avmedia/source/gstreamer/gstframegrabber.cxx

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /*
   3  * This file is part of the LibreOffice project.
   4  *
   5  * This Source Code Form is subject to the terms of the Mozilla Public
   6  * License, v. 2.0. If a copy of the MPL was not distributed with this
   7  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
   8  *
   9  * This file incorporates work covered by the following license notice:
  10  *
  11  *   Licensed to the Apache Software Foundation (ASF) under one or more
  12  *   contributor license agreements. See the NOTICE file distributed
  13  *   with this work for additional information regarding copyright
  14  *   ownership. The ASF licenses this file to you under the Apache
  15  *   License, Version 2.0 (the "License"); you may not use this file
  16  *   except in compliance with the License. You may obtain a copy of
  17  *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
  18  */
  19
  20 #include "gstframegrabber.hxx"
  21 #include "gstplayer.hxx"
  22
  23 #include <cppuhelper/supportsservice.hxx>
  24
  25 #include <gst/gstbuffer.h>
  26 #include <gst/video/video.h>
  27 #include <gst/video/gstvideosink.h>
  28 #include <o3tl/safeint.hxx>
  29 #include <vcl/graph.hxx>
  30 #include <vcl/BitmapTools.hxx>
  31
  32 #include <string>
  33
  34 #define AVMEDIA_GST_FRAMEGRABBER_IMPLEMENTATIONNAME "com.sun.star.comp.avmedia.FrameGrabber_GStreamer"
  35 #define AVMEDIA_GST_FRAMEGRABBER_SERVICENAME "com.sun.star.media.FrameGrabber_GStreamer"
  36
  37 using namespace ::com::sun::star;
  38
  39 namespace avmedia::gstreamer {
  40
  41 void FrameGrabber::disposePipeline()
  42 {
  43     if( mpPipeline != nullptr )
  44     {
  45         gst_element_set_state( mpPipeline, GST_STATE_NULL );
  46         g_object_unref( G_OBJECT( mpPipeline ) );
  47         mpPipeline = nullptr;
  48     }
  49 }
  50
  51 FrameGrabber::FrameGrabber( const OUString &rURL ) :
  52     FrameGrabber_BASE()
  53 {
  54     gchar *pPipelineStr;
  55     pPipelineStr = g_strdup_printf(
  56         "uridecodebin uri=%s ! videoconvert ! videoscale ! appsink "
  57         "name=sink caps=\"video/x-raw,format=RGB,pixel-aspect-ratio=1/1\"",
  58         OUStringToOString( rURL, RTL_TEXTENCODING_UTF8 ).getStr() );
  59
  60     GError *pError = nullptr;
  61     mpPipeline = gst_parse_launch( pPipelineStr, &pError );
  62     if( pError != nullptr) {
  63         g_warning( "Failed to construct frame-grabber pipeline '%s'\n", pError->message );
  64         g_error_free( pError );
  65         disposePipeline();
  66     }
  67
  68     if( mpPipeline ) {
  69         // pre-roll
  70         switch( gst_element_set_state( mpPipeline, GST_STATE_PAUSED ) ) {
  71         case GST_STATE_CHANGE_FAILURE:
  72         case GST_STATE_CHANGE_NO_PREROLL:
  73             g_warning( "failure pre-rolling media" );
  74             disposePipeline();
  75             break;
  76         default:
  77             break;
  78         }
  79     }
  80     if( mpPipeline &&
  81         gst_element_get_state( mpPipeline, nullptr, nullptr, 5 * GST_SECOND ) == GST_STATE_CHANGE_FAILURE )
  82         disposePipeline();
  83 }
  84
  85 FrameGrabber::~FrameGrabber()
  86 {
  87     disposePipeline();
  88 }
  89
  90 FrameGrabber* FrameGrabber::create( const OUString &rURL )
  91 {
  92     return new FrameGrabber( rURL );
  93 }
  94
  95 uno::Reference< graphic::XGraphic > SAL_CALL FrameGrabber::grabFrame( double fMediaTime )
  96 {
  97     uno::Reference< graphic::XGraphic > xRet;
  98
  99     if( !mpPipeline )
 100         return xRet;
 101
 102     gint64 gst_position = llround( fMediaTime * GST_SECOND );
 103     gst_element_seek_simple(
 104         mpPipeline, GST_FORMAT_TIME,
 105         GstSeekFlags(GST_SEEK_FLAG_KEY_UNIT | GST_SEEK_FLAG_FLUSH),
 106         gst_position );
 107
 108     GstElement *pSink = gst_bin_get_by_name( GST_BIN( mpPipeline ), "sink" );
 109     if( !pSink )
 110         return xRet;
 111
 112     GstBuffer *pBuf = nullptr;
 113     GstCaps *pCaps = nullptr;
 114
 115     // synchronously fetch the frame
 116     GstSample *pSample = nullptr;
 117     g_signal_emit_by_name( pSink, "pull-preroll", &pSample, nullptr );
 118
 119     if( pSample )
 120     {
 121         pBuf = gst_sample_get_buffer( pSample );
 122         pCaps = gst_sample_get_caps( pSample );
 123     }
 124
 125     // get geometry
 126     int nWidth = 0, nHeight = 0;
 127     if( !pCaps )
 128         g_warning( "could not get snapshot format\n" );
 129     else
 130     {
 131         GstStructure *pStruct = gst_caps_get_structure( pCaps, 0 );
 132
 133         /* we need to get the final caps on the buffer to get the size */
 134         if( !gst_structure_get_int( pStruct, "width", &nWidth ) ||
 135             !gst_structure_get_int( pStruct, "height", &nHeight ) )
 136             nWidth = nHeight = 0;
 137     }
 138
 139     if( pBuf && nWidth > 0 && nHeight > 0 &&
 140         // sanity check the size
 141         gst_buffer_get_size( pBuf ) >= o3tl::make_unsigned( nWidth * nHeight * 3 )
 142         )
 143     {
 144         sal_uInt8 *pData = nullptr;
 145         GstMapInfo aMapInfo;
 146         gst_buffer_map( pBuf, &aMapInfo, GST_MAP_READ );
 147         pData = aMapInfo.data;
 148
 149         int nStride = GST_ROUND_UP_4( nWidth * 3 );
 150         BitmapEx aBmp = vcl::bitmap::CreateFromData(pData, nWidth, nHeight, nStride, 24 );
 151
 152         gst_buffer_unmap( pBuf, &aMapInfo );
 153         xRet = Graphic( aBmp ).GetXGraphic();
 154     }
 155
 156     return xRet;
 157 }
 158
 159 OUString SAL_CALL FrameGrabber::getImplementationName(  )
 160 {
 161     return AVMEDIA_GST_FRAMEGRABBER_IMPLEMENTATIONNAME;
 162 }
 163
 164 sal_Bool SAL_CALL FrameGrabber::supportsService( const OUString& ServiceName )
 165 {
 166     return cppu::supportsService(this, ServiceName);
 167 }
 168
 169 uno::Sequence< OUString > SAL_CALL FrameGrabber::getSupportedServiceNames()
 170 {
 171     return { AVMEDIA_GST_FRAMEGRABBER_SERVICENAME };
 172 }
 173
 174 } // namespace
 175
 176 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */