我有一个简单的程序，它逐帧从视频流中读取 GdkPixbufs。问题是内存使用量以每秒大约 300-400MB 的速度增长！这样我的 8GB RAM 很快就用完了。Valgrind / Cachegrind 没有指向我任何地方，所以也许这是 gstreamer 中的错误？
// compiled with:
// g++ -std=c++11 `pkg-config --cflags gstreamer-1.0 gdk-pixbuf-2.0` test_c.cpp -o test `pkg-config --libs gstreamer-1.0 gdk-pixbuf-2.0`
// usage:
// ./test -i video_file.mpg # MUST BE SAME FORMAT AS TEST IMAGE DATA PROVIDED IN main.cpp BELOW!!!
#include <stdio.h>
#include <stdlib.h>
#include <string>
#include <memory.h>
#include <vector>
#include <gst/gst.h>
#include <gdk-pixbuf/gdk-pixbuf.h>
#include <gst/controller/controller.h> // GstPlugin
#include <glib.h>
#define APP_NAME "test"
typedef struct
{
int nWidth;
int nHeight;
GdkColorspace ColorSpace;
int nBitsPerChannel;
int nChannels;
gboolean bHasAlpha;
int nRowStride;
gsize nByteLength;
guchar *pPixels;
} tSImage;
typedef std::vector<tSImage *> tImagesList;
GMainLoop *g_pMainLoop;
gchar *g_pszInFile;
GstElement *g_pPipeline;
GstElement *g_pElementVideoSink;
tImagesList g_ImagesList;
// ----------------------------------------------------------------------------
void EatLotsOfMemory(tSImage *pFrame)
// ----------------------------------------------------------------------------
{
// access to pixel buffers leads to huge memory consumption!
for(tImagesList::const_iterator iImage=g_ImagesList.begin(); iImage!=g_ImagesList.end(); iImage++)
{
unsigned long test = 0;
for(int nPos=0; nPos < pFrame->nHeight * pFrame->nRowStride; nPos++)
{
if(pFrame->pPixels[nPos] == (*iImage)->pPixels[nPos])
{
test++;
}
}
}
}
///////////////////////////////////////////////////////////////////////////////
// ----------------------------------------------------------------------------
bool ParsePixBufMessage(const GValue *val)
// ----------------------------------------------------------------------------
{
gint64 pos;
if(gst_element_query_position(g_pPipeline, GST_FORMAT_TIME, &pos))
g_print("Time: %" GST_TIME_FORMAT " \r", GST_TIME_ARGS(pos));
GdkPixbuf *pPixBuf = GDK_PIXBUF(g_value_dup_object(val));
tSImage Image;
Image.ColorSpace = gdk_pixbuf_get_colorspace(pPixBuf);
Image.nChannels = gdk_pixbuf_get_n_channels(pPixBuf);
Image.bHasAlpha = gdk_pixbuf_get_has_alpha(pPixBuf);
Image.nBitsPerChannel = gdk_pixbuf_get_bits_per_sample(pPixBuf);
Image.nWidth = gdk_pixbuf_get_width(pPixBuf);
Image.nHeight = gdk_pixbuf_get_height(pPixBuf);
Image.nRowStride = gdk_pixbuf_get_rowstride(pPixBuf);
Image.nByteLength = gdk_pixbuf_get_byte_length(pPixBuf);
Image.pPixels = gdk_pixbuf_get_pixels(pPixBuf);
EatLotsOfMemory(&Image);
g_object_unref(pPixBuf);
return true;
}
// ----------------------------------------------------------------------------
static gboolean BusCallback(GstBus *bus, GstMessage *msg, gpointer data)
// ----------------------------------------------------------------------------
{
switch(GST_MESSAGE_TYPE(msg))
{
// ------------------------------------------------------------------------
case GST_MESSAGE_EOS:
g_print("End of stream\n");
g_main_loop_quit(g_pMainLoop);
break;
// ------------------------------------------------------------------------
case GST_MESSAGE_ERROR:
{
gchar *debug;
GError *error;
gst_message_parse_error(msg, &error, &debug);
g_free(debug);
g_printerr("Error: %s\n", error->message);
g_error_free(error);
g_main_loop_quit(g_pMainLoop);
}
break;
// ------------------------------------------------------------------------
case GST_MESSAGE_ELEMENT:
{
if(GST_MESSAGE_SRC(msg) != GST_OBJECT_CAST(g_pElementVideoSink))
break;
const GstStructure *pMsgStructure = gst_message_get_structure(msg);
if(!gst_structure_has_name(pMsgStructure, "preroll-pixbuf") && !gst_structure_has_name (pMsgStructure, "pixbuf"))
break;
const GValue *val = gst_structure_get_value(pMsgStructure, "pixbuf");
if(val != NULL)
if(!ParsePixBufMessage(val))
g_main_loop_quit(g_pMainLoop);
}
break;
// ------------------------------------------------------------------------
default:
// g_print("msg %u: \"%s\"\n", GST_MESSAGE_TYPE(msg), GST_MESSAGE_TYPE_NAME(msg));
break;
}
return TRUE;
}
// ----------------------------------------------------------------------------
static void on_decoder_pad_added(GstElement *element, GstPad *pPad, gpointer data)
// ----------------------------------------------------------------------------
{
GstElement *decoder = (GstElement *) data;
GstCaps *pCaps = gst_pad_get_current_caps(pPad);
GstStructure *pCapsStructure = gst_caps_get_structure(pCaps, 0);
if(pCapsStructure != NULL)
{
const gchar *pszStructName = gst_structure_get_name(pCapsStructure);
if(g_str_has_prefix(pszStructName, "video"))
{
GstPad *pSinkpad = gst_element_get_static_pad(decoder, "sink");
if(pSinkpad != NULL)
{
GstPadLinkReturn Ret = gst_pad_link(pPad, pSinkpad);
if(Ret != GST_PAD_LINK_OK)
g_print("failed to link pad! (%d)", Ret);
gst_object_unref(pSinkpad);
}
}
}
}
// ----------------------------------------------------------------------------
void Decode(gchar *pszFile)
// ----------------------------------------------------------------------------
{
g_pMainLoop = g_main_loop_new(NULL, FALSE);
g_pPipeline = gst_pipeline_new("pipeline");
GstBin *pBin = GST_BIN(g_pPipeline);
GstElement *pElementSource = gst_element_factory_make("filesrc", "file-source");
GstElement *pElementDecoder = gst_element_factory_make("decodebin", "decoder");
GstElement *pElementConvert = gst_element_factory_make("videoconvert", "convert"); // "autovideoconvert" ?
