Posts Tagged ‘youTube’

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Adding a YouTube show as a Podcast Feed

April 25, 2012

Vista busy cursor  The Sword & Laser podcast  is on the Frogpants network and features Tom Merritt and Veronica Belmont talking about sci-fi and fantasy books.  It was audio only for approaching 100 episodes, but recently a video variant was launched as part of Felicia Day’s Geek and Sundry YouTube channel.

I’m used to having the audio episodes delivered weekly to my Android phone over the air using the Doggcatcher podcast app, and hoped I might be able to get the video episodes in the same way. That is, I would like Doggcatcher to alert me automatically to a new episode and have it right there on the phone waiting for me to watch.  But the video episodes, being on YouTube, can only be streamed. They are not for download and not associated with any convenient RSS feed. On the face of it I can’t use Doggcatcher to help me at all. The best I can do is to subscribe on YouTube, to get email reminders. Worse, I am only offered the option to subscribe for the geekandsundry YouTube channel output as a whole, not just the Sword & Laser show.

The good news is that there is a solution of sorts.  Not a complete solution – there is no practical way around the inability to download the shows – but there is a way to use Doggcatcher to manage access to and consumption of the video episodes more or less in the same way as a conventional podcast.

The partial fix involves use of Yahoo Pipes. Yes, it still exists.  Thankfully, the implementation is trivial as explained below. And I didn’t even have to create a new Pipe –  I found an existing Pipe which does exactly what I need. The Pipe in question is “YouTube tags to RSS” by Eric. When the Pipe runs, it takes  a series of keywords as inputs, picks out only those YouTube videos having tags which match the keywords, and presents those videos as an RSS feed.

I found the first episode of the Sword & Laser show on YouTube and picked out all those tags which would not vary from episode to episode (I picked “Geek and Sundry”, “Sword and Laser”,” Veronica Belmont” and “Tom Merritt”), used them with the Pipe and selected “Get as RSS”. I used the URL of the resulting RSS feed to define a new feed on Doggcatcher.

This is the URL:

http://pipes.yahoo.com/pipes/pipe.run?_id=qLeMq8782xG2oyVwCB2yXQ&_render=rss&tags=Geek+and+Sundry+ Sword+and+Laser+Veronica+Belmont+Tom+Merritt

(If you copy and paste it make sure you eliminate any stray spaces)

All I can say is that it worked, and the exact same URL should work just as well for anyone. The tagging was clearly right because the only items in the feed were the pilot episode, first episode and bonus interview episode from the new Sword & Laser show, and the three episodes were added to the “downloaded video” queue where they appear together with the normal run of video podcasts.  The only difference is that the Sword & Laser video items are presented as stream only items, reflecting that they are on YouTube not actually downloaded to the phone.  When selected, they open automatically in the YouTube app and play.  This is nearly as good as if they were normal video podcasts except I have to be somewhere with connectivity before I can actually watch them.

To be clear, I’m not suggesting that this approach somehow magically turns a YouTube show into a genuine podcast. What it does is allow me to use a single app to capture the availability of new material relating to both both true podcasts and YouTube shows, and to launch them both from that same app. This is far more convenient than the alternatives.

The same idea would work with any YouTube show that can be uniquely identified through tags.  You don’t even need to go into Yahoo Pipes as such. You just need to provide the podcatcher app with the right URL.

Start with the URL below:

http://pipes.yahoo.com/pipes/pipe.run?_id=qLeMq8782xG2oyVwCB2yXQ&_render=rss&tags=tag1+tag2+tag3

Replace tag1, tag2, etc with the relevant tags to identify the show.  You can use as many tags as you need.  Just paste the edited URL into Doggcatcher, or other preferred podcatcher app, when setting up a new feed. When it updates the feed, the podcatcher will run the Pipe and pick up any new items.


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It’s okay to flash your stuff

February 4, 2008

Vista busy cursor There is nothing wrong with Flash as a format for Internet video. It is not, or should not be, synonymous with poor video quality.

It is though no great surprise that purists turn their nose up at it. Flash video is still the only show in town when it comes to on-line video because of the ubiquitousness of the Flash client for displaying in-browser embedded video. It has been popularised by the biggest video sharing websites such as YouTube and Google Video, and taken up by just about every other video website. But those websites are mainly targeting teenagers or otherwise purposes where immediacy and convenience take precedence over quality. Their key objective is that videos should start immediately and then play through without interruption for most users, including those with modest broadband connection speeds. That requires a low bitrate (ie less data to stream per unit of time), which is why quality is almost invariably shocking.

