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

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

#include <assert.h>
#include <string.h>

#ifdef HAVE_FFMPEG_UNINSTALLED
#include <avcodec.h>
#else
#include <ffmpeg/avcodec.h>
#endif

#include <gst/gst.h>

#include "gstffmpegcodecmap.h"

typedef struct _GstFFMpegDec GstFFMpegDec;

struct _GstFFMpegDec
{
  GstElement element;

  /* We need to keep track of our pads, so we do so here. */
  GstPad *srcpad;
  GstPad *sinkpad;

  AVCodecContext *context;
  AVFrame *picture;
  gboolean opened;
};

typedef struct _GstFFMpegDecClass GstFFMpegDecClass;

struct _GstFFMpegDecClass
{
  GstElementClass parent_class;

  AVCodec *in_plugin;
  GstPadTemplate *srctempl, *sinktempl;
};

typedef struct _GstFFMpegDecClassParams GstFFMpegDecClassParams;

struct _GstFFMpegDecClassParams
{
  AVCodec *in_plugin;
  GstCaps *srccaps, *sinkcaps;
};

#define GST_TYPE_FFMPEGDEC \
  (gst_ffmpegdec_get_type())
#define GST_FFMPEGDEC(obj) \
  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_FFMPEGDEC,GstFFMpegDec))
#define GST_FFMPEGDEC_CLASS(klass) \
  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_FFMPEGDEC,GstFFMpegDecClass))
#define GST_IS_FFMPEGDEC(obj) \
  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_FFMPEGDEC))
#define GST_IS_FFMPEGDEC_CLASS(obj) \
  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_FFMPEGDEC))

enum
{
  /* FILL ME */
  LAST_SIGNAL
};

enum
{
  ARG_0,
  /* FILL ME */
};

static GHashTable *global_plugins;

/* A number of functon prototypes are given so we can refer to them later. */
static void gst_ffmpegdec_base_init (GstFFMpegDecClass * klass);
static void gst_ffmpegdec_class_init (GstFFMpegDecClass * klass);
static void gst_ffmpegdec_init (GstFFMpegDec * ffmpegdec);
static void gst_ffmpegdec_dispose (GObject * object);

static GstPadLinkReturn gst_ffmpegdec_connect (GstPad * pad,
    const GstCaps * caps);
static void gst_ffmpegdec_chain (GstPad * pad, GstData * data);

static GstElementStateReturn gst_ffmpegdec_change_state (GstElement * element);

#if 0
/* some sort of bufferpool handling, but different */
static int gst_ffmpegdec_get_buffer (AVCodecContext * context,
    AVFrame * picture);
static void gst_ffmpegdec_release_buffer (AVCodecContext * context,
    AVFrame * picture);
#endif

static GstElementClass *parent_class = NULL;

/*static guint gst_ffmpegdec_signals[LAST_SIGNAL] = { 0 }; */

static void
gst_ffmpegdec_base_init (GstFFMpegDecClass * klass)
{
  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
  GstFFMpegDecClassParams *params;
  GstElementDetails details;
  GstPadTemplate *sinktempl, *srctempl;

  params = g_hash_table_lookup (global_plugins,
      GINT_TO_POINTER (G_OBJECT_CLASS_TYPE (gobject_class)));
  if (!params)
    params = g_hash_table_lookup (global_plugins, GINT_TO_POINTER (0));
  g_assert (params);

  /* construct the element details struct */
  details.longname = g_strdup_printf ("FFMPEG %s decoder",
      params->in_plugin->name);
  details.klass = g_strdup_printf ("Codec/%s/Decoder",
      (params->in_plugin->type == CODEC_TYPE_VIDEO) ? "Video" : "Audio");
  details.description = g_strdup_printf ("FFMPEG %s decoder",
      params->in_plugin->name);
  details.author = "Wim Taymans <wim.taymans@chello.be>, "
      "Ronald Bultje <rbultje@ronald.bitfreak.net>";
  gst_element_class_set_details (element_class, &details);
  g_free (details.longname);
  g_free (details.klass);
  g_free (details.description);

  /* pad templates */
  sinktempl = gst_pad_template_new ("sink", GST_PAD_SINK,
      GST_PAD_ALWAYS, params->sinkcaps);
  srctempl = gst_pad_template_new ("src", GST_PAD_SRC,
      GST_PAD_ALWAYS, params->srccaps);

  gst_element_class_add_pad_template (element_class, srctempl);
  gst_element_class_add_pad_template (element_class, sinktempl);

  klass->in_plugin = params->in_plugin;
  klass->srctempl = srctempl;
  klass->sinktempl = sinktempl;
}

static void
gst_ffmpegdec_class_init (GstFFMpegDecClass * klass)
{
  GObjectClass *gobject_class;
  GstElementClass *gstelement_class;

  gobject_class = (GObjectClass *) klass;
  gstelement_class = (GstElementClass *) klass;

  parent_class = g_type_class_peek_parent (klass);

  gobject_class->dispose = gst_ffmpegdec_dispose;
  gstelement_class->change_state = gst_ffmpegdec_change_state;
}

static void
gst_ffmpegdec_init (GstFFMpegDec * ffmpegdec)
{
  GstFFMpegDecClass *oclass =
      (GstFFMpegDecClass *) (G_OBJECT_GET_CLASS (ffmpegdec));

  /* setup pads */
  ffmpegdec->sinkpad = gst_pad_new_from_template (oclass->sinktempl, "sink");
  gst_pad_set_link_function (ffmpegdec->sinkpad, gst_ffmpegdec_connect);
  gst_pad_set_chain_function (ffmpegdec->sinkpad, gst_ffmpegdec_chain);
  ffmpegdec->srcpad = gst_pad_new_from_template (oclass->srctempl, "src");
  gst_pad_use_explicit_caps (ffmpegdec->srcpad);

  gst_element_add_pad (GST_ELEMENT (ffmpegdec), ffmpegdec->sinkpad);
  gst_element_add_pad (GST_ELEMENT (ffmpegdec), ffmpegdec->srcpad);

  /* some ffmpeg data */
  ffmpegdec->context = avcodec_alloc_context ();
  ffmpegdec->picture = avcodec_alloc_frame ();

  ffmpegdec->opened = FALSE;
}

static void
gst_ffmpegdec_dispose (GObject * object)
{
  GstFFMpegDec *ffmpegdec = (GstFFMpegDec *) object;

  G_OBJECT_CLASS (parent_class)->dispose (object);
  /* old session should have been closed in element_class->dispose */
  g_assert (!ffmpegdec->opened);

  /* clean up remaining allocated data */
  av_free (ffmpegdec->context);
  av_free (ffmpegdec->picture);
}

static GstPadLinkReturn
gst_ffmpegdec_connect (GstPad * pad, const GstCaps * caps)
{
  GstFFMpegDec *ffmpegdec = (GstFFMpegDec *) (gst_pad_get_parent (pad));
  GstFFMpegDecClass *oclass =
      (GstFFMpegDecClass *) (G_OBJECT_GET_CLASS (ffmpegdec));

  /* close old session */
  if (ffmpegdec->opened) {
    avcodec_close (ffmpegdec->context);
    ffmpegdec->opened = FALSE;
  }

  /* set defaults */
  avcodec_get_context_defaults (ffmpegdec->context);

#if 0
  /* set buffer functions */
  ffmpegdec->context->get_buffer = gst_ffmpegdec_get_buffer;
  ffmpegdec->context->release_buffer = gst_ffmpegdec_release_buffer;
#endif

  /* get size and so */
  gst_ffmpeg_caps_to_codectype (oclass->in_plugin->type,
      caps, ffmpegdec->context);

  /* we dont send complete frames - FIXME: we need a 'framed' property
   * in caps */
  if (oclass->in_plugin->capabilities & CODEC_CAP_TRUNCATED &&
      (ffmpegdec->context->codec_id == CODEC_ID_MPEG1VIDEO ||
          ffmpegdec->context->codec_id == CODEC_ID_MPEG2VIDEO))
    ffmpegdec->context->flags |= CODEC_FLAG_TRUNCATED;

  /* do *not* draw edges */
  ffmpegdec->context->flags |= CODEC_FLAG_EMU_EDGE;

  /* open codec - we don't select an output pix_fmt yet,
   * simply because we don't know! We only get it
   * during playback... */
  if (avcodec_open (ffmpegdec->context, oclass->in_plugin) < 0) {
    avcodec_close (ffmpegdec->context);
    GST_DEBUG ("ffdec_%s: Failed to open FFMPEG codec",
        oclass->in_plugin->name);
    return GST_PAD_LINK_REFUSED;
  }

