libavformat/rtpenc_jpeg.c

   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
  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 }