diff --git a/.gitignore b/.gitignore index 1c66740..d64bf78 100644 --- a/.gitignore +++ b/.gitignore @@ -1,3 +1,2 @@ *.o -*.swp fm_transmitter diff --git a/README.md b/README.md index ab98ad5..7295ea3 100644 --- a/README.md +++ b/README.md @@ -1,44 +1,47 @@ # fm_transmitter - -Use Raspberry Pi as FM transmitter. Works on any RPi board. +Use Raspberry Pi as FM transmitter. Works on any Raspberry Pi board. This project uses the general clock output to produce frequency modulated radio communication. It is based on idea originaly posted here: [http://icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter](http://icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter), but does not use DMA controller in order to distribute samples to output (clock generator), so sound quality is worse as in PiFm project and only mono transmition is available but this makes possible to run it on all kind of boards. ## How to use it - -To compile this project use commands below: +To use this project You will have to buid it. First, clone this repository, then use "make" command as shown below: ``` -sudo apt-get install make gcc g++ +git clone https://github.com/markondej/fm_transmitter +cd fm_transmitter make ``` - -Then you can use it by typing: +After successful build You can start transmitting by typing: ``` -sudo ./fm_transmitter [-f frequency] [-r] filename +sudo ./fm_transmitter -f 102.0 acoustic_guitar_duet.wav ``` -where: -* -f frequency - Specifies the frequency in MHz, default is 100.0 -* -r - Loops the file -* filename - WAVE file name +Where: +* -f 102.0 - Specifies the frequency in MHz, if not passed default is 100.0 +* acoustic_guitar_duet.wav - Sample WAVE file, You can use your own -### WAVE Files -You can open uncompressed WAVE (.wav) files or read audio data from stdin, eg.: +### Supported audio files +You can transmitt uncompressed WAVE (.wav) files directly or read audio data from stdin, eg.: ``` sox star_wars.wav -r 22050 -c 1 -b 16 -t wav - | sudo ./fm_transmitter -f 100.6 - ``` - +Notice only uncompressed WAVE files are supported. If You expire "corrupted data" error try converting file, eg. by using SoX: +``` +sox my-audio.mp3 -r 22050 -c 1 -b 16 -t wav my-converted-audio.wav +sudo ./fm_transmitter -f 100.6 my-converted-audio.wav +``` ### USB microphone To use a USB sound card microphone input use arecord, eg.: ``` arecord -D hw:1,0 -c1 -d 0 -r 22050 -f S16_LE | sudo ./fm_transmitter -f 100.6 - ``` -In case of performance dropdown use ```plughw:1,0``` instead of ```hw:1,0```. +In case of performance drop down use ```plughw:1,0``` instead of ```hw:1,0```. ## Legal note Please keep in mind that transmitting on certain frequencies without special permissions may be illegal in your country. ## New features -* works on RPi 1, 2 and 3 +* works on any Raspberry Pi model * reads mono and stereo files * reads data from stdin * based on threads + +Included sample audio was created by [graham_makes](https://freesound.org/people/graham_makes/sounds/449409/) and published on [freesound.org](https://freesound.org/) \ No newline at end of file diff --git a/acoustic_guitar_duet.wav b/acoustic_guitar_duet.wav new file mode 100644 index 0000000..896bb8c Binary files /dev/null and b/acoustic_guitar_duet.wav differ diff --git a/audio_format.h b/audio_format.h deleted file mode 100644 index 221b3b1..0000000 --- a/audio_format.h +++ /dev/null @@ -1,44 +0,0 @@ -/* - fm_transmitter - use Raspberry Pi as FM transmitter - - Copyright (c) 2015, Marcin Kondej - All rights reserved. - - See https://github.com/markondej/fm_transmitter - - Redistribution and use in source and binary forms, with or without modification, are - permitted provided that the following conditions are met: - - 1. Redistributions of source code must retain the above copyright notice, this list - of conditions and the following disclaimer. - - 2. Redistributions in binary form must reproduce the above copyright notice, this - list of conditions and the following disclaimer in the documentation and/or other - materials provided with the distribution. - - 3. Neither the name of the copyright holder nor the names of its contributors may be - used to endorse or promote products derived from this software without specific - prior written permission. - - THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY - EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES - OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT - SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED - TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR - BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN - CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY - WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -*/ - -#ifndef AUDIO_FORMAT_H -#define AUDIO_FORMAT_H - -struct AudioFormat -{ - unsigned short channels; - unsigned short bitsPerSample; - unsigned sampleRate; -}; - -#endif // AUDIO_FORMAT_H diff --git a/error_reporter.h b/error_reporter.h index 2e6fd25..4a35c2f 100644 --- a/error_reporter.h +++ b/error_reporter.h @@ -44,9 +44,9 @@ class ErrorReporter : public exception { public: explicit ErrorReporter(string message); - virtual ~ErrorReporter() throw(); + virtual ~ErrorReporter() throw(); - virtual const char* what() const throw(); + virtual const char* what() const throw(); protected: string errorMessage; }; diff --git a/main.cpp b/main.cpp index e0d3081..81f07cf 100644 --- a/main.cpp +++ b/main.cpp @@ -31,25 +31,17 @@ WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ -#include -#include "wave_reader.h" #include "transmitter.h" #include #include +#include +#include using namespace std; bool stop = false; Transmitter* transmitter = NULL; -AudioFormat* getFormat(string filename) { - stop = false; - WaveReader* reader = new WaveReader(filename, stop); - AudioFormat* format = reader->getFormat(); - delete reader; - return format; -} - void sigIntHandler(int sigNum) { if (transmitter != NULL) { @@ -64,23 +56,23 @@ int main(int argc, char** argv) double frequency = 100.0; bool loop = false; string filename; - bool showUsage = true; - for (int i = 1; i < argc; i++) { - if (string("-f") == argv[i]) { - if (i < argc - 1) { - frequency = ::atof(argv[i + 1]); - i++; - } - } else if (string("-r") == argv[i]) { - loop = true; - } else { - if (i == argc - 1) { - showUsage = false; - filename = argv[i]; - } + int opt; + + while ((opt = getopt(argc, argv, "rf:")) != -1) { + switch (opt) { + case 'r': + loop = true; + break; + case 'f': + frequency = ::atof(optarg); + break; } } + if (optind < argc) { + filename = argv[optind]; + showUsage = false; + } if (showUsage) { cout << "Usage: " << argv[0] << " [-f frequency] [-r] FILE" << endl; return 0; @@ -90,19 +82,13 @@ int main(int argc, char** argv) try { transmitter = Transmitter::getInstance(); - - if (filename != "-") { - AudioFormat* format = getFormat(filename); - cout << "Playing: " << filename << ", " - << format->sampleRate << " Hz, " - << format->bitsPerSample << " bits, " - << ((format->channels > 0x01) ? "stereo" : "mono") << endl; - delete format; - } else { - cout << "Playing: STDIN" << endl; - } - - transmitter->play(filename, frequency, loop); + WaveReader reader(filename != "-" ? filename : string(), stop); + PCMWaveHeader header = reader.getHeader(); + cout << "Playing: " << reader.getFilename() << ", " + << header.sampleRate << " Hz, " + << header.bitsPerSample << " bits, " + << ((header.channels > 0x01) ? "stereo" : "mono") << endl; + transmitter->play(&reader, frequency, 0, loop); } catch (exception &error) { cout << "Error: " << error.what() << endl; return 1; diff --git a/makefile b/makefile index 1094a22..6913d72 100644 --- a/makefile +++ b/makefile @@ -1,22 +1,24 @@ -CFLAGS += -Wall -fexceptions -pthread -lm -O3 -fpermissive -fno-strict-aliasing +FLAGS = -Wall -fexceptions -pthread -O3 -fpermissive -fno-strict-aliasing +INCLUDES = -I/opt/vc/include -L/opt/vc/lib +LIBS = -lm -lbcm_host TARGET = fm_transmitter CPP=$(CCPREFIX)g++ all: main.o error_reporter.o wave_reader.o transmitter.o - $(CPP) $(CFLAGS) -o $(TARGET) main.o error_reporter.o wave_reader.o transmitter.o + $(CPP) $(FLAGS) $(INCLUDES) $(LIBS) -o $(TARGET) main.o error_reporter.o wave_reader.o transmitter.o wave_reader.o: wave_reader.cpp wave_reader.h - $(CPP) $(CFLAGS) -c wave_reader.cpp + $(CPP) $(FLAGS) $(INCLUDES) $(LIBS) -c wave_reader.cpp error_reporter.o: error_reporter.cpp error_reporter.h - $(CPP) $(CFLAGS) -c error_reporter.cpp + $(CPP) $(FLAGS) $(INCLUDES) $(LIBS) -c error_reporter.cpp transmitter.o: transmitter.cpp transmitter.h - $(CPP) $(CFLAGS) -c transmitter.cpp + $(CPP) $(FLAGS) $(INCLUDES) $(LIBS) -c transmitter.cpp main.o: main.cpp - $(CPP) $(CFLAGS) -c main.cpp + $(CPP) $(FLAGS) $(INCLUDES) $(LIBS) -c main.cpp clean: rm *.o diff --git a/star_wars.wav b/star_wars.wav deleted file mode 100644 index 4ea3eac..0000000 Binary files a/star_wars.wav and /dev/null differ diff --git a/transmitter.cpp b/transmitter.cpp index 33c1595..8463066 100644 --- a/transmitter.cpp +++ b/transmitter.cpp @@ -32,16 +32,15 @@ */ #include "transmitter.h" -#include "wave_reader.h" +#include "error_reporter.h" +#include #include #include -#include -#include -#include #include #include using std::ostringstream; +using std::vector; #define GPIO_BASE 