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

content/media/gstreamer/GStreamerFormatHelper.cpp@97036ab72558 (annotated)

content/media/gstreamer/GStreamerFormatHelper.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.

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim:set ts=2 sw=2 sts=2 et cindent: */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 #include "GStreamerFormatHelper.h"
 #include "nsCharSeparatedTokenizer.h"
 #include "nsString.h"
 #include "GStreamerLoader.h"
 #define ENTRY_FORMAT(entry) entry[0]
 #define ENTRY_CAPS(entry) entry[1]
 namespace mozilla {
 GStreamerFormatHelper* GStreamerFormatHelper::gInstance = nullptr;
 bool GStreamerFormatHelper::sLoadOK = false;
 GStreamerFormatHelper* GStreamerFormatHelper::Instance() {
   if (!gInstance) {
     if ((sLoadOK = load_gstreamer())) {
       gst_init(nullptr, nullptr);
     }
     gInstance = new GStreamerFormatHelper();
   }
   return gInstance;
 }
 void GStreamerFormatHelper::Shutdown() {
   delete gInstance;
   gInstance = nullptr;
 }
 static char const *const sContainers[6][2] = {
   {"video/mp4", "video/quicktime"},
   {"video/quicktime", "video/quicktime"},
   {"audio/mp4", "audio/x-m4a"},
   {"audio/x-m4a", "audio/x-m4a"},
   {"audio/mpeg", "audio/mpeg, mpegversion=(int)1"},
   {"audio/mp3", "audio/mpeg, mpegversion=(int)1"},
 };
 static char const *const sCodecs[9][2] = {
   {"avc1.42E01E", "video/x-h264"},
   {"avc1.42001E", "video/x-h264"},
   {"avc1.58A01E", "video/x-h264"},
   {"avc1.4D401E", "video/x-h264"},
   {"avc1.64001E", "video/x-h264"},
   {"avc1.64001F", "video/x-h264"},
   {"mp4v.20.3", "video/3gpp"},
   {"mp4a.40.2", "audio/mpeg, mpegversion=(int)4"},
   {"mp3", "audio/mpeg, mpegversion=(int)1"},
 };
 static char const * const sDefaultCodecCaps[][2] = {
   {"video/mp4", "video/x-h264"},
   {"video/quicktime", "video/x-h264"},
   {"audio/mp4", "audio/mpeg, mpegversion=(int)4"},
   {"audio/x-m4a", "audio/mpeg, mpegversion=(int)4"},
   {"audio/mp3", "audio/mpeg, layer=(int)3"},
   {"audio/mpeg", "audio/mpeg, layer=(int)3"}
 };
 GStreamerFormatHelper::GStreamerFormatHelper()
   : mFactories(nullptr),
     mCookie(static_cast<uint32_t>(-1))
 {
   if (!sLoadOK) {
     return;
   }
   mSupportedContainerCaps = gst_caps_new_empty();
   for (unsigned int i = 0; i < G_N_ELEMENTS(sContainers); i++) {
     const char* capsString = sContainers[i][1];
     GstCaps* caps = gst_caps_from_string(capsString);
     gst_caps_append(mSupportedContainerCaps, caps);
   }
   mSupportedCodecCaps = gst_caps_new_empty();
   for (unsigned int i = 0; i < G_N_ELEMENTS(sCodecs); i++) {
     const char* capsString = sCodecs[i][1];
     GstCaps* caps = gst_caps_from_string(capsString);
     gst_caps_append(mSupportedCodecCaps, caps);
   }
 }
 GStreamerFormatHelper::~GStreamerFormatHelper() {
   if (!sLoadOK) {
     return;
   }
   gst_caps_unref(mSupportedContainerCaps);
   gst_caps_unref(mSupportedCodecCaps);
   if (mFactories)
     g_list_free(mFactories);
 }
 static GstCaps *
 GetContainerCapsFromMIMEType(const char *aType) {
   /* convert aMIMEType to gst container caps */
   const char* capsString = nullptr;
   for (uint32_t i = 0; i < G_N_ELEMENTS(sContainers); i++) {
     if (!strcmp(ENTRY_FORMAT(sContainers[i]), aType)) {
       capsString = ENTRY_CAPS(sContainers[i]);
       break;
     }
   }
   if (!capsString) {
     /* we couldn't find any matching caps */
     return nullptr;
   }
   return gst_caps_from_string(capsString);
 }
 static GstCaps *
 GetDefaultCapsFromMIMEType(const char *aType) {
   GstCaps *caps = GetContainerCapsFromMIMEType(aType);
   for (uint32_t i = 0; i < G_N_ELEMENTS(sDefaultCodecCaps); i++) {
     if (!strcmp(sDefaultCodecCaps[i][0], aType)) {
       GstCaps *tmp = gst_caps_from_string(sDefaultCodecCaps[i][1]);
       gst_caps_append(caps, tmp);
       return caps;
     }
   }
   return nullptr;
 }
 bool GStreamerFormatHelper::CanHandleMediaType(const nsACString& aMIMEType,
                                                const nsAString* aCodecs) {
   if (!sLoadOK) {
     return false;
   }
   const char *type;
   NS_CStringGetData(aMIMEType, &type, nullptr);
   GstCaps *caps;
   if (aCodecs && !aCodecs->IsEmpty()) {
     caps = ConvertFormatsToCaps(type, aCodecs);
   } else {
     // Get a minimal set of codec caps for this MIME type we should support so
     // that we don't overreport MIME types we are able to play.
     caps = GetDefaultCapsFromMIMEType(type);
   }
   if (!caps) {
     return false;
   }
   bool ret = HaveElementsToProcessCaps(caps);
   gst_caps_unref(caps);
   return ret;
 }
 GstCaps* GStreamerFormatHelper::ConvertFormatsToCaps(const char* aMIMEType,
                                                      const nsAString* aCodecs) {
   NS_ASSERTION(sLoadOK, "GStreamer library not linked");
   unsigned int i;
   GstCaps *caps = GetContainerCapsFromMIMEType(aMIMEType);
   if (!caps) {
     return nullptr;
   }
   /* container only */
   if (!aCodecs) {
     return caps;
   }
   nsCharSeparatedTokenizer tokenizer(*aCodecs, ',');
   while (tokenizer.hasMoreTokens()) {
     const nsSubstring& codec = tokenizer.nextToken();
     const char *capsString = nullptr;
     for (i = 0; i < G_N_ELEMENTS(sCodecs); i++) {
       if (codec.EqualsASCII(ENTRY_FORMAT(sCodecs[i]))) {
         capsString = ENTRY_CAPS(sCodecs[i]);
         break;
       }
     }
     if (!capsString) {
       gst_caps_unref(caps);
       return nullptr;
     }
     GstCaps* tmp = gst_caps_from_string(capsString);
     /* appends and frees tmp */
     gst_caps_append(caps, tmp);
   }
   return caps;
 }
 static gboolean FactoryFilter(GstPluginFeature *aFeature, gpointer)
 {
   if (!GST_IS_ELEMENT_FACTORY(aFeature)) {
     return FALSE;
   }
   // TODO _get_klass doesn't exist in 1.0
   const gchar *className =
     gst_element_factory_get_klass(GST_ELEMENT_FACTORY_CAST(aFeature));
   if (!strstr(className, "Decoder") && !strstr(className, "Demux")) {
     return FALSE;
   }
   return gst_plugin_feature_get_rank(aFeature) >= GST_RANK_MARGINAL;
 }
 /**
  * Returns true if any |aFactory| caps intersect with |aCaps|
  */
 static bool SupportsCaps(GstElementFactory *aFactory, GstCaps *aCaps)
 {
   for (const GList *iter = gst_element_factory_get_static_pad_templates(aFactory); iter; iter = iter->next) {
     GstStaticPadTemplate *templ = static_cast<GstStaticPadTemplate *>(iter->data);
     if (templ->direction == GST_PAD_SRC) {
       continue;
     }
     GstCaps *caps = gst_static_caps_get(&templ->static_caps);
     if (!caps) {
       continue;
     }
     if (gst_caps_can_intersect(gst_static_caps_get(&templ->static_caps), aCaps)) {
       return true;
     }
   }
   return false;
 }
 bool GStreamerFormatHelper::HaveElementsToProcessCaps(GstCaps* aCaps) {
   NS_ASSERTION(sLoadOK, "GStreamer library not linked");
   GList* factories = GetFactories();
   /* here aCaps contains [containerCaps, [codecCaps1, [codecCaps2, ...]]] so process
    * caps structures individually as we want one element for _each_
    * structure */
   for (unsigned int i = 0; i < gst_caps_get_size(aCaps); i++) {
     GstStructure* s = gst_caps_get_structure(aCaps, i);
     GstCaps* caps = gst_caps_new_full(gst_structure_copy(s), nullptr);
     bool found = false;
     for (GList *elem = factories; elem; elem = elem->next) {
       if (SupportsCaps(GST_ELEMENT_FACTORY_CAST(elem->data), caps)) {
         found = true;
         break;
       }
     }
     if (!found) {
       return false;
     }
     gst_caps_unref(caps);
   }
   return true;
 }
 bool GStreamerFormatHelper::CanHandleContainerCaps(GstCaps* aCaps)
 {
   NS_ASSERTION(sLoadOK, "GStreamer library not linked");
   return gst_caps_can_intersect(aCaps, mSupportedContainerCaps);
 }
 bool GStreamerFormatHelper::CanHandleCodecCaps(GstCaps* aCaps)
 {
   NS_ASSERTION(sLoadOK, "GStreamer library not linked");
   return gst_caps_can_intersect(aCaps, mSupportedCodecCaps);
 }
 GList* GStreamerFormatHelper::GetFactories() {
   NS_ASSERTION(sLoadOK, "GStreamer library not linked");
 #if GST_VERSION_MAJOR >= 1
   uint32_t cookie = gst_registry_get_feature_list_cookie(gst_registry_get());
 #else
   uint32_t cookie = gst_default_registry_get_feature_list_cookie();
 #endif
   if (cookie != mCookie) {
     g_list_free(mFactories);
 #if GST_VERSION_MAJOR >= 1
     mFactories =
       gst_registry_feature_filter(gst_registry_get(),
                                   (GstPluginFeatureFilter)FactoryFilter,
                                   false, nullptr);
 #else
     mFactories =
       gst_default_registry_feature_filter((GstPluginFeatureFilter)FactoryFilter,
                                           false, nullptr);
 #endif
     mCookie = cookie;
   }
   return mFactories;
 }
 } // namespace mozilla

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content/media/gstreamer/GStreamerFormatHelper.cpp@97036ab72558 (annotated)

content/media/gstreamer/GStreamerFormatHelper.cpp