Method for replacing a main content with at least one secondary content, corresponding content replacement device and computer program

A device for replacing a main content by at least one secondary content,

• said main content being carried by a transport stream, issued from a fixed transmitter and addressed to a plurality of broadcasting sites, called an original stream,
• wherein said device is associated with at least one of said broadcasting sites and comprises:
• a processor;
• and
• a non-transitory computer-readable medium comprising instructions stored thereon, which when executed by the processor configure the processor to perform acts comprising:
• determining an instant of video breaking and at least one instant of audio or subtitle breaking, from at least one breaking packet of said original stream,
• determining a ratio between the bit rate of said original stream and the video bit rate of said secondary content, called a video ratio,
• determining a ratio between the bit rate of said original stream and the audio bit rate of said secondary content, called an audio ratio and/or a ratio between the bit rate of said original stream and the bit rate of the subtitle of said secondary content, called a subtitle ratio,
• replacement, in said original stream:
• of at least one video packet of said main content, called a video packet to be replaced, by at least one video packet of said secondary content or by a null packet, called a replacement video packet, activated from said instant of video breaking, and
• at least one audio packet or subtitle packet of said main content, called an audio packet or subtitle packet to be replaced, by at least one audio packet or subtitle packet of said secondary content or by a null packet, called a replacement audio packet or subtitle packet, activated from said at least one instant of audio or subtitle breaking,
• delivering a stream,
• said replacement comprising:
• for replacement of at least one video packet to be replaced of said main content, operating a first counter representing a number of packets between two replacement video packets of the secondary content, at a null value, and a first variable representing a number of packets before the next video packet to be replaced at the value of a cumulative variable of video ratio, defined from said video ratio,
• for replacement of at least one audio packet or subtitle packet to be replaced of said main content, operating a second counter representing a number of packets between two replacement audio packets or subtitle packets of the secondary content at a null value, and a second variable representing a number of packets before the next audio packet or subtitle packet to be replaced at the value of a cumulative variable of audio or subtitle ratio, defined from said audio or subtitle ratio,
• updating in said modified stream:
• a reference clock,
• a continuity counter for counting video packets and at least one video reconstruction temporal information in said replacement video packet or packets, and
• a continuity counter of audio or subtitle packets and at least one audio or subtitle reconstruction temporal information in said replacement audio or subtitle packet or packets, taking account of said at least one video reconstruction temporal information.

At least one non-transitory computer-readable medium comprising a computer program stored thereon comprising instructions to implement a method of replacement of a main content by at least one secondary content, when this program can be executed by at least one processor in at least one device for replacing contents associated with at least one of said broadcasting sites, said main content being carried by a transport stream, issued by a fixed transmitter and addressed to a plurality of broadcasting sites, called an original stream, wherein the method implements the following steps in the at least one device:

• determining an instant of video breaking and at least one instant of audio or subtitle breaking, on the basis of at least one breaking packet of said original stream,
• determining a ratio between the bit rate of said original stream and the video bit rate of said secondary content, called a video ratio,
• determining a ratio between the bit rate of said original stream and the audio bit rate of said secondary content, called an audio ratio, and/or a ratio between the bit rate of said original stream and the subtitle bit rate of said secondary content, called a subtitle ratio,
• replacing in said original stream:
• at least one video packet of said main content, called a video packet to be replaced, by at least one video packet of said secondary content or by a null packet, called a replacement video packet, starting from said video breaking instant, and
• at least one audio packet or subtitle packet of said main content, called an audio packet or subtitle packet to be replaced, by at least one audio packet or subtitle packet of said secondary content or by a null packet, called a replacement audio packet or subtitle packet starting from said at least one audio or subtitle breaking instant,
• delivering a modified stream,
• said step of replacing implementing the following sub-steps:
• for the replacement of at least one video packet to be replaced of said main content:
• initialization of a first counter representing a number of packets between two replacement video packets of the secondary content at a null value and of a first variable representing a number of packets before the next video packet to be replaced at the value of a cumulative video ratio variable defined on the basis of said video ratio,
• at each video packet to be replaced of said original stream:
• incrementing of said first counter,
• replacement of said video packet to be replaced by one of said video packets of the secondary content when the value of said first counter is greater than or equal to the value of said first variable,
• replacement of said video packet to be replaced by a null packet, else,
• updating of said first variable;
• for the replacement of at least one audio packet or subtitle packet to be replaced of said main content:
• initialization of a second counter representing a number of packets between two replacement audio packets or subtitle packets of the secondary content at a null value, and of a second variable representing a number of packets before the next audio packet or subtitle packet to be replaced at the value of a cumulative variable of audio ratio or subtitle ratio defined on the basis of said audio or subtitle ratio,
• at each audio packet or subtitle packet to be replaced of said original stream:
• incrementing of said second counter,
• replacement of said audio packet or subtitle packet to be replaced by one of said audio or subtitle packets of the secondary content when the value of said second counter is greater than or equal to the value of said second variable,
• replacement of said audio packet to be replaced with a null packet, else,
• updating of said second variable,
• updating, in said modified stream:
• a reference clock,
• a continuity counter of video packets and at least one video reconstruction temporal information in said replacement video packet or packets, and
• a continuity counter of audio packets or subtitle packets and at least one audio or subtitle reconstruction temporal information in said replacement audio or subtitle packet or packets, taking account of said at least one video reconstruction temporal information.