gstreamer/gst/pnm/gstpnmdec.c

/* GStreamer
 *
 * 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:element-pnmdec
 *
 * Decodes pnm images.
 *
 * <refsect2>
 * <title>Example launch line</title>
 * |[
 * gst-launch filesrc location=test.pnm ! pnmdec ! ffmpegcolorspace ! autovideosink
 * ]| The above pipeline reads a pnm file and renders it to the screen.
 * </refsect2>
 */

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

#include "gstpnmdec.h"
#include "gstpnmutils.h"

#include <gst/gstutils.h>
#include <gst/video/video.h>

#include <string.h>

static GstElementDetails pnmdec_details = GST_ELEMENT_DETAILS ("PNM converter",
    "Codec/Decoder/Image", "Decodes PNM format",
    "Lutz Mueller <lutz@users.sourceforge.net>");

static GstElementClass *parent_class;

static GstStaticPadTemplate gst_pnmdec_src_pad_template =
    GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_RGB "; "
        "video/x-raw-gray, width =" GST_VIDEO_SIZE_RANGE ", "
        "height =" GST_VIDEO_SIZE_RANGE ", framerate =" GST_VIDEO_FPS_RANGE ", "
        "bpp= (int) 8, depth= (int) 8"));

static GstStaticPadTemplate gst_pnmdec_sink_pad_template =
GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
    GST_STATIC_CAPS (MIME_ALL));

static GstFlowReturn
gst_pnmdec_chain (GstPad * pad, GstBuffer * data)
{
  GstPnmdec *s = GST_PNMDEC (gst_pad_get_parent (pad));
  GstPad *src = gst_element_get_static_pad (GST_ELEMENT (s), "src");
  GstBuffer *buf;
  GstCaps *caps = NULL;
  GstFlowReturn r = GST_FLOW_OK;
  guint8 offset = 0;

  if (!(s->mngr.info.fields & GST_PNM_INFO_FIELDS_ALL)) {
    switch (gst_pnm_info_mngr_scan (&s->mngr, GST_BUFFER_DATA (data),
            GST_BUFFER_SIZE (data))) {
      case GST_PNM_INFO_MNGR_RESULT_FAILED:
        gst_buffer_unref (data);
        r = GST_FLOW_ERROR;
        goto out;
      case GST_PNM_INFO_MNGR_RESULT_READING:
        gst_buffer_unref (data);
        r = GST_FLOW_OK;
        goto out;
      case GST_PNM_INFO_MNGR_RESULT_FINISHED:
        offset = s->mngr.data_offset;
        caps = gst_caps_copy (gst_pad_get_pad_template_caps (src));
        switch (s->mngr.info.type) {
          case GST_PNM_TYPE_BITMAP_RAW:
          case GST_PNM_TYPE_BITMAP_ASCII:
          case GST_PNM_TYPE_GRAYMAP_RAW:
          case GST_PNM_TYPE_GRAYMAP_ASCII:
            gst_caps_remove_structure (caps, 0);
            s->size = s->mngr.info.width * s->mngr.info.height * 1;
            break;
          case GST_PNM_TYPE_PIXMAP_RAW:
          case GST_PNM_TYPE_PIXMAP_ASCII:
            gst_caps_remove_structure (caps, 1);
            s->size = s->mngr.info.width * s->mngr.info.height * 3;
            break;
        }
        gst_caps_set_simple (caps,
            "width", G_TYPE_INT, s->mngr.info.width,
            "height", G_TYPE_INT, s->mngr.info.height, "framerate",
            GST_TYPE_FRACTION, 0, 1, NULL);
        if (!gst_pad_set_caps (src, caps)) {
          gst_caps_unref (caps);
          r = GST_FLOW_ERROR;
          goto out;
        }
        gst_caps_unref (caps);
    }
  }

  if (offset == GST_BUFFER_SIZE (data)) {
    r = GST_FLOW_OK;
    goto out;
  }

  /* If we got the whole image, just push the buffer. */
  if (GST_BUFFER_SIZE (data) - offset == s->size) {
    buf = gst_buffer_create_sub (data, offset, s->size);
    gst_buffer_unref (data);
    memset (&s->mngr, 0, sizeof (GstPnmInfoMngr));
    s->size = 0;
    gst_buffer_set_caps (buf, GST_PAD_CAPS (src));
    r = gst_pad_push (src, buf);
    goto out;
  }

  /* We didn't get the whole image. */
  if (!s->buf) {
    s->buf = gst_buffer_create_sub (data, offset,
        GST_BUFFER_SIZE (data) - offset);
  } else {
    buf = gst_buffer_span (s->buf, 0, data,
        GST_BUFFER_SIZE (s->buf) + GST_BUFFER_SIZE (data) - offset);
    gst_buffer_unref (s->buf);
    s->buf = buf;
  }
  if (!s->buf) {
    r = GST_FLOW_ERROR;
    goto out;
  }

  /* Do we now have the full image? If yes, push. */
  if (GST_BUFFER_SIZE (s->buf) == s->size) {
    gst_buffer_set_caps (s->buf, GST_PAD_CAPS (src));
    r = gst_pad_push (src, s->buf);
    s->buf = NULL;
    memset (&s->mngr, 0, sizeof (GstPnmInfoMngr));
    s->size = 0;
  }

out:
  gst_object_unref (src);
  gst_object_unref (s);

  return r;
}

static void
gst_pnmdec_finalize (GObject * object)
{
  GstPnmdec *dec = GST_PNMDEC (object);

  if (dec->buf) {
    gst_buffer_unref (dec->buf);
    dec->buf = NULL;
  }

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

static void
gst_pnmdec_init (GstPnmdec * s, GstPnmdecClass * klass)
{
  GstPad *pad;

  pad =
      gst_pad_new_from_template (gst_static_pad_template_get
      (&gst_pnmdec_sink_pad_template), "sink");
  gst_pad_set_chain_function (pad, gst_pnmdec_chain);
  gst_element_add_pad (GST_ELEMENT (s), pad);

  pad =
      gst_pad_new_from_template (gst_static_pad_template_get
      (&gst_pnmdec_src_pad_template), "src");
  gst_element_add_pad (GST_ELEMENT (s), pad);
}

static void
gst_pnmdec_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_pnmdec_sink_pad_template));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&gst_pnmdec_src_pad_template));
  gst_element_class_set_details (element_class, &pnmdec_details);
}

static void
gst_pnmdec_class_init (GstPnmdecClass * klass)
{
  GObjectClass *gobject_class = (GObjectClass *) klass;

  parent_class = g_type_class_peek_parent (klass);

  gobject_class->finalize = gst_pnmdec_finalize;
}

GST_BOILERPLATE (GstPnmdec, gst_pnmdec, GstElement, GST_TYPE_ELEMENT)