Australian journalist Peter Greste, who was deported to his home country in February, is being tried in absentia.
Also on trial are Canadian reporter Mohamed Fahmy and Egyptian producer Baher Mohamed, as well as others, all of whom attended today's hearing as free men after the judge released them at their first retrial hearing.
Greste, Fahmy and Mohamed, who are accused of "spreading false news" while covering demonstrations after the army ousted Islamist president Mohamed Morsi in 2013, spent more than a year in prison.
Today, the court ordered creation of a new technical committee to review the videos used as prosecution evidence, said an AFP journalist who attended the trial.
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It also heard several witnesses, including a member of the technical committee whose testimony was used during the first trial.
The expert denied the conclusions of the technical report attributed to him that was used against the defendants in the first trial.
"Some videos have been edited, but I can not say if they have altered the reality (of events) or not," he added.
The journalists were arrested in December 2013 during a crackdown on Morsi's supporters.
Their initial trial came against the backdrop of strained ties between Egypt and Qatar, where Al-Jazeera is based and which supported Morsi.