moved files to pypo dir

python_apps/pypo/media/update/replaygain.py

@@ -0,0 +1,152 @@
+from subprocess import Popen, PIPE
+import re
+import os
+import sys
+import shutil
+import tempfile
+import logging
+
+
+logger = logging.getLogger()
+
+def get_process_output(command):
+    """
+    Run subprocess and return stdout
+    """
+    logger.debug(command)
+    p = Popen(command, shell=True, stdout=PIPE)
+    return p.communicate()[0].strip()
+
+def run_process(command):
+    """
+    Run subprocess and return "return code"
+    """
+    p = Popen(command, shell=True)
+    return os.waitpid(p.pid, 0)[1]
+
+def get_mime_type(file_path):
+    """
+    Attempts to get the mime type but will return prematurely if the process
+    takes longer than 5 seconds. Note that this function should only be called
+    for files which do not have a mp3/ogg/flac extension.
+    """
+
+    return get_process_output("timeout 5 file -b --mime-type %s" % file_path)
+
+def duplicate_file(file_path):
+    """
+    Makes a duplicate of the file and returns the path of this duplicate file.
+    """
+    fsrc = open(file_path, 'r')
+    fdst = tempfile.NamedTemporaryFile(delete=False)
+
+    logger.info("Copying %s to %s" % (file_path, fdst.name))
+
+    shutil.copyfileobj(fsrc, fdst)
+
+    fsrc.close()
+    fdst.close()
+
+    return fdst.name
+
+def get_file_type(file_path):
+    file_type = None
+    if re.search(r'mp3$', file_path, re.IGNORECASE):
+        file_type = 'mp3'
+    elif re.search(r'og(g|a)$', file_path, re.IGNORECASE):
+        file_type = 'vorbis'
+    elif re.search(r'flac$', file_path, re.IGNORECASE):
+        file_type = 'flac'
+    else:
+        mime_type = get_mime_type(file_path)
+        if 'mpeg' in mime_type:
+            file_type = 'mp3'
+        elif 'ogg' in mime_type:
+            file_type = 'vorbis'
+        elif 'flac' in mime_type:
+            file_type = 'flac'
+
+    return file_type
+
+
+def calculate_replay_gain(file_path):
+    """
+    This function accepts files of type mp3/ogg/flac and returns a calculated
+    ReplayGain value in dB.
+    If the value cannot be calculated for some reason, then we default to 0
+    (Unity Gain).
+
+    http://wiki.hydrogenaudio.org/index.php?title=ReplayGain_1.0_specification
+    """
+
+    try:
+        """
+        Making a duplicate is required because the ReplayGain extraction utilities we use
+        make unwanted modifications to the file.
+        """
+
+        search = None
+        temp_file_path = duplicate_file(file_path)
+
+        file_type = get_file_type(file_path)
+        nice_level = '15'
+
+        if file_type:
+            if file_type == 'mp3':
+                if run_process("which mp3gain > /dev/null") == 0:
+                    command = 'nice -n %s mp3gain -q "%s" 2> /dev/null' \
+                            % (nice_level, temp_file_path)
+                    out = get_process_output(command)
+                    search = re.search(r'Recommended "Track" dB change: (.*)', \
+                                       out)
+                else:
+                    logger.warn("mp3gain not found")
+            elif file_type == 'vorbis':
+                command = "which vorbisgain > /dev/null  && which ogginfo > \
+                        /dev/null"
+                if run_process(command) == 0:
+                    command = 'nice -n %s vorbisgain -q -f "%s" 2>/dev/null \
+                                >/dev/null' % (nice_level,temp_file_path)
+                    run_process(command)
+
+                    out = get_process_output('ogginfo "%s"' % temp_file_path)
+                    search = re.search(r'REPLAYGAIN_TRACK_GAIN=(.*) dB', out)
+                else:
+                    logger.warn("vorbisgain/ogginfo not found")
+            elif file_type == 'flac':
+                if run_process("which metaflac > /dev/null") == 0:
+
+                    command = 'nice -n %s metaflac --add-replay-gain "%s"' \
+                            % (nice_level, temp_file_path)
+                    run_process(command)
+
+                    command = 'nice -n %s metaflac \
+                            --show-tag=REPLAYGAIN_TRACK_GAIN "%s"' \
+                            % (nice_level, temp_file_path)
+
+                    out = get_process_output(command)
+                    search = re.search(r'REPLAYGAIN_TRACK_GAIN=(.*) dB', out)
+                else: logger.warn("metaflac not found")
+
+    except Exception, e:
+        logger.error(str(e))
+    finally:
+        #no longer need the temp, file simply remove it.
+        try: os.remove(temp_file_path)
+        except: pass
+
+    replay_gain = 0
+    if search:
+        matches = search.groups()
+        if len(matches) == 1:
+            replay_gain = matches[0]
+        else:
+            logger.warn("Received more than 1 match in: '%s'" % str(matches))
+
+    return replay_gain
+
+
+# Example of running from command line:
+# python replay_gain.py /path/to/filename.mp3
+if __name__ == "__main__":
+    print calculate_replay_gain(sys.argv[1])