  /* done! */
  ffmpegdec->opened = TRUE;

  return GST_PAD_LINK_OK;
}

#if 0
static int
gst_ffmpegdec_get_buffer (AVCodecContext * context, AVFrame * picture)
{
  GstBuffer *buf = NULL;
  gulong bufsize = 0;

  switch (context->codec_type) {
    case CODEC_TYPE_VIDEO:
      bufsize = avpicture_get_size (context->pix_fmt,
          context->width, context->height);
      buf = gst_buffer_new_and_alloc (bufsize);
      avpicture_fill ((AVPicture *) picture, GST_BUFFER_DATA (buf),
          context->pix_fmt, context->width, context->height);
      break;

    case CODEC_TYPE_AUDIO:
    default:
      g_assert (0);
      break;
  }

  /* tell ffmpeg we own this buffer
   *
   * we also use an evil hack (keep buffer in base[0])
   * to keep a reference to the buffer in release_buffer(),
   * so that we can ref() it here and unref() it there
   * so that we don't need to copy data */
  picture->type = FF_BUFFER_TYPE_USER;
  picture->age = G_MAXINT;
  picture->base[0] = (int8_t *) buf;
  gst_buffer_ref (buf);

  return 0;
}

static void
gst_ffmpegdec_release_buffer (AVCodecContext * context, AVFrame * picture)
{
  gint i;
  GstBuffer *buf = GST_BUFFER (picture->base[0]);

  gst_buffer_unref (buf);

  /* zero out the reference in ffmpeg */
  for (i = 0; i < 4; i++) {
    picture->data[i] = NULL;
    picture->linesize[i] = 0;
  }
}
#endif

static void
gst_ffmpegdec_chain (GstPad * pad, GstData * _data)
{
  GstBuffer *inbuf = GST_BUFFER (_data);
  GstBuffer *outbuf = NULL;
  GstFFMpegDec *ffmpegdec = (GstFFMpegDec *) (gst_pad_get_parent (pad));
  GstFFMpegDecClass *oclass =
      (GstFFMpegDecClass *) (G_OBJECT_GET_CLASS (ffmpegdec));
  guchar *data;
  gint size, len = 0;
  gint have_data;

  if (!ffmpegdec->opened) {
    GST_ELEMENT_ERROR (ffmpegdec, CORE, NEGOTIATION, (NULL),
        ("ffdec_%s: input format was not set before data start",
            oclass->in_plugin->name));
    return;
  }

  /* FIXME: implement event awareness (especially EOS
   * (av_close_codec ()) and FLUSH/DISCONT
   * (avcodec_flush_buffers ()))
   */

  data = GST_BUFFER_DATA (inbuf);
  size = GST_BUFFER_SIZE (inbuf);

  do {
    ffmpegdec->context->frame_number++;

    switch (oclass->in_plugin->type) {
      case CODEC_TYPE_VIDEO:
        /* workarounds, functions write to buffers:
         *  libavcodec/svq1.c:svq1_decode_frame writes to the given buffer.
         *  libavcodec/svq3.c:svq3_decode_slice_header too.
         * ffmpeg devs know about it and will fix it (they said). */
        if (oclass->in_plugin->id == CODEC_ID_SVQ1 ||
            oclass->in_plugin->id == CODEC_ID_SVQ3) {
          inbuf = gst_buffer_copy_on_write (inbuf);
          data = GST_BUFFER_DATA (inbuf);
          size = GST_BUFFER_SIZE (inbuf);
        }
        len = avcodec_decode_video (ffmpegdec->context,
            ffmpegdec->picture, &have_data, data, size);
        if (have_data) {
          /* libavcodec constantly crashes on stupid buffer allocation
           * errors inside. This drives me crazy, so we let it allocate
           * it's own buffers and copy to our own buffer afterwards... */
          AVPicture pic;
          gint size = avpicture_get_size (ffmpegdec->context->pix_fmt,
              ffmpegdec->context->width,
              ffmpegdec->context->height);

          outbuf = gst_buffer_new_and_alloc (size);
          avpicture_fill (&pic, GST_BUFFER_DATA (outbuf),
              ffmpegdec->context->pix_fmt,
              ffmpegdec->context->width, ffmpegdec->context->height);
          img_convert (&pic, ffmpegdec->context->pix_fmt,
              (AVPicture *) ffmpegdec->picture,
              ffmpegdec->context->pix_fmt,
              ffmpegdec->context->width, ffmpegdec->context->height);

          /* this isn't necessarily true, but it's better than nothing */
          GST_BUFFER_DURATION (outbuf) = GST_BUFFER_DURATION (inbuf);
        }
        break;

      case CODEC_TYPE_AUDIO:
        outbuf = gst_buffer_new_and_alloc (AVCODEC_MAX_AUDIO_FRAME_SIZE);
        len = avcodec_decode_audio (ffmpegdec->context,
            (int16_t *) GST_BUFFER_DATA (outbuf), &have_data, data, size);

        if (have_data) {
          GST_BUFFER_SIZE (outbuf) = have_data;
          GST_BUFFER_DURATION (outbuf) = (have_data * GST_SECOND) /
              (ffmpegdec->context->channels * ffmpegdec->context->sample_rate);
        } else {
          gst_buffer_unref (outbuf);
        }
        break;
      default:
        g_assert (0);
        break;
    }

    if (len < 0) {
      GST_ERROR_OBJECT (ffmpegdec, "ffdec_%s: decoding error",
          oclass->in_plugin->name);
      break;
    }

    if (have_data) {
      if (!GST_PAD_CAPS (ffmpegdec->srcpad)) {
        GstCaps *caps;

        caps = gst_ffmpeg_codectype_to_caps (oclass->in_plugin->type,
            ffmpegdec->context);
        if (caps == NULL ||
            !gst_pad_set_explicit_caps (ffmpegdec->srcpad, caps)) {
          GST_ELEMENT_ERROR (ffmpegdec, CORE, NEGOTIATION, (NULL),
              ("Failed to link ffmpeg decoder (%s) to next element",
                  oclass->in_plugin->name));
          return;
        }
      }

      GST_BUFFER_TIMESTAMP (outbuf) = GST_BUFFER_TIMESTAMP (inbuf);

      gst_pad_push (ffmpegdec->srcpad, GST_DATA (outbuf));
    }

    size -= len;
    data += len;
  } while (size > 0);

  gst_buffer_unref (inbuf);
}

static GstElementStateReturn
gst_ffmpegdec_change_state (GstElement * element)
{
  GstFFMpegDec *ffmpegdec = (GstFFMpegDec *) element;
  gint transition = GST_STATE_TRANSITION (element);

  switch (transition) {
    case GST_STATE_PAUSED_TO_READY:
      if (ffmpegdec->opened) {
        avcodec_close (ffmpegdec->context);
        ffmpegdec->opened = FALSE;
      }
      break;
  }

  if (GST_ELEMENT_CLASS (parent_class)->change_state)
    return GST_ELEMENT_CLASS (parent_class)->change_state (element);

  return GST_STATE_SUCCESS;
}

gboolean
gst_ffmpegdec_register (GstPlugin * plugin)
{
  GTypeInfo typeinfo = {
    sizeof (GstFFMpegDecClass),
    (GBaseInitFunc) gst_ffmpegdec_base_init,
    NULL,
    (GClassInitFunc) gst_ffmpegdec_class_init,
    NULL,
    NULL,
    sizeof (GstFFMpegDec),
    0,
    (GInstanceInitFunc) gst_ffmpegdec_init,
  };
  GType type;
  AVCodec *in_plugin;

  in_plugin = first_avcodec;

  global_plugins = g_hash_table_new (NULL, NULL);

  while (in_plugin) {
    GstFFMpegDecClassParams *params;
    GstCaps *srccaps, *sinkcaps;
    gchar *type_name;

    /* no quasi-codecs, please */
    if (in_plugin->id == CODEC_ID_RAWVIDEO ||
        (in_plugin->id >= CODEC_ID_PCM_S16LE &&
            in_plugin->id <= CODEC_ID_PCM_ALAW)) {
      goto next;
    }

    /* only decoders */
    if (!in_plugin->decode) {
      goto next;
    }

    /* first make sure we've got a supported type */
    sinkcaps = gst_ffmpeg_codecid_to_caps (in_plugin->id, NULL, FALSE);
    srccaps = gst_ffmpeg_codectype_to_caps (in_plugin->type, NULL);
    if (!sinkcaps || !srccaps) {
      if (sinkcaps) gst_caps_free (sinkcaps);
      if (srccaps) gst_caps_free (srccaps);
      goto next;
    }

    /* construct the type */
    type_name = g_strdup_printf ("ffdec_%s", in_plugin->name);

    /* if it's already registered, drop it */
    if (g_type_from_name (type_name)) {
      g_free (type_name);
      goto next;
    }

    params = g_new0 (GstFFMpegDecClassParams, 1);
    params->in_plugin = in_plugin;
    params->srccaps = srccaps;
    params->sinkcaps = sinkcaps;
    g_hash_table_insert (global_plugins,
        GINT_TO_POINTER (0), (gpointer) params);

    /* create the gtype now
     * (Ronald) MPEG-4 gets a higher priority because it has been well-
     * tested and by far outperforms divxdec/xviddec - so we prefer it. */
    type = g_type_register_static (GST_TYPE_ELEMENT, type_name, &typeinfo, 0);
    if (!gst_element_register (plugin, type_name,
            (in_plugin->id == CODEC_ID_MPEG4) ?
            GST_RANK_PRIMARY : GST_RANK_MARGINAL, type)) {
      g_free (type_name);
      return FALSE;
    }

    g_free (type_name);

    g_hash_table_insert (global_plugins,
        GINT_TO_POINTER (type), (gpointer) params);

  next:
    in_plugin = in_plugin->next;
  }
  g_hash_table_remove (global_plugins, GINT_TO_POINTER (0));

  return TRUE;
}