The Tor Browser: content/media/gstreamer/GStreamerReader-0.10.cpp@97036ab72558 (annotated)

content/media/gstreamer/GStreamerReader-0.10.cpp@97036ab72558 (annotated)

content/media/gstreamer/GStreamerReader-0.10.cpp

Tue, 06 Jan 2015 21:39:09 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Tue, 06 Jan 2015 21:39:09 +0100
branch: TOR_BUG_9701
changeset 8: 97036ab72558
permissions: -rw-r--r--

Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

 #include "nsError.h"
 #include "MediaDecoderStateMachine.h"
 #include "AbstractMediaDecoder.h"
 #include "MediaResource.h"
 #include "GStreamerReader.h"
 #include "GStreamerMozVideoBuffer.h"
 #include "GStreamerFormatHelper.h"
 #include "VideoUtils.h"
 #include "mozilla/dom/TimeRanges.h"
 #include "mozilla/Endian.h"
 #include "mozilla/Preferences.h"
 using namespace mozilla;
 using mozilla::layers::PlanarYCbCrImage;
 using mozilla::layers::ImageContainer;
 GstFlowReturn GStreamerReader::AllocateVideoBufferCb(GstPad* aPad,
                                                      guint64 aOffset,
                                                      guint aSize,
                                                      GstCaps* aCaps,
                                                      GstBuffer** aBuf)
 {
   GStreamerReader* reader = reinterpret_cast<GStreamerReader*>(gst_pad_get_element_private(aPad));
   return reader->AllocateVideoBuffer(aPad, aOffset, aSize, aCaps, aBuf);
 }
 GstFlowReturn GStreamerReader::AllocateVideoBuffer(GstPad* aPad,
                                                    guint64 aOffset,
                                                    guint aSize,
                                                    GstCaps* aCaps,
                                                    GstBuffer** aBuf)
 {
   nsRefPtr<PlanarYCbCrImage> image;
   return AllocateVideoBufferFull(aPad, aOffset, aSize, aCaps, aBuf, image);
 }
 GstFlowReturn GStreamerReader::AllocateVideoBufferFull(GstPad* aPad,
                                                        guint64 aOffset,
                                                        guint aSize,
                                                        GstCaps* aCaps,
                                                        GstBuffer** aBuf,
                                                        nsRefPtr<PlanarYCbCrImage>& aImage)
 {
   /* allocate an image using the container */
   ImageContainer* container = mDecoder->GetImageContainer();
   if (container == nullptr) {
     return GST_FLOW_ERROR;
   }
   nsRefPtr<PlanarYCbCrImage> image =
     container->CreateImage(ImageFormat::PLANAR_YCBCR).downcast<PlanarYCbCrImage>();
   /* prepare a GstBuffer pointing to the underlying PlanarYCbCrImage buffer */
   GstBuffer* buf = GST_BUFFER(gst_moz_video_buffer_new());
   GST_BUFFER_SIZE(buf) = aSize;
   /* allocate the actual YUV buffer */
   GST_BUFFER_DATA(buf) = image->AllocateAndGetNewBuffer(aSize);
   aImage = image;
   /* create a GstMozVideoBufferData to hold the image */
   GstMozVideoBufferData* bufferdata = new GstMozVideoBufferData(image);
   /* Attach bufferdata to our GstMozVideoBuffer, it will take care to free it */
   gst_moz_video_buffer_set_data(GST_MOZ_VIDEO_BUFFER(buf), bufferdata);
   *aBuf = buf;
   return GST_FLOW_OK;
 }
 gboolean GStreamerReader::EventProbe(GstPad* aPad, GstEvent* aEvent)
 {
   GstElement* parent = GST_ELEMENT(gst_pad_get_parent(aPad));
   switch(GST_EVENT_TYPE(aEvent)) {
     case GST_EVENT_NEWSEGMENT:
     {
       gboolean update;
       gdouble rate;
       GstFormat format;
       gint64 start, stop, position;
       GstSegment* segment;
       /* Store the segments so we can convert timestamps to stream time, which
        * is what the upper layers sync on.
        */
       ReentrantMonitorAutoEnter mon(mGstThreadsMonitor);
       gst_event_parse_new_segment(aEvent, &update, &rate, &format,
           &start, &stop, &position);
       if (parent == GST_ELEMENT(mVideoAppSink))
         segment = &mVideoSegment;
       else
         segment = &mAudioSegment;
       gst_segment_set_newsegment(segment, update, rate, format,
           start, stop, position);
       break;
     }
     case GST_EVENT_FLUSH_STOP:
       /* Reset on seeks */
       ResetDecode();
       break;
     default:
       break;
   }
   gst_object_unref(parent);
   return TRUE;
 }
 gboolean GStreamerReader::EventProbeCb(GstPad* aPad,
                                          GstEvent* aEvent,
                                          gpointer aUserData)
 {
   GStreamerReader* reader = reinterpret_cast<GStreamerReader*>(aUserData);
   return reader->EventProbe(aPad, aEvent);
 }
 nsRefPtr<PlanarYCbCrImage> GStreamerReader::GetImageFromBuffer(GstBuffer* aBuffer)
 {
   if (!GST_IS_MOZ_VIDEO_BUFFER (aBuffer))
     return nullptr;
   nsRefPtr<PlanarYCbCrImage> image;
   GstMozVideoBufferData* bufferdata = reinterpret_cast<GstMozVideoBufferData*>(gst_moz_video_buffer_get_data(GST_MOZ_VIDEO_BUFFER(aBuffer)));
   image = bufferdata->mImage;
   PlanarYCbCrImage::Data data;
   data.mPicX = data.mPicY = 0;
   data.mPicSize = gfx::IntSize(mPicture.width, mPicture.height);
   data.mStereoMode = StereoMode::MONO;
   data.mYChannel = GST_BUFFER_DATA(aBuffer);
   data.mYStride = gst_video_format_get_row_stride(mFormat, 0, mPicture.width);
   data.mYSize = gfx::IntSize(data.mYStride,
       gst_video_format_get_component_height(mFormat, 0, mPicture.height));
   data.mYSkip = 0;
   data.mCbCrStride = gst_video_format_get_row_stride(mFormat, 1, mPicture.width);
   data.mCbCrSize = gfx::IntSize(data.mCbCrStride,
       gst_video_format_get_component_height(mFormat, 1, mPicture.height));
   data.mCbChannel = data.mYChannel + gst_video_format_get_component_offset(mFormat, 1,
       mPicture.width, mPicture.height);
   data.mCrChannel = data.mYChannel + gst_video_format_get_component_offset(mFormat, 2,
       mPicture.width, mPicture.height);
   data.mCbSkip = 0;
   data.mCrSkip = 0;
   image->SetDataNoCopy(data);
   return image;
 }
 void GStreamerReader::CopyIntoImageBuffer(GstBuffer* aBuffer,
                                           GstBuffer** aOutBuffer,
                                           nsRefPtr<PlanarYCbCrImage> &aImage)
 {
   AllocateVideoBufferFull(nullptr, GST_BUFFER_OFFSET(aBuffer),
       GST_BUFFER_SIZE(aBuffer), nullptr, aOutBuffer, aImage);
   gst_buffer_copy_metadata(*aOutBuffer, aBuffer, (GstBufferCopyFlags)GST_BUFFER_COPY_ALL);
   memcpy(GST_BUFFER_DATA(*aOutBuffer), GST_BUFFER_DATA(aBuffer), GST_BUFFER_SIZE(*aOutBuffer));
   aImage = GetImageFromBuffer(*aOutBuffer);
 }
 GstCaps* GStreamerReader::BuildAudioSinkCaps()
 {
   GstCaps* caps;
 #if MOZ_LITTLE_ENDIAN
   int endianness = 1234;
 #else
   int endianness = 4321;
 #endif
   gint width;
 #ifdef MOZ_SAMPLE_TYPE_FLOAT32
   caps = gst_caps_from_string("audio/x-raw-float, channels={1,2}");
   width = 32;
 #else /* !MOZ_SAMPLE_TYPE_FLOAT32 */
   caps = gst_caps_from_string("audio/x-raw-int, channels={1,2}");
   width = 16;
 #endif
   gst_caps_set_simple(caps,
       "width", G_TYPE_INT, width,
       "endianness", G_TYPE_INT, endianness,
       NULL);
   return caps;
 }
 void GStreamerReader::InstallPadCallbacks()
 {
   GstPad* sinkpad = gst_element_get_static_pad(GST_ELEMENT(mVideoAppSink), "sink");
   gst_pad_add_event_probe(sinkpad,
                           G_CALLBACK(&GStreamerReader::EventProbeCb), this);
   gst_pad_set_bufferalloc_function(sinkpad, GStreamerReader::AllocateVideoBufferCb);
   gst_pad_set_element_private(sinkpad, this);
   gst_object_unref(sinkpad);
   sinkpad = gst_element_get_static_pad(GST_ELEMENT(mAudioAppSink), "sink");
   gst_pad_add_event_probe(sinkpad,
                           G_CALLBACK(&GStreamerReader::EventProbeCb), this);
   gst_object_unref(sinkpad);
 }

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content/media/gstreamer/GStreamerReader-0.10.cpp@97036ab72558 (annotated)

content/media/gstreamer/GStreamerReader-0.10.cpp