yading@11: /*
yading@11:  * RTP JPEG-compressed Video Depacketizer, 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 "avformat.h"
yading@11: #include "rtpdec.h"
yading@11: #include "rtpdec_formats.h"
yading@11: #include "libavutil/intreadwrite.h"
yading@11: #include "libavcodec/mjpeg.h"
yading@11: #include "libavcodec/bytestream.h"
yading@11: 
yading@11: /**
yading@11:  * RTP/JPEG specific private data.
yading@11:  */
yading@11: struct PayloadContext {
yading@11:     AVIOContext *frame;         ///< current frame buffer
yading@11:     uint32_t    timestamp;      ///< current frame timestamp
yading@11:     int         hdr_size;       ///< size of the current frame header
yading@11:     uint8_t     qtables[128][128];
yading@11:     uint8_t     qtables_len[128];
yading@11: };
yading@11: 
yading@11: static const uint8_t default_quantizers[128] = {
yading@11:     /* luma table */
yading@11:     16,  11,  12,  14,  12,  10,  16,  14,
yading@11:     13,  14,  18,  17,  16,  19,  24,  40,
yading@11:     26,  24,  22,  22,  24,  49,  35,  37,
yading@11:     29,  40,  58,  51,  61,  60,  57,  51,
yading@11:     56,  55,  64,  72,  92,  78,  64,  68,
yading@11:     87,  69,  55,  56,  80,  109, 81,  87,
yading@11:     95,  98,  103, 104, 103, 62,  77,  113,
yading@11:     121, 112, 100, 120, 92,  101, 103, 99,
yading@11: 
yading@11:     /* chroma table */
yading@11:     17,  18,  18,  24,  21,  24,  47,  26,
yading@11:     26,  47,  99,  66,  56,  66,  99,  99,
yading@11:     99,  99,  99,  99,  99,  99,  99,  99,
yading@11:     99,  99,  99,  99,  99,  99,  99,  99,
yading@11:     99,  99,  99,  99,  99,  99,  99,  99,
yading@11:     99,  99,  99,  99,  99,  99,  99,  99,
yading@11:     99,  99,  99,  99,  99,  99,  99,  99,
yading@11:     99,  99,  99,  99,  99,  99,  99,  99
yading@11: };
yading@11: 
yading@11: static PayloadContext *jpeg_new_context(void)
yading@11: {
yading@11:     return av_mallocz(sizeof(PayloadContext));
yading@11: }
yading@11: 
yading@11: static inline void free_frame_if_needed(PayloadContext *jpeg)
yading@11: {
yading@11:     if (jpeg->frame) {
yading@11:         uint8_t *p;
yading@11:         avio_close_dyn_buf(jpeg->frame, &p);
yading@11:         av_free(p);
yading@11:         jpeg->frame = NULL;
yading@11:     }
yading@11: }
yading@11: 
yading@11: static void jpeg_free_context(PayloadContext *jpeg)
yading@11: {
yading@11:     free_frame_if_needed(jpeg);
yading@11:     av_free(jpeg);
yading@11: }
yading@11: 
yading@11: static int jpeg_create_huffman_table(PutByteContext *p, int table_class,
yading@11:                                      int table_id, const uint8_t *bits_table,
yading@11:                                      const uint8_t *value_table)
yading@11: {
yading@11:     int i, n = 0;
yading@11: 
yading@11:     bytestream2_put_byte(p, table_class << 4 | table_id);
yading@11: 
yading@11:     for (i = 1; i <= 16; i++) {
yading@11:         n += bits_table[i];
yading@11:         bytestream2_put_byte(p, bits_table[i]);
yading@11:     }
yading@11: 
yading@11:     for (i = 0; i < n; i++) {
yading@11:         bytestream2_put_byte(p, value_table[i]);
yading@11:     }
yading@11:     return n + 17;
yading@11: }
yading@11: 
yading@11: static void jpeg_put_marker(PutByteContext *pbc, int code)
yading@11: {
yading@11:     bytestream2_put_byte(pbc, 0xff);
yading@11:     bytestream2_put_byte(pbc, code);
yading@11: }
yading@11: 
yading@11: static int jpeg_create_header(uint8_t *buf, int size, uint32_t type, uint32_t w,
yading@11:                               uint32_t h, const uint8_t *qtable, int nb_qtable)
yading@11: {
yading@11:     PutByteContext pbc;
yading@11:     uint8_t *dht_size_ptr;
yading@11:     int dht_size, i;
yading@11: 
yading@11:     bytestream2_init_writer(&pbc, buf, size);
yading@11: 
yading@11:     /* Convert from blocks to pixels. */
yading@11:     w <<= 3;
yading@11:     h <<= 3;
yading@11: 
yading@11:     /* SOI */
yading@11:     jpeg_put_marker(&pbc, SOI);
yading@11: 
yading@11:     /* JFIF header */
yading@11:     jpeg_put_marker(&pbc, APP0);
yading@11:     bytestream2_put_be16(&pbc, 16);
