libavformat/rtpdec_jpeg.c

   1 /*
   2  * RTP JPEG-compressed Video Depacketizer, 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 "avformat.h"
  23 #include "avio_internal.h"
  24 #include "rtpdec.h"
  25 #include "rtpdec_formats.h"
  26 #include "libavutil/intreadwrite.h"
  27 #include "libavcodec/jpegtables.h"
  28 #include "libavcodec/mjpeg.h"
  29 #include "libavcodec/bytestream.h"
  30
  31 /**
  32  * RTP/JPEG specific private data.
  33  */
  34 struct PayloadContext {
  35     AVIOContext *frame;         ///< current frame buffer
  36     uint32_t    timestamp;      ///< current frame timestamp
  37     int         hdr_size;       ///< size of the current frame header
  38     uint8_t     qtables[128][128];
  39     uint8_t     qtables_len[128];
  40 };
  41
  42 static const uint8_t default_quantizers[128] = {
  43     /* luma table */
  44     16,  11,  12,  14,  12,  10,  16,  14,
  45     13,  14,  18,  17,  16,  19,  24,  40,
  46     26,  24,  22,  22,  24,  49,  35,  37,
  47     29,  40,  58,  51,  61,  60,  57,  51,
  48     56,  55,  64,  72,  92,  78,  64,  68,
  49     87,  69,  55,  56,  80,  109, 81,  87,
  50     95,  98,  103, 104, 103, 62,  77,  113,
  51     121, 112, 100, 120, 92,  101, 103, 99,
  52
  53     /* chroma table */
  54     17,  18,  18,  24,  21,  24,  47,  26,
  55     26,  47,  99,  66,  56,  66,  99,  99,
  56     99,  99,  99,  99,  99,  99,  99,  99,
  57     99,  99,  99,  99,  99,  99,  99,  99,
  58     99,  99,  99,  99,  99,  99,  99,  99,
  59     99,  99,  99,  99,  99,  99,  99,  99,
  60     99,  99,  99,  99,  99,  99,  99,  99,
  61     99,  99,  99,  99,  99,  99,  99,  99
  62 };
  63
  64 static void jpeg_close_context(PayloadContext *jpeg)
  65 {
  66     ffio_free_dyn_buf(&jpeg->frame);
  67 }
  68
  69 static int jpeg_create_huffman_table(PutByteContext *p, int table_class,
  70                                      int table_id, const uint8_t *bits_table,
  71                                      const uint8_t *value_table)
  72 {
  73     int i, n = 0;
  74
  75     bytestream2_put_byte(p, table_class << 4 | table_id);
  76
  77     for (i = 1; i <= 16; i++) {
  78         n += bits_table[i];
  79         bytestream2_put_byte(p, bits_table[i]);
  80     }
  81
  82     for (i = 0; i < n; i++) {
  83         bytestream2_put_byte(p, value_table[i]);
  84     }
  85     return n + 17;
  86 }
  87
  88 static void jpeg_put_marker(PutByteContext *pbc, int code)
  89 {
  90     bytestream2_put_byte(pbc, 0xff);
  91     bytestream2_put_byte(pbc, code);
  92 }
  93
  94 static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w,
  95                               uint32_t h, const uint8_t *qtable, int nb_qtable,
  96                               int dri)
  97 {
  98     PutByteContext pbc;
  99     uint8_t *dht_size_ptr;
 100     int dht_size, i;
 101
 102     bytestream2_init_writer(&pbc, buf, size);
 103
 104     /* Convert from blocks to pixels. */
 105     w <<= 3;
 106     h <<= 3;
 107
 108     /* SOI */
 109     jpeg_put_marker(&pbc, SOI);
 110
 111     /* JFIF header */
 112     jpeg_put_marker(&pbc, APP0);
 113     bytestream2_put_be16(&pbc, 16);
 114     bytestream2_put_buffer(&pbc, "JFIF", 5);
 115     bytestream2_put_be16(&pbc, 0x0102);
 116     bytestream2_put_byte(&pbc, 0);
 117     bytestream2_put_be16(&pbc, 1);
 118     bytestream2_put_be16(&pbc, 1);
 119     bytestream2_put_byte(&pbc, 0);
 120     bytestream2_put_byte(&pbc, 0);
 121
 122     if (dri) {
 123         jpeg_put_marker(&pbc, DRI);
 124         bytestream2_put_be16(&pbc, 4);
 125         bytestream2_put_be16(&pbc, dri);
 126     }
 127
 128     /* DQT */
 129     jpeg_put_marker(&pbc, DQT);
 130     bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
 131
 132     for (i = 0; i < nb_qtable; i++) {
 133         bytestream2_put_byte(&pbc, i);
 134
 135         /* Each table is an array of 64 values given in zig-zag
 136          * order, identical to the format used in a JFIF DQT
 137          * marker segment. */
 138         bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
 139     }
 140
 141     /* DHT */
 142     jpeg_put_marker(&pbc, DHT);
 143     dht_size_ptr = pbc.buffer;
 144     bytestream2_put_be16(&pbc, 0);
 145
 146     dht_size  = 2;
 147     dht_size += jpeg_create_huffman_table(&pbc, 0, 0,ff_mjpeg_bits_dc_luminance,
 148                                           ff_mjpeg_val_dc);
 149     dht_size += jpeg_create_huffman_table(&pbc, 0, 1, ff_mjpeg_bits_dc_chrominance,
 150                                           ff_mjpeg_val_dc);
 151     dht_size += jpeg_create_huffman_table(&pbc, 1, 0, ff_mjpeg_bits_ac_luminance,
 152                                           ff_mjpeg_val_ac_luminance);
