A Different Tune

Youtube is the undisputed leader of the video-sharing game with world-wide market share of 66%. Everyone wants a piece of that market, and there are lots of new players entering the business. To attract users they have to offer something different, something compelling.

This post shares my experience with two providers: Youtube and Viddler. There are significant differences between the two, and some of these are not obvious. Check out the feature-by-feature comparison. Read on for the details, or cut to the chase.

My Experience

I recently attended some events organised by the local web industry association, including a Barcamp and Webjam. I took my camera to record some of the action, and then went looking for a video sharing site to host my videos. Youtube might seem an obvious choice but my videos were around 30 minutes each, well over Youtube's 10 minute limit. Looking briefly at a couple of alternatives, I settled on Viddler because it seemed to have some innovative features in its player, including the ability to attach comments and tags to at particular times in the video.

I recorded my video on a JVC MG-505AA (Everio) hard disk camera. This stores video natively in DVD-quality 16:9 MPEG-2 format (video: MPEG2 720x576 25fps 8400Kbit/s, audio: MP3 48000Hz stereo 256Kbit/s). Some of the original files were over 1Gb each which is well over any hosting site's upload limits so I had to do some initial transcoding just to get the files onto the site. After some tweaking I got what I considered a good balance between size and quality, using DIVX/MPEG-4 at 512x288 with an overall data rate of 512Kbit/s (384K video, 128K audio).

I uploaded my files to Viddler, but wasn't happy with the quality of the audio. It was obviously overcompressed - I could hear a "warbly" background noise and the high frequencies were distorted. On top of that, the video looked too "blocky". One of my videos was chosen as feature video for the day, so I contacted the Viddler folks and asked how to improve the audio quality. We tried a few things, including encoding at a higher audio bit-rate but the problem remained, at least to my ear. Feeling discouraged, I tried Youtube and found that the results were better. After a few days I began to wonder what had gone wrong, so I decided to investigate by downloading and comparing the encoded files.

Viddler resampled the audio to 44KHz stereo. This has a data rate of 16 (bits per sample) x 2 (stereo) * 44100 (samples per second) = 1380Kbits/s, so compressing it to 48Kbit/s is a factor of almost 30 times. On the other hand, Youtube resampled to 22KHz mono. This requires only 16 * 1 * 22050 = 335Kbits/s, so compressing it to 64Kbit/s is a factor of only 5.5 times. Less compression means better quality.

By preprocessing my audio to 22050Hz mono, I found that I could get reasonable quality on Viddler. Likewise, I could improve the video quality by reducing the video resolution. But my experience showed that you have to (1) be lucky or (2) know what you're doing to get a good result. Viddler is flexible regarding video format but does not offer sufficient information to make good decisions. Customers will just go elsewhere if the result is bad. I did, and I know that others have too. If you'd like to compare for yourself, check out my original videos on both Viddler and Youtube.

Later I raised the issue on Viddler's support forum. The staff acknowledged the problem and promised to offer some specific advice in their FAQ. They also hinted at an "advanced encoding" feature which would allow the user finer control over the way Viddler encodes files. I'm looking forward to seeing how this works.

Feature Comparison

Probably the most significant difference between Youtube and Viddler is their encoding strategy. Files are converted to a fixed bit-rate. Youtube resamples the video to give a consistent quality at this bit-rate. Viddler does not resample the video, so the quality depends on how well the input video matches the output bit-rate.

Here are some details of other differences.

Format and Encoding

Youtube encodes to a fixed format. Video is 320x240 25fps FLASH video, using H.263 at around 250Kbit/s. Audio is 22050Hz mono using MP3 at 64Kbit/s.

Viddler attempts to preserve the original format, changing the specs only when required to match the requirements of FLASH. Video is at the original frame size, 30fps FLASH video, using the VP6 at 400Kbit/s. Audio is in the original format (max 44Khz) using MP3 at 48Kbit/s. VP6 is the "flagship" codec for Flash Player 8, intended to deliver better quality at lower bit rates.

Youtube encodes to a lower bit rate so may work better over slower links. Youtube's format is constant, so the quality is constant. Viddler encodes to a higher bitrate and uses more compression, so it is capable of delivering better quality although at the cost of more data and CPU processing. Viddler's video format is variable, so the quality is also variable.

Youtube's 320x200 format is OK for 4:3 video, but is not good for other formats. For example, 16:9 video is letterboxed so the effective resolution of the frame is only 320x180. Viddler retains the original size, so can support 16:9 or any other format.

File Upload

Youtube has a limit of 10 minutes and 100Mb on uploaded videos. Upload is via a two-step process where you initially enter the videos details, and then select a file to upload.

Viddler has a limit of 500Mb, but no time limit. Upload is via a batch process where you initially select any number of files, and then enter the video details as the files are uploading. I like this a lot, and have found it a real time-saver.

Player

(Updated November 2007)

When I first did this comparison, Viddler had a clear advantage in navigability. Youtube's player was fairly basic. When you pressed "play" the video began downloading. You could pause the playback or rewind to the start. With the position slider you could seek to any position that has been downloaded so far. Viddler's player had some additional features. Perhaps most importantly Viddler supported two connection modes: Progressive and Streaming. Progressive mode downloads the file sequentially from the start, so like Youtube's player you could seek to any time that has been downloaded so far. Streaming mode streamed the file from the playback point, and allows you to seek to any time. This is especially useful for long videos.

Recently, Youtube added support for seekable playback. Download is still progressive, but can be started at any point by clicking in the seek bar. Around November 2007, Viddler turned off streaming support in their player, saying that it was "expensive and unreliable". They plan to move to a progressive seek player similar to those now offered by Youtube and Google. Until then they seem to have lost one of their most useful features : the ability to navigate via comments to arbitrary points in the video as described below.

Example of timed comments in the Viddler's seek bar. Click on the image to try it out.

Viddler also allows you to add tags or comments at any point in the file. The comment points are displayed in the seek-bar, and you can see the comments by mousing over the comment points. Clicking jumps to that point, providing you are in streaming mode. Comments also pop up as playback reaches that point. This is great for adding narratives or explanations to a clip, or for highlighting interesting events for your viewers (like in this video). Likewise, viewers can add their own comments (if you allow it) which will then be shared with other viewers. This is one of my favourite Viddler features.

Other additional features in Viddler's player are the ability to get a link to an embedded video, or get the embed code itself.

Viddler does not interpolate when scaling videos for playback, resulting in a grainy image (left) when compared with other players (right).

Viddler requires the FLASH 9 player. Youtube requires only FLASH 7 players, which means that its videos will work on a larger variety of systems including "embedded browsers" (eg. Opera the Nintendo Wii game console).

My biggest complaint with Viddler's player is that it appears to rescale the output image without using interpolation. This image compares the same video shown in Viddler and Mplayer. Note the jagged edges on Viddler's playback. This tends to produce a "grainy" look, giving the impression that the quality of the video is worse than it actually is.

User model

I can't say I've looked into this very deeply. Both Youtube and Viddler have "members", "friends" and "groups". Youtube also has "subscribers". Viddler also has "forums", which seem to be implemented using "groups" on Youtube. Both sites have video "tags" and descriptions. Viddler has both "global tags" which apply to an entire video, and "timed tags" which apply to a specific time in a video. It also has timed and global comments.

Both sites offer featured videos where especially interesting videos are showcased to the users. Youtube also includes optional "active sharing", which means that when viewing a video you can see and connect with other users that are viewing the video at the same time.

Access and Privacy

Youtube allows videos to be public or private. For private videos you can nominate up to 25 users who are allowed to view the video. This is useful for example, if you just want to share a file with family members. Video files are not downloadable, although there are third-party web sites (eg. kissyoutube.com) which allow you to retrieve the encoded FLASH file.

