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 "libavutil/intreadwrite.h"
27 void ff_rtp_send_jpeg(AVFormatContext *s1, const uint8_t *buf, int size)
29 RTPMuxContext *s = s1->priv_data;
30 const uint8_t *qtables = NULL;
35 int off = 0; /* fragment offset of the current JPEG frame */
40 s->timestamp = s->cur_timestamp;
42 /* convert video pixel dimensions from pixels to blocks */
43 w = s1->streams[0]->codec->width >> 3;
44 h = s1->streams[0]->codec->height >> 3;
46 /* get the pixel format type or fail */
47 if (s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUVJ422P ||
48 (s1->streams[0]->codec->color_range == AVCOL_RANGE_JPEG &&
49 s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUV422P)) {
51 } else if (s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUVJ420P ||
52 (s1->streams[0]->codec->color_range == AVCOL_RANGE_JPEG &&
53 s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUV420P)) {
56 av_log(s1, AV_LOG_ERROR, "Unsupported pixel format\n");
60 /* preparse the header for getting some infos */
61 for (i = 0; i < size; i++) {
65 if (buf[i + 1] == DQT) {
67 av_log(s1, AV_LOG_WARNING,
68 "Only 8-bit precision is supported.\n");
70 /* a quantization table is 64 bytes long */
71 nb_qtables = AV_RB16(&buf[i + 2]) / 65;
72 if (i + 4 + nb_qtables * 65 > size) {
73 av_log(s1, AV_LOG_ERROR, "Too short JPEG header. Aborted!\n");
77 qtables = &buf[i + 4];
78 } else if (buf[i + 1] == SOF0) {
79 if (buf[i + 14] != 17 || buf[i + 17] != 17) {
80 av_log(s1, AV_LOG_ERROR,
81 "Only 1x1 chroma blocks are supported. Aborted!\n");
84 } else if (buf[i + 1] == SOS) {
85 /* SOS is last marker in the header */
86 i += AV_RB16(&buf[i + 2]) + 2;
91 /* skip JPEG header */
95 for (i = size - 2; i >= 0; i--) {
96 if (buf[i] == 0xff && buf[i + 1] == EOI) {
97 /* Remove the EOI marker */
107 if (off == 0 && nb_qtables)
108 hdr_size += 4 + 64 * nb_qtables;
110 /* payload max in one packet */
111 len = FFMIN(size, s->max_payload_size - hdr_size);
113 /* set main header */
114 bytestream_put_byte(&p, 0);
115 bytestream_put_be24(&p, off);
116 bytestream_put_byte(&p, type);
117 bytestream_put_byte(&p, 255);
118 bytestream_put_byte(&p, w);
119 bytestream_put_byte(&p, h);
121 if (off == 0 && nb_qtables) {
122 /* set quantization tables header */
123 bytestream_put_byte(&p, 0);
124 bytestream_put_byte(&p, 0);
125 bytestream_put_be16(&p, 64 * nb_qtables);
127 for (i = 0; i < nb_qtables; i++)
128 bytestream_put_buffer(&p, &qtables[65 * i + 1], 64);
131 /* copy payload data */
134 /* marker bit is last packet in frame */
135 ff_rtp_send_data(s1, s->buf, len + hdr_size, size == len);