No wonder, then, that Flash video is associated with poor quality. But the real villain of the piece is the low bitrate used by YouTube et al, not the Flash technology itself.

You might argue that the compression technology available for use with Flash video is not up with the best and that is true. The codecs used in practice are Sorenson Spark H.263 or On2’s VP6, neither of which compare favourably with say H.264, but that does not mean they can’t produce perfectly good quality video. It all comes down to the bitrate. In general, with any codec you can vary the quality all the way up or all the way down by choice of bitrate. What marks out one codec as better than another, in the main, is that it can deliver the same or similar quality at significantly lower bitrate. The “poorer” codec can still achieve a target video quality provided it is given enough bitrate to play with.

Give Flash video enough bitrate and you will think you are watching a DVD via your browser. Clearly there are constraints. You would need a reasonably new computer with up to the minute processor, and a well above average broadband connection or the maximum streaming rate will not keep up with the bitrate required for playback and the video will keep stopping and starting.

The latest version of Flash can support H.264 video files natively but that technology has yet to penetrate the mass market. Combined with a trend of improving broadband connection speeds this will eventually do away with the ropey video which is so characteristic of YouTube today.

In the meantime, decent quality embedded video is perfectly possible by rolling your own Flash video files and hosting on a website such as blip.tv which accepts video files for upload in Flash format and does not place any restrictions on the file sizes, bitrate or indeed anything else.

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Video Website Datasheets #4: Google Video

January 16, 2008

Vista busy cursor Not surprisingly (given that Google owns YouTube) there is great similarity between Google Video and YouTube flash encoding.  What is surprising is that the bitrate on Google Video is even lower than on YouTube and therefore so is the quality.

Google Video

A. Output Quality

File Format: flv (Flash video)

Video Codec: Sorenson H.263 (FLV1)

Video Resolution: Resizes to 320 x 240

Video Bitrate: 283 kbps

Max. GOP: 60 frames

Frame-rate: As source (in this case 25fps)

Always re-encoded: No. See comments below

Audio Format: MPEG-2 Audio layer 3

Audio Channels: mono

Audio Sampling Rate: 22.05 kHz

Audio Resolution: 16 bit

B. Input Flexibility

Input File Formats include: avi, .asf, .mov, .wmv, .mpg, .mpeg, .mp4, .ra, .ram, .mod, .flv

Input Video Codecs include: H.264, H.263, MPEG 1/2/4, motion JPEG

Input Audio Codecs include: AAC, MP3

Max. Video Length: None

Max. File Size: 100Mb as single file or 1Gb using Desktop Uploader

C. Comments

  • The technical guidance on Google Video states that flash files cannot be uploaded, but they can. Files uploaded in flv format (FLV1 compliant – using Sorenson H.263 codec) appear not to be re-encoded, presumably subject to some overall maximum bitrate – limit not yet established.
  • Google Video has a much shorter max. GOP (Group of Pictures) setting than YouTube. In particular a maximum of 2 seconds (at 30 fps) between fully-rendered keyframes, as opposed to around 8s with YouTube.  That should help quality, but the test video produced distinctly lower quality than YouTube.  Partly this will be the result of the 12% lower overall video bitrate (283 kbps plays 320 kbps).  It may also reflect that much of this restricted bitrate may be getting used up rendering the more frequent keyframes given the lower max. GOP.

Summary of just the key data affecting video quality for all websites analysed can be found here.

For all Video Datasheet posts click here.

[GoogleVideo=http://video.google.co.uk/videoplay?docid=7191744957200400342&hl=en-GB]

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Video Website Datasheets #3: veoh

January 10, 2008

Vista busy cursor Hard on the heels of the technical analysis of vimeo, another video website which has acquired a reputation for quality – veoh. The results are interesting and surprising.

veoh

A. Output Quality

File Format: flv (Flash video)

Video Codec: Sorenson H.263 (FLV1)

Video Resolution: 540 x 406

Video Bitrate: 534 kbps

Max. GOP: 12 frames

Frame-rate: 12 fps

Always re-encoded: Yes

Audio Format: MPEG-2 Audio layer 3

Audio Channels: mono

Audio Bitrate: 64 kbps (CBR)