 153     dht_size += jpeg_create_huffman_table(&pbc, 1, 1, ff_mjpeg_bits_ac_chrominance,
 154                                           ff_mjpeg_val_ac_chrominance);
 155     AV_WB16(dht_size_ptr, dht_size);
 156
 157     /* SOF0 */
 158     jpeg_put_marker(&pbc, SOF0);
 159     bytestream2_put_be16(&pbc, 17); /* size */
 160     bytestream2_put_byte(&pbc, 8); /* bits per component */
 161     bytestream2_put_be16(&pbc, h);
 162     bytestream2_put_be16(&pbc, w);
 163     bytestream2_put_byte(&pbc, 3); /* number of components */
 164     bytestream2_put_byte(&pbc, 1); /* component number */
 165     bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
 166     bytestream2_put_byte(&pbc, 0); /* matrix number */
 167     bytestream2_put_byte(&pbc, 2); /* component number */
 168     bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
 169     bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
 170     bytestream2_put_byte(&pbc, 3); /* component number */
 171     bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
 172     bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
 173
 174     /* SOS */
 175     jpeg_put_marker(&pbc, SOS);
 176     bytestream2_put_be16(&pbc, 12);
 177     bytestream2_put_byte(&pbc, 3);
 178     bytestream2_put_byte(&pbc, 1);
 179     bytestream2_put_byte(&pbc, 0);
 180     bytestream2_put_byte(&pbc, 2);
 181     bytestream2_put_byte(&pbc, 17);
 182     bytestream2_put_byte(&pbc, 3);
 183     bytestream2_put_byte(&pbc, 17);
 184     bytestream2_put_byte(&pbc, 0);
 185     bytestream2_put_byte(&pbc, 63);
 186     bytestream2_put_byte(&pbc, 0);
 187
 188     /* Return the length in bytes of the JPEG header. */
 189     return bytestream2_tell_p(&pbc);
 190 }
 191
 192 static void create_default_qtables(uint8_t *qtables, uint8_t q)
 193 {
 194     int factor = q;
 195     int i;
 196     uint16_t S;
 197
 198     factor = av_clip(q, 1, 99);
 199
 200     if (q < 50)
 201         S = 5000 / factor;
 202     else
 203         S = 200 - factor * 2;
 204
 205     for (i = 0; i < 128; i++) {
 206         int val = (default_quantizers[i] * S + 50) / 100;
 207
 208         /* Limit the quantizers to 1 <= q <= 255. */
 209         val = av_clip(val, 1, 255);
 210         qtables[i] = val;
 211     }
 212 }
 213
 214 static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
 215                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,
 216                              const uint8_t *buf, int len, uint16_t seq,
 217                              int flags)
 218 {
 219     uint8_t type, q, width, height;
 220     const uint8_t *qtables = NULL;
 221     uint16_t qtable_len;
 222     uint32_t off;
 223     int ret, dri = 0;
 224
 225     if (len < 8) {
 226         av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
 227         return AVERROR_INVALIDDATA;
 228     }
 229
 230     /* Parse the main JPEG header. */
 231     off    = AV_RB24(buf + 1);  /* fragment byte offset */
 232     type   = AV_RB8(buf + 4);   /* id of jpeg decoder params */
 233     q      = AV_RB8(buf + 5);   /* quantization factor (or table id) */
 234     width  = AV_RB8(buf + 6);   /* frame width in 8 pixel blocks */
 235     height = AV_RB8(buf + 7);   /* frame height in 8 pixel blocks */
 236     buf += 8;
 237     len -= 8;
 238
 239     if (type & 0x40) {
 240         if (len < 4) {
 241             av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
 242             return AVERROR_INVALIDDATA;
 243         }
 244         dri = AV_RB16(buf);
 245         buf += 4;
 246         len -= 4;
 247         type &= ~0x40;
 248     }
 249     if (type > 1) {
 250         avpriv_report_missing_feature(ctx, "RTP/JPEG type %"PRIu8, type);
 251         return AVERROR_PATCHWELCOME;
 252     }
 253
 254     /* Parse the quantization table header. */
 255     if (off == 0) {
 256         /* Start of JPEG data packet. */
 257         uint8_t new_qtables[128];
 258         uint8_t hdr[1024];
 259
 260         if (q > 127) {
 261             uint8_t precision;
 262             if (len < 4) {
 263                 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
 264                 return AVERROR_INVALIDDATA;
 265             }
 266
 267             /* The first byte is reserved for future use. */
 268             precision  = AV_RB8(buf + 1);    /* size of coefficients */
 269             qtable_len = AV_RB16(buf + 2);   /* length in bytes */
 270             buf += 4;
 271             len -= 4;
 272
 273             if (precision)
 274                 av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
 275
 276             if (qtable_len > 0) {
 277                 if (len < qtable_len) {
 278                     av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