yading@11:     bytestream2_put_buffer(&pbc, "JFIF", 5);
yading@11:     bytestream2_put_be16(&pbc, 0x0201);
yading@11:     bytestream2_put_byte(&pbc, 0);
yading@11:     bytestream2_put_be16(&pbc, 1);
yading@11:     bytestream2_put_be16(&pbc, 1);
yading@11:     bytestream2_put_byte(&pbc, 0);
yading@11:     bytestream2_put_byte(&pbc, 0);
yading@11: 
yading@11:     /* DQT */
yading@11:     jpeg_put_marker(&pbc, DQT);
yading@11:     bytestream2_put_be16(&pbc, 2 + nb_qtable * (1 + 64));
yading@11: 
yading@11:     for (i = 0; i < nb_qtable; i++) {
yading@11:         bytestream2_put_byte(&pbc, i);
yading@11: 
yading@11:         /* Each table is an array of 64 values given in zig-zag
yading@11:          * order, identical to the format used in a JFIF DQT
yading@11:          * marker segment. */
yading@11:         bytestream2_put_buffer(&pbc, qtable + 64 * i, 64);
yading@11:     }
yading@11: 
yading@11:     /* DHT */
yading@11:     jpeg_put_marker(&pbc, DHT);
yading@11:     dht_size_ptr = pbc.buffer;
yading@11:     bytestream2_put_be16(&pbc, 0);
yading@11: 
yading@11:     dht_size  = 2;
yading@11:     dht_size += jpeg_create_huffman_table(&pbc, 0, 0,avpriv_mjpeg_bits_dc_luminance,
yading@11:                                           avpriv_mjpeg_val_dc);
yading@11:     dht_size += jpeg_create_huffman_table(&pbc, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
yading@11:                                           avpriv_mjpeg_val_dc);
yading@11:     dht_size += jpeg_create_huffman_table(&pbc, 1, 0, avpriv_mjpeg_bits_ac_luminance,
yading@11:                                           avpriv_mjpeg_val_ac_luminance);
yading@11:     dht_size += jpeg_create_huffman_table(&pbc, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
yading@11:                                           avpriv_mjpeg_val_ac_chrominance);
yading@11:     AV_WB16(dht_size_ptr, dht_size);
yading@11: 
yading@11:     /* SOF0 */
yading@11:     jpeg_put_marker(&pbc, SOF0);
yading@11:     bytestream2_put_be16(&pbc, 17); /* size */
yading@11:     bytestream2_put_byte(&pbc, 8); /* bits per component */
yading@11:     bytestream2_put_be16(&pbc, h);
yading@11:     bytestream2_put_be16(&pbc, w);
yading@11:     bytestream2_put_byte(&pbc, 3); /* number of components */
yading@11:     bytestream2_put_byte(&pbc, 1); /* component number */
yading@11:     bytestream2_put_byte(&pbc, (2 << 4) | (type ? 2 : 1)); /* hsample/vsample */
yading@11:     bytestream2_put_byte(&pbc, 0); /* matrix number */
yading@11:     bytestream2_put_byte(&pbc, 2); /* component number */
yading@11:     bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
yading@11:     bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
yading@11:     bytestream2_put_byte(&pbc, 3); /* component number */
yading@11:     bytestream2_put_byte(&pbc, 1 << 4 | 1); /* hsample/vsample */
yading@11:     bytestream2_put_byte(&pbc, nb_qtable == 2 ? 1 : 0); /* matrix number */
yading@11: 
yading@11:     /* SOS */
yading@11:     jpeg_put_marker(&pbc, SOS);
yading@11:     bytestream2_put_be16(&pbc, 12);
yading@11:     bytestream2_put_byte(&pbc, 3);
yading@11:     bytestream2_put_byte(&pbc, 1);
yading@11:     bytestream2_put_byte(&pbc, 0);
yading@11:     bytestream2_put_byte(&pbc, 2);
yading@11:     bytestream2_put_byte(&pbc, 17);
yading@11:     bytestream2_put_byte(&pbc, 3);
yading@11:     bytestream2_put_byte(&pbc, 17);
yading@11:     bytestream2_put_byte(&pbc, 0);
yading@11:     bytestream2_put_byte(&pbc, 63);
yading@11:     bytestream2_put_byte(&pbc, 0);
yading@11: 
yading@11:     /* Return the length in bytes of the JPEG header. */
yading@11:     return bytestream2_tell_p(&pbc);
yading@11: }
yading@11: 
yading@11: static void create_default_qtables(uint8_t *qtables, uint8_t q)
yading@11: {
yading@11:     int factor = q;
yading@11:     int i;
yading@11: 
yading@11:     factor = av_clip(q, 1, 99);
yading@11: 
yading@11:     if (q < 50)
yading@11:         q = 5000 / factor;
yading@11:     else
yading@11:         q = 200 - factor * 2;
yading@11: 
yading@11:     for (i = 0; i < 128; i++) {
yading@11:         int val = (default_quantizers[i] * q + 50) / 100;
yading@11: 