Viddler allows videos to be public, private (only accessible to you), or shared (accessible to you and your "friends"). In addition to viewing rights, Viddler allows you to control who is allowed to comment, tag, embed, or download your video. You have separate controls over downloading the original file, or the encoded flash version. This allows you to distribute high quality videos in their original format which can effectively be viewed on-line via the FLASH player. Viddler also allows you to create a "secret URL" which can be used to access a private video. This means that you can share a private video with users that are not members of the system, something that is not possible on Youtube.

Viddler keeps extensive statistics on video views. It reports the number page views and embedded views. It also tracks all of the links to your video, reporting the number of views for each link. Where the link is from a web page, it shows you the title of the page and some context around the link (like a trackback). You can follow these links back to the original page. It also works for pages that embed your video. This allows you to instantly see who is watching the video, and what is being said about it on the web. Youtube's reporting is more basic: it reports total plays, and lists any links to the video's web page; it does not appear to track embedded plays.

Propriety

Youtube is now owned by Google. There are no limitations on what you can upload, but your video may be taken down if the copyright owner objects. Youtube is currently fighting a $1 billion lawsuit with Viacom over copyright. Youtube generates revenue via advertisements placed in its web pages, and has recently launched in-video advertisements.

Viddler only allows upload of video for which the member owns copyright. It tends to focus on user-generated content. Viddler is a small company, and its not clear how they intend to derive revenue from their services. But small can also be an advantage. The staff and community seem friendly and attentive. While Youtube obviously offers a larger user-base, it can seem a little more impersonal. Viddler openly identifies community and its anti-piracy stance as among its core strengths.

Conclusion

Viddler offers the user many compelling features not found on Youtube:

• Support for videos longer than 10 minutes, with upload sizes to 500Mb.
• Improved control over access to shared videos
• Improved navigation via streaming play, timed tags and timed comments (note: streaming play currently unavailable)
• Support for any resolution format including 16:9
• Extensive statistics and link reporting

Areas where Youtube has the advantage are:

• Size of user base
• More consistent quality of encoding
• More compatible player

There is a fundamental difference in encoding strategy. The host needs to encode video to make it compatible with the player's codec, and to reduce the bit-rate so that it can be delivered in real-time. Bit rate can be reduced by increasing the compression, or reducing the sampling rate / resolution. One option is to upload a high resolution video and let the host choose the best resampling and compression. Another option is to let you choose the resampling.

Youtube always resamples your video (320x200 video, 22050Hz mono audio) before compression so the quality is consistent. Viddler does not resample video, allowing for a wider range of video formats (eg. it supports 16:9 video). However, unless you start with the right resolution you may end up with a poor quality result. Viddler does not provide sufficient information for you to make the relevant decisions. It needs to either be more open about the process, or provide a set of encoding profiles that are known to work well.

If you're prepared to work around some of the teething problems with Viddler you'll have access to some great features not found elsewhere. Its great to see the Viddler folks pushing the envelope and coming up with some fresh ideas. In an arena where there are so many "me too" players, its the guys who take the lead that ultimately drive progress forwards.

Feature	Youtube	Viddler
Required Plugin	Flash 7	Flash 9
Video Encoding	FLASH H.263	FLASH VP6
Video Format	320x200, 25fps	variable, 30fps
Video Bit Rate	250Kbit/s	400Kbit/s
Audio Encoding	MP3	MP3
Audio Format	22KHz, mono	variable, max 44KHz
Audio Bit Rate	64Kbit/s	48Kbit/s
Total Bit Rate (approx)	310Kbit/s	448Kbit/s
Supports 16:9 video	no. letterboxes to 4:3	yes
File Upload Limit	100Mb	500Mb
Video Time Limit	10 minutes	none
Batch Uploader	no. Via 3rd party	yes
Progressive Play	yes	yes
Streaming Play	no	no
Seekable Playback	yes	no
Active Sharing	yes	no
Global Tags	yes	yes
Timed Tags	no	yes
Global Comments	yes	yes
Timed Comments	no	yes
Control Embedding	yes	yes
Download encoded video	no. via 3rd party	controlled
Download original video	no	controlled
Tracks Links	yes	yes
Private share with non-user	no	via "Secret URL"