As part of my efforts with the ICOMOS-UK digital committee, I’ve started to collect metadata specifications relevant to heritage and culture.
My aim is to produce a superset with copious documentation and guides to subsets, so that all data is interchangeable. After all, if the Digital Production Partnership can join European and North American delivery standards for television in this way, isn’t anything possible?
Work begins at the link below. Suggestions are most welcome.
UPDATE: now uses an .xz archive: much more efficient compression, though users need the xz program to open the archive (or a utility such as 7zip).
UPDATE: Easier to open archive: now uses .zip files readable by Windows Explorer.
Please see the GitHub page for other updates.
Up-to-date Windows binaries of the FFmpeg multimedia suite and many other tools used here on a daily basis are now available for download. Some of these binaries are statically linked, but the larger programs are dynamically linked. They’re Windows 64-bit binaries, and are tested on Windows 10.
The best thing to do is read the README file in my GitHub repository:
https://github.com/Warblefly/MultimediaTools-mingw-w64/blob/master/README.md
The REAME above is more up-to-date. But, best of all, look inside the archive.
To use these binaries, just use the compressed installer. You’ll want the xz program (or an archiver such as 7zip) to decompress it before installation.
http://gallery.johnwarburton.net/MultimediaTools-mingw-w64-Open-source.exe.xz
The installer sets these (and other) environment variables for you:
FONTCONFIG_FILE=fonts.conf
FONTCONFIG_PATH=C:\Users\—YOUR-USER-NAME—\AppData\Local\fontconfig
FREI0R_PATH=C:\Program Files\ffmpeg\lib\frei0r-1
TESSDATA_PREFIX=C:\Program Files\ffmpeg\share\
TERMINFO=C:\Program Files\ffmpeg\share\terminfo
The entire set of scripts and patches used to generate these utilities is available as a Git source tree for anyone’s use or modification.
A GNU/Linux machine running Fedora is used to compile the binaries, using scripts that owe much of their writing to Roger Pack and the Zeranoe team. I have modified Roger’s script to include, additionally, some extra programs and libraries used here. It is fair to say that the script is almost entirely Roger’s, and I’m very grateful indeed for its development.
Built by the script and, therefore, included in the binary distribution are the following programs among others. In the case of FFmpeg, just about every optional library has been compiled in, including the libfdk_aac audio codec. In most cases, each library or piece of software has been retrieved from its latest development sources so it is very up-to-date. I try to test all binaries; if you find that one you’re using is unsuitable for production use, please contact me and I’ll attend to the problem, or send you an earlier version.
Download the FFmpeg, mpv, sox, x264, x265 and many other binaries here:
http://gallery.johnwarburton.net/MultimediaTools-mingw-w64-Open-source.exe
To clone the Git source tree, install Git and do this:
git clone https://github.com/Warblefly/MultimediaTools-mingw-w64.git
Browse the tree here:
https://github.com/Warblefly/MultimediaTools-mingw-w64
Everything is open source. In the cross-compilation script, there are links to every source code distribution. There is no charge for source code, and no charge for these binaries. Please read the licences.
The venerable FFmpeg audio/video tool can now package its output in Avid Op-Atom format directly, without always needing to have its output wrapped by the raw2bmx tool. This method is very fast and, crucially, can be used on any computer; not just the machine with your Avid licence. However, certain features of the Avid Op-Atom MXF wrapper are either not yet tested, or not available. For these features, I still advise using the bmxlib suite.
The advantage of this method is that video and audio data is very quickly imported into your Avid, at the full rate that the FFmpeg encoder can manage. Furthermore, your Avid will be using its native formats (e.g. DNxHD), rather than converting, say, XAVC on-the-fly with the AMA functions. The disadvantage is that metadata is quite messy, and lacking certain elements altogether, until I’ve figured out the full MXF Op-Atom metadata tags. Particularly, audio and video tracks are not linked into a single multi-track clip in an Avid bin: you must synchronise them yourself.
