Client Side Recording: Lync 2013

Meeting recordings are a core component of Microsoft’s Unified Communications solution. They have a rich legacy in Microsoft’s conferencing products and service offerings and fulfill a key requirement for many companies and individuals.

Generally speaking, recording consists of enabling a meeting participant to capture the information and activity in a meeting in a format that can be played back or shared with others. Crucially, recordings are about getting value from meetings afterthe meetings have concluded.

Lync’s meeting recordings are an entirely client-side feature which enables all participants in a meeting who have permissions to record to do so. All audio, active-speaker’s video, content and Instant Messages are captured in Lync recordings and presented from the perspective of a virtual participant in the meeting. This ensures that Lync recordings are neutral in their presentation and will not typically differ for users recording the same meeting on disparate endpoints.

While Lync recordings strive to be accurate in presenting content, audio, video and IMs exchanged during a meeting, they must not be treated as a compliance or archiving mechanism. Our intention is to provide a shareable, accurate and complete view of the meeting to those recording the meeting – nothing more or less.


Recording Format

With Lync 2013, we wanted to achieve the following goals with recordings:


  • Ensure cross-platform and device support
  • Become more standards compliant
  • Enable we are well setup to take advantage of native hardware support for encoding purposes in the near to medium term future

With these goals in mind, Lync 2013 recordings are now available in the mp4 format. This is different from Lync 2010 where they are available in a Lync-specific .crec format for rich immediate playback and wmv format for distribution. The reasons compelling this change are detailed as follows:

1. Having two disparate formats for Lync 2010 recordings ( .crec and wmv) was confusing and introduced greater complexity than intended. The move to a single format (mp4) ensures ease of use and the elimination of confusion around the utility of one format over the other.

2. MP4 is widely supported on mobile devices, tablets and operating systems. WMV does not enjoy the level of support across platforms that mp4 does. CREC format was only supported on the Windows platform and could only run on Lync 2010.

3. MP4 is largely emerging as the industry standard.

4. The codecs required to support mp4 (.H264 codecs) are expected to receive hardware support for encoding purposes. That would help reduce the time and resources it takes to produce a Lync recording.

5. When compared to the .crec format, mp4s are easily distributable because they are well contained in a single file whereas .crec format requires multiple files to run. MP4s are much easier to upload and share.


Immediate Publishing

In Lync 2010, you had to wait for long while after the recording was stopped for the wmv file to be available for playback. This prevented you from being able to distribute your recordings within a few minutes after the meeting. With Lync 2013, this should no longer be an issue: recording mp4s are available only a few minutes after the recording is stopped. This would enable you to consume and share your recordings within a few minutes after the meeting instead of waiting much longer.

The process of capturing the meeting content, audio, active speaker video and IMs and converting them to mp4 format now happens during the meeting itself. In the best case, meeting recordings are available within the first 5 minutes after the recording is stopped! Previously, this process would begin after the recording was stopped resulting in the publishing (to wmv) process taking about as long as the recording duration itself. This process of mp4 generation during the meeting itself is referred to as ‘immediate publishing’.

Capture and publishing of meeting modalities (audio, video, content, IMs) in to a recording mp4 is CPU-intensive. During the meeting itself, it is undesirable for the recording processes to result in degrading the meeting experience. To prevent this from happening, the publishing process for recording mp4s runs in a low-priority thread which does not aggressively compete for resources with the meeting experience itself. In addition, when the device is operating on battery power, ‘immediate publishing’ is suspended and the publishing process will resume after the device is plugged back in to power. This helps conserve precious resources and power while the device is not plugged in.

The Recording mp4


Lync Recording mp4 showing Content + Active Speaker video layout


Lync Recording mp4 showing IM + Content + Active Speaker video layout

The characteristics of the Lync 2013 recording mp4 can be summarized as follows:

  • Most recording mp4s are available within a few minutes after the recording is stopped.
  • ‘Immediate publishing’ is paused while the device is on battery power. This is to converse battery resources during the meeting because the capture and publishing of the recording material is CPU-intensive.
  • All modalities shared in a meeting (audio, video, content, IMs) are automatically captured in the recording generated as a result of ‘immediate publishing’. You can still exclude certain modalities from the recording mp4 by re-publishing the recoding and choosing the modalities to exclude (details in the next section).
  • Unlike Lync 2010 recording wmvs, recording mp4s are now of a fixed resolution (800x600)
  • The average bitrate for the mp4s is 25 kbps.
  • The frame-rate for the mp4s is 10 fps


Republishing a Recording

The Lync Recording Manager is your one-stop-shop for managing your Lync 2013 recordings. You can perform various tasks such as Playing your recording, Browsing to the recording mp4 location, Renaming the recording, Deleting the mp4 and (Re)Publishing the recording.

Publishing a chosen recording will regenerate the recording. This can help under the following circumstances:

1. The previous attempt at generating a recording mp4 results in an error—while not a common occurrence, the mp4 generation process can fail. Under most circumstances, publishing the recording again will help resolve the issues.

2. You want to view the recording mp4 without certain modalities (audio, video, content, IM).

In order to publish the recording again, please follow the steps outlines below:

(i) Open the Lync Recording Manager

(ii) Select the recording mp4 you want to republish


(iii) Click on Publish

(iv) From the Save and Publish dialog, select Options to choose modalities to select/unselect


(v) Choose the modalities you want to choose to publish in the recording mp4

(vi) Click Ok


Note: upon re-publishing the recording, the previous mp4 will be overwritten by the new instance. If you want to generate multiple copies of the same meeting recording please make a copy of each mp4 manually.


Lync Recordings increase your productivity

Lync recordings have been designed to help increase productivity and efficiency of your meeting experiences. We believe you should not have to worry about missing that critical bit of information during the meeting and keep wondering how to recall. You can not only use your Lync recordings for personal purposes but also share the meeting experience with those who were not able to make it or to a wider audience in general. With the introduction of ‘immediate publishing’ and availability of higher quality recording output, you will find the experience more efficient and fulfilling.

Jehangir Amjad

Program Manager, Lync Client