Question: What is a key requirement for a PSS (Packet-switched Streaming Service) client's video decoder when receiving a packet stream over a constant-delay reliable transmission channel?
Option 1: The decoder must introduce additional latency to synchronize with the server's clock.
Option 2: The decoder shall output frames at the correct rate defined by the P time-stamps of the received packet stream.
Option 3: The client can adjust the frame rate based on the available bandwidth.
Option 4: The decoder is not required to handle post-decoder buffering when using a reliable transmission channel.
Explanation: This option is correct because, according to specifications, the PSS client's video decoder must ensure outputting frames at the precise rate dictated by the P time-stamps within the received packet stream, maintaining synchronization and quality as intended by the content provider.