So, in this article, I will show you how to take video and/or audio from any format that FFmpeg will read, and output immediately MXF files in Avid-friendly codecs that Avid Media Composer’s “Media Tool” will pick up for you.
This post shows my earliest tests. I have not yet fully explored how to link files, or add other attributes, that raw2bmx adds or, indeed, Avid’s own import and capture tools add. However, the advantage of not using raw2bmx is a much faster import process.
Here, we start with a file of any format with a mono soundtrack, and output Avid DNxHD files at a resolution of 1280×720 and a bit-rate of 90Mbit/s, straight into the Avid MediaFiles directory, and ready for editing. This workflow assumes the frame-rate is for UK television, at 25fps, progressive encoding. I have not attempted to detect the number of audio channels in use, and therefore they are not encoded separately. This is, however, easy to achieve by using FFmpeg’s “asplit” audio filter and is detailed on the FFmpeg website.
ffmpeg -i "MY_CLIP.f4v" -vf scale=1280:720:lanczos -an -metadata project="MY PROJECT" -metadata material_package_name="MY CLIP" -b:v 90M -f mxf_opatom "M:\Avid MediaFiles\MXF\1\MY_CLIP_v1.mxf" -vn -metadata project="MY PROJECT" -ac 1 -ar 48000 -metadata material_package_name="MY CLIP" -f mxf_opatom "M:\Avid MediaFiles\MXF\1\MY_CLIP_a1.mxf"
Here is a break-down of that command line:
-i "MY_CLIP.f4v"
Here is the incoming clip.
-vf scale=1280:720:lanczos
We start with producing an output video MXF. Here, we ensure that the video is resized to the particular flavour of HD we’re editing in. In this case, we’re using 720p, and resizing using the algorithm I consider to be the best.
-an
The video output can contain only one track: video, in this case. This command instructs that the output must contain no audio. (Literally: “audio, none”)
-metadata project="MY PROJECT"
Here, we embed into the MXF metadata a value for “project”. This corresponds to your Avid project name. It is true that, upon analysing Avid’s own MXF files, the project name is contained within the metadata tag “project_name”, but my shorter tag appears also to work.
-metadata material_package_name="MY CLIP"
This is the name of your clip, as it will appear in your Avid bins and in the Media Tool.
-b:v 90M
Here, set the bit-rate. Using FFmpeg’s built-in DNxHD encoder, you can choose from several bit-rates, which FFmpeg’s error messages will be happy to tell you about if you set this wrongly. We don’t explicitly set the encoder itself, because FFmpeg does that for you: its default for this muxer is DNxHD.
-f mxf_opatom
This explicitly instructs FFmpeg to wrap your data in an Op-Atom MXF wrapper, ready for your Avid Media Composer to use.
"M:\Avid MediaFiles\MXF\1\MY_CLIP_v1.mxf"
Finally, for the video file, here is the output file. In this case, I’m putting it straight into Avid’s media file storage area on my ‘M’ drive, for media. There is a "_v1" suffix so that the file is marked as a video file, for my own ease of comprehension.
-vn
After the video output file is named, we start listing the options for encoding the audio file. This first option instructs FFmpeg to produce an audio-only MXF file, without a video track. (Literally: “video, none”)
-metadata project="MY PROJECT"
As with the video file, we embed into the metadata the name of the Avid project that needs this file.
-metadata material_package_name="MY CLIP"
As above, this is the clip name as it will appear in your Avid bins or Media Tool.
-ac 1
This is a quick-and-dirty kludge to mix down all the incoming audio tracks to a single track. In real life, you’ll want to use FFmpeg’s filter “asplit” to handle each incoming audio track separately. At the moment, this command line produces only a single audio file, mixing together all incoming tracks.
