Difference between revisions of "Hardware or Software Decoder?"

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The old standard for DVB cards was to have a hardware MPEG decoder on the card itself. That would decode the incoming MPEG stream, therefore not use the CPU resources (but more PCI bus resources). These cards are often called [[full-featured Card]]s.
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It use to be common for DVB cards to contain a hardware MPEG2 decoder, so that the incoming MPEG stream would be decoded on the card itself.
  
Nowadays, most cards are [[budget]], i.e. they don't have that additional chip. Instead, the still encoded, unchanged stream goes to the CPU and some viewers software then does the decoding.  
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* these cards featured a decoder that is capable of MP@ML only ... i.e. up to SDTV resolutions only). 
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* therefore alleviating the host system's CPU from such a task i.e don't use the CPU resources (but more PCI bus resources are used though...large uncompressed SDTV stream).  
  
See also
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This hardware decoding class of cards are often referred to as Premium or [[Full-featured Card]]s.  This is rather a misnomer given that:
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* the MPEG decoders are incapable of MP@HL
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* ATSC hardware decoding cards -- uncommon to see such labels applied to them, and yet, they were capable of MP@HL (i.e more full-featured then their DVB-x counterparts)
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Nowadays, most cards can be classified as software decoding devices. Instead, the still encoded, unchanged stream goes to the CPU and is decoded based upon the algorithms of a software decoder. These cards are also sometimes referred to, in antiquated terms, as [[budget]] cards, i.e. a reference to the fact that they lack a MPEG decoder chip, as would be found on a so called "premium" or "full-featured card".
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==Also see:==
 
* [[VDR Software Decoder Plugin]]
 
* [[VDR Software Decoder Plugin]]
 
* [http://www.linuxtv.org/vdrwiki/index.php/Output_devices Output devices (VDR wiki)]
 
* [http://www.linuxtv.org/vdrwiki/index.php/Output_devices Output devices (VDR wiki)]

Revision as of 19:37, 27 March 2007

It use to be common for DVB cards to contain a hardware MPEG2 decoder, so that the incoming MPEG stream would be decoded on the card itself.

  • these cards featured a decoder that is capable of MP@ML only ... i.e. up to SDTV resolutions only).
  • therefore alleviating the host system's CPU from such a task i.e don't use the CPU resources (but more PCI bus resources are used though...large uncompressed SDTV stream).

This hardware decoding class of cards are often referred to as Premium or Full-featured Cards. This is rather a misnomer given that:

  • the MPEG decoders are incapable of MP@HL
  • ATSC hardware decoding cards -- uncommon to see such labels applied to them, and yet, they were capable of MP@HL (i.e more full-featured then their DVB-x counterparts)

Nowadays, most cards can be classified as software decoding devices. Instead, the still encoded, unchanged stream goes to the CPU and is decoded based upon the algorithms of a software decoder. These cards are also sometimes referred to, in antiquated terms, as budget cards, i.e. a reference to the fact that they lack a MPEG decoder chip, as would be found on a so called "premium" or "full-featured card".


Also see: