yading@11: /*
yading@11:  * RTP JPEG-compressed video Packetizer, RFC 2435
yading@11:  * Copyright (c) 2012 Samuel Pitoiset
yading@11:  *
yading@11:  * This file is part of FFmpeg.
yading@11:  *
yading@11:  * FFmpeg is free software; you can redistribute it and/or
yading@11:  * modify it under the terms of the GNU Lesser General Public
yading@11:  * License as published by the Free Software Foundation; either
yading@11:  * version 2.1 of the License, or (at your option) any later version.
yading@11:  *
yading@11:  * FFmpeg is distributed in the hope that it will be useful,
yading@11:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@11:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@11:  * Lesser General Public License for more details.
yading@11:  *
yading@11:  * You should have received a copy of the GNU Lesser General Public
yading@11:  * License along with FFmpeg; if not, write to the Free Software
yading@11:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@11:  */
yading@11: 
yading@11: #include "libavcodec/bytestream.h"
yading@11: #include "libavcodec/mjpeg.h"
yading@11: #include "libavutil/intreadwrite.h"
yading@11: #include "rtpenc.h"
yading@11: 
yading@11: void ff_rtp_send_jpeg(AVFormatContext *s1, const uint8_t *buf, int size)
yading@11: {
yading@11:     RTPMuxContext *s = s1->priv_data;
yading@11:     const uint8_t *qtables = NULL;
yading@11:     int nb_qtables = 0;
yading@11:     uint8_t type = 1; /* default pixel format is AV_PIX_FMT_YUVJ420P */
yading@11:     uint8_t w, h;
yading@11:     uint8_t *p;
yading@11:     int off = 0; /* fragment offset of the current JPEG frame */
yading@11:     int len;
yading@11:     int i;
yading@11: 
yading@11:     s->buf_ptr   = s->buf;
yading@11:     s->timestamp = s->cur_timestamp;
yading@11: 
yading@11:     /* convert video pixel dimensions from pixels to blocks */
yading@11:     w = s1->streams[0]->codec->width  >> 3;
yading@11:     h = s1->streams[0]->codec->height >> 3;
yading@11: 
yading@11:     /* check if pixel format is not the normal 420 case */
yading@11:     if (s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUVJ422P) {
yading@11:         type = 0;
yading@11:     } else if (s1->streams[0]->codec->pix_fmt == AV_PIX_FMT_YUVJ420P) {
yading@11:         type = 1;
yading@11:     } else {
yading@11:         av_log(s1, AV_LOG_ERROR, "Unsupported pixel format\n");
yading@11:         return;
yading@11:     }
yading@11: 
yading@11:     /* preparse the header for getting some infos */
yading@11:     for (i = 0; i < size; i++) {
yading@11:         if (buf[i] != 0xff)
yading@11:             continue;
yading@11: 
yading@11:         if (buf[i + 1] == DQT) {
yading@11:             if (buf[i + 4])
yading@11:                 av_log(s1, AV_LOG_WARNING,
yading@11:                        "Only 8-bit precision is supported.\n");
yading@11: 
yading@11:             /* a quantization table is 64 bytes long */
yading@11:             nb_qtables = AV_RB16(&buf[i + 2]) / 65;
yading@11:             if (i + 4 + nb_qtables * 65 > size) {
yading@11:                 av_log(s1, AV_LOG_ERROR, "Too short JPEG header. Aborted!\n");
yading@11:                 return;
yading@11:             }
yading@11: 
yading@11:             qtables = &buf[i + 4];
yading@11:         } else if (buf[i + 1] == SOF0) {
yading@11:             if (buf[i + 14] != 17 || buf[i + 17] != 17) {
yading@11:                 av_log(s1, AV_LOG_ERROR,
yading@11:                        "Only 1x1 chroma blocks are supported. Aborted!\n");
yading@11:                 return;
yading@11:             }
yading@11:         } else if (buf[i + 1] == SOS) {
yading@11:             /* SOS is last marker in the header */
yading@11:             i += AV_RB16(&buf[i + 2]) + 2;
yading@11:             break;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     /* skip JPEG header */
yading@11:     buf  += i;
yading@11:     size -= i;
yading@11: 
yading@11:     for (i = size - 2; i >= 0; i--) {
yading@11:         if (buf[i] == 0xff && buf[i + 1] == EOI) {
yading@11:             /* Remove the EOI marker */
yading@11:             size = i;
yading@11:             break;
yading@11:         }
yading@11:     }
yading@11: 
yading@11:     p = s->buf_ptr;
yading@11:     while (size > 0) {
yading@11:         int hdr_size = 8;
yading@11: 
yading@11:         if (off == 0 && nb_qtables)
yading@11:             hdr_size += 4 + 64 * nb_qtables;
yading@11: 
yading@11:         /* payload max in one packet */
yading@11:         len = FFMIN(size, s->max_payload_size - hdr_size);
yading@11: 
yading@11:         /* set main header */
yading@11:         bytestream_put_byte(&p, 0);
yading@11:         bytestream_put_be24(&p, off);
yading@11:         bytestream_put_byte(&p, type);
yading@11:         bytestream_put_byte(&p, 255);
yading@11:         bytestream_put_byte(&p, w);
yading@11:         bytestream_put_byte(&p, h);
yading@11: 
yading@11:         if (off == 0 && nb_qtables) {
yading@11:             /* set quantization tables header */
yading@11:             bytestream_put_byte(&p, 0);
yading@11:             bytestream_put_byte(&p, 0);
yading@11:             bytestream_put_be16(&p, 64 * nb_qtables);
yading@11: 
yading@11:             for (i = 0; i < nb_qtables; i++)
yading@11:                 bytestream_put_buffer(&p, &qtables[65 * i + 1], 64);
yading@11:         }
yading@11: 
yading@11:         /* copy payload data */
yading@11:         memcpy(p, buf, len);
yading@11: 
yading@11:         /* marker bit is last packet in frame */
yading@11:         ff_rtp_send_data(s1, s->buf, len + hdr_size, size == len);
yading@11: 
yading@11:         buf  += len;
yading@11:         size -= len;
yading@11:         off  += len;
yading@11:         p     = s->buf;
yading@11:     }
yading@11: }