/* GStreamer

 * Copyright (C) 1999 Erik Walthinsen <omega@cse.ogi.edu>

 * Copyright (C) 2005 Edgard Lima <edgard.lima@gmail.com>

 * Copyright (C) 2005 Zeeshan Ali <zeenix@gmail.com>

 * Copyright (C) 2008 Axis Communications <dev-gstreamer@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., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

#ifdef HAVE_CONFIG_H

#  include "config.h"

#endif

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <gst/rtp/gstrtpbuffer.h>

#include <gst/audio/audio.h>

#include "gstrtpg726depay.h"

#include "gstrtputils.h"

GST_DEBUG_CATEGORY_STATIC (rtpg726depay_debug);

#define GST_CAT_DEFAULT (rtpg726depay_debug)

#define DEFAULT_BIT_RATE 32000

#define DEFAULT_BLOCK_ALIGN 4

#define SAMPLE_RATE 8000

#define LAYOUT_G726 "g726"

/* RtpG726Depay signals and args */

enum

{

  /* FILL ME */

  LAST_SIGNAL

};

#define DEFAULT_FORCE_AAL2	TRUE

enum

{

  PROP_0,

  PROP_FORCE_AAL2

};

static GstStaticPadTemplate gst_rtp_g726_depay_sink_template =

    GST_STATIC_PAD_TEMPLATE ("sink",

    GST_PAD_SINK,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS ("application/x-rtp, "

        "media = (string) \"audio\", "

        "encoding-name = (string) { \"G726\", \"G726-16\", \"G726-24\", \"G726-32\", \"G726-40\", "

        "\"AAL2-G726-16\", \"AAL2-G726-24\", \"AAL2-G726-32\", \"AAL2-G726-40\" }, "

        "clock-rate = (int) 8000;")

    );

static GstStaticPadTemplate gst_rtp_g726_depay_src_template =

GST_STATIC_PAD_TEMPLATE ("src",

    GST_PAD_SRC,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS ("audio/x-adpcm, "

        "channels = (int) 1, "

        "rate = (int) 8000, "

        "bitrate = (int) { 16000, 24000, 32000, 40000 }, "

        "block_align = (int) { 2, 3, 4, 5 }, " "layout = (string) \"g726\"")

    );

static void gst_rtp_g726_depay_get_property (GObject * object, guint prop_id,

    GValue * value, GParamSpec * pspec);

static void gst_rtp_g726_depay_set_property (GObject * object, guint prop_id,

    const GValue * value, GParamSpec * pspec);

static GstBuffer *gst_rtp_g726_depay_process (GstRTPBaseDepayload * depayload,

    GstRTPBuffer * rtp);

static gboolean gst_rtp_g726_depay_setcaps (GstRTPBaseDepayload * depayload,

    GstCaps * caps);

#define gst_rtp_g726_depay_parent_class parent_class

G_DEFINE_TYPE (GstRtpG726Depay, gst_rtp_g726_depay,

    GST_TYPE_RTP_BASE_DEPAYLOAD);

static void

gst_rtp_g726_depay_class_init (GstRtpG726DepayClass * klass)

{

  GObjectClass *gobject_class;

  GstElementClass *gstelement_class;

  GstRTPBaseDepayloadClass *gstrtpbasedepayload_class;

  GST_DEBUG_CATEGORY_INIT (rtpg726depay_debug, "rtpg726depay", 0,

      "G.726 RTP Depayloader");

  gobject_class = (GObjectClass *) klass;

  gstelement_class = (GstElementClass *) klass;

  gstrtpbasedepayload_class = (GstRTPBaseDepayloadClass *) klass;

  gobject_class->set_property = gst_rtp_g726_depay_set_property;

  gobject_class->get_property = gst_rtp_g726_depay_get_property;

  g_object_class_install_property (G_OBJECT_CLASS (klass), PROP_FORCE_AAL2,

      g_param_spec_boolean ("force-aal2", "Force AAL2",

          "Force AAL2 decoding for compatibility with bad payloaders",

          DEFAULT_FORCE_AAL2, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));

  gst_element_class_add_static_pad_template (gstelement_class,

      &gst_rtp_g726_depay_src_template);

  gst_element_class_add_static_pad_template (gstelement_class,

      &gst_rtp_g726_depay_sink_template);

  gst_element_class_set_static_metadata (gstelement_class,

      "RTP G.726 depayloader", "Codec/Depayloader/Network/RTP",

      "Extracts G.726 audio from RTP packets",

      "Axis Communications <dev-gstreamer@axis.com>");

  gstrtpbasedepayload_class->process_rtp_packet = gst_rtp_g726_depay_process;

  gstrtpbasedepayload_class->set_caps = gst_rtp_g726_depay_setcaps;

