/* GStreamer

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

 *

 * 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:element-pngdec

 *

 * Decodes png images. If there is no framerate set on sink caps, it sends EOS

 * after the first picture.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "gstpngdec.h"

#include <stdlib.h>

#include <string.h>

#include <gst/video/video.h>

#include <gst/gst-i18n-plugin.h>

static const GstElementDetails gst_pngdec_details =

GST_ELEMENT_DETAILS ("PNG image decoder",

    "Codec/Decoder/Image",

    "Decode a png video frame to a raw image",

    "Wim Taymans <wim@fluendo.com>");

GST_DEBUG_CATEGORY_STATIC (pngdec_debug);

#define GST_CAT_DEFAULT pngdec_debug

static void gst_pngdec_base_init (gpointer g_class);

static void gst_pngdec_class_init (GstPngDecClass * klass);

static void gst_pngdec_init (GstPngDec * pngdec);

static gboolean gst_pngdec_libpng_init (GstPngDec * pngdec);

static gboolean gst_pngdec_libpng_clear (GstPngDec * pngdec);

static GstStateChangeReturn gst_pngdec_change_state (GstElement * element,

    GstStateChange transition);

static gboolean gst_pngdec_sink_activate_push (GstPad * sinkpad,

    gboolean active);

static gboolean gst_pngdec_sink_activate_pull (GstPad * sinkpad,

    gboolean active);

static gboolean gst_pngdec_sink_activate (GstPad * sinkpad);

static GstFlowReturn gst_pngdec_caps_create_and_set (GstPngDec * pngdec);

static void gst_pngdec_task (GstPad * pad);

static GstFlowReturn gst_pngdec_chain (GstPad * pad, GstBuffer * buffer);

static gboolean gst_pngdec_sink_event (GstPad * pad, GstEvent * event);

static gboolean gst_pngdec_sink_setcaps (GstPad * pad, GstCaps * caps);

static GstElementClass *parent_class = NULL;

GType

gst_pngdec_get_type (void)

{

  static GType pngdec_type = 0;

  if (!pngdec_type) {

    static const GTypeInfo pngdec_info = {

      sizeof (GstPngDecClass),

      gst_pngdec_base_init,

      NULL,

      (GClassInitFunc) gst_pngdec_class_init,

      NULL,

      NULL,

      sizeof (GstPngDec),

      0,

      (GInstanceInitFunc) gst_pngdec_init,

    };

    pngdec_type = g_type_register_static (GST_TYPE_ELEMENT, "GstPngDec",

        &pngdec_info, 0);

  }

  return pngdec_type;

}

static GstStaticPadTemplate gst_pngdec_src_pad_template =

    GST_STATIC_PAD_TEMPLATE ("src",

    GST_PAD_SRC,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS (GST_VIDEO_CAPS_RGBA ";" GST_VIDEO_CAPS_RGB)

    );

static GstStaticPadTemplate gst_pngdec_sink_pad_template =

GST_STATIC_PAD_TEMPLATE ("sink",

    GST_PAD_SINK,

    GST_PAD_ALWAYS,

    GST_STATIC_CAPS ("image/png")

    );

static void

gst_pngdec_base_init (gpointer g_class)

{

  GstElementClass *element_class = GST_ELEMENT_CLASS (g_class);

  gst_element_class_add_pad_template (element_class,

      gst_static_pad_template_get (&gst_pngdec_src_pad_template));

  gst_element_class_add_pad_template (element_class,

      gst_static_pad_template_get (&gst_pngdec_sink_pad_template));

  gst_element_class_set_details (element_class, &gst_pngdec_details);

}

static void

gst_pngdec_class_init (GstPngDecClass * klass)

{

  GstElementClass *gstelement_class;

  gstelement_class = (GstElementClass *) klass;

  parent_class = g_type_class_peek_parent (klass);

  gstelement_class->change_state = gst_pngdec_change_state;

  GST_DEBUG_CATEGORY_INIT (pngdec_debug, "pngdec", 0, "PNG image decoder");

}

static void

gst_pngdec_init (GstPngDec * pngdec)

{

  pngdec->sinkpad =

      gst_pad_new_from_static_template (&gst_pngdec_sink_pad_template, "sink");

  gst_pad_set_activate_function (pngdec->sinkpad, gst_pngdec_sink_activate);

  gst_pad_set_activatepush_function (pngdec->sinkpad,

      gst_pngdec_sink_activate_push);

  gst_pad_set_activatepull_function (pngdec->sinkpad,

      gst_pngdec_sink_activate_pull);

  gst_pad_set_chain_function (pngdec->sinkpad, gst_pngdec_chain);

  gst_pad_set_event_function (pngdec->sinkpad, gst_pngdec_sink_event);

  gst_pad_set_setcaps_function (pngdec->sinkpad, gst_pngdec_sink_setcaps);

