I wrote a simple custom pod that will allow you to stream high quality live video from the Flash Media Server to the free custom pod mentioned here that is being shared in a meeting room in Adobe Connect. For now the custom pod only supports live video not vod (file based video).
This approach does not nullify bandwidth requirements but it allows you to benefit from the capabilities that Flash Media Server provides around streaming high quality video. In other words if you stream a 2 Mpbs video to this custom pod hosted in a Connect meeting room the attendees of that meeting room will need more than 2Mbps to view it. The reason they will need more than the video requirement is that the Connect meeting room as a bandwidth requirement as well that needs to be taken into account.
When you download the custom pod you will notice that it is just a Flash file (swf). This custom pod is provided free as is with no support. Open an Adobe Connect meeting room. Open a share pod if one is not already open and click the button labeled “Documents” from the popup menu select “Select from My Computer…”. Navigate to the custom pod (fmsVideo.swf) select and upload it to the meeting room.
Notice the green dot in the upper left hand corner of the custom pod. That is used to open and close the settings. The setting will automatically close when the custom pod makes contact with a Flash Media Server. It also functions as a visual indicator of your connection state. Green indicates that you are connected and red indicates that you are not connected. The indicator does not change immediately when you connect or disconnect there may be a several second delay between changes in that indicator.
You will also notice in the preceding screen (custom pod) that only two elements are required in order to play the live stream ( server url starting with rtmp and the stream name). These elements correspond to settings in the Flash Media Live Encoder output panel.
Once you have the stream published from Flash Media Live Encoder to the Flash Media Server simply copy and paste the FMS URL and Stream (name) from the Flash Media Live Encoder into the same fields in the custom pod and hit the connect button. That should do it.
All to often marketing rhetoric is mistaken for technical reality. One one hand we hear Steve Jobs tell the world that Flash does not work well on their devices and with the other hand he is making sure that it does not by denying Flash access to the ability that they retain for only their applications and technology. It is becoming more and more difficult to make these claims as the Open Screen Project is beginning to have an effect. We are starting to see the results of this effort in devices such as the up coming HP Slate. In addition there are a few people that have taken up the gauntlet and did a little research to better understand the issue. I hope you take a look but if you do not an article by Dan Rayburn summarizes the results very well:
“When it comes to efficient video playback, the ability to access hardware acceleration is the single most important factor in the overall CPU load. On Windows, where Flash can access hardware acceleration, the CPU requirements drop to negligible levels.
Overall, it’s inaccurate to conclude that Flash is inherently inefficient. Rather, Flash is efficient on platforms where it can access hardware acceleration and less efficient where it can’t. With Flash Player 10.1, Flash has the opportunity for a true leap in video playback performance on all platforms that enable hardware acceleration.
Apple complaining about Flash being a CPU Hog while not exposing “the appropriate hooks” to enable Adobe to access hardware acceleration seems disingenuous at best.”
Thanks to Dan Rayburn for the lucid approach to this political topic!
I am very impressed with HP of late. I am currently using an HP laptop (EliteBook 8730) and love it. I recently watched a video preview of the HP Slate and I have to say that it looks impressive. As with any device the proof is in the use but as a preview it looks good. This is the first of many devices that will support the full web (Flash enabled) this year. The result of a very successful venture called the Open Screen Project.
Every now and then I will find a website or content example that lives up to my belief that the web has so much more potential than the majority of the content available today. I am constantly looking for that amazing “lean forward” experience that draws you in and makes you want to reach out to the other people interacting with the content to see if their experience even remotely matches your own. Good news, I have found it and it is called “CIRCLE OF EIGHT”. It is a multi-episode supernatural thriller that combines social media, gaming and a great plot line. The quality of this production is fantastic. Could this be a block buster series that finds all or most of its potential on the web? I think that it could be but only time will tell.
Imagine finding the perfect training video but it is an hour long and you need to find the specific part of the video that covers your specific interest. Or possibly you are an advertiser and you would like to have content aware advertising in some specific online videos. You would like to have your advertising show up on a page when a specific word is mentioned in a video or maybe when a video is searched for a specific word, does that sound familiar it should as it is the google model for advertising and now it can apply to video.
The solution that I will cover in this article will allow you to transcribe the spoken word in videos into text and allow a user to search that text to find relevant areas of the video. The example that we will cover is only the beginning. I could imagine an entire searchable library of video or possibly even a web search engine that easily finds and displays video starting at the location where the search engine found a word that was spoken in the video. Before we jump in it might be helpful to see an example.
I should start by telling you what I am not going to cover. I am not going to cover how to get started with Premiere Pro, Soundbooth and the Flash Media Server. There are a number of great resources for each of these products. What I am going to cover is the specific functionality in each of these products that relate to creating searchable video. Lets start with Adobe Premiere Pro.
Once your project is created and the video and sound edited to your satisfaction it is time to transcribe the video. This is a very straight forward step. Simply open or expand the Metadata panel and you should see a button at the bottom of the panel called Transcribe. If you do not see the panel you can open it from the Window menu. The following panel allows you to transcribe as well as edit an existing transcription.
When you click the Transcribe button you will see the following dialog that allows you to choose the language, quality and whether to identify speakers.
The language choice is pretty straight forward. As for the quality I see no reason to ever choose anything other than high. When you choose identify speakers you will notice in the exported xml something like the following <Name>Speaker 1</Name>. I can see this being an interesting addition to an application but for this example I did not take advantage of this feature.
This process can take some time to complete. Keep in mind that an accurate transcription relies on two very important criteria. First and foremost a good quality sound track is critically important. If you have background noise or a muffled speaker you will not get a very accurate transcription. Second is the dictionary that is used to recognize words. In order to give you some context, imagine attending a lecture where the speaker spoke in a language that you did not understand. A custom library is a library with specific word definitions that allow Premiere to more accurately identify and transcribe the spoken word. This is an area that you will see expanded on in future versions of the Production Premium Creative Suite.
When the transcription process is complete the xml that represents that transcription is stored as XMP Metadata as part of the video file. It is possible to access and use XMP Metadata that is stored in a swf, flv and f4v via Actionscript but this should be carefully considered. If you create a long format video that contains a great deal of speech to be transcribed that finished transcription can represent a fairly large increase in file size. As an example the following represents two files encoded with the same settings and length the larger file has metadata and the smaller does not.
Storing and accessing the transcription metadata stored in the final video file can also cause problems for streamed video from the Flash Media Server because of the way that text is stored in the video file. I found the best way to use this transcription to create online searchable video was to export the xml file so that it did not remain part of the video file. This may be addressed in the future but for now if your video is longer than say 15 minutes and you plan to stream that video it would be best to export the xml that represents transcription to an xml file that is stored outside the video file.
I would suggest that you exclude the metadata for the final video that will be displayed online. In order to exclude metadata during export from Premiere Pro CS4 click the panel menu button on the right hand side of the options panel in the export dialog box. In the popup deselect Include Source XMP Metadata.
One more slight wrinkle in the process is that you cannot export the transcription as xml from Premiere. The only way to export the transcription is from Soundbooth.
Editing The Transcription:
Anyone familiar with speech to text knows that it is not possible to get one hundred percent accuracy. With that said it is possible to get a high degree of accuracy given the criteria mentioned earlier in this article. There are a number of tools that can help you clean up the transcription in both Soundbooth and Premiere. Once the transcription process is complete and you see the text in Metadata panel you should see the play, loop and transcribe buttons. You should also see a search field at the to of the Metadata panel in both Soundbooth and Premiere. The search field allows you to search for words that are in the transcription. This functionality can prove very useful when you find a word that was not transcribed properly and may show up in multiple locations through out the transcription. Once you find a word that needs to be corrected simply double click the word and you will be able to edit that word. Depending on how the word was recognized during the transcription process you may that you need additional functionality. If you right click on a word in the Metadata panel you will see the additional features.
