• Encoding Q&A

    Here are the top encoding questions that we typically hear. Feel free to let us know if you have any more questions:

    Q) How do Hollywood studios get such good quality at very high compression? EG getting 8GB on a 4.7 GB disk at HD quality?

    A: This is a common question and the answer actually comes way before the video is ever compressed. Always consider the source first! Hollywood studios typically spend a great deal of time and money on great cameras, lighting, and audio equipment. After that, they enhance the video quality with filters to improve brightness, contrast, and color. With a great looking source file that has very little if any noise, compression is relatively simple. Most people do not have the budget or talent in house to shoot Hollywood quality source footage. For those of you who do not, you can try and compensate with noise removal, brightness and contrast filters, deinterlacers, and other filters that can compensate for lower quality cameras, bad lighting, and poor mics, that create noisy audio and video that looks washed out.

    Q) Is the H264 Baseline Profile without fees, also after the test period, ending 2016? Regardless of paid or free content?

    A: Sorenson Media’s tools include encoding fees only. Decoding fees are managed by individual players and actual playback fees must be managed by the person or persons displaying the content. All of these fees are explained in detail at http://www.mpegla.com/main/programs/AVC/Pages/FAQ.aspx

    Q) What is the best codec, quality wise to upload to YouTube (Squeeze 5)?

    A: The answer today is H.264 and really crank up the data rate. However, VP8 is a new codec that comes close, and may catch up.

    Q) What are the advantages of dedicated video server for streaming?

    A: It really comes down to resources and the number of requests put on the server. A dedicated video server is only needed when there is a big demand upon the resources on the server.

    Q) Hardware vs software encoding differences in quality or other advantages?

    A: Typically, software encoding offers higher quality than hardware encoding. This is and has been the case because hardware is usually focused on delivery speed over quality. While this is true, the discrepancy between quality between the two has been becoming less evident over the last few years.

    Q) What are your plans to incorporate segmenting of files for HTTP Adaptive Bitrate Streaming into your encoding tools?

    A: We truly see adaptive bit rate as one of the leading ways that video will be delivered in the future and we have already put plans in place to build support for it. The main difference between Sorenson and what others are offering is that Sorenson Media will make it easy to create and deliver adaptive bit rate to your customer and viewership.

    Q) What are recommended bit-rates for file delivery over the Internet and to mobile devices? IS there a general range, say 300kbps, 600kbps, 1Mbps, etc.?

    A: It REALLY depends on the audiences connection. I would not go less the 500kbps for today’s internet connections and I would consider going up as high as 1200kbps.

    Q) We have all heard about problems of streaming video online for a variety of heterogeneous devices, displays,networks, speeds, qualities, frame rates, manufacturers,etc! Still why is there a disinterest of the industry in using the H.264 SVC encoding, as it brings to the table solutions for the problems above. Why isn't H.264-SVC finding widespread deployment yet, despite its advantages!

    A: I understand your question and frustration. The answer is that the their are many companies and organizations that want and need to keep video and the parts that are needed to play it back, proprietary, in order to control it and make money. I would love to see this change and think that it will do so over time, but the leaders are fighting to maintain control for themselves by either not adopting standards, or manipulating the standards to fit their needs and differentiate from the rest.

    Q) At this point our business is only using Squeeze for encoding. Our customers request video for use on their website ony (not streaming servers)...what are your recommendations for formats to use for general viewing? (Our clients generally ask for WMV files because their customers view the videos on PCs.) Do you offer software for this purpose; if so what is it and how much does it cost?

    A: I would focus on using H.264 as an MP4 file. The Windows Media player and every other competitive player on the market can play back this file type.

    Q) What is a common bit-rate and resolution for an enterprise environment?

    A: I would recommend between 768–1200kbps

    Q) How do you see HTML5 effecting me as an encoder and how it will effect the end consumer's applications?

    A: HTML5 is simply a new and upcoming presentation and playback technology like Flash. It is an open standard that is likely to get widespread adoption over the next few years.

    Q) Do you have a product that will work cross platform ex H264 (+) and HTML5 and so on.

    A: All of our encoding solutions provide H.264 output that conforms to HTML5.

    Q) How about encoder settings for web streaming playback? Flash is what I use, VP6 350k 12 fps, de-interlaced.

    A: Sorenson Squeeze has presets built in for Sorenson 360 that are perfect for web streaming. Use CBR method and keep your data-rates at levels that your customers internet connection can keep up with. 768–1200Kbps is a great range but you may have to go as low as 50Kbps depending on your audience's internet connection.

    Q) Here at the State Department we deal with much of the world's most impoverished regions that have some of the slowest bandwidth but at the same time rapidly expanding use of mobile. What advice do you have for delivering video to those with super slow web access?

    A: Know your audience and what they are experiencing. This may take some research but you need to find out what speeds they are connecting at and what they are viewing from and then deliver accordingly.

    Q) Whats the difference between a codec and container, how can you tell if the codec is the container.

    A: A container is the file exertion and can include .avi, .mov, .mp4, etc. Codecs are the COmpression DECompression algorithms that do the actual work. Essentially a Container is a box and the codecs are the goods inside. Although
    some containers appear to have the same name as the codec (.mp4, etc) it isn't necessarily the case. For example, a .mp4 file might have the x264 codec or the main concept h.264 codec.

    Q) when making a one hour bluray disk which codec do you recommend, mpeg2 or h.264 thanks

    A: the answer depends on a variety of issues. Is your consuming audience going to have newer players, or should you shoot for a wider range? If you want to reach a greater audience MPEG-2 is a better choice as it is more widely compatible with older player. The other question is, what is the time frame? Speed is a major issue with h.264, the reason it looks so great is because the math behind the scenes is much more complicated than mpeg2, so it takes much longer to encode. 1 hour of mpeg2 on a fast machine might take 2 hours to encode, where with h.264 it would be as much as 6-8.

    Q) How do you Secure your content on the web?

    A: There are currently a myriad of ways to take video from the web, especially simple progressive download video. The best way to secure your video on the web is to deliver it in a streaming format, preferable RTMPE or Encrypted Rich Transport Media Protection. RTMPE streaming protect your content in two ways, 1. Since the file is not downloaded locally to a computer, the file ins't easily picked up, as is the case with progressive download. 2. The stream is encrypted so even with stream download tools the file cannot be saved without the encryption key.

    Q) advantage/disadvantage to use X264 (open source tool?) to encode into final video.

    A: The Advantages to using X.264 is that it is a decent codec as far as quality and encoding speed are concerned, also it is “Open Source” so many people encode using free tools. The Disadvantages to using X.264 is that it is not the best codec for quality and the learning curve for the tools that use X.264 is extreme. When we ran quality comparison tests here at Sorenson Media it took so much time to figure out the tools and start encoding that we felt that hurdle alone was reason enough to consider not using it.

    Q) is it bad to use H.264 video muxed with MP3 audio, or should i be using AAC audio? can MP3 support surround sound also?

    A: AAC is a better audio codec but MP3 can be used with H.264 video, there are no real advantages though and you would still have to deal with licensing issues through Fraunhofer. MP3 does not support Surround Sound or 5.1 Channel Audio in Squeeze.

    Q) what is advantage/disadvantage to use from .MP4 VS .MKV containers?

    A: In general the Advantage of using .MKV over .MP4 is that .MKV supports multiple Audio tracks and multiple Subtitle tracks. The Disadvantage to using .MKV is that is isn’t as widely supported. In Squeeze, which doesn’t yet support .MKV, the advantage to using .MKV over .WebM for VP8 Video would be the support of Markers and Metadata when using the .MKV container. Squeeze 6.5 will support .MKV and .WebM containers for using the VP8 Video Codec, if you would like to learn more about .WebM and .MKV support in Squeeze please email us at SqueezeBeta@sorensonmedia.com

    Q) is it okay to use DVD as source, and encode into standard def 1MB VBR, or should i be asking for better source for this? does it make a different at my 1MB VBR rates?

    A: In our experience using DVD as a source poses a few problems, quality and source format being the biggest issues. VOB files are supported in Squeeze but there are so many different flavors and combinations that problems can arise when using this format as your source file. When speaking to quality remember that video encoding is lossy meaning that working from a DVD source encoded at 6000Kbps already has had data removed and you are now compressing the file even further, removing more data and lowering the image quality. DVD’s as a source file can be done but it makes the process more difficult.

    Q) Please expand on issues with Pixel Aspect Ratio versus Display Aspect Ratio.

    A: Display aspect ratio is built into the video meta data letting the player know that it needs to be played in a specific Aspect Ratio whereas Pixel Aspect Ratio is a pixel by pixel Aspect Ratio.

    Q) What does inverse telecine mean?

    A: First; Telecine is the process of transferring motion picture film into electronic form, or the machine used in this process. Telecine enables a motion picture, captured originally on film, to be viewed with standard video equipment, such as televisions, video cassette decks or computers. So Inverse Telecine is the process where video editing tools reverse telecine process. Basically inverse telecine brings back movie's original frame rate from NTSC's 29.97fps to 24fps.

    Q) What are some codecs that work well enough to not require 2 pass?

    A: Using the 2-Pass Encoding Method is almost always a good idea but you can sometimes get away without using it on source material that doesn’t have a lot of scene changes or fast moving content. Only consider skipping the 2-Pass if you are using a newer codec such as MainConcept H.264, VP6, or VP8. VP8 is not yet supported in Squeeze but if you are interested please send an email to SqueezeBeta@sorensonmedia.com

    Q) What's a GOP?

    A: A Group Of Pictures (GOP) consists of all the pictures that follow a GOP header before another GOP header. The GOP layer allows random access because the first picture after the GOP header is an intra-picture that means that it doesn't need any reference to any other picture. The GOP layer is optional, i.e. it's not mandatory to put any GOP header in the bit stream. In the header there is also the time code of the first picture of the GOP to be displayed.

    Q) Please explain WebM.

    A: WebM is a container used for VP8 video with Vorbis audio created by Google for consideration in the HTML5 specifications. Squeeze 7 supports outputting this video file type. To learn more please visit the WebM Project Page http://www.webmproject.org/about/faq/

    Q) If you want to stream at a low bit-rate (256K), what is the ideal key frame and frame rate to maintain quality?

    A: I would recommend 15 frames per second at that low data rate with key frames every 10 seconds.

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