 279                     return AVERROR_INVALIDDATA;
 280                 }
 281                 qtables = buf;
 282                 buf += qtable_len;
 283                 len -= qtable_len;
 284                 if (q < 255) {
 285                     if (jpeg->qtables_len[q - 128] &&
 286                         (jpeg->qtables_len[q - 128] != qtable_len ||
 287                          memcmp(qtables, &jpeg->qtables[q - 128][0], qtable_len))) {
 288                         av_log(ctx, AV_LOG_WARNING,
 289                                "Quantization tables for q=%d changed\n", q);
 290                     } else if (!jpeg->qtables_len[q - 128] && qtable_len <= 128) {
 291                         memcpy(&jpeg->qtables[q - 128][0], qtables,
 292                                qtable_len);
 293                         jpeg->qtables_len[q - 128] = qtable_len;
 294                     }
 295                 }
 296             } else {
 297                 if (q == 255) {
 298                     av_log(ctx, AV_LOG_ERROR,
 299                            "Invalid RTP/JPEG packet. Quantization tables not found.\n");
 300                     return AVERROR_INVALIDDATA;
 301                 }
 302                 if (!jpeg->qtables_len[q - 128]) {
 303                     av_log(ctx, AV_LOG_ERROR,
 304                            "No quantization tables known for q=%d yet.\n", q);
 305                     return AVERROR_INVALIDDATA;
 306                 }
 307                 qtables    = &jpeg->qtables[q - 128][0];
 308                 qtable_len =  jpeg->qtables_len[q - 128];
 309             }
 310         } else { /* q <= 127 */
 311             if (q == 0 || q > 99) {
 312                 av_log(ctx, AV_LOG_ERROR, "Reserved q value %d\n", q);
 313                 return AVERROR_INVALIDDATA;
 314             }
 315             create_default_qtables(new_qtables, q);
 316             qtables    = new_qtables;
 317             qtable_len = sizeof(new_qtables);
 318         }
 319
 320         /* Skip the current frame in case of the end packet
 321          * has been lost somewhere. */
 322         ffio_free_dyn_buf(&jpeg->frame);
 323
 324         if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
 325             return ret;
 326         jpeg->timestamp = *timestamp;
 327
 328         /* Generate a frame and scan headers that can be prepended to the
 329          * RTP/JPEG data payload to produce a JPEG compressed image in
 330          * interchange format. */
 331         jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
 332                                             height, qtables,
 333                                             qtable_len / 64, dri);
 334
 335         /* Copy JPEG header to frame buffer. */
 336         avio_write(jpeg->frame, hdr, jpeg->hdr_size);
 337     }
 338
 339     if (!jpeg->frame) {
 340         av_log(ctx, AV_LOG_ERROR,
 341                "Received packet without a start chunk; dropping frame.\n");
 342         return AVERROR(EAGAIN);
 343     }
 344
 345     if (jpeg->timestamp != *timestamp) {
 346         /* Skip the current frame if timestamp is incorrect.
 347          * A start packet has been lost somewhere. */
 348         ffio_free_dyn_buf(&jpeg->frame);
 349         av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
 350         return AVERROR_INVALIDDATA;
 351     }
 352
 353     if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
 354         av_log(ctx, AV_LOG_ERROR,
 355                "Missing packets; dropping frame.\n");
 356         return AVERROR(EAGAIN);
 357     }
 358
 359     /* Copy data to frame buffer. */
 360     avio_write(jpeg->frame, buf, len);
 361
 362     if (flags & RTP_FLAG_MARKER) {
 363         /* End of JPEG data packet. */
 364         uint8_t buf[2] = { 0xff, EOI };
 365
 366         /* Put EOI marker. */
 367         avio_write(jpeg->frame, buf, sizeof(buf));
 368
 369         /* Prepare the JPEG packet. */
 370         if ((ret = ff_rtp_finalize_packet(pkt, &jpeg->frame, st->index)) < 0) {
 371             av_log(ctx, AV_LOG_ERROR,
 372                    "Error occurred when getting frame buffer.\n");
 373             return ret;
 374         }
 375
 376         return 0;
 377     }
 378
 379     return AVERROR(EAGAIN);
 380 }
 381
 382 const RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
 383     .enc_name          = "JPEG",
 384     .codec_type        = AVMEDIA_TYPE_VIDEO,
 385     .codec_id          = AV_CODEC_ID_MJPEG,
 386     .priv_data_size    = sizeof(PayloadContext),
 387     .close             = jpeg_close_context,
 388     .parse_packet      = jpeg_parse_packet,
 389     .static_payload_id = 26,
 390 };