-ar 48000
With this command, we convert the sample-rate of the incoming audio to the standard sampling rate for television: 48,000 samples per second. Avid can, of course, convert sample rates on-the-fly while editing, but it is better to perform this work at the import stage to give Avid less to do when editing. Again, the codec itself (pcm_s16le, meaning linear PCM, 16-bit, little-endian) is not explicitly specified because FFmpeg sets this as the default for Avid import.
-f mxf_opatom
As before, this explicitly instructs FFmpeg to wrap your data in an Op-Atom MXF wrapper, ready for your Avid Media Composer to use.
"M:\Avid MediaFiles\MXF\1\MY_CLIP_a1.mxf"
Here is the filename for the audio output. In this example, I have placed it in the same directory as the video output created earlier in this command line. It is suffixed with "_a1" for my own ease of comprehension.
There are additional options associated with this FFmpeg muxer, which are listed here. I have not experimented with these, but can see that the -mxf_audio_edit_rate might need to be adjusted for non-European television or film work e.g. 30000/1001 for American television work, or 24 or 24000/1001 for 24fps film work. Also, you would probably want to set the -signal_standard bt601 or -signal_standard 1 for standard definition television work.
Muxer mxf_opatom [MXF (Material eXchange Format) Operational Pattern Atom]:
MXF-OPAtom muxer AVOptions:
Honesty is sometimes the best policy. When a marriage in infamously fickle Hollywood survives for sixty years — as it did for the protagonists of this documentary — the magic combination of perseverance, optimism and honesty is well-rewarded by an honest telling of the story. Director Daniel Raim manages this not only in his interviewing technique, pulling in genuine tributes from A-listers including Danny DeVito (executive producer of this film), but also more subtly in his approach to constructing what might otherwise be an uncritical paean to a highly talented couple.
Against considerable odds, amusingly and refreshingly related on camera by Lillian, mid-20th-century American society finally permitted Harold Michelson to marry her and take her across the nation to Hollywood, where Harold’s career as an artist was intermittently moving forward. His talent was picked-up in World War II, when his paintings created during his time as a gunner in aircraft were noticed by his commanding officer. The skill of combining art with the precision of understanding angles of view as seen through a gun-sight translated perfectly to the optics of Hollywood cameras. Throughout Harold’s career as a storyboard artist then as a production designer, directors could not get enough of his visualisations of scripts that allowed cinematographers quickly to create iconic scenes that have gone down in history. It is his idea that saw a young Dustin Hoffman viewed through the triangle created by Mrs. Robinson’s legs, and it was Harold who gave us the commanding of the Red Sea’s turbulent obedience in “The Ten Commandments”. In fact, from the 1950s to “Star Trek”, it is impossible to overstate the influence of his art — often uncredited — on our collective movie memories.
Lillian’s first steps into motherhood in her new life with Harold are painfully documented by her exposé of once-fashionable treatments available to her autistic child, while her feminism shines through as she fights against the confinement that 1950s mothers were expected to suffer in a male-dominated society. Her breakout discovery of a volunteering opportunity in a film studio research library was the start of another career of great influence in film-making: she became the unofficial dean of accurate research over many decades of famous movies. When a ballroom needed re-creating, Lillian’s library had the answers; when war scenes needed to be shot, her shelves of expertly-catalogued books showed exactly how to make each uniform and each prop. And when one studio would decide it no longer needed a comprehensive research library, Lillian’s reputation and persuasive skills would find it another home. If this lovingly-curated collection were to be broken-up in Lillian’s retirement, the film industry would lose its great Library at Alexandria.
The director’s good sense allows us to spend much time with both Harold (in well-respected archive footage) and Lillian, through whose attractive personalities many stories are told whose value last far beyond the end of the screening. Lillian’s observation of Tom Waits’ conversation as, “everything that came out him sounded like it should be a police confession”, and her delight in using her library to “float among the centuries” are nuggets that give hope to anyone beginning a career in a supporting role.
