在deepstream中使用mp4文件，与rtsp类似，使用uridecodebin即可，（可见官方test.py文件）
def create_source_bin(index, uri):print("Creating source bin")# Create a source GstBin to abstract this bin's content from the rest of the# pipelinebin_name = "source-bin-%02d" % indexprint(bin_name)nbin = Gst.Bin.new(bin_name)if not nbin:sys.stderr.write(" Unable to create source bin \n")# Source element for reading from the uri.# We will use decodebin and let it figure out the container format of the# stream and the codec and plug the appropriate demux and decode plugins.uri_decode_bin = Gst.ElementFactory.make("uridecodebin", "uri-decode-bin")if not uri_decode_bin:sys.stderr.write(" Unable to create uri decode bin \n")# We set the input uri to the source elementuri_decode_bin.set_property("uri", uri)# Connect to the "pad-added" signal of the decodebin which generates a# callback once a new pad for raw data has beed created by the decodebinuri_decode_bin.connect("pad-added", cb_newpad, nbin)uri_decode_bin.connect("child-added", decodebin_child_added, nbin)# We need to create a ghost pad for the source bin which will act as a proxy# for the video decoder src pad. The ghost pad will not have a target right# now. Once the decode bin creates the video decoder and generates the# cb_newpad callback, we will set the ghost pad target to the video decoder# src pad.Gst.Bin.add(nbin, uri_decode_bin)bin_pad = nbin.add_pad(Gst.GhostPad.new_no_target("src", Gst.PadDirection.SRC))if not bin_pad:sys.stderr.write(" Failed to add ghost pad in source bin \n")return Nonereturn nbin
1、错误：
Error: gst-resource-error-quark: Invalid URI “/home/打码/打码.mp4”. (3): gsturidecodebin.c(1383): gen_source_element (): /GstPipeline:pipeline0/GstBin:source-bin-03/GstURIDecodeBin:uri-decode-bin
解决方案：
如果是文件系统中的mp4文件，记得加上file://前缀，如将输入设为file:///home/打码/打码.mp4。
2.错误：
Error: gst-stream-error-quark: memory type configured and i/p buffer mismatch ip_surf 2 muxer 3 (1): gstnvstreammux.c(643): gst_nvstreammux_chain (): /GstPipeline:pipeline0/GstNvStreamMux:Stream-muxer
解决方案：
不同类型的输入（如rtsp流和mp4文件）会产生不同的内存类型，为了解决这个问题需要保证连接到streammux的输入产生相同的内存类型（即都是ftsp或者都是mp4）。或者，也可以找到下面的代码：
streammux.set_property("nvbuf-memory-type", mem_type)
将其注释掉即可。