Close #47 - Show error message when ffmpeg not found, fix ffmpeg test

src/echonest/remix/support/ffmpeg.py

@@ -77,14 +77,18 @@ def ffmpeg(infile, outfile=None, overwrite=True, bitRate=None,
         log.info(command)
 
     (lin, mac, win) = get_os()
-    p = subprocess.Popen(
-            command,
-            shell=False,
-            stdin=(None if filename else subprocess.PIPE),
-            stdout=subprocess.PIPE,
-            stderr=subprocess.PIPE,
-            close_fds=(not win)
-    )
+    try:
+        p = subprocess.Popen(
+                command,
+                shell=False,
+                stdin=(None if filename else subprocess.PIPE),
+                stdout=subprocess.PIPE,
+                stderr=subprocess.PIPE,
+                close_fds=(not win)
+        )
+    except OSError as err:
+        if err.errno == 2:
+            raise_not_found_error()
 
     if filename:
         f, e = p.communicate()
@@ -199,12 +203,16 @@ def settings_from_ffmpeg(parsestring):
                     chans = 1
     return freq, chans
 
-ffmpeg_install_instructions = """
-en-ffmpeg not found! Please make sure ffmpeg is installed and create a link as follows:
-    sudo ln -s `which ffmpeg` /usr/local/bin/en-ffmpeg
-Alternatively, import echonest.remix.support.ffmpeg and modify ffmpeg.FFMPEG to name
-the appropriate binary.
-"""
+def raise_not_found_error():
+    ffmpeg_install_instructions = """
+    en-ffmpeg not found! Please make sure ffmpeg is installed and create a link as follows:
+        sudo ln -s `which ffmpeg` /usr/local/bin/en-ffmpeg
+    Alternatively, import echonest.remix.support.ffmpeg and modify ffmpeg.FFMPEG to name
+    the appropriate binary.
+    """
+
+    raise RuntimeError(ffmpeg_install_instructions)
+
 
 def ffmpeg_error_check(parsestring):
     "Looks for known errors in the ffmpeg output"
@@ -217,8 +225,6 @@ def ffmpeg_error_check(parsestring):
                    "Could not find codec",  # corrupted, incomplete, or otherwise bad file
                     ]
     for num, line in enumerate(parse):
-        if "command not found" in line or FFMPEG+": not found" in line:
-            raise RuntimeError(ffmpeg_install_instructions)
         for error in error_cases:
             if error in line:
                 report = "\n\t".join(parse[num:])

tests/test_ffmpeg.py

@@ -5,8 +5,8 @@
 
 Run the tests like this:
     python test_ffmpeg.py
-    
-If you want to test that your version of ffmpeg can handle a particular file, 
+
+If you want to test that your version of ffmpeg can handle a particular file,
 (like if you're planning on analyzing OggVorbis files and want to make sure
 your ffmpeg can decode them), run like this:
     python test_ffmpeg.py my_crazy_audio_file.mp47
@@ -16,46 +16,41 @@
 import sys
 import tempfile
 
-from echonest import audio
+from echonest.remix.support import ffmpeg
 
 def main():
     """Run some tests"""
     if len(sys.argv) > 1:
         input_filename = sys.argv[1]
     else:
-	    input_filename = 'input_file.mp3'
+        input_filename = 'input_file.mp3'
     test_en_ffmpeg_exists(input_filename)
     test_round_trip(input_filename)
 
 def test_en_ffmpeg_exists(input_filename):
     """Don't do any conversion, just see if en-ffmpeg, the command used
     by Remix, is installed."""
-    result = audio.ffmpeg(input_filename, overwrite=False, verbose=True)
-    audio.ffmpeg_error_check(result[1])
+    ffmpeg.ffmpeg(input_filename, overwrite=False, verbose=True)
 
 def test_round_trip(input_filename):
     """Convert the input file to a wav file, then back to an mp3 file."""
-    result = audio.ffmpeg(input_filename, overwrite=False, verbose=True)
-    audio.ffmpeg_error_check(result[1])
-    sampleRate, numChannels = audio.settings_from_ffmpeg(result[1])
-
     temp_file_handle, temp_filename = tempfile.mkstemp(".wav")
-    result = audio.ffmpeg(input_filename, temp_filename, overwrite=True, 
-        numChannels=numChannels, sampleRate=sampleRate, verbose=True)
-    audio.ffmpeg_error_check(result[1])
-
+
+    result = ffmpeg.ffmpeg(input_filename, outfile=temp_filename, overwrite=True,
+        verbose=True)
+    sampleRate, numChannels = result
+
     temp_filesize = os.path.getsize(temp_filename)
     print 'temp file size: %s bytes' % temp_filesize
-    
+
     output_filename = 'output_file.mp3'
-    result = audio.ffmpeg(temp_filename, output_filename, overwrite=True, 
+    result = ffmpeg.ffmpeg(temp_filename, output_filename, overwrite=True,
         numChannels=numChannels, sampleRate=sampleRate, verbose=True)
-    audio.ffmpeg_error_check(result[1])
-
+
     if temp_file_handle is not None:
         os.close(temp_file_handle)
         os.remove(temp_filename)
-    
+
     input_filesize = os.path.getsize(input_filename)
     output_filesize = os.path.getsize(output_filename)
     difference = output_filesize - input_filesize
@@ -67,5 +62,5 @@ def test_round_trip(input_filename):
         print 'Ok!'
 
 if __name__ == '__main__':
-	main()
+    main()