}

static void

gst_rtp_g726_depay_init (GstRtpG726Depay * rtpG726depay)

{

  GstRTPBaseDepayload *depayload;

  depayload = GST_RTP_BASE_DEPAYLOAD (rtpG726depay);

  gst_pad_use_fixed_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (depayload));

  rtpG726depay->force_aal2 = DEFAULT_FORCE_AAL2;

}

static gboolean

gst_rtp_g726_depay_setcaps (GstRTPBaseDepayload * depayload, GstCaps * caps)

{

  GstCaps *srccaps;

  GstStructure *structure;

  gboolean ret;

  gint clock_rate;

  const gchar *encoding_name;

  GstRtpG726Depay *depay;

  depay = GST_RTP_G726_DEPAY (depayload);

  structure = gst_caps_get_structure (caps, 0);

  if (!gst_structure_get_int (structure, "clock-rate", &clock_rate))

    clock_rate = 8000;          /* default */

  depayload->clock_rate = clock_rate;

  depay->aal2 = FALSE;

  encoding_name = gst_structure_get_string (structure, "encoding-name");

  if (encoding_name == NULL || g_ascii_strcasecmp (encoding_name, "G726") == 0) {

    depay->bitrate = DEFAULT_BIT_RATE;

    depay->block_align = DEFAULT_BLOCK_ALIGN;

  } else {

    if (g_str_has_prefix (encoding_name, "AAL2-")) {

      depay->aal2 = TRUE;

      encoding_name += 5;

    }

    if (g_ascii_strcasecmp (encoding_name, "G726-16") == 0) {

      depay->bitrate = 16000;

      depay->block_align = 2;

    } else if (g_ascii_strcasecmp (encoding_name, "G726-24") == 0) {

      depay->bitrate = 24000;

      depay->block_align = 3;

    } else if (g_ascii_strcasecmp (encoding_name, "G726-32") == 0) {

      depay->bitrate = 32000;

      depay->block_align = 4;

    } else if (g_ascii_strcasecmp (encoding_name, "G726-40") == 0) {

      depay->bitrate = 40000;

      depay->block_align = 5;

    } else

      goto unknown_encoding;

  }

  GST_DEBUG ("RTP G.726 depayloader, bitrate set to %d\n", depay->bitrate);

  srccaps = gst_caps_new_simple ("audio/x-adpcm",

      "channels", G_TYPE_INT, 1,

      "rate", G_TYPE_INT, clock_rate,

      "bitrate", G_TYPE_INT, depay->bitrate,

      "block_align", G_TYPE_INT, depay->block_align,

      "layout", G_TYPE_STRING, LAYOUT_G726, NULL);

  ret = gst_pad_set_caps (GST_RTP_BASE_DEPAYLOAD_SRCPAD (depayload), srccaps);

  gst_caps_unref (srccaps);

  return ret;

  /* ERRORS */

unknown_encoding:

  {

    GST_WARNING ("Could not determine bitrate from encoding-name (%s)",

        encoding_name);

    return FALSE;

  }

}

static GstBuffer *

gst_rtp_g726_depay_process (GstRTPBaseDepayload * depayload, GstRTPBuffer * rtp)

{

  GstRtpG726Depay *depay;

  GstBuffer *outbuf = NULL;

  gboolean marker;

  depay = GST_RTP_G726_DEPAY (depayload);

  marker = gst_rtp_buffer_get_marker (rtp);

  GST_DEBUG ("process : got %" G_GSIZE_FORMAT " bytes, mark %d ts %u seqn %d",

      gst_buffer_get_size (rtp->buffer), marker,

      gst_rtp_buffer_get_timestamp (rtp), gst_rtp_buffer_get_seq (rtp));

  if (depay->aal2 || depay->force_aal2) {

    /* AAL2, we can just copy the bytes */

    outbuf = gst_rtp_buffer_get_payload_buffer (rtp);

    if (!outbuf)

      goto bad_len;

    gst_rtp_drop_non_audio_meta (depay, outbuf);

  } else {

    guint8 *in, *out, tmp;

    guint len;

    GstMapInfo map;

    in = gst_rtp_buffer_get_payload (rtp);

    len = gst_rtp_buffer_get_payload_len (rtp);

    outbuf = gst_rtp_buffer_get_payload_buffer (rtp);

    if (!outbuf)

      goto bad_len;

    outbuf = gst_buffer_make_writable (outbuf);

    gst_rtp_drop_non_audio_meta (depay, outbuf);

    gst_buffer_map (outbuf, &map, GST_MAP_WRITE);

    out = map.data;

    /* we need to reshuffle the bytes, input is always of the form

     * A B C D ... with the number of bits depending on the bitrate. */

    switch (depay->bitrate) {

      case 16000:

      {

        /*  0               

         *  0 1 2 3 4 5 6 7 

         * +-+-+-+-+-+-+-+-+-

         * |D D|C C|B B|A A| ...

