The Linux Journey
Getting Started - What is Linux? - Installing Ubuntu Site Navigation - Home - About - Recent News - Downloads Account - Login - Register - Logout Search Other Links	Latest News Converting Videos to iPod Format March 27th, 2008 I'm going to start off by giving a warning that this may get a little complicated. What we are going to do in this tutorial is download a couple programs, and then make a script that uses the functionality of these programs to produce a video file that the iPod can read and play. I'm going to write this tutorial as if you were using Ubuntu, but I'm sure it will work with other distributions of Linux as well. First of all we are going to need a program called ffmpeg. Unfortunately for us, ffmpeg doen't come fully enabled due to legal reasons, so we're going to have to build it from source. Heres the tutorial I wrote on the subject: Installing a Fully Enabled ffmpeg. Next we need to download the script we are going to use. Download pypodconv and save it where ever you want it. Please note that I did not create this script. If you would rather create this script yourself then copy the following into a blank file and name it pypodconv. #!/usr/bin/python # # Python ffmpeg frontend for iPod-compatible video ripping # By John Dong <jdong@ubuntu.com> # Licensed under the GPL # import sys import os from optparse import OptionParser import time class VideoInfo: def __init__(self,w=640,h=480): self.w=w self.h=h def scale(self,max_width,max_height): if self.w > max_width: r=float(max_width)/self.w self.w=max_width self.h=int(self.h * r) if self.h > max_height: r=float(max_height)/self.h self.h=max_height self.w=int(self.w * r) if self.w % 2: self.w -= 1 if self.h % 2: self.h -= 1 def __repr__(self): return "<VideoInfo: %sx%s>"%(self.w, self.h) class UnsupportedCodecError: pass class AVEncoder: def __init__(self,input_file,output_file, maps=None): self.vcodec="h264" self.acodec="aac" self.twopass=True self.vbitrate=200 self.abitrate=96 self.resolution=parseVideoInfo(input_file,maps) self.threads=1 self.input_file=input_file self.output_file=output_file self.maps=maps def doscale(self,to_low): if to_low: self.resolution.scale(320,240) else: self.resolution.scale(640,480) def getvParams(self): if self.vcodec == 'h264': return "-v 1 -vcodec h264 -b %s -bt 175 -refs 2 -loop 1 -deblockalpha 0 -deblockbeta 0 -parti4x4 1 -partp8x8 1 -partb8x8 1 -brdo 1 -me_range 21 -chroma 1 -max_b_frames 0 -level 30 -g 300 -keyint_min 30 -sc_threshold 40 -rc_eq 'blurCplx^(1-qComp)' -qcomp 0.7 -qmax 51 -max_qdiff 4 -i_quant_factor 0.71428572 -b_quant_factor 0.76923078 -rc_max_rate 1500 -rc_buffer_size 244 -cmp 1 -s %sx%s" % (self.vbitrate, self.resolution.w, self.resolution.h) elif self.vcodec == 'xvid': return "-vcodec xvid -maxrate 2500 -b %s -qmin 3 -qmax 5 -bufsize 4096 -g 300 -s %sx%s" % (self.vbitrate, self.resolution.w, self.resolution.h) elif self.vcodec == 'mpeg4': return "-vcodec mpeg4 -maxrate 2500 -b %s -qmin 3 -qmax 5 -bufsize 4096 -g 300 -s %sx%s" % (self.vbitrate, self.resolution.w, self.resolution.h) else: raise UnsupportedCodecError, "Unsupported video codec "+self.vcodec def getaParams(self): if self.acodec == "aac": return "-acodec aac -ab %s -ar 48000 -ac 2" % self.abitrate else: raise UnsupportedCodecError, "Unsupported audio codec "+self.acodec def getCommands(self): def getmaps(self,video_only=False): m=self.maps if not m: m=[0,1] if video_only: return " -map 0.%s " % m[0] else: return reduce(str.__add__,[" -map 0.%s " % i for i in m]) cmds=[] if self.twopass: cmds= ['ffmpeg -y -i "%s" -f mp4 -pass 1 -subq 1 -threads %s -an %s %s /dev/null' % (self.input_file, self.threads, self.getvParams(), getmaps(self,True)), 'ffmpeg -y -i "%s" -f mp4 -pass 2 -subq 6 -threads %s %s %s %s "%s"' % (self.input_file, self.threads, self.getvParams(), self.getaParams(), getmaps(self), ".tmp.mp4"), 'rm -f ffmpeg2pass-0.log x264_2pass.log'] else: cmds= ['ffmpeg -y -i "%s" -f mp4 -threads %s -subq 6 %s %s %s "%s"' % (self.input_file, self.threads, self.getvParams(), self.getaParams(), getmaps(self), ".tmp.mp4")] cmds+=['rm -f .tmp.new.mp4', 'MP4Box -add .tmp.mp4 .tmp.new.mp4', 'mv .tmp.new.mp4 "%s"' % self.output_file, 'rm -f .tmp.mp4', 'rm -f .tmp.new.mp4'] return cmds def parseVideoInfo(input_file, want_maps=None): def trunc_numeral(expr): if expr.isdigit(): return expr for index in range(len(expr)): if not expr[index].isdigit(): if index == 0: break else: return expr[:index] raise ValueError, "Could not determine stream number from: %s" % expr output=os.popen('ffmpeg -i "%s" 2>&1' % input_file).readlines() vstreams={} astreams={} for line in output: if line.strip().startswith("Stream"): streamno=int(trunc_numeral(line.split()[1][:-1].split('.')