Exporting The XML:
As I mentioned previously you cannot export the XML file required for this example from Premiere that must be done in Soundbooth. Soundbooth has many fantastic features including volume correction and my favorite visual audio healing. You might wonder why I am mentioning Soundbooth features under the Exporting The XML heading; to refresh your memory it is because you cannot export the XML transcription from Premiere. If you have any last minute touch-ups for your audio track it might be a good idea to leave them to just before you export the transcription as xml. Then it is a simple matter to right click the audio track in Premiere and select Edit in Adobe Soundbooth and then Render and Replace.
From Soundbooth you will be able to clean up your audio, if required, and export the transcription as xml. The changes that you make in Soundbooth will show up in Premiere as soon as you save thanks to Dynamic Link. Once you are in Soundbooth you should see that the transcription has come over with the audio track. To export the xml file simply go to the File menu and then down to Export then select Speech Transcription.
Once the xml file is exported it is time to finish encoding your video into either an FLV or an F4V. If you have made changes to the audio in Soundbooth save and return to Premiere to finish encoding your video. When considering the functionality required to create searchable video streaming vs progressive is an important consideration. Progressive video is video that is accessed by using the http protocol. Streaming video is accessed by using RTMP. For searchable video there are a couple of key differences that should help you choose the right technology. First navigation with in the video is key to the idea of searchable video. With progressive you would have to download all of the video from the start of the video to the place a user is navigating to in the video. If the video is fairly long this can be very frustrating for a user. You can imagine doing a search and finding the word you are looking for close to the end of say a forty minute video and having to wait for that amount of video to download before being able to jump to that portion of the video. Streaming on the other hand simply starts sending the video from the part of the video requested. Streaming makes searchable video usable for even long format video. Another key feature of the Flash Media Server that assists in making searchable video a reality is something called enhanced seek. The following is a definition from the online documentation:
“Enhanced seeking is a Boolean flag in the Application.xml file. By default, this flag is set to false. When a play occurs, the server seeks to the closest video keyframe possible and starts from that keyframe. For example, if you want to play at time 15, and there are keyframes only at time 11 and time 17, seeking will start from time 17 instead of time 15. This is an approximate seeking method that works well with compressed streams.
If the flag is set to true, some compression is invoked on the server. Using the previous example, if the flag is set to true, the server creates a keyframe–based on the preexisting keyframe at time 11–for each keyframe from 11 through 15. Even though a keyframe does not exist at the seek time, the server generates a keyframe, which involves some processing time on the server.”
The preceding should be fairly easy to understand how searchable video would benefit from this functionality but to make sure I will put this functionality in the context of this example. Imagine doing a number of searches on a long video. If the keyframes were not placed on every frame what you would notice is that some percentage of searches would take you past the point where the word was spoken in the video leaving you to wonder if the word was found at all.
The Final Step:
At this point you should have a video encoded as either an FLV or an F4V and an xml file that represents the transcription from the video file. In the second paragraph of this article there is a link to an example, the sample provided with this article has very close to the same functionality as that example. You can download the sample with the link provided at the bottom this article. Once you have downloaded those files and unpacked you should have the following files:
You should also have a skins folder. All of the files and the skins folder should be in the same directory on a web server or in the webroot in the Flash Media Server installation directory. The following is the typical path for the webroot folder when installed on Windows XP.
C:\Program Files\Adobe\Flash Media Server 3.5\webroot
This is of course required so that you can access the content from a web browser. The searchableVideo.html file is the html wrapper that hosts the swf. This is not required you can use your own html page to host the searchableVideo.swf. It is easy to add the searchableVideo.swf to your own html page from within Dreamweaver. Just add these files and the skins folder to your Dreamweaver site files and create a new page or open an existing page and simply drag the swf file (searchableVideo.swf) onto that page. Dreamweaver will create the object and embed code for you. Keep in mind that the searchableVideoPrefs.xml file needs to be in the same directory as the searchableVideo.swf on the web server. Organizing files for access over the web is much easier now with the Flash Media Server 3.5 because it has an embedded web server. You can simply drop the html and swf files that you would like someone to access using a web browser in to the webroot folder in the installation folder of the Flash Media Server. Once you have the files setup it is time to edit the searchableVideoPrefs.xml which allows you to specify the location of the transcription xml file and video. In addition you can also make changes to some of the player functionality and appearance from this same searchableVideoPrefs.xml file.
