gstreamer/gst/pnm/gstpnmenc.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-pnmenc
 *
 * Encodes pnm images.
 *
 * <refsect">
 * <title>Example launch line</title>
 * |[
 * gst-launch videotestsrc num_buffers=1 ! pnmenc ! filesink location=test.pnm
 * ]| The above pipeline writes a test pnm file.
 * </refsect2>
 */

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

#include "gstpnmenc.h"
#include "gstpnmutils.h"

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

#include <string.h>

static GstElementDetails pnmenc_details =
GST_ELEMENT_DETAILS ("PNM converter", "Codec/Encoder/Image",
    "Encodes in PNM format",
    "Lutz Mueller <lutz@users.sourceforge.net>");

static GstStaticPadTemplate sink_pad_template =
GST_STATIC_PAD_TEMPLATE ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
    GST_STATIC_CAPS (GST_VIDEO_CAPS_BGRx));

static GstStaticPadTemplate src_pad_template =
GST_STATIC_PAD_TEMPLATE ("src", GST_PAD_SRC, GST_PAD_ALWAYS,
    GST_STATIC_CAPS (MIME_ALL));

static gboolean
gst_pnmenc_set_srccaps (GstPnmenc * s, GstPad * pad)
{
  guint i;
  GstCaps *othercaps, *caps = NULL;

  othercaps = gst_pad_peer_get_caps (pad);
  if (!othercaps) {
    caps = gst_caps_from_string (MIME_BM);
    gst_pad_set_caps (pad, caps);
    gst_caps_unref (caps);
    return TRUE;
  }

  s->info.fields &= ~GST_PNM_INFO_FIELDS_TYPE;
  for (i = 0; i < gst_caps_get_size (othercaps); i++) {
    GstStructure *structure = gst_caps_get_structure (othercaps, i);
    const gchar *mime = gst_structure_get_name (structure);

    if (!strcmp (mime, MIME_BM)) {
      s->info.type = GST_PNM_TYPE_BITMAP_RAW;
      caps = gst_caps_from_string (MIME_BM);
      break;
    }
    if (!strcmp (mime, MIME_GM)) {
      s->info.type = GST_PNM_TYPE_GRAYMAP_RAW;
      caps = gst_caps_from_string (MIME_GM);
      break;
    }
    if (!strcmp (mime, MIME_PM) || !strcmp (mime, MIME_AM)) {
      s->info.type = GST_PNM_TYPE_PIXMAP_RAW;
      caps = gst_caps_from_string (MIME_PM);
      break;
    }
  }
  gst_caps_unref (othercaps);
  if (!caps) {
    return FALSE;
  }
  s->info.max = 255;
  s->info.fields |= GST_PNM_INFO_FIELDS_TYPE | GST_PNM_INFO_FIELDS_MAX;

  gst_pad_set_caps (pad, caps);
  gst_caps_unref (caps);
  return TRUE;
}

static GstFlowReturn
gst_pnmenc_chain (GstPad * pad, GstBuffer * buf)
{
  GstPnmenc *s = GST_PNMENC (gst_pad_get_parent (pad));
  GstPad *src = gst_element_get_static_pad (GST_ELEMENT (s), "src");
  GstFlowReturn r;
  gchar *header;
  GstBuffer *out;

  /* The caps on the source may not be set. */
  if (!GST_PAD_CAPS (src)) {
    if (!gst_pnmenc_set_srccaps (s, src)) {
      r = GST_FLOW_NOT_NEGOTIATED;
      goto out;
    }
  }

  /* Assumption: One buffer, one image. That is, always first write header. */
  header = g_strdup_printf ("P%i\n%i %i\n%i\n",
      s->info.type, s->info.width, s->info.height, s->info.max);
  out = gst_buffer_new ();
  gst_buffer_set_data (out, (guchar *) header, strlen (header));
  gst_buffer_set_caps (out, GST_PAD_CAPS (src));
  if ((r = gst_pad_push (src, out)) != GST_FLOW_OK)
    goto out;

  /* Pass through the data. */
  buf = gst_buffer_make_metadata_writable (buf);
  gst_buffer_set_caps (buf, GST_PAD_CAPS (src));
  r = gst_pad_push (src, buf);

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

  return r;
}

static gboolean
gst_pnmenc_setcaps_func_sink (GstPad * pad, GstCaps * caps)
{
  GstPnmenc *s = GST_PNMENC (gst_pad_get_parent (pad));
  GstStructure *structure = gst_caps_get_structure (caps, 0);

  if (!gst_structure_get_int (structure, "width", (int *) &s->info.width) ||
      !gst_structure_get_int (structure, "height", (int *) &s->info.height))
    return FALSE;
  s->info.fields = GST_PNM_INFO_FIELDS_WIDTH | GST_PNM_INFO_FIELDS_HEIGHT;

  gst_object_unref (s);

  return TRUE;
}

static void
gst_pnmenc_init (GstPnmenc * s, GstPnmencClass * klass)
{
  GstPad *pad;

  pad =
      gst_pad_new_from_template (gst_static_pad_template_get
      (&sink_pad_template), "sink");
  gst_pad_set_setcaps_function (pad, gst_pnmenc_setcaps_func_sink);
  gst_pad_set_chain_function (pad, gst_pnmenc_chain);
  gst_pad_use_fixed_caps (pad);
  gst_element_add_pad (GST_ELEMENT (s), pad);

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

static void
gst_pnmenc_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 (&sink_pad_template));
  gst_element_class_add_pad_template (element_class,
      gst_static_pad_template_get (&src_pad_template));
  gst_element_class_set_details (element_class, &pnmenc_details);
}

static void
gst_pnmenc_class_init (GstPnmencClass * klass)
{
  /* Nothing to see here. Move along. */
}

GST_BOILERPLATE (GstPnmenc, gst_pnmenc, GstElement, GST_TYPE_ELEMENT)