2435 requires standard Huffman tables for jpeg\n");
111 } else if (buf[i + 1] == SOS) {
112 /* SOS is last marker in the header */
113 i += AV_RB16(&buf[i + 2]) + 2;
115 av_log(s1, AV_LOG_ERROR,
116 "Insufficient data. Aborted!\n");
122 if (nb_qtables && nb_qtables != 2)
123 av_log(s1, AV_LOG_WARNING,
124 "RFC 2435 suggests two quantization tables, %d provided\n",
127 /* skip JPEG header */
131 for (i = size - 2; i >= 0; i--) {
132 if (buf[i] == 0xff && buf[i + 1] == EOI) {
133 /* Remove the EOI marker */
143 if (off == 0 && nb_qtables)
144 hdr_size += 4 + 64 * nb_qtables;
146 /* payload max in one packet */
147 len = FFMIN(size, s->max_payload_size - hdr_size);
149 /* set main header */
150 bytestream_put_byte(&p, 0);
151 bytestream_put_be24(&p, off);
152 bytestream_put_byte(&p, type);
153 bytestream_put_byte(&p, 255);
154 bytestream_put_byte(&p, w);
155 bytestream_put_byte(&p, h);
157 if (off == 0 && nb_qtables) {
158 /* set quantization tables header */
159 bytestream_put_byte(&p, 0);
160 bytestream_put_byte(&p, 0);
161 bytestream_put_be16(&p, 64 * nb_qtables);
163 for (i = 0; i < nb_qtables; i++)
164 bytestream_put_buffer(&p, qtables[i], 64);
167 /* copy payload data */
170 /* marker bit is last packet in frame */
171 ff_rtp_send_data(s1, s->buf, len + hdr_size, size == len);