I watch and download a lot of videos from Channel 9 and because I’m a developer and always looking for ways to speed up anything I do, I searched for a PowerShell script. I eventually found one (can’t remember where) and immediately set it up to download This Week on Channel 9 and Ping Show. Over time, I have added many other shows, events and series. The initial script I found with some modifications was:
$url="http://channel9.msdn.com/Shows/This+Week+On+Channel+9/feed/mp4high"
$rss=invoke-webrequest -uri $url
$destination="Z:\Media\Videos\ch9\This Week on ch9\"
[xml]$rss.Content|foreach{
$_.SelectNodes("rss/channel/item/enclosure")
}|foreach{
"Checking $($_.url.split("/")[-1]), we will skip it if it already exists in $($destination)"
if(!(test-path ($destination + $_.url.split("/")[-1]))){
"Downloading: " + $_.url
start-bitstransfer $_.url $destination
}
}
Because of the amount of shows growing that I was interested in, I added another piece to this. On the root level of all my Channel 9 videos, I added a PowerShell file that would run all the other PowerShell files that looked like:
cd Z:\Media\Videos\ch9
$psScripts = Get-ChildItem -Recurse -Filter "*.ps1" |
ForEach-Object -Process { if($_.Name -ne "Download All.ps1"){ Write-Text "$($_.Name)"; . $_.FullName; } }
Write-Output "Done"
This was working great as I wouldn’t need to go and run multiple files in order to update all my videos. Recently because of all the new stuff that was released because of the announcements at #VS2013Launch, I had to add about 5 new feeds to my collection. This took quite a while as I needed to create a new folder for the show, then get a copy of the first PowerShell script above and then alter the feed url and location to save the videos to. This led to yet another script, the way I saw it, I could either write a script that automates the create of the folder and script or I could do the longer but right thing and start “fresh”. The script I now run takes in an array of the url of the show, series, event or any other type of channel that has an RSS feed, basically everything after http://channel9.msdn.com/. The new and improved script looks like:
cls
Write-Output "Starting"
$feedTypeNameList = $("Events/Build/2014",
"Shows/PingShow",
"Shows/This+Week+On+Channel+9",
"Series/Microsoft-Research-Luminaries",
"Shows/Windows-Azure-Friday",
"Blogs/One-Dev-Minute",
"Shows/Visual-Studio-Toolbox",
"Events/Visual-Studio/Launch-2013",
"Series/Application-Insights-for-Visual-Studio-Online",
"Series/Visual-Studio-Online",
"Series/Visual-Studio-Online-Monaco",
"Series/Visual-Studio-2012-Premium-and-Ultimate-Overview",
"Blogs/MadsKristensen",
"Blogs/C9Team",
"Series/PerfView-Tutorial",
"Blogs/IE",
"Shows/Edge")
$baseSaveLocation = "N:\s\ch9`$"
$mediaFormat = "high"
$mediaType = "mp4"
$fileExtension = "mp4"
$pathToRemoveInvalidFileNameCharsScript = "$baseSaveLocation\Remove-InvalidFileNameChars.ps1"
. "$pathToRemoveInvalidFileNameCharsScript"
foreach($feedTypeName in $feedTypeNameList)
{
$channelType = $feedTypeName.Split("/")[0]
$feedUrl="http://channel9.msdn.com/$($feedTypeName.Trim("/"))/RSS/$($mediaType + $mediaFormat)"
Write-Output @"
Downloading Feed: $feedUrl
"@
$rss=invoke-webrequest -uri $feedUrl
$destination="$baseSaveLocation\$($feedTypeName.Replace("/","\").Trim("\"))\"
if (!(Test-Path $destination)) {
New-Item -ItemType directory -Path $destination
}
$videos = @()
[xml]$rss.Content|foreach{
$_.SelectNodes("rss/channel/item")|foreach{
[Array]$array = @($_.SelectSingleNode("enclosure").url,$_.SelectSingleNode("title").InnerText)
$videos += , $array
}
}
[Array]::Reverse($videos)
foreach($video in $videos){
$url = $video[0]
$title = $video[1]
if (![string]::IsNullOrEmpty("$url"))
{
$fileName = $($url.split("/")[-1])
$mp4fileName = $($fileName.Replace("." + $fileExtension,"") + "-" +
(Remove-InvalidFileNameChars $title.Replace(" ","-")) + ".$fileExtension")
if ($mp4fileName.Contains("_"))
{
$pptxFileName = $mp4fileName.Remove($mp4fileName.LastIndexOf("_")) + ".pptx"
$pptxFileNameSaveAs = $mp4fileName.Remove($mp4fileName.LastIndexOf("_")) +
"-" + (Remove-InvalidFileNameChars $title.Replace(" ","-")) + ".pptx"
}
else
{
$pptxFileName = $mp4fileName.Remove($mp4fileName.LastIndexOf(".")) + ".pptx"
$pptxFileNameSaveAs = $mp4fileName.Remove($mp4fileName.LastIndexOf(".")) +
"-" + (Remove-InvalidFileNameChars $title.Replace(" ","-")) + ".pptx"
}
if (![string]::IsNullOrEmpty("$mp4fileName"))
{
"Checking $mp4fileName, we will skip it if it already exists in $($destination)"
#if we have the file from the previous script rename it or delete it
if(Test-Path ($destination + $fileName))
{
if(!(Test-Path ($destination + $mp4fileName)))
{
"Renaming: " + $fileName
Rename-Item $($destination + $fileName) $($destination + $mp4fileName)
}
else
{
"Deleting: " + $fileName
Remove-Item $($destination + $fileName)
}
}
else
{
#download media if it doesn't exists
if(!(Test-Path ($destination + $mp4fileName)))
{
$dest = $($destination + $mp4fileName)
"Downloading: '$url' to '$dest'"
Start-BitsTransfer $url $dest
}
}
}
#download pptx if it doesn't exists
if ($channelType -eq "Events") #only attempt to get pptx file for events
{
if (![string]::IsNullOrEmpty("$pptxFileName"))
{
"Checking $pptxFileName, we will skip it if it already exists in $($destination)"
$dest = $($destination + $pptxFileNameSaveAs)
if(!(Test-Path ($dest)))
{
$urlToDownload = $url.Remove($url.LastIndexOf("/")) + "/" + $pptxFileName
"Downloading: '$urlToDownload' to '$dest'"
Start-BitsTransfer $urlToDownload $dest -ErrorAction SilentlyContinue
}
}
}
}
}
}
Write-Output "Done"
This script caters for renaming of media files from the old just file name format to including the title in the file name. In order to add this extra script that I used for trimming funny characters from the file names.
Function Remove-InvalidFileNameChars {
[CmdletBinding()]
param([Parameter(Mandatory=$true,
Position=0,
ValueFromPipeline=$true,
ValueFromPipelineByPropertyName=$true)]
[String]$Name
)
return [RegEx]::Replace($Name, "[{0}]"
-f ([RegEx]::Escape([String][System.IO.Path]::GetInvalidFileNameChars())), '')
}
Hope this helps others that download Channel 9 videos to watch offline as well 
.
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