/* GStreamer
 * Copyright (C) 2008 Axis Communications <dev-gstreamer@axis.com>
 * @author Bjorn Ostby <bjorn.ostby@axis.com>
 * @author Peter Kjellerstedt <peter.kjellerstedt@axis.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/**
 * SECTION:rtpjpegpay
 *
 * Payload encode JPEG pictures into RTP packets according to RFC 2435.
 * For detailed information see: http://www.rfc-editor.org/rfc/rfc2435.txt
 *
 * The payloader takes a JPEG picture, scans the header for quantization
 * tables (if needed) and constructs the RTP packet header followed by
 * the actual JPEG entropy scan.
 *
 * The payloader assumes that correct width and height is found in the caps.
 */

#ifdef HAVE_CONFIG_H
#  include "config.h"
#endif

#include <string.h>
#include <gst/rtp/gstrtpbuffer.h>

#include "gstrtpjpegpay.h"

/* elementfactory information */
static const GstElementDetails gst_rtp_jpeg_pay_details =
GST_ELEMENT_DETAILS ("RTP JPEG payloader",
    "Codec/Payloader/Network",
    "Payload-encodes JPEG pictures into RTP packets (RFC 2435)",
    "Axis Communications <dev-gstreamer@axis.com>");

static GstStaticPadTemplate gst_rtp_jpeg_pay_sink_template =
    GST_STATIC_PAD_TEMPLATE ("sink",
    GST_PAD_SINK,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("image/jpeg, "
        "  height = (int) [0, 2040], "
        "  width = (int) [0, 2040];  "
        "video/x-jpeg, "
        "  height = (int) [0, 2040], " "  width = (int) [0, 2040]")
    );

static GstStaticPadTemplate gst_rtp_jpeg_pay_src_template =
GST_STATIC_PAD_TEMPLATE ("src",
    GST_PAD_SRC,
    GST_PAD_ALWAYS,
    GST_STATIC_CAPS ("application/x-rtp, "
        "  media = (string) \"video\", "
        "  payload = (int) 26 ,        "
        "  clock-rate = (int) 90000,   " "  encoding-name = (string) \"JPEG\"")
    );

GST_DEBUG_CATEGORY_STATIC (rtpjpegpay_debug);
#define GST_CAT_DEFAULT (rtpjpegpay_debug)

/*
 * QUANT_PREFIX_LEN:
 *
 * Prefix length in the header before the quantization tables:
 * Two size bytes and one byte for precision
 */
#define QUANT_PREFIX_LEN     3

/*
 * DEFAULT_JPEG_QUALITY:
 *
 */
#define DEFAULT_JPEG_QUALITY 255

/*
 * DEFAULT_JPEG_TYPE:
 *
 */
#define DEFAULT_JPEG_TYPE    1

typedef enum _RtpJpegMarker RtpJpegMarker;

/*
 * RtpJpegMarker:
 * @JPEG_MARKER: Prefix for JPEG marker
 * @JPEG_MARKER_SOI: Start of Image marker
 * @JPEG_MARKER_JFIF: JFIF marker
 * @JPEG_MARKER_CMT: Comment marker
 * @JPEG_MARKER_DQT: Define Quantization Table marker
 * @JPEG_MARKER_SOF: Start of Frame marker
 * @JPEG_MARKER_DHT: Define Huffman Table marker
 * @JPEG_MARKER_SOS: Start of Scan marker
 * @JPEG_MARKER_EOI: End of Image marker
 *
 * Identifers for markers in JPEG header
 */
enum _RtpJpegMarker
{
  JPEG_MARKER = 0xFF,
  JPEG_MARKER_SOI = 0xD8,
  JPEG_MARKER_JFIF = 0xE0,
  JPEG_MARKER_CMT = 0xFE,
  JPEG_MARKER_DQT = 0xDB,
  JPEG_MARKER_SOF = 0xC0,
  JPEG_MARKER_DHT = 0xC4,
  JPEG_MARKER_SOS = 0xDA,
  JPEG_MARKER_EOI = 0xD9,
};

enum
{
  PROP_0,
  PROP_JPEG_QUALITY,
  PROP_JPEG_TYPE
};

enum
{
  Q_TABLE_0 = 0,
  Q_TABLE_1,
  Q_TABLE_MAX                   /* only support for two tables at the moment */
};

typedef struct _RtpJpegHeader RtpJpegHeader;
typedef struct _RtpQuantHeader RtpQuantHeader;

/*
 * RtpJpegHeader:
 * @type_spec: type specific
 * @offset: fragment offset
 * @type: type field
 * @q: quantization table for this frame
 * @width: width of image in 8-pixel multiples
 * @height: height of image in 8-pixel multiples
 *
 * 0                   1                   2                   3
 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * | Type-specific |              Fragment Offset                  |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |      Type     |       Q       |     Width     |     Height    |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
struct _RtpJpegHeader
{
#if (G_BYTE_ORDER == G_LITTLE_ENDIAN)
  guint type_spec:8;
  guint offset:24;
#else
  guint offset:24;
  guint type_spec:8;
#endif
  guint8 type;
  guint8 q;
  guint8 width;
  guint8 height;
};

/*
 * RtpQuantHeader
 * @mbz: must be zero
 * @precision: specify size of quantization tables
 * @length: length of quantization data
 *
 * 0                   1                   2                   3
 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |      MBZ      |   Precision   |             Length            |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                    Quantization Table Data                    |
 * |                              ...                              |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 */
struct _RtpQuantHeader
{
  guint8 mbz;
  guint8 precision;
  guint16 length;
};

/* FIXME: restart marker header currently unsupported */

static void gst_rtp_jpeg_pay_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec);

static void gst_rtp_jpeg_pay_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec);

static gboolean gst_rtp_jpeg_pay_setcaps (GstBaseRTPPayload * basepayload,
    GstCaps * caps);

static GstFlowReturn gst_rtp_jpeg_pay_handle_buffer (GstBaseRTPPayload * pad,
    GstBuffer * buffer);

GST_BOILERPLATE (GstRtpJPEGPay, gst_rtp_jpeg_pay, GstBaseRTPPayload,
    GST_TYPE_BASE_RTP_PAYLOAD);

static void
gst_rtp_jpeg_pay_base_init (gpointer klass)
{
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);

  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&gst_rtp_jpeg_pay_src_template));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&gst_rtp_jpeg_pay_sink_template));

  gst_element_class_set_details (element_class, &gst_rtp_jpeg_pay_details);
}

static void
gst_rtp_jpeg_pay_class_init (GstRtpJPEGPayClass * klass)
{
  GObjectClass *gobject_class;
  GstBaseRTPPayloadClass *gstbasertppayload_class;

  gobject_class = (GObjectClass *) klass;
  gstbasertppayload_class = (GstBaseRTPPayloadClass *) klass;

  gobject_class->set_property = gst_rtp_jpeg_pay_set_property;
  gobject_class->get_property = gst_rtp_jpeg_pay_get_property;

  gstbasertppayload_class->set_caps = gst_rtp_jpeg_pay_setcaps;
  gstbasertppayload_class->handle_buffer = gst_rtp_jpeg_pay_handle_buffer;

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_JPEG_QUALITY,
      g_param_spec_int ("quality", "Quality", "Quality factor on JPEG data",
          0, 255, DEFAULT_JPEG_QUALITY, G_PARAM_READWRITE));

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_JPEG_TYPE,
      g_param_spec_int ("type", "Type", "JPEG Type",
          0, 255, DEFAULT_JPEG_TYPE, G_PARAM_READWRITE));

  GST_DEBUG_CATEGORY_INIT (rtpjpegpay_debug, "rtpjpegpay", 0,
      "Motion JPEG RTP Payloader");
}

static void
gst_rtp_jpeg_pay_init (GstRtpJPEGPay * rtpjpegpay, GstRtpJPEGPayClass * klass)
{
  rtpjpegpay->quality = DEFAULT_JPEG_QUALITY;
  rtpjpegpay->type = DEFAULT_JPEG_TYPE;
}

static gboolean
gst_rtp_jpeg_pay_setcaps (GstBaseRTPPayload * basepayload, GstCaps * caps)
{
  GstStructure *caps_structure = gst_caps_get_structure (caps, 0);
  GstRtpJPEGPay *rtpjpegpay;

  rtpjpegpay = GST_RTP_JPEG_PAY (basepayload);

  if (!gst_structure_get_int (caps_structure, "height", &rtpjpegpay->height)) {
    goto caps_fail;
  }

  if (!gst_structure_get_int (caps_structure, "width", &rtpjpegpay->width)) {
    goto caps_fail;
  }

  rtpjpegpay->height /= 8;
  rtpjpegpay->width /= 8;

  gst_basertppayload_set_options (basepayload, "video", TRUE, "JPEG", 90000);
  gst_basertppayload_set_outcaps (basepayload, NULL);

  return TRUE;

caps_fail:
  GST_ERROR_OBJECT (rtpjpegpay, "Failed to get width/height from caps");
  return FALSE;
}


static guint
gst_rtp_jpeg_pay_header_size (const guint8 * data, guint offset)
{
  return data[offset] << 8 | data[offset + 1];
}

static guint
gst_rtp_jpeg_pay_read_quant_table (const guint8 * data, guint offset,
    const guint8 ** quantizer_table, RtpQuantHeader * qtable, guint8 index)
{
  gint quant_size = gst_rtp_jpeg_pay_header_size (data, offset);

  qtable->precision |= (data[offset + 2] & 0x10) ? (1 << index) : 0x00;

  /* ommit length and precision prefix from table */
  quantizer_table[index] = &data[offset + QUANT_PREFIX_LEN];
  quant_size -= QUANT_PREFIX_LEN;

  qtable->length += quant_size;

  return quant_size;
}

static RtpJpegMarker
gst_rtp_jpeg_pay_scan_marker (const guint8 * data, guint size, guint * offset)
{
  while ((data[(*offset)++] != JPEG_MARKER) && ((*offset) < size));

  if (G_UNLIKELY ((*offset) >= size)) {
    return JPEG_MARKER_EOI;
  } else {
    return data[(*offset)++];
  }
}

static GstFlowReturn
gst_rtp_jpeg_pay_handle_buffer (GstBaseRTPPayload * basepayload,
    GstBuffer * buffer)
{
  GstRtpJPEGPay *rtpjpegpay;
  GstClockTime timestamp;
  GstFlowReturn ret = GST_FLOW_ERROR;
  RtpJpegHeader jpeg_header;
  RtpQuantHeader quant_header;
  const guint8 *jpeg_quantizer_table[Q_TABLE_MAX] = { NULL };
  guint8 *data;
  guint8 quant_table_index = 0;
  guint size;
  guint mtu;
  guint bytes_left;
  guint quant_data_size = sizeof (quant_header);
  guint jpeg_header_size = 0;
  guint offset = 0;
  gboolean frame_done = FALSE;
  gboolean sos_found = FALSE;

  rtpjpegpay = GST_RTP_JPEG_PAY (basepayload);
  mtu = GST_BASE_RTP_PAYLOAD_MTU (rtpjpegpay);

  jpeg_header.type_spec = 0;
  jpeg_header.offset = 0;
  jpeg_header.type = rtpjpegpay->type;
  jpeg_header.q = rtpjpegpay->quality;
  jpeg_header.width = rtpjpegpay->width;
  jpeg_header.height = rtpjpegpay->height;

  size = GST_BUFFER_SIZE (buffer);
  data = GST_BUFFER_DATA (buffer);
  timestamp = GST_BUFFER_TIMESTAMP (buffer);

  /* parse the jpeg header for 'start of scan' and read quant tables if needed */
  while (!sos_found && (offset < size)) {
    switch (gst_rtp_jpeg_pay_scan_marker (data, size, &offset)) {
      case JPEG_MARKER_JFIF:
      case JPEG_MARKER_CMT:
      case JPEG_MARKER_SOF:
      case JPEG_MARKER_DHT:
        offset += gst_rtp_jpeg_pay_header_size (data, offset);
        break;
      case JPEG_MARKER_DQT:{
        if ((jpeg_header.q >= 128) && (quant_table_index < Q_TABLE_MAX)) {
          if (!quant_table_index) {
            quant_header.length = 0;
            quant_header.precision = 0;
            quant_header.mbz = 0;
          }
          quant_data_size += gst_rtp_jpeg_pay_read_quant_table (data, offset,
              jpeg_quantizer_table, &quant_header, quant_table_index);

          quant_table_index++;
        }
        offset += gst_rtp_jpeg_pay_header_size (data, offset);
      }
        break;
      case JPEG_MARKER_SOS:
        sos_found = TRUE;
        jpeg_header_size = offset + gst_rtp_jpeg_pay_header_size (data, offset);
        break;
      case JPEG_MARKER_EOI:
        GST_WARNING ("EOI reached before SOS!");
        break;
      case JPEG_MARKER_SOI:
      default:
        break;
    }
  }

  size -= jpeg_header_size;
  data += jpeg_header_size;
  offset = 0;

  bytes_left = sizeof (jpeg_header) + quant_data_size + size;

  while (!frame_done) {
    GstBuffer *outbuf;
    guint8 *payload;
    guint payload_size = (bytes_left < mtu ? bytes_left : mtu);

    outbuf = gst_rtp_buffer_new_allocate (payload_size, 0, 0);
    GST_BUFFER_TIMESTAMP (outbuf) = timestamp;

    if (payload_size == bytes_left) {
      frame_done = TRUE;
      gst_rtp_buffer_set_marker (outbuf, 1);
    }

    payload = gst_rtp_buffer_get_payload (outbuf);

    memcpy (payload, &jpeg_header, sizeof (jpeg_header));
    payload += sizeof (jpeg_header);
    payload_size -= sizeof (jpeg_header);

    /* only send quant table with first packet */
    if (G_UNLIKELY (quant_data_size > 0)) {
      guint8 index;
      const guint8 table_size = quant_header.length / quant_table_index;

      quant_header.length = g_htons (quant_header.length);

      memcpy (payload, &quant_header, sizeof (quant_header));
      payload += sizeof (quant_header);

      for (index = 0; index < quant_table_index; index++) {
        memcpy (payload, jpeg_quantizer_table[index], table_size);
        payload += table_size;
      }

      payload_size -= quant_data_size;
      bytes_left -= quant_data_size;
      quant_data_size = 0;
    }

    memcpy (payload, &data[offset], payload_size);

    ret = gst_basertppayload_push (basepayload, outbuf);
    if (ret != GST_FLOW_OK)
      break;

    bytes_left -= payload_size;
    offset += payload_size;

#if (G_BYTE_ORDER == G_LITTLE_ENDIAN)
    jpeg_header.offset = ((offset & 0x0000FF) << 16) |
        ((offset & 0xFF0000) >> 16) | (offset & 0x00FF00);
#else
    jpeg_header.offset = offset;
#endif
  }

  gst_buffer_unref (buffer);

  return ret;
}

static void
gst_rtp_jpeg_pay_set_property (GObject * object, guint prop_id,
    const GValue * value, GParamSpec * pspec)
{
  GstRtpJPEGPay *rtpjpegpay;

  rtpjpegpay = GST_RTP_JPEG_PAY (object);

  switch (prop_id) {
    case PROP_JPEG_QUALITY:
      rtpjpegpay->quality = g_value_get_int (value);
      GST_DEBUG_OBJECT (object, "quality = %d", rtpjpegpay->quality);
      break;
    case PROP_JPEG_TYPE:
      rtpjpegpay->type = g_value_get_int (value);
      GST_DEBUG_OBJECT (object, "type = %d", rtpjpegpay->type);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

static void
gst_rtp_jpeg_pay_get_property (GObject * object, guint prop_id,
    GValue * value, GParamSpec * pspec)
{
  GstRtpJPEGPay *rtpjpegpay;

  rtpjpegpay = GST_RTP_JPEG_PAY (object);

  switch (prop_id) {
    case PROP_JPEG_QUALITY:
      g_value_set_int (value, rtpjpegpay->quality);
      break;
    case PROP_JPEG_TYPE:
      g_value_set_int (value, rtpjpegpay->type);
      break;
    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
      break;
  }
}

gboolean
gst_rtp_jpeg_pay_plugin_init (GstPlugin * plugin)
{
  return gst_element_register (plugin, "rtpjpegpay", GST_RANK_NONE,
      GST_TYPE_RTP_JPEG_PAY);
}