2020-02956 - PhD Position F/M Optimization of a multi-profile video compression scheme
Le descriptif de l’offre ci-dessous est en Anglais

Type de contrat : CDD

Niveau de diplôme exigé : Bac + 5 ou équivalent

Fonction : Doctorant

A propos du centre ou de la direction fonctionnelle

The Inria Rennes - Bretagne Atlantique Centre is one of Inria's eight centres and has more than thirty research teams. The Inria Center is a major and recognized player in the field of digital sciences. It is at the heart of a rich R&D and innovation ecosystem: highly innovative PMEs, large industrial groups, competitiveness clusters, research and higher education players, laboratories of excellence, technological research institute, etc.

Contexte et atouts du poste

In the context of a partnership between Inria and MediaKind France, Inria-Rennes Bretagne Atlantique is recruiting a PhD candidate with a background in image processing, signal processing, and image/video compression. The expected duration of the contract is 3 years. The start date is open (early 2021).

Location: The PhD candidate will be based at Rennes, half-time at Inria Rennes (Campus universitaire de Beaulieu, 263, avenue du Général Leclerc, Rennes), half-time at MediaKind Rennes (5 rue Louis Jacques Daguerre, Saint Jacques De la Lande - Rennes).

Mission confiée

Handling rapidly growing video traffic, which exhausts the overall network traffic, is of great importance. In particular,
reducing the infrastructure size and usage will help to also reduce the industrial costs and will have a huge impact on the digital ecosystem. 

The challenge in live streaming is to propose a video content to as many people as possible and disseminate this content on as many different platforms as possible. As a consequence, a video is encoded and stored in several formats (resolution, bitrate, etc).  To adapt the bitrate to the network bandwidth and deliver the best user-experience, an adaptive bitrate streaming technique, such as MPEG-DASH [2] is then used.

Still this solution is suboptimal in terms of CPU usage. Indeed, several representations have to be computed and stored in either short-term or long-term memory to respond fast to any request. To reduce the computational complexity while maintaining a high quality of service, a tradeoff has to be found between the processing performed at the server and the amount of stored data.

The goal of the PhD will be to investigate new video representations at the server in order to exploit all the correlations among the several video formats and thus to reduce the computational complexity and the storage. In particular, the solution will depart from the standardized but also suboptimal scalable coding [1] and will instead investigate some new video coding schemes with partial transcoding techniques such as [3,4] or inspired by information theory such as [5,6].

[1] J. M. Boyce, Y. Ye, J. Chen and A. K. Ramasubramonian, "Overview of SHVC: Scalable Extensions of the High Efficiency Video Coding Standard," in IEEE Transactions on Circuits and Systems for Video Technology, vol. 26, no. 1, pp. 20-34, Jan. 2016.
[2] I. Sodagar, “MPEG-DASH: The Standard for Multimedia Streaming Over Internet”, ISO/IEC JTC1/SC29/WG11 W13533, April 2012, Incheon, KR
[3] C. Hollmann, R. Sjöberg, “Guided transcoding using Deflation and Inflation”, Packet Video Workshop 2018, July 2018.
[4]  K. Goswami et al., "Adaptive Multi-Resolution Encoding for ABR Streaming," IEEE International Conference on Image Processing (ICIP), Athens, 2018.
[5] T. Maugey, A. Roumy, E. Dupraz and M. Kieffer. ``Incremental coding for extractable compression in the context of Massive Random Access'', IEEE Transactions on Signal and Information Processing over Networks Accepted in Feb. 2020.
[6] N. Mahmoudian-Bidgoli, T. Maugey, A. Roumy, ``Fine granularity access in interactive compression of 360-degree images based on rate adaptive channel codes'', accepted in IEEE Transactions on Multimedia, June 2020.

Principales activités

How to apply Each application should consist of

  • a CV,
  • a letter of introduction
  • a copy of the student’s university transcripts.

(PDF format would be appreciated).

In the letter, the applicant should include the following details:

  • An explanation of his/her interest in the research we conduct and why he/she believes he/she is suitable for the position.
  • Details of final year undergraduate project (if applicable)
  • Details of MSc project (if applicable).
  • Details of any relevant modules previously taken, at undergraduate and/or Masters Level.
  • Details of any relevant work experience (if applicable).


  • Subsidized meals
  • Partial reimbursement of public transport costs


  monthly gross salary amounting to 1982 euros for the first and second years and 2085 euros for the third year