I would suggest that you open the searchableVideoPrefs.xml file in either Dreamweaver or an xml editor do not use a word processor. Once the file is open you should see the <sourceURI> tag. It is important that you do not edit any of the tags only the content between them. For instance make sure that when you are editing the <sourceURI> which represents the location of the video you do not change either <sourceURI> or </sourceURI> in anyway only the text between those tags. This is true for any tags in this file. If you wanted to play a video on a server with a dns name of foo.com and the video was in a Flash Media Server application called lectureVideos and the name of the video was chem101.flv the <sourceURI> tag should look like the following:
This may seem complex but it is really fairly simple. When you install the Flash Media Server on windows it has two pre-installed applications vod and live. These applications are represented as folders in the following location C:\Program Files\Adobe\Flash Media Server 3.5\applications. The name of the application is the name of the folder in that location. In the example that we mentioned you would have a folder called lectureVideo in the application directory mentioned above (e.g. C:\Program Files\Adobe\Flash Media Server 3.5\applications\lectureVideo). In side of that folder you will have a folder called streams and inside of that you will have a folder called _defInst_ and inside of that folder you will have your video file. So the entire path to your video file on the Flash Media Server would be C:\Program Files\Adobe\Flash Media Server 3.5\applications\lectureVideo\streams\_defInst_\chem101.flv. Remember that if you are using an f4v file that you must prefix the file name with mp4:. For instance if the previous example was an f4v not an flv the sourceURI tag would be the following:
As I mentioned previously there are many resources for learning about the different tools and servers used in this example.
Now you should have the hang of editing the searchableVideoPrefs.xml file. Next we are going to edit the location of the transcription xml file that was generated in Premiere and exported from Soundbooth. The same precaution holds true for editing this tag, do not change the tags in anyway only the contents. This location can either be relative to the swf or a complete http uri. For instance both of the following are correct:
In the first example it would mean that the RedWorkflow.xml (i.e. transcription xml file) would be in an assets folder which would be in the same folder as the searchableVideo.swf and searchableVideoPrefs.xml files. In the second example the RedWorkflow.xml file could be stored on the same or a different server and access by using the http protocol.
Lets take a look at how the finished example should look and label some of the areas of the example so that it is easier to follow along.
In the following image I have highlighted and labeled the important areas of the player so that it will be easier to understand my references:
The Text Cloud section represents the highest occurring words in the transcription. This allows the viewer to get an idea of the kind of content in the video. The viewer can click on any of the keywords in the Text Cloud in order to display those results in the Found Items section. The Relevant Text section is displayed when a viewer clicks an item in the Found Items section, it displays the text surrounding the found text. The Video Display shows the video as well as markers representing the found text. A viewer can rollover the marker to display the surrounding text as well as seek to that portion of the video. The Search Field allows a user to enter and search on one or more words and the Found Items section displays the result. It is also possible to sort the columns in the Found Items section by clicking the column headings.
There are a number of other settings in the searchableVideoPrefs.xml that you can use to change the functionality and appearance of the searchable video player. First minwordLength, use this to set the minimum word length for the text cloud at the bottom of the example. A setting of 5 will mean that no words shorter than 5 letters will show up in the word cloud. Next there is videoInitStartSeconds which determines the initial start time of the video when the player is first launched. There are a few other settings that will affect the appearance of the player and they are as follows:
globalTextColor : sets the color for ALL text on screen
swfBackgroundColor : sets the background color of the player
foundTextHighLightColor : changes the color of the text in the relevant text display
textBackGroundColor changes the background color for the text cloud and the relevant text area
Well that should get you started. If you have problems, interests or comments please leave them on this site so that I can respond. There are many possible additions and changes that I can think of for this example. I am eagerly waiting to see and hear how people have used this example so please leave me a comment.
For years the only way to play Streaming Video in Flash was to create your own video player in the Flash or Flex authoring software. It was and is still not difficult if you were familiar with either of these applications as there are components for both environments that make it a fairly trivial task. With that said there are many people that are not familiar and do not have the time to get familiar with either of those applications but would still like to stream Flash video. Good news, there is a fully functional player that is installed with Flash Media Server 3.5 that is easy to configure and includes multi-bitrate support.