I will turn to the evidence of honesty, and its subtlety, in a moment. But first, Daniel Raim’s talent rises far above the genre of legacy films, in that he not only takes the trouble to discover the lessons that Harold and Lillian leave behind for all people who seek successful relationships, but also commissions sympathetic contributions from the cream of Hollywood’s directing and artistic talent who have lined up to be interviewed. Perhaps their motive is not entirely altruistic, because the strengths of the Michelsons, if rediscovered in younger form, would serve another two generations of film-makers well.
However, more than merely the icing on the visual cake is the work of modern-day artist Patrick Mate, whose frequent storyboard-style drawings of our protagonists’ real-life story resoundingly capture Lillian’s charm and personality, and simultaneously reflect Harold’s habits, practical nature and sometimes salty comments. This art is worth a book of its own.
Illustrating the honesty of the medium of film is difficult to manage subtly, but director Raim achieves this by allowing the cracks to show just sufficiently. He demonstrates the point that film-makers use artifice to suspend disbelief, but sometimes it must not interrupt the truth of the documentary. For example, jump-cuts are permitted in vision, so we are aware that sound-bites are constructed to allow reality to fit into the short spaces of our busy lives. The lavalier microphones are visible in-shot, rather than hidden beneath clothing, so we are reminded we are observers on a formal documentary film set, not merely guests invited to tea. Occasionally, the camera wobbles (it is easy to nudge a tripod in a small room), but the shot is not cut around; and footage taken from the Internet or from preview sources has not been replaced by the raw clips, possibly a measure to save thousands of dollars in budget without destroying the impact of the images. These are few and far between.
Although visual thrills are not the point of Raim’s documentary, there are enough great viewing and listening pleasures for an audience to be grateful for the honest manner of telling this story of hard work, hard talent, social history, and glimpses behind the edges of the proscenium arch. If storyboard artists, production designers and researchers have not been sufficiently acknowledged before, the top directors in this film might be starting to assuage their guilt on screen for all our pleasures in this documentary.
Ever wondered what the structure of your H.264 or other motion-predicted video stream is? With FFmpeg and a Unix (e.g. Linux, BSD, Cygwin) command line, you can find out.
ffprobe -show_frames -select_streams v:0 YOURFILE.EXT | grep pict_type | sed s/pict_type=// | tr -d '\n'
The output is something like this:
IPPPPPPPPPPPPPPPPIPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPIIPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPPIPPPPPPPPBPBBBPBBBPBBBPBBBPBBBPBBBPPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPPIBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPPBBBPBBBPBBBPBBBPBBPIBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBPBBPBPBPBPBPBPPPPPPPPBBBPBBBPBBBPBBBPBBBPBBBPPIIBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPBPIPPPBPPPPPPPPPPPPPPPPPPPPPPPPPPIIBPPBPBPPPBPBPBPBPPPBPBPBPBPBPPBPPBPPPBPBPPBPBPPPBPBPBPPBPPPBPBPBPPPIBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPBBBPIBBBPBBBPBBBPBBBPBBBPIBBPB...
An open-source codec project, x262, is attempting to bring the best of x264’s coding techniques to the encoding of MPEG2 video. X264 is a very popular, world-class open-source H.264 encoder.
The open-source multimedia utility FFmpeg has its own MPEG2 video encoder, but its quality falls far behind that of x264. However, whilst it is possible to incorporate x262 within FFmpeg, one then loses the ability to compile-in the most up-to-date x264 encoder.
This is because the x262 project generates a library and a commmand-line utility that replaces x264, and extends its capabilities. Unfortunately, x262 isn’t tracking the latest x264 encoder right now, so it is best compiled as a separate utility.
In my own compilation of FFmpeg and associated utilities, I have kept x262 and x264 separate, so this blog post will show how to encode for DVD using x262 and FFmpeg, fully retaining FFmpeg’s x264 capabilities, and encoding MPEG2 video at greater quality than FFmpeg’s native encoder for this.
Here is the command-line, as set up for a 25FPS production converting the video from a 24fps cinema file. This is for video only. You’ll use a separate command line for audio, then combine the two files, again using FFmpeg.
To explain:
Here is the complete command line just described. The output is an MPEG2 encoded video file, noticeably better in quality than a file of the same bandwidth produced by FFmpeg’s native MPEG2 encoder.
ffmpeg -r 25 -i 24FPS-FILM-FILE -vf scale=720:576:lanczos,smartblur=1.0:-0.4,colormatrix=bt709:bt601,setdar=16/9,setsar=64/45 -an -pix_fmt yuv420p -f yuv4mpegpipe - | x262 --fps 25 --demuxer y4m --mpeg2 --preset placebo --open-gop --tune film --keyint 12 --fake-interlaced --vbv-maxrate 8800 --vbv-bufsize 1835 --range tv --colorprim bt470bg --transfer bt470bg --colormatrix bt470bg --sar 16:9 --crf 1 -o FILENAME.vob -
This is a simple formula for low-cost conversion from PAL to NTSC material or, more accurately, 576/25i to 480/30i (or 30000/1001 fps to be exact). It uses field-blending, and there is no motion interpolation. Therefore, the method is quick to use on ordinary computers, but will not meet broadcast standards if you use it for a sustained length of time, or for a large part of your footage in a completed programme.
Prerequisties are AviSynth and FFmpeg with the AviSynth front end compiled in. You can get this, compiled for Windows 64-bit, from my website (see earlier blogs).
First, get your material into 25fps form. My source for this test was a DVD of a film, so the pictures are PsF (progressively scanned in an interlaced frame).
Use an AviSynth script like this, which I’ve called 25to2997.avs. I’ve used the FFmpegSource2 plugin to import the footage, but you can use anything else for input if you have it.
# Import the video. Disregard the sound for now.
FFmpegSource2("C:\Users\john_000\Videos\billsfilm\film-stereo.mp4")
# If this is a DV source, you'll want to switch the fields because PAL DV tapes
# record the fields the wrong way around i.e. Bottom Field First instead of
# Top Field First
# ComplementParity()
# Now deinterlace the pictures, producing a whole new frame for each field
Bob()
# ConvertFPS is AviSynth's function to convert frame rate by blending frames
# to achieve an illusion of continuous motion.
# The first number is the numerator, and the second the denominator, for fractional
# frame rates such as 29.97
ConvertFPS(60000, 1001)
# Now blend the frames back into interlaced fields
SeparateFields.SelectEvery(4,0,3)
Weave()
You now have interlaced, field-blended video at 29.97fps. If this is a PAL to NTSC standard-definition conversion, you’ll also need to change the size of the frames from 720×576 to 720×480.
This is where FFmpeg can perform the scaling and the encoding in one pass. Some other problems with the incoming video are corrected also. FFmpeg additionally brings in the audio from the original file, disregarding the video using the -map option. Here’s my command line for converting this widescreen PAL film into a widescreen NTSC file suitable for burning to a DVD.
So, what you have here is an FFmpeg command line that:
$ ffmpeg -i C:\Users\john_000\Documents\25to2997.avs -i C:\Users\john_000\Videos\billsfilm\film-stereo.mp4 -map 0:0 -map 1:1 -vf scale=720:480:lanczos:interl=1:out_color_matrix=bt601,smartblur=1.0:-0.6,setdar=16/9,setfield=tff -target ntsc-dvd -flags +ilme+ildct -bufsize 1835008 -b:v 5.5M -aspect 16:9 -g 15 -bf 2 -trellis 2 -cmp 3 -subcmp 3 -mbd 2 -me_method epzs -intra_vlc 1 -acodec ac3 -b:a 256k film-stereo-30fps.vob
Background: this is the injunction issued today to delay Network Rail’s alterations to the historic railway level crossing at Plumpton, pending planning approval. The works began without such approval.
In the County Court at Brighton
Claim number: B01BN100
Date: 20 October 2015
LEWES DISTRICT COUNCIL (Claimant) ref: LCD/JCS/4367
NETWORK RAIL INFRASTRUCTURE LTD (290587) (Defendant)
Before His Honour Judge Simpkiss sitting at the County Court at Brighton, William Street, Brighton, East Sussex, BN2 0RF
Upon hearing the Solicitor for the Claimant
To:
Network Rail Infrastructure Limited (290587)
Network Rail
One Eversholt Street
London
NW11 2DN
PENAL NOTICE
IF YOU THE WITHIN NAMED, NETWORK RAIL INFRASTRUCTURE LIMITED, BY ITS SERVANTS, AGENTS, OFFICERS OR OTHERWISE, DISOBEY THIS ORDER YOU MAY BE HELD TO BE IN CONTEMPT OF COURT AND LIABLE TO IMPRISONMENT OR FINED OR YOUR ASSETS SEIZED.
An application was made today 20th October 2015 by Lewes District Council Legal Services for the Applicant to HHJ Simpkiss who heard the ex parte application.
The judge read the witness statement of Andrew Hill listed in Schedule A.
As a result of the application IT IS ORDERED THAT Network Rail, by its servants, agents, officers or otherwise be forbidden from causing or permitting any works to be carried out without Listed Building Consent for the removal of the Plumpton Level Crossing Gates, or recovering any associated equipment or any mechanism for the operation of the gates situate at Station Road, Plumpton Green, until 4th November 2015 with permission to apply on 48 hours notice to vary or set aside this order.
COSTS OF THE APPLICATION
The Respondent shall pay the Applicant’s costs of this Application.
RETURN DATE
The Injunction is adjourned to 10am on the 3rd November 2015 at Lewes County Court, High Street, Lewes, BN7 1YB.
SCHEDULE A
The Judge read the following witness statement before making this Order:
Mr. Andrew Hill
One of the older native codecs in Avid, the Meridien motion-JPEG (MJPEG) codec, can be read by the FFmpeg utility and, therefore, converted into other more popular codecs and wrappers. However, there is a caveat concerning the luminance levels.
Meridien MJPEG files, whether wrapped as MXF or OMF, are signalled as full-range (0 – 255) files, but in fact they contain limited range (16 – 235) data, leaving room for super-white and super-black excursions. Their pixel format is read as yuvj422p but, in conversion to the usual yuv420p used for most consumer-oriented formats, the range is reduced yet again. So, this must be prevented.
Remember also that Avid’s Meridien files contain 16 blank lines at the top for VBI information. These need to be cropped.
There is a simple solution, using FFmpeg’s scaler. For SD 576-line files (“PAL” standard), include, early in the video filter chain, this:
scale=src_range=0:dst_range=1,crop=x=0:y:16:w=720:h=576
For 480-line (“NTSC” standard) files, use this:
scale=src_range=0:dst_range=1,crop=x=0:y=16:w=720:h=480
A full command line to convert a UK television picture might be:
$ ffmpeg -i VIDEO.mxf -i AUDIO.wav -vcodec libx264 -acodec libfdk_aac -vf scale=src_range=0:dst_range=1,crop=x=0:y=16:w=720:h=576,setdar=16/9 -aspect 16:9 VIDEO-AND-AUDIO-H264.mkv
While waiting for a file to convert, I typed help commands into the Avid console. These might be useful to some Avid users. There are many, many more.
The command every Avid user should know is subsys monpane debug, allowing precomputes and other unusual media to be loaded directly into the composer window, and used as edit sources.
These console commands are from Media Composer 8.2.2. Later versions may vary.
Access the console from the “Tools” menu, or by typing CTRL-6 or COMMAND-6.
\\OFFLINE_001\MyDirectory\Filename.mov
answer "How many beans make five?" with "One" OR "Two" OR "Five"
Disable3D
Avid MediaFiles to more accurately reflect the project name and clip name.