  gst_element_add_pad (GST_ELEMENT (pngdec), pngdec->sinkpad);

  pngdec->srcpad =

      gst_pad_new_from_static_template (&gst_pngdec_src_pad_template, "src");

  gst_pad_use_fixed_caps (pngdec->srcpad);

  gst_element_add_pad (GST_ELEMENT (pngdec), pngdec->srcpad);

  pngdec->buffer_out = NULL;

  pngdec->png = NULL;

  pngdec->info = NULL;

  pngdec->endinfo = NULL;

  pngdec->setup = FALSE;

  pngdec->color_type = -1;

  pngdec->width = -1;

  pngdec->height = -1;

  pngdec->bpp = -1;

  pngdec->fps_n = 0;

  pngdec->fps_d = 1;

  pngdec->in_timestamp = GST_CLOCK_TIME_NONE;

  pngdec->in_duration = GST_CLOCK_TIME_NONE;

  gst_segment_init (&pngdec->segment, GST_FORMAT_UNDEFINED);

  pngdec->image_ready = FALSE;

}

static void

user_error_fn (png_structp png_ptr, png_const_charp error_msg)

{

  GST_ERROR ("%s", error_msg);

}

static void

user_warning_fn (png_structp png_ptr, png_const_charp warning_msg)

{

  GST_WARNING ("%s", warning_msg);

}

static void

user_info_callback (png_structp png_ptr, png_infop info)

{

  GstPngDec *pngdec = NULL;

  GstFlowReturn ret = GST_FLOW_OK;

  size_t buffer_size;

  GstBuffer *buffer = NULL;

  pngdec = GST_PNGDEC (png_ptr->io_ptr);

  GST_LOG ("info ready");

  /* Generate the caps and configure */

  ret = gst_pngdec_caps_create_and_set (pngdec);

  if (ret != GST_FLOW_OK) {

    goto beach;

  }

  /* Allocate output buffer */

  pngdec->rowbytes = png_get_rowbytes (pngdec->png, pngdec->info);

  buffer_size = pngdec->height * GST_ROUND_UP_4 (pngdec->rowbytes);

  ret =

      gst_pad_alloc_buffer_and_set_caps (pngdec->srcpad, GST_BUFFER_OFFSET_NONE,

      buffer_size, GST_PAD_CAPS (pngdec->srcpad), &buffer);

  if (ret != GST_FLOW_OK) {

    goto beach;

  }

  pngdec->buffer_out = buffer;

beach:

  pngdec->ret = ret;

}

static void

user_endrow_callback (png_structp png_ptr, png_bytep new_row,

    png_uint_32 row_num, int pass)

{

  GstPngDec *pngdec = NULL;

  pngdec = GST_PNGDEC (png_ptr->io_ptr);

  /* FIXME: implement interlaced pictures */

  /* If buffer_out doesn't exist, it means buffer_alloc failed, which 

   * will already have set the return code */

  if (GST_IS_BUFFER (pngdec->buffer_out)) {

    size_t offset = row_num * GST_ROUND_UP_4 (pngdec->rowbytes);

    GST_LOG ("got row %u, copying in buffer %p at offset %" G_GSIZE_FORMAT,

        (guint) row_num, pngdec->buffer_out, offset);

    memcpy (GST_BUFFER_DATA (pngdec->buffer_out) + offset, new_row,

        pngdec->rowbytes);

    pngdec->ret = GST_FLOW_OK;

  }

}

static gboolean

buffer_clip (GstPngDec * dec, GstBuffer * buffer)

{

  gboolean res = TRUE;

  gint64 cstart, cstop;

  if ((!GST_CLOCK_TIME_IS_VALID (GST_BUFFER_TIMESTAMP (buffer))) ||

      (!GST_CLOCK_TIME_IS_VALID (GST_BUFFER_DURATION (buffer))) ||

      (dec->segment.format != GST_FORMAT_TIME))

    goto beach;

  cstart = GST_BUFFER_TIMESTAMP (buffer);

  cstop = GST_BUFFER_DURATION (buffer);

  if ((res = gst_segment_clip (&dec->segment, GST_FORMAT_TIME,

              cstart, cstart + cstop, &cstart, &cstop))) {

    GST_BUFFER_TIMESTAMP (buffer) = cstart;

    GST_BUFFER_DURATION (buffer) = cstop - cstart;

  }

beach:

  return res;

}

static void

user_end_callback (png_structp png_ptr, png_infop info)

{

  GstPngDec *pngdec = NULL;

  pngdec = GST_PNGDEC (png_ptr->io_ptr);

  GST_LOG_OBJECT (pngdec, "and we are done reading this image");

  if (!pngdec->buffer_out)

    return;

  if (GST_CLOCK_TIME_IS_VALID (pngdec->in_timestamp))

