If good capture is achieved a good transmission should be guaranteed also but not without taking into account internet connectivity. Obviously internet connectivity is very important when it comes to streaming such events with such high resolution standards so the best bet would be a high speed cable connection. Wireless Internet may also be used in some situations if nothing else is available but its not advised.
The problem with broadcasting via WIFI is that transcoding servers (CDN) can handle a certain amount of data oscillations but if using WIFI which can have an extreme drop of signal, the oscillation to this amount of data being transmitted will remain with its decreased data.
(i.e. video and audio resolution is decreased during transmission, and drops of signal can occur until refresh is made which will stop and re-start the transmission)
Although Daria´s recital was not transmitted it was established that a video resolution of 720p would make justice to images that were being captured by the HD cameras without hindering the live transmission, together with a frame rate of 30fps while 320Kbps mp3 audio proved to make a smooth stream without interruptions. Even a single millisecond interruption will disrupt the viewing and recording as well. So transmission must be seamless from beginning to end.
In the case of slower connection or problems with network provider a compromise in streaming quality must be done and video/audio resolution maybe adjusted.
Transmission will have Livestream website as destination, site which offers several possibilities for channel production like the flash player embeddable anywhere using a simple HTML code. Of course an alternative is host or server space in which case a custom video player must be arranged.
Streamline only provides the technical service so copyrights must be always granted by all parties involved including production.
A great advantage of such live streams is the possibility to further edit and produce the material since all is captured in high quality which allows for the production of DVD video of the performance, Audio CD or both.
In this case 4 audio tracks where used in combination with 3 video cameras so there are multiple possibilities regarding post-production. In the case of and orchestra or larger ensemble more audio tracks and microphones may be used which will lead to the eventual mixdown of the several tracks to a single stereo.
The Lunch Concert was a great opportunity to try out this set up which proved to be very efficient to transmit events of this kind where refined music is at order. It is obvious that a piano recital with pieces by Handel must be perfect (without interruption or buffering time) to keep its musical integrity.
It is also a strong indicator that this will be common procedure at concerts and events everywhere in the near future as internet connections grow faster and bandwidth broader.
A warm thank you to Jorinke van Deelen, Daria van den Bercken and the technicians at Het Concertgebouw who assisted in these recordings and try-outs. All are for educational purposes only.
Lunchconcert Kleine Zaal Het Concertgebouw
Woensdag 30 november 2011
Daria van den Bercken
George Friedrich Handel (1685-1759) Suite in kl.t. HWV 428 (1720)
George Friedrich Handel (1685-1759) Menuet in g kl.t. HWV 434/4 (ca. 1733)
George Friedrich Handel (1685-1759) Chaconne in G gr.t. HWV 435 (ca. 1733)
Streamline Media is a recently formed company and concept dedicated to stream and record live music events over the internet in high quality resolution and therefore mostly apt to Classical, Jazz and/or traditional music.
These genres are usually played acoustic (i.e. without electrical or amplification aid) which makes it rather difficult to capture soft dynamics and nuances on a live internet stream that suffers with heavy compression and slow buffering times. Until quite recently this type of transmission just didn’t make justice to the music.
This is where Streamlinemedia.org comes in with a specific set up of HD cameras and high quality microphones to guarantee the signals captured are of the best quality possible. Further is a custom build computer with enough processing power to handle these high resolution signals and transmission.
After capture and recording, broadcast is done using software Wirecast or similar which enables several options for optimal transmission of the event. Image resolution, frame rates and audio quality settings are chosen in accordance to internet download/upload speed connectivity and bandwidth.
Of course the higher the internet speed is the higher the quality of the broadcast will be but a compromise must be achieved as users may have slower internet connections causing the broadcast to buffer thus disrupting the live stream.
With this in mind a great event can be transmitted over the World Wide Web to be enjoyed by users sitting far away in their homes using their computers.
The capture of Daria van den Bercken piano recital which took place at the Kleine Zaal of Het Concertgebouw on the 30th November was done using 2 Canon HD cams and one extra Logitech webcam for back up and full view of the venue.
The audio was picked up with 2x Nakamichi cardioid condenser microphones in a stereo XY position using a single mic stand and also with the feed from the in-house Midas desk signal, which was picked-up with the ceiling stereo mics of the venue.
The place to mount the equipment was chosen next to where the patch connections and electricity sockets are and the regie usually stands, on the second floor of the zaal, as it gave a perfect full view of the venue and stage and acoustic conditions are optimal.
A trial run was done before at a rehearsal session so the placement had been tested which made the process of choosing a camera spot and angle much easier. Today´s technology allows for a small set up to be mobile and easily mounted and dismounted without interfering with the audience.
Wirecast software allows for both option of record to hard-disk or record to server (i.e internet sites and applications like Livestream) so video capture is done simultaneously with transmission. Hard-disk recording keeps the original material in h.264 format preferably and transmission signal is set to flash format. At this stage image resolution and aspect ratio is crucial as once it is recorded there is no turning back. Video transmission on the other hand can be set to any resolution during, before or after.
Capturing is done using multiple cameras to allow highlighting of solo parts and other moments without ever loosing full view of the concert. Titles, credit details and logos are also placed during capture so a previous template should be created to avoid any mistake being included in the final content.
Audio should be captured at the highest possible resolution which for Streamline Media is set for now at 96Khrz 24bit WAV audio. This resolution is particularly helpful as it is exact multiple of 48Khrz, standard sample rate used in video coding so in the event of a post DVD production this would be ideal as it simplifies the digital down-sample process avoiding possible aliasing. Other sample rates may be use depending on circumstance.
This first stage of the audio capturing goes to an extra computer and hard-disk recorder and is than fed into the broadcast station via balanced outputs to prevent signal loss and noise introduction. Control over gain and volume is available at this stage as well as after at broadcasting.