         * |0 1|0 1|0 1|0 1|

         * +-+-+-+-+-+-+-+-+-

         */

        while (len > 0) {

          tmp = *in++;

          *out++ = ((tmp & 0xc0) >> 6) |

              ((tmp & 0x30) >> 2) | ((tmp & 0x0c) << 2) | ((tmp & 0x03) << 6);

          len--;

        }

        break;

      }

      case 24000:

      {

        /*  0                   1                   2

         *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3

         * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

         * |C C|B B B|A A A|F|E E E|D D D|C|H H H|G G G|F F| ...

         * |1 2|0 1 2|0 1 2|2|0 1 2|0 1 2|0|0 1 2|0 1 2|0 1|

         * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

         */

        while (len > 2) {

          tmp = *in++;

          *out++ = ((tmp & 0xe0) >> 5) |

              ((tmp & 0x1c) << 1) | ((tmp & 0x03) << 6);

          tmp = *in++;

          *out++ = ((tmp & 0x80) >> 7) |

              ((tmp & 0x70) >> 3) | ((tmp & 0x0e) << 4) | ((tmp & 0x01) << 7);

          tmp = *in++;

          *out++ = ((tmp & 0xc0) >> 6) |

              ((tmp & 0x38) >> 1) | ((tmp & 0x07) << 5);

          len -= 3;

        }

        break;

      }

      case 32000:

      {

        /*  0                   1

         *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5

         * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

         * |B B B B|A A A A|D D D D|C C C C| ...

         * |0 1 2 3|0 1 2 3|0 1 2 3|0 1 2 3|

         * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

         */

        while (len > 0) {

          tmp = *in++;

          *out++ = ((tmp & 0xf0) >> 4) | ((tmp & 0x0f) << 4);

          len--;

        }

        break;

      }

      case 40000:

      {

        /*  0                   1                   2                   3                   4

         *  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 2 3 4 5 6 7 8 9 0

         * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

         * |B B B|A A A A A|D|C C C C C|B B|E E E E|D D D D|G G|F F F F F|E|H H H H H|G G G|

         * |2 3 4|0 1 2 3 4|4|0 1 2 3 4|0 1|1 2 3 4|0 1 2 3|3 4|0 1 2 3 4|0|0 1 2 3 4|0 1 2|   

         * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-

         */

        while (len > 4) {

          tmp = *in++;

          *out++ = ((tmp & 0xf8) >> 3) | ((tmp & 0x07) << 5);

          tmp = *in++;

          *out++ = ((tmp & 0xc0) >> 6) |

              ((tmp & 0x3e) << 1) | ((tmp & 0x01) << 7);

          tmp = *in++;

          *out++ = ((tmp & 0xf0) >> 4) | ((tmp & 0x0f) << 4);

          tmp = *in++;

          *out++ = ((tmp & 0x80) >> 7) |

              ((tmp & 0x7c) >> 1) | ((tmp & 0x03) << 6);

          tmp = *in++;

          *out++ = ((tmp & 0xe0) >> 5) | ((tmp & 0x1f) << 3);

          len -= 5;

        }

        break;

      }

    }

    gst_buffer_unmap (outbuf, &map);

  }

  if (marker) {

    /* mark start of talkspurt with RESYNC */

    GST_BUFFER_FLAG_SET (outbuf, GST_BUFFER_FLAG_RESYNC);

  }

  return outbuf;

bad_len:

  {

    return NULL;

  }

}

static void

gst_rtp_g726_depay_set_property (GObject * object, guint prop_id,

    const GValue * value, GParamSpec * pspec)

{

  GstRtpG726Depay *rtpg726depay;

  rtpg726depay = GST_RTP_G726_DEPAY (object);

  switch (prop_id) {

    case PROP_FORCE_AAL2:

      rtpg726depay->force_aal2 = g_value_get_boolean (value);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

}

static void

gst_rtp_g726_depay_get_property (GObject * object, guint prop_id,

    GValue * value, GParamSpec * pspec)

{

  GstRtpG726Depay *rtpg726depay;

  rtpg726depay = GST_RTP_G726_DEPAY (object);

  switch (prop_id) {

    case PROP_FORCE_AAL2:

      g_value_set_boolean (value, rtpg726depay->force_aal2);

      break;

    default:

      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);

      break;

  }

}

gboolean

gst_rtp_g726_depay_plugin_init (GstPlugin * plugin)

{

  return gst_element_register (plugin, "rtpg726depay",

      GST_RANK_SECONDARY, GST_TYPE_RTP_G726_DEPAY);

}