Today I present a (relatively) simple script that I wrote to convert videos to a format suitable for viewing on the Nokia N900. I know that there are many solutions for doing this, but none could handle subtitles (especially styled ones like SSA) well. Also I wanted the script to be scriptable, e.g. for converting a whole directory. Finally its a follow-up from my old n800-encode.sh script. So here is my solution to creating N900-friendly MP4:
The simplest way is to just run this command:
n900-encode.py -i some_video.avi -o n900_video.mp4
for more available options see the script below or use the included help function (-h)
#!/usr/bin/env python ########################################################################################### # n900-encode.py: Encode almost any Video to an Nokia N900-compatible format (h264,aac,mp4) # Disclaimer: This program is provided without any warranty, USE AT YOUR OWN RISK! # # (C) 2010 Stefan Brand <seiichiro@seiichiro0185.org> # # Version 0.2 ########################################################################################### import sys, os, getopt, subprocess, re, atexit from signal import signal, SIGTERM, SIGINT from time import sleep version = "0.2" ########################################################################################### # Default values, feel free to adjust ########################################################################################### _basewidth = 800 # Base width for widescreen Video _basewidth43 = 640 # Base width for 4:3 Video _maxheight = 480 # maximum height allowed _abitrate = 112 # Audio Bitrate in kBit/s _vbitrate = 22 # Video Bitrate, if set to value < 52 it is used as a CRF Value for Constant rate factor encoding _threads = 0 # Use n Threads to encode (0 means use number of CPUs / Cores) _mpbin = None # mplayer binary, if set to None it is searched in your $PATH _mcbin = None # mencoder binary, if set to None it is searched in your $PATH _m4bin = None # MP4Box binary, if set to None it is searched in your $PATH ########################################################################################### # Main Program, no changes needed below this line ########################################################################################### def main(argv): """Main Function, cli argument processing and checking""" # CLI Argument Processing try: opts, args = getopt.getopt(argv, "i:o:m:v:a:t:hf", ["input=", "output=", "mpopts=", "abitrate=", "vbitrate=", "threads=", "help", "force-overwrite"]) except getopt.GetoptError, err: print str(err) usage() input = None output = "n900encode.mp4" mpopts = "" abitrate = _abitrate vbitrate = _vbitrate threads = _threads overwrite = False for opt, arg in opts: if opt in ("-i", "--input"): input = arg elif opt in ("-o" "--output"): output = arg elif opt in ("-m" "--mpopts"): mpopts = arg elif opt in ("-a", "--abitrate"): abitrate = int(arg) elif opt in ("-v", "--vbitrate"): vbitrate = int(arg) elif opt in ("-t", "--threads"): threads = arg elif opt in ("-f", "--force-overwrite"): overwrite = True elif opt in ("-h", "--help"): usage() # Check for needed Programs global mpbin mpbin = None if not _mpbin == None and os.path.exists(_mpbin) and not os.path.isdir(_mpbin): mpbin = _mpbin else: mpbin = progpath("mplayer") if mpbin == None: print "Error: mplayer not found in PATH and no binary given, Aborting!" sys.exit(1) global mcbin mcbin = None if not _mcbin == None and os.path.exists(_mcbin) and not os.path.isdir(_mcbin): mcbin = _mcbin else: mcbin = progpath("mencoder") if mcbin == None: print "Error: mencoder not found in PATH and no binary given, Aborting!" sys.exit(1) global m4bin m4bin = None if not _m4bin == None and os.path.exists(_m4bin) and not os.path.isdir(_m4bin): m4bin = _m4bin else: m4bin = progpath("MP4Box") if m4bin == None: print "Error: MP4Box not found in PATH and no binary given, Aborting!" sys.exit(1) # Check input and output files if not os.path.isfile(input): print "Error: input file is not a valid File or doesn't exist" sys.exit(2) if os.path.isfile(output): if overwrite: os.remove(output) else: print "Error: output file " + output + " already exists, force overwrite with -f" sys.exit(1) # Start Processing res = calculate(input) convert(input, output, res, _abitrate, vbitrate, threads, mpopts) sys.exit(0) def calculate(input): """Get Characteristics from input video and calculate resolution for output""" # Get characteristics using mplayer cmd=[mpbin, "-ao", "null", "-vo", "null", "-frames", "0", "-identify", input] mp = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate() try: s = re.compile("^ID_VIDEO_ASPECT=(.