Перейти к основному содержимому

Skaņas kartes

Внимание

Дата публикации: 22 сентября 2023 года

Ievads​

Ta ir pereferijas gan ievad gan izvad ierice, kas parveido ienakošo analogu skaņas signalu digitalo formatu un saglaba kā datnes kodejot audio informaciju, vai atkal parveido skaņa analogo formatu lai izvadid uz skalruniem, vai izvadid skalruniem vai citiem sistemam.

Darbibas princips​

Iedalijums​

Pēc uzbūves​

  • Integrated MD (main board) (audio chip, part of SB (South Bridge)) — system
  • Sound cards — perepherals (ISA, EISA, MCA, PCI, PCI-X, PCIe), ārējas (USB, …)

Pēc audio kanāliem​

  • Mono — 1 channel (iebuvēts skaļrunis datorā)
  • Stereo — 2 channels (1 left + 1 right)
    • 2.0 — l + r
    • 2.1 — l + r + subwoofer (sw)
  • Quadphonic 4.0 — 4.0 channels: l + f (front), l + r (rear)
  • Surround
    • 5.1 — l + f (front/30gr.) + l + r (rear/100gr.) + central (c) + sw
    • 7.1 — l + f (front/30gr.) + l + r (rear/100gr.) + central (c) + sw + l + r (surround/90gr.)

Pēc kodekiem (codec)​

Optical Drives​

  • PCM (Pulse code modulation)
    • CD (compact disk) → DA (digital audio)
  • DSD (direct stream digital)
    • Super Audio CD
  • Dolby Digital (AC-3)
    • DVD Audio (digital versitle disk)
  • Dolby Thrue HD
    • BD (Blue-ray Disk)

Computers (integrated, sound cards)​

  • AC’97
    • Stereo 2.0, 7.1
  • Intel HD Audio
    • Surround 5.1, 7.1

Digital skaņas tehnoloģijas un ātrumi​

CD Audio​

  • 1980 g.
  • Philips & Sony
  • Duration 79.8 min — 1.411 Mb/s

AWS/EBU​

  • 1985 g.
  • Standart IEC60958 — 2.625 Mb
    • Type 1: Balances XLR connector (coaxial)
    • Type 2: Unbalanced RCA connector (coaxial)
    • Type 3: F0S / TOSLINK (Toshiba link) connector (fiber optics)

S/PDIF (Sony/Philips Digital Interface)​

  • Type 2 and Type 3 (for end users) — 3.072 Mb/s

ADAT​

  • 1991 g.
  • Alexis Digital
  • Audio Tape S-VHS
  • TOSLINK — 9.216 Mb/s

AC’97 (Audio Codec)​

  • 1997 g. by Intel
  • Interconnection between integrated circuits — 12.288 Mb/s

HDMI (High Definition Multimedia Interface)​

  • 2002 g. (v1), 2013 g. (v2)
  • Video + audio with HDCP (high bandwith digital copy protection) — 36.864 Mb/s

DisplayPort​

  • 2006 g.
  • Video + audio with DPCP (displayport connect protection) — 36.864 Mb/s

Intel HD Audio (High Definition)​

  • 2004 g.
  • Successor to AC’97 — 48 Mb/s

MADI (Microchannel Audio Digital Interface)​

  • 1991 g.
  • 02AES10
  • Audio systems interconnection
  • LAN integration — 100 Mb

Uzbūve​

  • PCB (printed circuit board)
  • SMT (surface mount technology)
    • Integrated circuits, transistors, resistors, capacitors, diodes, …
  • DSP (digital signal processor)
  • ADC (analog-to-digital converter)
  • DAC (digital-to-analog converter)
  • ADC + DAC = CODEC (hardware)
  • BIOS, ROM
  • Bus (kopne)
  • Connectors (Input / Output)

Parametri​

  • DSP frekvence, Hz; platums, bits
  • RAM frekvence Hz; apjoms, Bytes
  • Kopnes platums, bits
  • Skaņas kvalitāte
    • THD (total harmonic distortion), %
    • SNR (signal-to-noise ratio), dB
  • ADC, DAC capacity, bits
  • Skaņas frekvence: cilvēka dzirdes diapazons (analog) — 20Hz–20000Hz (20kH)
  • Sampling rate (digital), samples/sec → Hz, piem. 44100 Hz (for CD audio)
  • Volume, dB
  • Equalizing, mixing
  • Channels format
  • Codecs
  • Bus: PIC-E, …
  • Connectors (I/O)
  • API (application programming interface)
    • Allow the sound card to communicate with OS
  • Certifications: Dolby Master, THX, …

Skaņas formati​

  • Uncompressed: WAV, AIFF, AU, PCM, …
  • Compressed
    • Lossless: FLAC, TTA, WV, ATRAC, …
    • Lossy: MP3, AAC, WMA, …

Konnektoru komplekts un krāsu shēma​

Mini Jack 3.5mm​

  • Pink: microphone (input)
  • Light blue: analog line (input)
  • Lime green: headphones, front (l + r) (output)
  • Orange: c + sw (output)
  • Black: rear (l + r) — 5.1 (surround) (output)
  • Silver/grey: 7.1 (surround (l + r)) (output)

15 Pin D​

  • Game port (joystick)
  • MIDI port (instrumental music)