    GST_BUFFER_TIMESTAMP (pngdec->buffer_out) = pngdec->in_timestamp;

  if (GST_CLOCK_TIME_IS_VALID (pngdec->in_duration))

    GST_BUFFER_DURATION (pngdec->buffer_out) = pngdec->in_duration;

  /* buffer clipping */

  if (buffer_clip (pngdec, pngdec->buffer_out)) {

    /* Push our buffer and then EOS if needed */

    GST_LOG_OBJECT (pngdec, "pushing buffer with ts=%" GST_TIME_FORMAT,

        GST_TIME_ARGS (GST_BUFFER_TIMESTAMP (pngdec->buffer_out)));

    pngdec->ret = gst_pad_push (pngdec->srcpad, pngdec->buffer_out);

  } else {

    GST_LOG_OBJECT (pngdec, "dropped decoded buffer");

    gst_buffer_unref (pngdec->buffer_out);

  }

  pngdec->buffer_out = NULL;

  pngdec->image_ready = TRUE;

}

static void

user_read_data (png_structp png_ptr, png_bytep data, png_size_t length)

{

  GstPngDec *pngdec;

  GstBuffer *buffer;

  GstFlowReturn ret = GST_FLOW_OK;

  guint size;

  pngdec = GST_PNGDEC (png_ptr->io_ptr);

  GST_LOG ("reading %" G_GSIZE_FORMAT " bytes of data at offset %d", length,

      pngdec->offset);

  ret = gst_pad_pull_range (pngdec->sinkpad, pngdec->offset, length, &buffer);

  if (ret != GST_FLOW_OK)

    goto pause;

  size = GST_BUFFER_SIZE (buffer);

  if (size != length)

    goto short_buffer;

  memcpy (data, GST_BUFFER_DATA (buffer), size);

  gst_buffer_unref (buffer);

  pngdec->offset += length;

  return;

  /* ERRORS */

pause:

  {

    GST_INFO_OBJECT (pngdec, "pausing task, reason %s",

        gst_flow_get_name (ret));

    gst_pad_pause_task (pngdec->sinkpad);

    if (GST_FLOW_IS_FATAL (ret) || ret == GST_FLOW_NOT_LINKED) {

      GST_ELEMENT_ERROR (pngdec, STREAM, FAILED,

          (_("Internal data stream error.")),

          ("stream stopped, reason %s", gst_flow_get_name (ret)));

      gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ());

    }

    return;

  }

short_buffer:

  {

    gst_buffer_unref (buffer);

    GST_ELEMENT_ERROR (pngdec, STREAM, FAILED,

        (_("Internal data stream error.")),

        ("Read %u, needed %" G_GSIZE_FORMAT "bytes", size, length));

    ret = GST_FLOW_ERROR;

    goto pause;

  }

}

static GstFlowReturn

gst_pngdec_caps_create_and_set (GstPngDec * pngdec)

{

  GstFlowReturn ret = GST_FLOW_OK;

  GstCaps *caps = NULL, *res = NULL;

  GstPadTemplate *templ = NULL;

  gint bpc = 0, color_type;

  png_uint_32 width, height;

  g_return_val_if_fail (GST_IS_PNGDEC (pngdec), GST_FLOW_ERROR);

  /* Get bits per channel */

  bpc = png_get_bit_depth (pngdec->png, pngdec->info);

  /* We don't handle 16 bits per color, strip down to 8 */

  if (bpc == 16) {

    GST_LOG_OBJECT (pngdec,

        "this is a 16 bits per channel PNG image, strip down to 8 bits");

    png_set_strip_16 (pngdec->png);

  }

  /* Get Color type */

  color_type = png_get_color_type (pngdec->png, pngdec->info);

#if 0

  /* We used to have this HACK to reverse the outgoing bytes, but the problem

   * that originally required the hack seems to have been in ffmpegcolorspace's

   * RGBA descriptions. It doesn't seem needed now that's fixed, but might

   * still be needed on big-endian systems, I'm not sure. J.S. 6/7/2007 */

  if (color_type == PNG_COLOR_TYPE_RGB_ALPHA)

    png_set_bgr (pngdec->png);

#endif

  /* Gray scale converted to RGB and upscaled to 8 bits */

  if ((color_type == PNG_COLOR_TYPE_GRAY_ALPHA) ||

      (color_type == PNG_COLOR_TYPE_GRAY)) {

    GST_LOG_OBJECT (pngdec, "converting grayscale png to RGB");

    png_set_gray_to_rgb (pngdec->png);

    if (bpc < 8) {              /* Convert to 8 bits */

      GST_LOG_OBJECT (pngdec, "converting grayscale image to 8 bits");

      png_set_gray_1_2_4_to_8 (pngdec->png);

    }

  }

  /* Palette converted to RGB */

  if (color_type == PNG_COLOR_TYPE_PALETTE) {

    GST_LOG_OBJECT (pngdec, "converting palette png to RGB");

    png_set_palette_to_rgb (pngdec->png);

  }

  /* Update the info structure */

  png_read_update_info (pngdec->png, pngdec->info);

  /* Get IHDR header again after transformation settings */

  png_get_IHDR (pngdec->png, pngdec->info, &width, &height,

      &bpc, &pngdec->color_type, NULL, NULL, NULL);

  pngdec->width = width;

  pngdec->height = height;

  GST_LOG_OBJECT (pngdec, "this is a %dx%d PNG image", pngdec->width,

      pngdec->height);

  switch (pngdec->color_type) {

    case PNG_COLOR_TYPE_RGB:

      GST_LOG_OBJECT (pngdec, "we have no alpha channel, depth is 24 bits");

      pngdec->bpp = 24;

      break;

    case PNG_COLOR_TYPE_RGB_ALPHA:

      GST_LOG_OBJECT (pngdec, "we have an alpha channel, depth is 32 bits");

      pngdec->bpp = 32;

      break;

    default:

      GST_ELEMENT_ERROR (pngdec, STREAM, NOT_IMPLEMENTED, (NULL),

          ("pngdec does not support this color type"));

      ret = GST_FLOW_NOT_SUPPORTED;

      goto beach;

  }

  caps = gst_caps_new_simple ("video/x-raw-rgb",

      "width", G_TYPE_INT, pngdec->width,

      "height", G_TYPE_INT, pngdec->height,

      "bpp", G_TYPE_INT, pngdec->bpp,

      "framerate", GST_TYPE_FRACTION, pngdec->fps_n, pngdec->fps_d, NULL);

  templ = gst_static_pad_template_get (&gst_pngdec_src_pad_template);

  res = gst_caps_intersect (caps, gst_pad_template_get_caps (templ));

  gst_caps_unref (caps);

  gst_object_unref (templ);

  if (!gst_pad_set_caps (pngdec->srcpad, res))

    ret = GST_FLOW_NOT_NEGOTIATED;

  GST_DEBUG_OBJECT (pngdec, "our caps %" GST_PTR_FORMAT, res);

  gst_caps_unref (res);

  /* Push a newsegment event */

  if (pngdec->need_newsegment) {

    gst_pad_push_event (pngdec->srcpad,

        gst_event_new_new_segment (FALSE, 1.0, GST_FORMAT_TIME, 0, -1, 0));

    pngdec->need_newsegment = FALSE;

  }

beach:

  return ret;

}

static void

gst_pngdec_task (GstPad * pad)

{

  GstPngDec *pngdec;

  GstBuffer *buffer = NULL;

  size_t buffer_size = 0;

  gint i = 0;

  png_bytep *rows, inp;

  png_uint_32 rowbytes;

  GstFlowReturn ret = GST_FLOW_OK;

  pngdec = GST_PNGDEC (GST_OBJECT_PARENT (pad));

  GST_LOG_OBJECT (pngdec, "read frame");

  /* Let libpng come back here on error */

  if (setjmp (png_jmpbuf (pngdec->png))) {

    ret = GST_FLOW_ERROR;

    goto pause;

  }

  /* Set reading callback */

  png_set_read_fn (pngdec->png, pngdec, user_read_data);

  /* Read info */

  png_read_info (pngdec->png, pngdec->info);

  /* Generate the caps and configure */

  ret = gst_pngdec_caps_create_and_set (pngdec);

  if (ret != GST_FLOW_OK) {

    goto pause;

  }

  /* Allocate output buffer */

  rowbytes = png_get_rowbytes (pngdec->png, pngdec->info);

  buffer_size = pngdec->height * GST_ROUND_UP_4 (rowbytes);

  ret =

      gst_pad_alloc_buffer_and_set_caps (pngdec->srcpad, GST_BUFFER_OFFSET_NONE,

      buffer_size, GST_PAD_CAPS (pngdec->srcpad), &buffer);

  if (ret != GST_FLOW_OK)

    goto pause;

  rows = (png_bytep *) g_malloc (sizeof (png_bytep) * pngdec->height);

  inp = GST_BUFFER_DATA (buffer);

  for (i = 0; i < pngdec->height; i++) {

    rows[i] = inp;

    inp += GST_ROUND_UP_4 (rowbytes);

  }

  /* Read the actual picture */

  png_read_image (pngdec->png, rows);

  free (rows);

  /* Push the raw RGB frame */

  ret = gst_pad_push (pngdec->srcpad, buffer);

  if (ret != GST_FLOW_OK)

    goto pause;

  /* And we are done */

  gst_pad_pause_task (pngdec->sinkpad);

  gst_pad_push_event (pngdec->srcpad, gst_event_new_eos ());

  return;

pause: