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 Libav.
   6  *
   7  * Libav 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  * Libav 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 Libav; 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 "rtpdec.h"
  24 #include "rtpdec_formats.h"
  25 #include "libavutil/intreadwrite.h"
  26 #include "libavcodec/mjpeg.h"
  27 #include "libavcodec/bytestream.h"
  28
  29 /**
  30  * RTP/JPEG specific private data.
  31  */
  32 struct PayloadContext {
  33     AVIOContext *frame;         ///< current frame buffer
  34     uint32_t    timestamp;      ///< current frame timestamp
  35     int         hdr_size;       ///< size of the current frame header
  36     uint8_t     qtables[128][128];
  37     uint8_t     qtables_len[128];
  38 };
  39
  40 static const uint8_t default_quantizers[128] = {
  41     /* luma table */
  42     16,  11,  12,  14,  12,  10,  16,  14,
  43     13,  14,  18,  17,  16,  19,  24,  40,
  44     26,  24,  22,  22,  24,  49,  35,  37,
  45     29,  40,  58,  51,  61,  60,  57,  51,
  46     56,  55,  64,  72,  92,  78,  64,  68,
  47     87,  69,  55,  56,  80,  109, 81,  87,
  48     95,  98,  103, 104, 103, 62,  77,  113,
  49     121, 112, 100, 120, 92,  101, 103, 99,
  50
  51     /* chroma table */
  52     17,  18,  18,  24,  21,  24,  47,  26,
  53     26,  47,  99,  66,  56,  66,  99,  99,
  54     99,  99,  99,  99,  99,  99,  99,  99,
  55     99,  99,  99,  99,  99,  99,  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 };
  61
  62 static PayloadContext *jpeg_new_context(void)
  63 {
  64     return av_mallocz(sizeof(PayloadContext));
  65 }
  66
  67 static inline void free_frame_if_needed(PayloadContext *jpeg)
  68 {
  69     if (jpeg->frame) {
  70         uint8_t *p;
  71         avio_close_dyn_buf(jpeg->frame, &p);
  72         av_free(p);
  73         jpeg->frame = NULL;
  74     }
  75 }
  76
  77 static void jpeg_free_context(PayloadContext *jpeg)
  78 {
  79     free_frame_if_needed(jpeg);
  80     av_free(jpeg);
  81 }
  82
  83 static int jpeg_create_huffman_table(PutByteContext *p, int table_class,
  84                                      int table_id, const uint8_t *bits_table,
  85                                      const uint8_t *value_table)
  86 {
  87     int i, n = 0;
  88
  89     bytestream2_put_byte(p, table_class << 4 | table_id);
  90
  91     for (i = 1; i <= 16; i++) {
  92         n += bits_table[i];
  93         bytestream2_put_byte(p, bits_table[i]);
  94     }
  95
  96     for (i = 0; i < n; i++) {
  97         bytestream2_put_byte(p, value_table[i]);
  98     }
  99     return n + 17;
 100 }
 101
 102 static void jpeg_put_marker(PutByteContext *pbc, int code)
 103 {
 104     bytestream2_put_byte(pbc, 0xff);
 105     bytestream2_put_byte(pbc, code);
 106 }
 107
 108 static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w,
 109                               uint32_t h, const uint8_t *qtable, int nb_qtable)
 110 {
 111     PutByteContext pbc;
 112     uint8_t *dht_size_ptr;
 113     int dht_size, i;
 114
 115     bytestream2_init_writer(&pbc, buf, size);
 116
 117     /* Convert from blocks to pixels. */
 118     w <<= 3;
 119     h <<= 3;
 120
 121     /* SOI */
 122     jpeg_put_marker(&pbc, SOI);
 123
 124     /* JFIF header */
 125     jpeg_put_marker(&pbc, APP0);
 126     bytestream2_put_be16(&pbc, 16);
 127     bytestream2_put_buffer(&pbc, "JFIF", 5);
 128     bytestream2_put_be16(&pbc, 0x0201);
 129     bytestream2_put_byte(&pbc, 0);
 130     bytestream2_put_be16(&pbc, 1);
 131     bytestream2_put_be16(&pbc, 1);
 132     bytestream2_put_byte(&pbc, 0);
 133     bytestream2_put_byte(&pbc, 0);
 134
 135     /* DQT */
 136     jpeg_put_marker(&pbc, DQT);
 137     bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
 138
 139     for (i = 0; i < nb_qtable; i++) {
 140         bytestream2_put_byte(&pbc, i);
 141
 142         /* Each table is an array of 64 values given in zig-zag
 143          * order, identical to the format used in a JFIF DQT
 144          * marker segment. */
 145         bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
 146     }
 147
 148     /* DHT */
 149     jpeg_put_marker(&pbc, DHT);
 150     dht_size_ptr = pbc.buffer;
 151     bytestream2_put_be16(&pbc, 0);
 152
 153     dht_size  = 2;
 154     dht_size += jpeg_create_huffman_table(&pbc, 0, 0,avpriv_mjpeg_bits_dc_luminance,
 155                                           avpriv_mjpeg_val_dc);
 156     dht_size += jpeg_create_huffman_table(&pbc, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
 157                                           avpriv_mjpeg_val_dc);
 158     dht_size += jpeg_create_huffman_table(&pbc, 1, 0, avpriv_mjpeg_bits_ac_luminance,
 159                                           avpriv_mjpeg_val_ac_luminance);
 160     dht_size += jpeg_create_huffman_table(&pbc, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
 161                                           avpriv_mjpeg_val_ac_chrominance);
 162     AV_WB16(dht_size_ptr, dht_size);
 163
 164     /* SOF0 */
 165     jpeg_put_marker(&pbc, SOF0);
 166     bytestream2_put_be16(&pbc, 17); /* size */
 167     bytestream2_put_byte(&pbc, 8); /* bits per component */
 168     bytestream2_put_be16(&pbc, h);
 169     bytestream2_put_be16(&pbc, w);
 170     bytestream2_put_byte(&pbc, 3); /* number of components */
 171     bytestream2_put_byte(&pbc, 1); /* component number */
 172     bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
 173     bytestream2_put_byte(&pbc, 0); /* matrix number */
 174     bytestream2_put_byte(&pbc, 2); /* component number */
 175     bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
 176     bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
 177     bytestream2_put_byte(&pbc, 3); /* component number */
 178     bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
 179     bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
 180
 181     /* SOS */
 182     jpeg_put_marker(&pbc, SOS);
 183     bytestream2_put_be16(&pbc, 12);
 184     bytestream2_put_byte(&pbc, 3);
 185     bytestream2_put_byte(&pbc, 1);
 186     bytestream2_put_byte(&pbc, 0);
 187     bytestream2_put_byte(&pbc, 2);
 188     bytestream2_put_byte(&pbc, 17);
 189     bytestream2_put_byte(&pbc, 3);
 190     bytestream2_put_byte(&pbc, 17);
 191     bytestream2_put_byte(&pbc, 0);
 192     bytestream2_put_byte(&pbc, 63);
 193     bytestream2_put_byte(&pbc, 0);
 194
 195     /* Return the length in bytes of the JPEG header. */
 196     return bytestream2_tell_p(&pbc);
 197 }
 198
 199 static void create_default_qtables(uint8_t *qtables, uint8_t q)
 200 {
 201     int factor = q;
 202     int i;
 203
 204     factor = av_clip(q, 1, 99);
 205
 206     if (q < 50)
 207         q = 5000 / factor;
 208     else
 209         q = 200 - factor * 2;
 210
 211     for (i = 0; i < 128; i++) {
 212         int val = (default_quantizers[i] * q + 50) / 100;
 213
 214         /* Limit the quantizers to 1 <= q <= 255. */
 215         val = av_clip(val, 1, 255);
 216         qtables[i] = val;
 217     }
 218 }
 219
 220 static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
 221                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,
 222                              const uint8_t *buf, int len, uint16_t seq,
 223                              int flags)
 224 {
 225     uint8_t type, q, width, height;
 226     const uint8_t *qtables = NULL;
 227     uint16_t qtable_len;
 228     uint32_t off;
 229     int ret;
 230
 231     if (len < 8) {
 232         av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
 233         return AVERROR_INVALIDDATA;
 234     }
 235
 236     /* Parse the main JPEG header. */
 237     off    = AV_RB24(buf + 1);  /* fragment byte offset */
 238     type   = AV_RB8(buf + 4);   /* id of jpeg decoder params */
 239     q      = AV_RB8(buf + 5);   /* quantization factor (or table id) */
 240     width  = AV_RB8(buf + 6);   /* frame width in 8 pixel blocks */
 241     height = AV_RB8(buf + 7);   /* frame height in 8 pixel blocks */
 242     buf += 8;
 243     len -= 8;
 244
 245     /* Parse the restart marker header. */
 246     if (type > 63) {
 247         av_log(ctx, AV_LOG_ERROR,
 248                "Unimplemented RTP/JPEG restart marker header.\n");
 249         return AVERROR_PATCHWELCOME;
 250     }
 251     if (type > 1) {
 252         av_log(ctx, AV_LOG_ERROR, "Unimplemented RTP/JPEG type %d\n", type);
 253         return AVERROR_PATCHWELCOME;
 254     }
 255
 256     /* Parse the quantization table header. */
 257     if (off == 0) {
 258         /* Start of JPEG data packet. */
 259         uint8_t new_qtables[128];
 260         uint8_t hdr[1024];
 261
 262         if (q > 127) {
 263             uint8_t precision;
 264             if (len < 4) {
 265                 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
 266                 return AVERROR_INVALIDDATA;
 267             }
 268
 269             /* The first byte is reserved for future use. */
 270             precision  = AV_RB8(buf + 1);    /* size of coefficients */
 271             qtable_len = AV_RB16(buf + 2);   /* length in bytes */
 272             buf += 4;
 273             len -= 4;
 274
 275             if (precision)
 276                 av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
 277
 278             if (qtable_len > 0) {
 279                 if (len < qtable_len) {