yading@11:         /* Limit the quantizers to 1 <= q <= 255. */
yading@11:         val = av_clip(val, 1, 255);
yading@11:         qtables[i] = val;
yading@11:     }
yading@11: }
yading@11: 
yading@11: static int jpeg_parse_packet(AVFormatContext *ctx, PayloadContext *jpeg,
yading@11:                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,
yading@11:                              const uint8_t *buf, int len, uint16_t seq,
yading@11:                              int flags)
yading@11: {
yading@11:     uint8_t type, q, width, height;
yading@11:     const uint8_t *qtables = NULL;
yading@11:     uint16_t qtable_len;
yading@11:     uint32_t off;
yading@11:     int ret;
yading@11: 
yading@11:     if (len < 8) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     /* Parse the main JPEG header. */
yading@11:     off    = AV_RB24(buf + 1);  /* fragment byte offset */
yading@11:     type   = AV_RB8(buf + 4);   /* id of jpeg decoder params */
yading@11:     q      = AV_RB8(buf + 5);   /* quantization factor (or table id) */
yading@11:     width  = AV_RB8(buf + 6);   /* frame width in 8 pixel blocks */
yading@11:     height = AV_RB8(buf + 7);   /* frame height in 8 pixel blocks */
yading@11:     buf += 8;
yading@11:     len -= 8;
yading@11: 
yading@11:     /* Parse the restart marker header. */
yading@11:     if (type > 63) {
yading@11:         av_log(ctx, AV_LOG_ERROR,
yading@11:                "Unimplemented RTP/JPEG restart marker header.\n");
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     }
yading@11:     if (type > 1) {
yading@11:         av_log(ctx, AV_LOG_ERROR, "Unimplemented RTP/JPEG type %d\n", type);
yading@11:         return AVERROR_PATCHWELCOME;
yading@11:     }
yading@11: 
yading@11:     /* Parse the quantization table header. */
yading@11:     if (off == 0) {
yading@11:         /* Start of JPEG data packet. */
yading@11:         uint8_t new_qtables[128];
yading@11:         uint8_t hdr[1024];
yading@11: 
yading@11:         if (q > 127) {
yading@11:             uint8_t precision;
yading@11:             if (len < 4) {
yading@11:                 av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
yading@11:                 return AVERROR_INVALIDDATA;
yading@11:             }
yading@11: 
yading@11:             /* The first byte is reserved for future use. */
yading@11:             precision  = AV_RB8(buf + 1);    /* size of coefficients */
yading@11:             qtable_len = AV_RB16(buf + 2);   /* length in bytes */
yading@11:             buf += 4;
yading@11:             len -= 4;
yading@11: 
yading@11:             if (precision)
yading@11:                 av_log(ctx, AV_LOG_WARNING, "Only 8-bit precision is supported.\n");
yading@11: 
yading@11:             if (qtable_len > 0) {
yading@11:                 if (len < qtable_len) {
yading@11:                     av_log(ctx, AV_LOG_ERROR, "Too short RTP/JPEG packet.\n");
yading@11:                     return AVERROR_INVALIDDATA;
yading@11:                 }
yading@11:                 qtables = buf;
yading@11:                 buf += qtable_len;
yading@11:                 len -= qtable_len;
yading@11:                 if (q < 255) {
yading@11:                     if (jpeg->qtables_len[q - 128] &&
yading@11:                         (jpeg->qtables_len[q - 128] != qtable_len ||
yading@11:                          memcmp(qtables, &jpeg->qtables[q - 128][0], qtable_len))) {
yading@11:                         av_log(ctx, AV_LOG_WARNING,
yading@11:                                "Quantization tables for q=%d changed\n", q);
yading@11:                     } else if (!jpeg->qtables_len[q - 128] && qtable_len <= 128) {
yading@11:                         memcpy(&jpeg->qtables[q - 128][0], qtables,
yading@11:                                qtable_len);
yading@11:                         jpeg->qtables_len[q - 128] = qtable_len;
yading@11:                     }
yading@11:                 }
yading@11:             } else {
yading@11:                 if (q == 255) {
yading@11:                     av_log(ctx, AV_LOG_ERROR,
yading@11:                            "Invalid RTP/JPEG packet. Quantization tables not found.\n");
