Merge pull request #5546 from avalonmediasystem/wav_tmpfile

Store http sources as tempfiles on disk to avoid issue with ffmpeg blocking

app/services/waveform_service.rb

@@ -82,15 +82,27 @@ def get_normalized_peaks(uri)
     factor = max_peak.zero? ? 1 : res / max_peak.to_f
     peaks.map { |peak| peak.collect { |num| (num * factor).to_i } }
   ensure
-    Process.wait(wave_io.pid) if wave_io&.pid
+    if wave_io.is_a? Tempfile
+      wave_io.close
+      wave_io.unlink
+    else
+      Process.wait(wave_io.pid) if wave_io&.pid
+    end
   end
 
   def get_wave_io(uri)
     headers = "-headers $'Referer: #{Rails.application.routes.url_helpers.root_url}\r\n'" if uri.starts_with? "http"
     normalized_uri = uri.starts_with?("file") ? Addressable::URI.unencode(uri) : uri
     timeout = 60000000 # Must be in microseconds. Current value = 1 minute.
-    cmd = "#{Settings.ffmpeg.path} #{headers} -rw_timeout #{timeout} -i '#{normalized_uri}' -f wav -ar 44100 - 2> /dev/null"
-    IO.popen(cmd)
+    tmpfile = Tempfile.new if uri.starts_with?("http")
+    cmd = "#{Settings.ffmpeg.path} #{headers} -rw_timeout #{timeout} -i '#{normalized_uri}' -f wav -ar 44100 #{tmpfile&.path || "-"} 2> /dev/null"
+    Rails.logger.debug("Getting wav file for waveform generation using ffmpeg command: #{cmd}")
+    if tmpfile
+      Kernel.system(cmd)
+      tmpfile
+    else
+      IO.popen(cmd)
+    end
   end
 
   def gather_peaks(wav_file)

spec/services/waveform_service_spec.rb

@@ -67,11 +67,16 @@
 
     context "http file" do
       let(:uri) { "http://domain/to/video.mp4" }
-      let(:cmd) {"#{Settings.ffmpeg.path} -headers $'Referer: http://test.host/\r\n' -rw_timeout 60000000 -i '#{uri}' -f wav -ar 44100 - 2> /dev/null"}
+      let(:cmd) {"#{Settings.ffmpeg.path} -headers $'Referer: http://test.host/\r\n' -rw_timeout 60000000 -i '#{uri}' -f wav -ar 44100 /tmp"}
+
+      before do
+        allow(Kernel).to receive(:system).and_return(nil)
+      end
 
       it "should call ffmpeg with headers" do
-        service.send(:get_wave_io, uri)
-        expect(IO).to have_received(:popen).with(cmd)
+        io = service.send(:get_wave_io, uri)
+        expect(Kernel).to have_received(:system).with(start_with(cmd))
+        expect(io).to be_a Tempfile
       end
     end