 280                     av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
 281                     return AVERROR_INVALIDDATA;
 282                 }
 283                 qtables = buf;
 284                 buf += qtable_len;
 285                 len -= qtable_len;
 286                 if (q < 255) {
 287                     if (jpeg->qtables_len[q - 128] &&
 288                         (jpeg->qtables_len[q - 128] != qtable_len ||
 289                          memcmp(qtables, &jpeg->qtables[q - 128][0], qtable_len))) {
 290                         av_log(ctx, AV_LOG_WARNING,
 291                                "Quantization tables for q=%d changed\n", q);
 292                     } else if (!jpeg->qtables_len[q - 128] && qtable_len <= 128) {
 293                         memcpy(&jpeg->qtables[q - 128][0], qtables,
 294                                qtable_len);
 295                         jpeg->qtables_len[q - 128] = qtable_len;
 296                     }
 297                 }
 298             } else {
 299                 if (q == 255) {
 300                     av_log(ctx, AV_LOG_ERROR,
 301                            "Invalid RTP/JPEG packet. Quantization tables not found.\n");
 302                     return AVERROR_INVALIDDATA;
 303                 }
 304                 if (!jpeg->qtables_len[q - 128]) {
 305                     av_log(ctx, AV_LOG_ERROR,
 306                            "No quantization tables known for q=%d yet.\n", q);
 307                     return AVERROR_INVALIDDATA;
 308                 }
 309                 qtables    = &jpeg->qtables[q - 128][0];
 310                 qtable_len =  jpeg->qtables_len[q - 128];
 311             }
 312         } else { /* q <= 127 */
 313             if (q == 0 || q > 99) {
 314                 av_log(ctx, AV_LOG_ERROR, "Reserved q value %d\n", q);
 315                 return AVERROR_INVALIDDATA;
 316             }
 317             create_default_qtables(new_qtables, q);
 318             qtables    = new_qtables;
 319             qtable_len = sizeof(new_qtables);
 320         }
 321
 322         /* Skip the current frame in case of the end packet
 323          * has been lost somewhere. */
 324         free_frame_if_needed(jpeg);
 325
 326         if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
 327             return ret;
 328         jpeg->timestamp = *timestamp;
 329
 330         /* Generate a frame and scan headers that can be prepended to the
 331          * RTP/JPEG data payload to produce a JPEG compressed image in
 332          * interchange format. */
 333         jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
 334                                             height, qtables,
 335                                             qtable_len / 64);
 336
 337         /* Copy JPEG header to frame buffer. */
 338         avio_write(jpeg->frame, hdr, jpeg->hdr_size);
 339     }
 340
 341     if (!jpeg->frame) {
 342         av_log(ctx, AV_LOG_ERROR,
 343                "Received packet without a start chunk; dropping frame.\n");
 344         return AVERROR(EAGAIN);
 345     }
 346
 347     if (jpeg->timestamp != *timestamp) {
 348         /* Skip the current frame if timestamp is incorrect.
 349          * A start packet has been lost somewhere. */
 350         free_frame_if_needed(jpeg);
 351         av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
 352         return AVERROR_INVALIDDATA;
 353     }
 354
 355     if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
 356         av_log(ctx, AV_LOG_ERROR,
 357                "Missing packets; dropping frame.\n");
 358         return AVERROR(EAGAIN);
 359     }
 360
 361     /* Copy data to frame buffer. */
 362     avio_write(jpeg->frame, buf, len);
 363
 364     if (flags & RTP_FLAG_MARKER) {
 365         /* End of JPEG data packet. */
 366         uint8_t buf[2] = { 0xff, EOI };
 367
 368         /* Put EOI marker. */
 369         avio_write(jpeg->frame, buf, sizeof(buf));
 370
 371         /* Prepare the JPEG packet. */
 372         if ((ret = ff_rtp_finalize_packet(pkt, &jpeg->frame, st->index)) < 0) {
 373             av_log(ctx, AV_LOG_ERROR,
 374                    "Error occurred when getting frame buffer.\n");
 375             return ret;
 376         }
 377
 378         return 0;
 379     }
 380
 381     return AVERROR(EAGAIN);
 382 }
 383
 384 RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
 385     .enc_name          = "JPEG",
 386     .codec_type        = AVMEDIA_TYPE_VIDEO,
 387     .codec_id          = AV_CODEC_ID_MJPEG,
 388     .alloc             = jpeg_new_context,
 389     .free              = jpeg_free_context,
 390     .parse_packet      = jpeg_parse_packet,
 391     .static_payload_id = 26,
 392 };