yading@11:                     return AVERROR_INVALIDDATA;
yading@11:                 }
yading@11:                 if (!jpeg->qtables_len[q - 128]) {
yading@11:                     av_log(ctx, AV_LOG_ERROR,
yading@11:                            "No quantization tables known for q=%d yet.\n", q);
yading@11:                     return AVERROR_INVALIDDATA;
yading@11:                 }
yading@11:                 qtables    = &jpeg->qtables[q - 128][0];
yading@11:                 qtable_len =  jpeg->qtables_len[q - 128];
yading@11:             }
yading@11:         } else { /* q <= 127 */
yading@11:             if (q == 0 || q > 99) {
yading@11:                 av_log(ctx, AV_LOG_ERROR, "Reserved q value %d\n", q);
yading@11:                 return AVERROR_INVALIDDATA;
yading@11:             }
yading@11:             create_default_qtables(new_qtables, q);
yading@11:             qtables    = new_qtables;
yading@11:             qtable_len = sizeof(new_qtables);
yading@11:         }
yading@11: 
yading@11:         /* Skip the current frame in case of the end packet
yading@11:          * has been lost somewhere. */
yading@11:         free_frame_if_needed(jpeg);
yading@11: 
yading@11:         if ((ret = avio_open_dyn_buf(&jpeg->frame)) < 0)
yading@11:             return ret;
yading@11:         jpeg->timestamp = *timestamp;
yading@11: 
yading@11:         /* Generate a frame and scan headers that can be prepended to the
yading@11:          * RTP/JPEG data payload to produce a JPEG compressed image in
yading@11:          * interchange format. */
yading@11:         jpeg->hdr_size = jpeg_create_header(hdr, sizeof(hdr), type, width,
yading@11:                                             height, qtables,
yading@11:                                             qtable_len / 64);
yading@11: 
yading@11:         /* Copy JPEG header to frame buffer. */
yading@11:         avio_write(jpeg->frame, hdr, jpeg->hdr_size);
yading@11:     }
yading@11: 
yading@11:     if (!jpeg->frame) {
yading@11:         av_log(ctx, AV_LOG_ERROR,
yading@11:                "Received packet without a start chunk; dropping frame.\n");
yading@11:         return AVERROR(EAGAIN);
yading@11:     }
yading@11: 
yading@11:     if (jpeg->timestamp != *timestamp) {
yading@11:         /* Skip the current frame if timestamp is incorrect.
yading@11:          * A start packet has been lost somewhere. */
yading@11:         free_frame_if_needed(jpeg);
yading@11:         av_log(ctx, AV_LOG_ERROR, "RTP timestamps don't match.\n");
yading@11:         return AVERROR_INVALIDDATA;
yading@11:     }
yading@11: 
yading@11:     if (off != avio_tell(jpeg->frame) - jpeg->hdr_size) {
yading@11:         av_log(ctx, AV_LOG_ERROR,
yading@11:                "Missing packets; dropping frame.\n");
yading@11:         return AVERROR(EAGAIN);
yading@11:     }
yading@11: 
yading@11:     /* Copy data to frame buffer. */
yading@11:     avio_write(jpeg->frame, buf, len);
yading@11: 
yading@11:     if (flags & RTP_FLAG_MARKER) {
yading@11:         /* End of JPEG data packet. */
yading@11:         uint8_t buf[2] = { 0xff, EOI };
yading@11: 
yading@11:         /* Put EOI marker. */
yading@11:         avio_write(jpeg->frame, buf, sizeof(buf));
yading@11: 
yading@11:         /* Prepare the JPEG packet. */
yading@11:         if ((ret = ff_rtp_finalize_packet(pkt, &jpeg->frame, st->index)) < 0) {
yading@11:             av_log(ctx, AV_LOG_ERROR,
yading@11:                    "Error occurred when getting frame buffer.\n");
yading@11:             return ret;
yading@11:         }
yading@11: 
yading@11:         return 0;
yading@11:     }
yading@11: 
yading@11:     return AVERROR(EAGAIN);
yading@11: }
yading@11: 
yading@11: RTPDynamicProtocolHandler ff_jpeg_dynamic_handler = {
yading@11:     .enc_name          = "JPEG",
yading@11:     .codec_type        = AVMEDIA_TYPE_VIDEO,
yading@11:     .codec_id          = AV_CODEC_ID_MJPEG,
yading@11:     .alloc             = jpeg_new_context,
yading@11:     .free              = jpeg_free_context,
yading@11:     .parse_packet      = jpeg_parse_packet,
yading@11:     .static_payload_id = 26,
yading@11: };