g_pElementVideoSink = gst_element_factory_make("gdkpixbufsink", "pixbufsink"); // "imagefreeze" ? "autovideosink" ?
// g_pElementVideoSink = gst_element_factory_make("fakesink", "fakesink"); // test
if(pElementSource == NULL || pElementDecoder == NULL || pElementConvert == NULL || g_pElementVideoSink == NULL)
{
g_print("Failed to create elements\n");
return;
}
// configure elements
g_object_set(G_OBJECT(pElementSource), "location", pszFile, NULL);
g_object_set(G_OBJECT(g_pElementVideoSink), "qos", FALSE, "max-lateness", (gint64) - 1, "sync", false, "async", false, NULL);
// set up pipeline
gst_bin_add(pBin, pElementSource);
// add elements to pipeline
gst_bin_add_many(pBin, pElementDecoder, pElementConvert, g_pElementVideoSink, NULL);
// link the elements together
gboolean bOK;
bOK = gst_element_link(pElementSource, pElementDecoder);
bOK &= gst_element_link(pElementConvert, g_pElementVideoSink);
if(!bOK)
{
g_print("Failed to link elements\n");
return;
}
// link decoder's video-stream pad dynamically
g_signal_connect(pElementDecoder, "pad-added", G_CALLBACK(on_decoder_pad_added), pElementConvert);
// add message handler
GstBus *pBus = gst_element_get_bus(g_pPipeline);
guint bus_watch_id = gst_bus_add_watch(pBus, BusCallback, NULL /* app data */);
// set the pipeline to "playing" state
gst_element_set_state(g_pPipeline, GST_STATE_PLAYING);
// iterate
g_main_loop_run(g_pMainLoop);
// out of the main loop, clean up nicely
gst_element_set_state(g_pPipeline, GST_STATE_NULL);
gst_object_unref(pBus);
gst_object_unref(GST_OBJECT(g_pPipeline));
g_source_remove(bus_watch_id);
g_main_loop_unref(g_pMainLoop);
}
///////////////////////////////////////////////////////////////////////////////
// main
///////////////////////////////////////////////////////////////////////////////
// ----------------------------------------------------------------------------
bool ParseOptions(int argc, char *argv[])
// ----------------------------------------------------------------------------
{
GError *err = NULL;
GOptionContext *ctx;
GOptionEntry entries[] =
{
{ "input", 'i', G_OPTION_FLAG_FILENAME, G_OPTION_ARG_FILENAME, &g_pszInFile, "input video file", NULL },
{ NULL }
};
ctx = g_option_context_new("- " APP_NAME);
g_option_context_add_main_entries(ctx, entries, NULL);
g_option_context_add_group(ctx, gst_init_get_option_group());
if(!g_option_context_parse(ctx, &argc, &argv, &err))
{
g_print("Failed to initialize: %s\n", err->message);
g_error_free(err);
g_option_context_free(ctx);
return false;
}
if(g_pszInFile == NULL)
{
g_print("%s", g_option_context_get_help(ctx, TRUE, NULL));
g_option_context_free(ctx);
return false;
}
g_option_context_free(ctx);
return true;
}
// ----------------------------------------------------------------------------
int main(int argc, char *argv[])
// ----------------------------------------------------------------------------
{
gst_init(&argc, &argv); // must be called here
if(!ParseOptions(argc, argv))
return EXIT_FAILURE;
// !!! test image data - must match video input format !!!
for(int i=0; i<3; i++)
{
tSImage *pImage = new tSImage();
pImage->nWidth = 720;
pImage->nHeight = 576;
pImage->ColorSpace = GDK_COLORSPACE_RGB;
pImage->nBitsPerChannel = 8;
pImage->nChannels = 3;
pImage->bHasAlpha = false;
pImage->nRowStride = pImage->nWidth * pImage->nChannels;
pImage->nByteLength = 0;
pImage->pPixels = new guchar[pImage->nHeight * pImage->nRowStride];
memset(pImage->pPixels, (unsigned char) rand(), pImage->nHeight * pImage->nRowStride);
g_ImagesList.push_back(pImage);
}
Decode(g_pszInFile);
// clear images list
for(tImagesList::iterator iImage=g_ImagesList.begin(); iImage!=g_ImagesList.end(); iImage++)
{
if((*iImage)->pPixels != NULL)
delete [] (*iImage)->pPixels;
delete (*iImage);
}
g_ImagesList.clear();
return EXIT_SUCCESS;
}