*)$", re.M) m = s.search(mp[0]) orig_aspect = m.group(1) s = re.compile("^ID_VIDEO_WIDTH=(.*)$", re.M) m = s.search(mp[0]) orig_width = m.group(1) s = re.compile("^ID_VIDEO_HEIGHT=(.*)$", re.M) m = s.search(mp[0]) orig_height = m.group(1) s = re.compile("^ID_VIDEO_FPS=(.*)$", re.M) m = s.search(mp[0]) fps = m.group(1) except: print "Error: unable to identify source video, exiting!" sys.exit(2) # Calculate output resolution if float(orig_aspect) == 0 or orig_aspect == "": orig_aspect = float(orig_width)/float(orig_height) width = _basewidth height = int(round(_basewidth / float(orig_aspect) / 16) * 16) if (height > _maxheight): width = _basewidth43 height = int(round(_basewidth43 / float(orig_aspect) / 16) * 16) return (width, height, fps) def convert(input, output, res, abitrate, vbitrate, threads, mpopts): """Convert the Video""" # Needed for cleanup function global h264, aac # define some localvariables pid = os.getpid() h264 = output + ".h264" aac = output + ".aac" width = str(res[0]) height = str(res[1]) fps = str(res[2]) if (vbitrate < 52): vbr = "crf=" + str(vbitrate) else: vbr = "bitrate=" + str(vbitrate) # Define mencoder command for video encoding mencvideo = [ mcbin, "-ovc", "x264", "-x264encopts", vbr + ":bframes=0:trellis=0:nocabac:no8x8dct:level_idc=30:frameref=4:me=umh:weightp=0:vbv_bufsize=2000:vbv_maxrate=1800:threads=" + str(threads), "-sws", "9", "-vf", "scale=" + width + ":" + height + ",dsize=" + width + ":" + height + ",fixpts=fps=" + fps + ",ass,fixpts,harddup", "-of", "rawvideo", "-o", h264, "-nosound", "-noskip", "-ass", input ] if (mpopts != ""): for mpopt in mpopts.split(" "): mencvideo.append(mpopt) # Define mencoder command for audio encoding mencaudio = [ mcbin, "-oac", "faac", "-faacopts", "br=" + str(abitrate) + ":mpeg=4:object=2", "-ovc", "copy", "-mc", "0", "-vf", "softskip", "-of", "rawaudio", "-o", aac, "-noskip", input ] if (mpopts != ""): for mpopt in mpopts.split(" "): mencaudio.append(mpopt) # Define MB4Box Muxing Command mp4mux = [ m4bin, "-fps", fps, "-new", "-add", h264, "-add", aac, output ] # Encode Video print "### Starting Video Encode ###" try: subprocess.check_call(mencvideo) print "### Video Encoding Finished. ###" except subprocess.CalledProcessError: print "Error: Video Encoding Failed!" sys.exit(3) print "### Starting Audio Encode ###" try: subprocess.check_call(mencaudio) print "### Audio Encode Finished. ###" except subprocess.CalledProcessError: print "Error: Audio Encoding Failed!" sys.exit(3) # Mux Video and Audio to MP4 print "### Starting MP4 Muxing ###" try: subprocess.check_call(mp4mux) print "### MP4 Muxing Finished. Video is now ready! ###" except subprocess.CalledProcessError: print "Error: Encoding thread failed!" sys.exit(4) def progpath(program): """Get Full path for given Program""" for path in os.environ.get('PATH', '').split(':'): if os.path.exists(os.path.join(path, program)) and not os.path.isdir(os.path.join(path, program)): return os.path.join(path, program) return None def cleanup(): """Clean up when killed""" # Cleanup try: os.remove(h264) os.remove(aac) finally: sys.exit(0) def usage(): """Print avaiable commandline arguments""" print "This is n900-encode.py Version" + version + "(C) 2010 Stefan Brand <seiichiro0185 AT tol DOT ch>" print "Usage:" print " n900-encode.py --input <file> [opts]\n" print "Options:" print " --input <file> [-i]: Video to Convert" print " --output <file> [-o]: Name of the converted Video" print " --mpopts \"<opts>\" [-m]: Additional options for mplayer (eg -sid 1 or -aid 1) Must be enclosed in \"\"" print " --abitrate <br> [-a]: Audio Bitrate in KBit/s" print " --vbitrate <br> [-v]: Video Bitrate in kBit/s, values < 52 activate h264 CRF-Encoding, given value is used as CRF Factor" print " --threads <num> [-t]: Use <num> Threads to encode, giving 0 will autodetect number of CPUs" print " --force-overwrite [-f]: Overwrite output-file if existing" print " --help [-h]: Print this Help" sys.exit(0) # Start the Main Function if __name__ == "__main__": # Catch kill and clean up atexit.register(cleanup) signal(SIGTERM, lambda signum, stack_frame: exit(1)) signal(SIGINT, lambda signum, stack_frame: exit(1)) # Check min params and start if sufficient if len(sys.argv) > 1: main(sys.argv[1:]) else: print "Error: You have to give an input file at least!" usage()
Simply use the download link above the code to get the script and put it into your PATH.
If you have questions or suggestions, or if you find bugs feel free to use the comment section below or drop me an email.