[-1])) #Gets the stream number, i.e. Stream #0.X if line.split(':')[1].strip() == "Video": #Video stream --parse out VideoInfo try: (w,h)=[int(i) for i in line.split(',')[2].split("x")] vstreams[streamno]= VideoInfo(w,h) except ValueError: pass except IndexError: pass else: #Audio Stream, just split out string descriptor of audio astreams[streamno]= line.split(':')[2].strip() if not vstreams or not astreams: print "Could not find at least one video and one audio stream" print "Sorry, I do not support this kind of file." raise UnknownCodecError if want_maps: try: astreams[want_maps[1]] # Just try to access to see if it's a valid stream return vstreams[want_maps[0]] except KeyError: raise "Unable to find wanted video/audio stream. Sure your --maps arguments exist, and/or your video file is valid?" else: if len(vstreams) > 1 or len(astreams) > 1: print "====WARNING====" print "Video Streams:" for key in vstreams.keys(): print " %s: %s" % (key, vstreams[key]) print "Audio Streams:" for key in astreams.keys(): print " %s: %s" % (key, astreams[key]) print "There are multiple video or audio streams (LISTED ABOVE) in your source file." print "This could be because your source file has audio tracks in several languages," print "Or your file is just plain weird." print print "Either way, by default this script will most likely choose the" print "FIRST video stream (0) and the FIRST audio stream (1)" print "If this is not the behavior you want, then use the -m (--map) option" print "to override. For example, if you want Video Stream 0 and Audio Stream 2," print "you would use --map 0,2" print "===============" print "Press CTRL+C to abort... Will continue in 15 seconds..." time.sleep(15) return vstreams[0] def numcpus(): return int(os.popen('cat /proc/cpuinfo | grep "^processor" | wc -l').read()[:-1]) parser=OptionParser() parser.add_option("-i","--input", help="Source file to encode" , action="store",type="string",dest="input") parser.add_option("--sd","--320","--standard-definition",help="Encode to Standard Definition (that is, 320xNNN, native iPod screen resolution) [DEFAULT]", action="store_true", dest="hd", default=False) parser.add_option("--hd","--640","--high-definition",help="Encode to High Definition (that is, 640xNNN, maximum iPod-supported resolution", action="store_false", dest="hd", default=True) parser.add_option("-c", "--codec", help="Video Codec: h264 [DEFAULT], xvid, or mpeg4.", action="store", dest="codec") parser.add_option("-o","--output", help="Output file, with file extension.", action="store",type="string", dest="output") parser.add_option("-m","--map", help="Specify video and audio stream to encode. For example, --map 0,2 maps Video Stream 0 and Audio Stream 2 to the output file. This program will warn you when this is necessary to use", action="store", dest="maps") parser.add_option("-b", "--vbitrate", help="Video Bitrate, in kbit/s. (default: 200)", action="store", dest="vbitrate", default=str("200")) parser.add_option("-p", "--passes", help="Number of passes. (Default: 2)", action="store",dest="passes") parser.add_option("-t", "--threads", help="Number of threads. (Default: CPUs*1.5)", action="store",dest="threads") parser.add_option("-s","--simulate","--dry-run",help="Simulate (print out commands, but don't run)", action="store_true", dest="simulate", default=False) parser.usage = "%prog -i input -o output [other_options]\n\ With no other options will create 2-pass 320xNNN h.264 @ 200kbit/s" (options, args) = parser.parse_args() if not (options.input and options.output): parser.print_help() sys.exit(-1) if options.maps: try: options.maps=[int(i) for i in options.maps.split(',')] except: print "Invalid -m/--maps. Should be a comma-separated list of two numbers. (i.e. --maps 0,1)" sys.exit(-5) enc=AVEncoder(options.input,options.output,options.maps) enc.doscale(options.hd) if(options.threads): enc.threads=int(options.threads) else: enc.threads=int(numcpus()*1.5) enc.vbitrate=int(options.vbitrate) if(options.passes): try: enc.twopass = (int(options.passes) == 2) except: pass if options.codec: enc.vcodec=options.codec for command in enc.getCommands(): if options.simulate: print command elif os.system(command) != 0: print "Encode step FAILED: ",command sys.exit(-2) if not options.simulate: print "Job finished successfully!" print "Output:",options.output You also need to make sure this script has execution privileges. In Ubuntu (and possibly other distributions) you do this by right-clicking the file and going to properties. Go to the Permissions tab and check the box that says "Allow Executing file as program. The last thing we need to do before that script will work is download gpac. You can download it through Synaptic, or simply type this in the terminal: sudo apt-get install gpac Alright, now that everything is set I just need to explain how the script works. I'll explain it by giving an example of my set up. Lets say I'm in my home folder, I saved pypodconv in a folder called Documents, and the file I want to convert is called movie.avi and is in a folder called Videos. To convert this video I would go to the terminal and type: Documents/pypodconv -i Videos/movie.avi -o movie.mov --hd As you can see, whatever is after the "-i" is the input and whatever is after the "-o" is the file we want to create. The "--hd" is optional, but what it does is create a higher resolution video for better quality. Now all you can do is sit back and wait for the video to be encoded. This takes a good bit of time, especially if you used the "--hd" option. One last thing I would like to add is that if you saved pypodconv to your home folder instead of to a folder called Documents you would replace the last command with this: ./pypodconv -i Videos/movie.avi -o movie.mov --hd This tells the computer that the file pypodconv is in the same folder you are in. Well thats the end of the tutorial. Feel free to bookmark this page for future reference in case you ever forget how to use the script. Comments Type Your Comment Here. You must be logged in to comment.