Inside the installation directory for the Flash Media Server you will find a “samples” directory and in that directory you will find a directory called “videoPlayer”. When you installed the Flash Media Server 3.5 you had an option to install Apache. You can confirm that your Flash Media Server installation is working simply by opening a browser on the same PC that has the Flash Media Server installation and browsing to http://localhost. When the page loads you should see the following image.
If the preceding page does not load it is most likely do to a conflict with another http server installed on the same PC. De install or turn off the other http server and browse to localhost, that should fix the problem. You may need to restart the PC for the changes to take effect. Once you know that the Flash Media Server installation is working correctly copy the “videoPlayer” directory to the webroot of the Flash Media Server installation directory which should resemble something like the following:
C:\Program Files\Adobe\Flash Media Server 3.5\webroot
Open the “videoplayer.html” file in a browser, scroll to the bottom of the page and select and copy the object and embed code in the white text box. Create a new blank html page and paste the object and embed code between the body tags of the new blank html page. The html with the object and embed tag (in blue) should look like the following:
Save the new html page in the same directory as the “videoplayer.html”.
C:\Program Files\Adobe\Flash Media Server 3.5\webroot\videoPlayer
Now we are going to edit the parameters that will allow you to use this player to play your own videos. The simplest way to play your own video using this player is to simply change the “serverURL” to reflect the location of the video you would like to stream. For instance the following example:
is referencing a video with the name “sample1_700kbps.f4v” in the following directory:
C:\Program Files\Adobe\Flash Media Server 3.5\applications\vod\media
When you stream MP4 or F4V files you need to add the prefix “mp4:” to the front of the file name. That is not the case with VP6. Do not forget that there are two “serverURL” parameters that you will need to change in the object and embed code (i.e. one for the object and one for the embed) so that the intended video plays in all browsers. Change the “serverURL” parameter to reflect the video that you would like to play. Just copy the video that you would like to play to the following directory:
C:\Program Files\Adobe\Flash Media Server 3.5\applications\vod\media
The name of the video that I am going to use for this example is “Redworkflow.f4v”. With that in mind the edited “serverURL” parameter should look like the following:
Since I am running everything off of the same PC I am using “localhost” for the server address. In a real environment you would substitute either the real server ip address or the dns name of the server for “localhost”. There is one additional change that you are going to want to make to the object and embed code and that is to change “dsControl” parameter from “manual” to “auto”. This setting allows the switching between streams to happen automatically.
When you run the html page in the browser the video should play. This example is simple and straight forward but will not provide for the best experience. Choosing a single video to stream ignores the fact that the internet and most networks will not provide a constant amount of bandwidth to most users. In other words you may start out playing video with out a problem only to find it skipping frames because someone on your network decided to download a large file at the same time that you were watching the video. The solution to this problem is “Dynamic Streaming“. Dyanamic Streaming adjusts to serve different quality streams based on the current capability of the viewer. The player that we have been using for this example supports “Dynamic Streaming” through the use of a smil file. You will notice that there is a file with the name “dynamicStream.smil” in the following directory.
C:\Program Files\Adobe\Flash Media Server 3.5\webroot\videoPlayer
That is the same directory where you saved the html page with the edited object and embed tag. Open the “dynamicStream.smil” in a text editor and you should see the following:
In the preceding there are five files and bandwidth triggers (e.g. bitrate=”xxxxxx”). For this example I am going to use only three to keep things simple. The files that I am going to use were encoded with the Adobe Media Encoder that is included with Creative Suite 4. They were encoded using On2 VP6 using a constant bitrate. The names of the files are:
You might have noticed that bitrate is in bits not kilobits. In other words 300000 is 300kbps (kilobits per second). Notice that I changed the bitrate attribute to reflect the data rate that the video file was encoded to using the “Adobe Media Encoder“.
The following is an example of what your finished project could look like using the sample Flash video player included with the installation of the Flash Media Server.
Well that should get you started. Drop me a line if you have success or problems.