Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Playing stereo_44100.wav too slow and without RDS #81

Open
andimik opened this issue Dec 23, 2020 · 2 comments
Open

Playing stereo_44100.wav too slow and without RDS #81

andimik opened this issue Dec 23, 2020 · 2 comments

Comments

@andimik
Copy link

andimik commented Dec 23, 2020

I am using a RPI3B and could build PiFmAdv without any problem.

But when I want to test it with the stereo_44100.wav I hear a male voice but this is very very slow. I can even not understand what the voice is saying.

$ sudo ./pi_fm_adv -a stereo_44100.wav -f 87.9
Carrier: 87.90 Mhz, VCO: 966.9 MHz, Multiplier: 50.359375, Divider: 11
Allocating physical memory: size = 4354048, mem_ref = 8, bus_addr = fe40e000, virt_addr = 0x767ca000
Master PLLA Locked
PPM correction is 0.0000, divider is 2120.3947 (2120 + 1616*2^-12).
Using audio file: stereo_44100.wav
Input: 44100 Hz, upsampling factor: 5.17
2 channels, generating stereo multiplex.
Created preemphasis with cutoff at 3185 Hz
Created low-pass FIR filter for audio channels, with cutoff at 15000 Hz
RDS Options:
RDS: 1, PI: 1234, PS: "PiFmAdv", PTY: 15
RT: "PiFmAdv: Advanced FM transmitter for the Raspberry Pi"
Starting to transmit on 87.9 MHz.
^CTerminating: cleanly deactivated the DMA engine and killed the carrier.

I've added gpu_freq=250 to /boot/config.txt

$ cat /proc/cpuinfo
processor	: 0
model name	: ARMv7 Processor rev 4 (v7l)
BogoMIPS	: 38.40
Features	: half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32 
CPU implementer	: 0x41
CPU architecture: 7
CPU variant	: 0x0
CPU part	: 0xd03
CPU revision	: 4

processor	: 1
model name	: ARMv7 Processor rev 4 (v7l)
BogoMIPS	: 38.40
Features	: half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32 
CPU implementer	: 0x41
CPU architecture: 7
CPU variant	: 0x0
CPU part	: 0xd03
CPU revision	: 4

processor	: 2
model name	: ARMv7 Processor rev 4 (v7l)
BogoMIPS	: 38.40
Features	: half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32 
CPU implementer	: 0x41
CPU architecture: 7
CPU variant	: 0x0
CPU part	: 0xd03
CPU revision	: 4

processor	: 3
model name	: ARMv7 Processor rev 4 (v7l)
BogoMIPS	: 38.40
Features	: half thumb fastmult vfp edsp neon vfpv3 tls vfpv4 idiva idivt vfpd32 lpae evtstrm crc32 
CPU implementer	: 0x41
CPU architecture: 7
CPU variant	: 0x0
CPU part	: 0xd03
CPU revision	: 4

Hardware	: BCM2835
Revision	: 2a02082
Serial		: 00000000b5d9d67a
Model		: Raspberry Pi 3 Model B Rev 1.2

This is the audio file

gqrx_20201223_200613_87900000.zip

The Pilot is NOT at 19 kHz and RDS is not on 57 kHz.

Screenshot (204)

@evertverduin
Copy link

evertverduin commented Jan 1, 2021

There is no support, at least, no one of the devs responds.
Edited 02-01-2021:

My solution was to erase raspberry os!
install Raspbian Jesse lite, and install gpu_freq=250 in config.txt

DON'T USE MODERN RASPBERRY PI-OS!

Symptoms are:
Baseband signal is at half of it's sampling rate. Audio to slow, pilot on 9.5 khz and rds at rds/2.

Solution -> install Raspbian Jesse. with gpu_freq=250 in config.txt

And IT Will work!

BR

Evert

@andimik
Copy link
Author

andimik commented Jan 20, 2021

I solved it by using https://github.com/mundeeplamport/PiFM instead. This fork allows option -p (which does not work in PiFmAdv, only in PiFmRds and PiFM)

No need to reinstall OS.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants