VS1053B Datasheet, PDF (76/79 Pages) List of Unclassifed Manufacturers – Ogg Vorbis/MP3/AAC/WMA/MIDI AUDIO CODEC

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VS1053b preliminary
VS1053B
11. VS1053 VERSION CHANGES
11 VS1053 Version Changes
This chapter describes the lastest and most important changes done to VS1053.
11.1 Changes Between VS1033c and VS1053a/b Firmware, 2007-03-08
Completely new or major changes:
• No software reset required between files when used correctly.
• Ogg Vorbis decoding added. Non-fatal ogg or vorbis decode errors cause automatic resync.
This allows easy rewind and fast forward. Decoding ends if the ”last frame” flag is reached or
SM CANCEL is set.
• HE-AAC v2 Level 3 decoding added. It is possible to disable PS and SBR processing and control
the upsampling modes through parametric x.control1.
• Like the WMA decoder, the AAC decoder uses the clock adder (see SCI CLOCKF) if it needs
more clock to decode the file. HE-AAC features are dropped one by one, if the file can not be
decoded correctly even with the highest allowed clock. Parametric stereo is the first feature to
be dropped, then downsampled mode is used, and as the final resort Spectral Band Replication is
disabled. Features are automatically restored for the next file.
• Completely new volume control with zero-cross detection prevents pops when volume is changed.
• Audio FIFO underrun detection (with slow fade to zero) instead of looping the audio buffer content.
• Average bitrate calculation (byteRate) for all codecs.
• All codecs support fast play mode with selectable speeds for the best-quality fast forward opera-
tion. Fast play also advances DECODE TIME faster.
• WMA and Ogg Vorbis provide an absolute decode position in milliseconds.
• When SM CANCEL is detected, the firmware also discards the stream buffer contents.
• Bit SCIST DO NOT JUMP in SCI STATUS is ’1’ when jumps in the file should not be done:
during header processing and with Midi files.
• IMA ADPCM encode now supports stereo encoding and selectable samplerate.
• I2S pins are now GPIO4-GPIO7 and do not overlap with SPI boot pins.
Other changes or additions:
• Delayed volume and bass/treble control calculation reduces the time the corresponding SCI oper-
ations take. This delayed handling and the new volume control hardware prevents audio samples
from being missed during volume change.
• SCI DECODE TIME only cleared at hardware and software reset to allow files to be played back-
to-back or looped.
• Read and write to YRAM at 0xe000..0xffff added to SCI WRAMADDR/SCI WRAM.
• The resync parameter (parametric x.resync) is set to 32767 after reset to allow inifinite resyn-
chronization attempts (or until SM CANCEL is set). Old operation can be restored by writing 0
to resync after reset.
Version 0.5, 2007-12-03
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