Search found 18 matches

by destmaster
Today 11:52
Forum: Microcontroller Software
Topic: VS1053 sample rate fine tuning value changes after a while
Replies: 9
Views: 277

Re: VS1053 sample rate fine tuning value changes after a while

There's some register that indicate audio frames drop count or something like that... to verify if VS1053 has discarded some audio frames? No, when there's an error, the next frame header is found and decoding continues. Fortunately Layer II frames are self-contained (layer III uses bit reservoir),...
by destmaster
Yesterday 9:41
Forum: Microcontroller Software
Topic: VS1053 sample rate fine tuning value changes after a while
Replies: 9
Views: 277

Re: VS1053 sample rate fine tuning value changes after a while

NB: I decode an MPEG 1 Layer II stream Is the stream guaranteed to be error-free? Are you able to store the data you send to vs1053b? However, I would expect bit errors to cause audio frames to be discarded, and then the finetune value should become negative to play the audio slower to account for ...
by destmaster
Tue 2021-02-23 18:27
Forum: Microcontroller Software
Topic: VS1053 sample rate fine tuning value changes after a while
Replies: 9
Views: 277

Re: VS1053 sample rate fine tuning value changes after a while

Temperature (and voltage) variation affect the oscillation frequency. Capacitance also affects the oscillation frequency - how well protected is your card? Is it in a metal enclosure? The card being a different temperature would explain some long-term variance. During winter the air is quite dry an...
by destmaster
Tue 2021-02-23 11:04
Forum: Microcontroller Software
Topic: VS1053 sample rate fine tuning value changes after a while
Replies: 9
Views: 277

Re: VS1053 sample rate fine tuning value changes after a while

Here another measurement... The system has running for about 20 hours with stabilized SRC and buffer value then the buffer filling increase instantaneously without any apparent reason (I'm monitoring the input stream and it has constant rate). The SRC control algo compensate the buffer filling and t...
by destmaster
Mon 2021-02-22 17:09
Forum: Microcontroller Software
Topic: VS1053 sample rate fine tuning value changes after a while
Replies: 9
Views: 277

VS1053 sample rate fine tuning value changes after a while

We have experienced a problem using your VS1053 with the sample rate fine tuning. We extract a MP2 stream from a live satellite DVB transport stream and send it to the VS1053, and then send de decoded audio (in I2S format) to an FPGA to process the audio. We are using the last (2.9) VS1053 FLAC_LATM...
by destmaster
Fri 2017-07-21 16:05
Forum: Slave Decoder Applications
Topic: VS1053b streaming: slow data request using SRC
Replies: 3
Views: 1786

Re: VS1053b streaming: slow data request using SRC

Hi Pasi, To modify the sample rate I use the fine tuning by using this function available with Patch 2.4 (15/16 resampler is also enabled) void AdjustRate(int32_t ppm2) { VS1053_Write_Reg(SCI_WRAMADDR, 0x1e07); VS1053_Write_Reg(SCI_WRAM, ppm2); VS1053_Write_Reg(SCI_WRAM, ppm2 >> 16); // oldClock4KHz...
by destmaster
Thu 2017-07-20 12:04
Forum: Slave Decoder Applications
Topic: VS1053b streaming: slow data request using SRC
Replies: 3
Views: 1786

VS1053b streaming: slow data request using SRC

Dear support, I'm using the VS1053b with patch 2.4 with FLAC plugin. My application decode an MPEG2 (MPEG1 layer 2) audio streaming coming from satellite. An FPGA extracts the ES from the satellite transport stream and puts in a FIFO. This FIFO is read by an MCU that fills a local buffer. 32 bytes o...
by destmaster
Fri 2017-03-10 12:36
Forum: Slave Decoder Applications
Topic: VS1053b streaming: fine tuning seems not works
Replies: 3
Views: 1426

Re: VS1053b streaming: fine tuning seems not works

Hi, Thank you for your answer! My next question is: how I can find the right "tuning word" (fine tuning value) to follow the encoder clock and prevent fifo overflows/underlows? The solution is to implement a software PLL that calculate the tuning word based on FIFO filling indication, then I've impl...
by destmaster
Fri 2017-03-03 18:43
Forum: Slave Decoder Applications
Topic: VS1053b streaming: fine tuning seems not works
Replies: 3
Views: 1426

VS1053b streaming: fine tuning seems not works

I'm trying to receive a MP2 stream from a SPI (serial peripheral interface) and send to the VS1053b (with FLAC patch 2.4). I receive 4 bytes at time and send immediately to the VS1053b if ((fpga_datavailable() == 1) && (vs_request() == 1)) { //Read from SPI FPGA_Read_Audio(localbuf, FPGA_READBUF); /...
by destmaster
Tue 2017-02-28 16:44
Forum: Slave Decoder Applications
Topic: VS1053b sample rate converter I2S output syncro
Replies: 3
Views: 1606

Re: VS1053b sample rate converter I2S output syncro

If I've understand right, the I2S output is taken before the SRC not affected by the SRC rate changes. On your opinion, how I can guarantee that will not be any buffer under/overrun into decoder? My idea is to slow shift (upper or lower) the 12,288MHz (XTALI) clock to follow the FIFO filling indicat...