Transcoding with Theora 1.1/1.2 using ffmpeg2theora 0.28 or better for your own collection in Linux and HTML 5 video

Introduction



Today, I am going to be showing you how to encode with Theora 1.1 library using ffmpeg2theora 0.28 tool in Linux. Briefly, Theora is an open source video codec, that was donated to the Xiph.org foundation by On2 video in 2004 (The same company Google recently bought that consists of VP8 codec portion in WebM!). Attempts where made to include it in the HTML 5 standard in 2007, by members of the W3C. Those attempts were met with heavy resistance. One of the main problem with the earlier builds of Theora, was the perceived lack "quality" with encoder and how it was not on "par" with H.264 standard put forth by the MPEG consortium. Proponents of the H.264 video, claimed it was "inferior", because it did not have the same level of glossy sophistication and there were too many macro-blocking artifacts, due to a older codebase with no bi-predictive frames, such as those of the newer more advanced H.264 codec.

The lead developer and engineer of many Xiph.org projects "Monty", attempted to alleviate those problems by optimizing Theora gradually over a number of years using a number of "hacks" to improve the overall PSNR (Perceptual Signal Noise Ratio), which are used to measure the "perceived" quality of video codecs. As of the 0.28 release, Theora might not have the same quality as the high profile mode in H.264 or WebM, but it most certainly can match the baseline profile of H.264, which is used by many low-end AVCHD higher definition camera's! Therefore, you can use it as an alternative to WebM and H.264, due to the fact that it still looks good on a lot of transcoded SD and HD film clips. This is especially true with the recent "hacks", which deal with motion compensation in "dark contrast" area's, much more efficiently.

Think of Theora as yet another "open" alternative that can be used in different situations, rather then a project that should be shunned forever! Now that we have got the a substantial portion of History out of the way, I can begin to show you how to encode with either Theora 1.1/1.2 depending on what libraries the ffmpeg2theora [1] tool was compiled with in your distro! I will not show you how to compile custom builds yourself in this post. I will leave that part up to you, if you so wish to do so using alpha 1.2 libraries (I don't think it will be necessary and you should proceed at your own risk if you decide to go that route, but you are welcome to do so). Now I can begin to show you a number of command-line samples, that you can "tweak" to encode different clips for different types of input:

Common Usage: Encoding a group of MPEG-2 files filmed in MPEG-2 480i standard definition using a regular camcorder.



Example one: Transcoding and upsampling a group of MPEG-2 SD 480i files with a 4:3 aspect ratio to HD 720p using bicubic interpolation single pass "good" quality with a 5.1 surround track.

$ffmpeg2theora -v 10 -x 1280 -y 720 --resize-method bicubic --a 2 --deinterlace /home/USER/Videos/*.vob

Common Usage: Encoding a group of H.264 files filmed in high definition using an AVCHD camcorder.



Example two: Transcoding a group of H.264 files filmed in 720p with a 16:9 aspect ratio in high definition using an AVCHD camcorder using single pass "good" quality with 5.1 audio track.

$ffmpeg2theora -v 8 -x 1280 -y 720 -a 2 /home/USER/Videos/*.mp4

Common Usage: Encoding a group of H.264 files filmed in high definition using an AVCHD camcorder.



Example three: Transcoding a group of H.264 files filmed in 1080p with a 16:9 aspect ratio in high definition using an AVCHD camcorder using single pass "good" quality with 5.1 audio track.

$ffmpeg2theora -v 8 -x 1920 -y 1080 -a 2 /home/USER/Videos/*.mp4

Common Usage: Encoding a group of H.264 files filmed in high definition using a high definition webcam



Example four: Transcoding a group of H.264 files filmed in high definition 720p with a 4:3 aspect ratio using a high definition webcam using two pass "good" quality with a stereo soundtrack.

$ffmpeg2theora -v 8 -x 1280 -y 720 --two-pass -a 5 /home/USER/Videos/*.mp4

Those are just a few example of what you can do with Theora to encode material and place them within a webpage using HTML 5. Theora maybe "shunned" by many, but with newer releases comes slightly newer improvements. It's still quite popular on websites like Wikipedia and Internet Archive, therefore is not "loosing" any ground. Hopefully, this tutorial has provided you with some insight and motivation to begin encoding with Theora including some presets you can use! Enjoy. If you have any comments or question, and you can think of ways in which we can improve this tutorial do not hesitate to leave any comments or contact me. I will more then likely, be back with one more entry, before the week is over or next week, with a completely new entry of a different I.T topic from the "old" blog or new entry all together. Thanks for reading! Have a nice weekend. Take care!

Reference:



1. Theora. "ffmpeg2theora". http://v2v.cc/~j/ffmpeg2theora/ accessed 29 Nov 2012. 2011


Comments

Post a Comment

Popular posts from this blog

Encoding Opus files in Linux with opusenc for your own collection and HTML 5

Introduction Hello everyone! I am finally back to writing a new blog entry, after taking a very long month off. I hope all of my U.S readers had a great Fourth of July and are enjoying the summer. Today, I am going to be discussing and showing you how to encode with the the new IETF working audio codec called "Opus". Briefly, Opus is a combination of Xiph.org "CELT" codec and Skype's "SILK" codec combined into one project. It's a low-latency audio codec that was designed with "scalability" in mind and does things "fundamentally" different, even though it should sound the same if not better in different situations for speech and music. The project was finally completed this past winter and standardized and will be used in the new WebRTC project (for video conferencing), Skype (for video calls), and other companies that wish to use it. Google is NOW (as of July 2013) incorporating it, into the next generation codebase of WebM, wh
Read more

Encoding Vorbis files in Linux using oggenc for your own music collection and HTML 5

Introduction In today's topic, I will be showing readers different ways you can encode your music collection, if you just moved over to Linux from Windows using open source codecs! You do not have to encode your music files with Vorbis, due to the fact that MP3 is also supported in Linux and HTML 5, but there are some substantial benefits to doing in this day and age (at least from the perspective of an open-source nerd 8-)). The first is you don't have to worry about royalty's and licensing rates (especially if you are opening up a store for indie musicians). The second is that both objectively and subjectively Vorbis sounds substantially better and has been greatly improved with the help of dedicated "audiophiles" and the open source community, since it's first public release over a decade ago, way back in 2002. Today, I will show you some tips and tricks if you are new to encoding your music collection in Linux using the oggenc command-line program in Li
Read more

Transcoding H.264 files to Google's WebM format (VP8/Vorbis) in FFMPEG 0.6 or better using Linux for your own collection and HTML 5

Introduction Note: I want to stress that I DO NOT CONDONE using this guide to encode movies that are infringing upon international and local copyright laws (which include the WIPO Treaty in Europe and the DMCA in the U.S). These examples ASSUME your encoding material in which you OWN The RIGHTS too! I will not be held responsible for individuals that are using it to encode copyrighted material in those respective countries! If there are disputes about this or any other questions please DO NOT hesitate to contact me right away! Thank you. This week I am going to focus on showing you how to transcode videos to WebM, which is playable in both VLC and most HTML 5 compatible web browsers including Firefox, Chrome, Opera, and I.E 10! If you recall way back several months ago (if you had been following my old blog) I showed you some code snippets for how to encode directly to WebM using an older version of libvpx 0.6.1 code named "Bali", that came out last year, but has since be
Read more