Audio Sampling Rate: 22.05 kHz

Audio Resolution: 16 bit

B. Input Flexibility

Input File Formats: AVI, MPEG, Quicktime, and Windows Media Video (not flv)

Max. Video Length: None

Max. File Size: None

C. Comments

  • The flv format is not accepted, so video files are always re-encoded.
  • Like YouTube, veoh forces a resolution change but to 540 x 406. That’s 2.85 times the number of pixels you get with YouTube’s titchy 320 x 240 resolution. The max. GOP (Group of Pictures) is only 12, eschewing YouTube’s trick of having gaps of many seconds between keyframes. All of this would lead you to expect significantly better quality than YouTube or for that matter vimeo, but at the cost of a far larger file size, yet the video bitrate is only a little higher than vimeo’s at 534 kbps. Something has to give to stop the bitrate getting out of hand – and it’s the frame-rate. Veoh forces a frame-rate of only 12 fps. The result is exceptionally good image quality, but slightly jerky playback. The impact of the poor frame-rate is noticeable.
  • So everyone needs a trick to keep bitrate under control. Vimeo uses a long GOP (large gap between keyframes), veoh goes for a low frame-rate instead.

    Summary of just the key data affecting video quality for all websites analysed can be found here.

    For all Video Datasheet posts click here.

    Vodpod videos no longer available.

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    Video Website Datasheets #2: vimeo

    January 7, 2008

    Vista busy cursor If YouTube was an obvious starting place for my series of investigations into video websites then the second should provide something of a contrast. I’ve chosen vimeo as a service with pretensions of better quality. Vimeo offers an HD service, although I only address the standard definition option here. I am treating HD as a specialist offering, not part of the mainstream.

    vimeo

    Updated 20 January 2008 

    A. Output Quality

    File Format: flv (Flash video)

    Video Codec: On2 VP6

    Video Resolution: As source ( maximum 504 x 404)

    Video Bitrate: 471 kbps

    Max. GOP: 300 frames

    Frame-rate: As source

    Always re-encoded: Yes

    Audio Format: mp3 (MPEG-1 Audio layer 3)

    Audio Channels: stereo

    Audio Bitrate: 64 kbps (CBR)

    Audio Sampling Rate: 44.1 kHz

    Audio Resolution: 16 bit

    B. Input Flexibility

    Input File Formats: asf, asx, avi, divx, dv, dvx, m4v, mov, mp4, mpeg, mpg, qt, wmv, 3g2, 3gp, 3ivx and 3vx (not flv)

    Max. Video Length: None

    Max. File Size: 500MB weekly upload limit

    C. Comments

    • The flv format is not accepted, so everything always has to be re-encoded regardless.
    • Higher bitrate than YouTube, more advanced video codec and retention of original resolution (within limits) all make for better video quality. Note that increasing the resolution is not accompanied by higher bitrate so may be self-defeating. If higher resolution is important it may be advisable to use vimeo’s HD option.
    • The On2 VP6 video codec performs better at low bitrates than the Sorenson Spark H.263 codec used by YouTube, but it only plays on Flash 8 and later.

    Summary of just the key data affecting video quality for all websites analysed can be found here.

    For all Video Datasheet posts click here.


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    Video Website Datasheets #1: YouTube

    January 4, 2008

    Vista busy cursor I’m starting a new series looking at video hosting websites, very much focusing on video quality. I’m approaching this from the point of view of someone wanting to embed video clips in blog posts, but not impressed by the quality of YouTube and looking for something better.

    I have already made some comparisons, but that was purely qualitative. To get anywhere we need to be rather more scientific, so I have been conducting technical analyses of the main video websites.

    In this and future posts in the Video Datasheets series I shall be publishing the results of my analyses in the form of technical datasheets and embedding the corresponding videos.

    My method is to start with a decent quality video which I use as a standard source for test purposes. I chose a 2m 50s video which started life as an AVI file in DV format (PAL, 720 x 576, 25fps, PCM audio 48kHz) and which has been encoded as H.264 (qp=26) in an mp4 container, 448 x 336, video bitrate 700 kbps, 25fps with AAC audio.

    For encoding details see method here. You can download the test .mp4 file here, from the vimeo website (Download Quicktime version 17.02MB).

    I have uploaded this video file to the various websites under review, which invariably re-encode it and convert to a Flash Video file (.flv). I play back the converted videos and retrieve the downloaded flv files from the browser cache for analysis using a range of software tools.

    I’m starting with YouTube. What else?

    YouTube

    A. Output Quality

    File Format: flv (Flash video)

    Video Codec: Sorenson H.263 (FLV1)

    Video Resolution: Resizes to 320 x 240

    Video Bitrate: 320 kbps

    Max. GOP: 250 frames

    Frame-rate: As source (in this case 25fps)

    Always re-encoded: No. See comments below

    Audio Format: MPEG-2 Audio layer 3

    Audio Channels: mono

    Audio Sampling Rate: 22.05 kHz

    Audio Resolution: 16 bit

    B. Input Flexibility

    Input File Formats include: MPEG, MOV, WMV, AVI, MP4, RA, RAM, ASF, 3GP, FLV

    Input Video Codecs include: H.263, H.264, VC1, DivX, XviD, SVQ3, DV

    Input Audio Codecs include: AAC, MP3

    Max. Video Length: 10 minutes

    Max. File Size: 100Mb as single file or 1Gb using YouTube Uploader

    C. Comments

    • Files uploaded in flv format (FLV1 compliant – using Sorenson H.263 codec) will not be re-encoded provided the overall bitrate (including audio) is strictly under 350 kpbs.
    • YouTube philosophy appears to be about immediacy and reliability of the user experience. Low bitrate is used to ensure that as far as possible video starts playing without delay and continues to play without interruption, even if user has modest broadband connection. YouTube have though recently (December 2007) suggested that from a future date users with higher bandwidth will be able to enjoy better quality (subject to source material).
    • YouTube videos have a long GOP (Group of Pictures) setting. That is, gap between key frames (which are encoded in full) may be as much as 250, corresponding to 10 seconds of video at 25fps. Intervening frames only hold information about changes in pixels from frame to frame, greatly reducing file size but at the expense of quality. For example, typical GOP settings for a DVD (encoded using MPEG2) would be 12 or 15. The long GOP has been a masterstroke for YouTube in terms of reducing bitrate, and the idea seems in general to have been copied by their competitors. The forced resize down to only 320 x 240 is also vital in bitrate control.

    Summary of just the key data affecting video quality for all websites analysed can be found here.

    For all Video Datasheet posts click here.

    [youTube=http://youtube.com/watch?v=l-jP9Wrqjcw]

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    Vista’s Video Nasties #2

    November 16, 2007

    Vista busy cursor I think I am closing in on a reliable, largely automated method of encoding DV video clips, for uploading to on-line video hosting sites such as Vimeo or youTube, in a way that yields decent quality.

    As mentioned in earlier posts in the Vista’s Video Nasties series, it has not exactly been plain sailing.

    I abandoned the XviD codec because it could be relied upon to crash Vista’s COM Surrogate process, and accessing an XviD file in a Windows folder could bring down and force a restart of Windows Explorer.

    For a while I switched to DivX, which did not seem to upset Vista’s delicate constitution as much. This at least allowed me to bring the COM Surrogate back within DEP‘s protective fold.

    I then turned my attention to H.264 in the search for better quality at lower file sizes, having decided that Vimeo, rather than youTube, was the way to go. Now for Mac users, producing H.264 encoded video is trivial. It drops out of iMovie without a second thought. For Windows users, the options are far more limited. That probably explains why Vimeo’s guidance on preparing video for upload is so Apple-centric.

    I wanted to experiment with H.264, but there is only one free option, namely x264. This is a command line program for encoding avi files into H.264 format. The encoding options are numerous and baffling, but at least there is a GUI program for it called meGUI which handles all the details. This includes the automatic creation of an “avs” file whose job it is to control a pre-processing tool called AviSynth which I am familiar with from my old DVD encoding experiences. AviSynth handles the resizing, deinterlacing and so forth which is required before passing the video to x264 for compression.

    It seemed too good to be true, and was too good to be true. I could open meGUI but whenever I tried to open up a video file for processing I was greeted with a Windows dialog box announcing the fact that “meGUI had stopped working”, whereupon meGUI closed.

    I spent a while looking for answers on the Internet, but was not able to find any. I could run meGUI on XP which is how I produced the H.264 encoded clip of Sunlight Rock (Gulangyu Island, China) which I then uploaded to Vimeo. But nothing could induce meGUI to run on Vista.

    The only advice I was able to find on the web was that it might start working if I reinstalled Vista from scratch. Really useful. Thanks, pal!

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