0x00200000 #define CLK0_BASE 0x00101070 @@ -51,40 +50,14 @@ using std::ostringstream; #define ACCESS(base, offset) *(volatile unsigned*)((int)base + offset) #define ACCESS64(base, offset) *(volatile unsigned long long*)((int)base + offset) -bool Transmitter::transmitting = false; -bool Transmitter::restart = false; -unsigned Transmitter::clockDivisor = 0; -unsigned Transmitter::frameOffset = 0; -vector* Transmitter::buffer = NULL; -void* Transmitter::peripherals = NULL; - Transmitter::Transmitter() { - bool isBcm2835 = true; - - FILE* pipe = popen("uname -m", "r"); - if (pipe) { - char buffer[64]; - string machine = ""; - while (!feof(pipe)) { - if (fgets(buffer, 64, pipe)) { - machine += buffer; - } - } - pclose(pipe); - - machine = machine.substr(0, machine.length() - 1); - if (machine != "armv6l") { - isBcm2835 = false; - } - } - int memFd; if ((memFd = open("/dev/mem", O_RDWR | O_SYNC)) < 0) { throw ErrorReporter("Cannot open /dev/mem (permission denied)"); } - peripherals = mmap(NULL, 0x002FFFFF, PROT_READ | PROT_WRITE, MAP_SHARED, memFd, isBcm2835 ? 0x20000000 : 0x3F000000); + peripherals = mmap(NULL, bcm_host_get_peripheral_size(), PROT_READ | PROT_WRITE, MAP_SHARED, memFd, bcm_host_get_peripheral_address()); close(memFd); if (peripherals == MAP_FAILED) { throw ErrorReporter("Cannot obtain access to peripherals (mmap error)"); @@ -93,7 +66,7 @@ Transmitter::Transmitter() Transmitter::~Transmitter() { - munmap(peripherals, 0x002FFFFF); + munmap(peripherals, bcm_host_get_peripheral_size()); } Transmitter* Transmitter::getInstance() @@ -102,7 +75,7 @@ Transmitter* Transmitter::getInstance() return &instance; } -void Transmitter::play(string filename, double frequency, bool loop) +void Transmitter::play(WaveReader* reader, double frequency, unsigned char dmaChannel, bool loop) { if (transmitting) { throw ErrorReporter("Cannot play, transmitter already in use"); @@ -111,40 +84,45 @@ void Transmitter::play(string filename, double frequency, bool loop) transmitting = true; forceStop = false; - WaveReader* reader = new WaveReader(filename != "-" ? filename : string(), forceStop); - AudioFormat* format = reader->getFormat(); + PCMWaveHeader header = reader->getHeader(); + unsigned bufferFrames = (unsigned)((unsigned long long)header.sampleRate * BUFFER_TIME / 1000000); + vector* frames = reader->getFrames(bufferFrames, forceStop); + if (frames == NULL) { + return; + } + bool eof = frames->size() < bufferFrames; + vector* buffer = frames; - clockDivisor = (unsigned)((500 << 12) / frequency + 0.5); - unsigned bufferFrames = (unsigned)((unsigned long long)format->sampleRate * BUFFER_TIME / 1000000); + unsigned frameOffset = 0; + unsigned clockDivisor = (unsigned)((500 << 12) / frequency + 0.5); + bool restart = false; - frameOffset = 0; - restart = false; + void* params[8] = { + peripherals, + (void*)(unsigned*)&buffer, + (void*)(unsigned*)&frameOffset, + (void*)(unsigned*)&clockDivisor, + (void*)(unsigned*)&transmitting, + (void*)(unsigned*)&restart, + (void*)(unsigned*)&dmaChannel, + (void*)(unsigned*)&header.sampleRate + }; + + pthread_t thread; + int returnCode = pthread_create(&thread, NULL, &Transmitter::transmit, (void*)¶ms); + if (returnCode) { + delete frames; + ostringstream oss; + oss << "Cannot create new thread (code: " << returnCode << ")"; + throw ErrorReporter(oss.str()); + } + + usleep(BUFFER_TIME / 2); + + bool isError = false; + string errorMessage; try { - vector* frames = reader->getFrames(bufferFrames, forceStop); - if (frames == NULL) { - delete format; - delete reader; - return; - } - eof = frames->size() < bufferFrames; - buffer = frames; - - pthread_t thread; - void* params = (void*)&format->sampleRate; - - int returnCode = pthread_create(&thread, NULL, &Transmitter::transmit, params); - if (returnCode) { - delete reader; - delete format; - delete frames; - ostringstream oss; - oss << "Cannot create new thread (code: " << returnCode << ")"; - throw ErrorReporter(oss.str()); - } - - usleep(BUFFER_TIME / 2); - while (!forceStop) { while (!eof && !forceStop) { if (buffer == NULL) { @@ -178,72 +156,73 @@ void Transmitter::play(string filename, double frequency, bool loop) forceStop = true; } } - transmitting = false; - - pthread_join(thread, NULL); - } catch (ErrorReporter &error) { - delete reader; - delete format; - throw error; + } catch (ErrorReporter &error) { + errorMessage = error.what(); + isError = true; } - - delete reader; - delete format; - } + transmitting = false; + pthread_join(thread, NULL); + if (isError) { + throw ErrorReporter(errorMessage); + } +} void* Transmitter::transmit(void* params) { + void* peripherals = ((void**)params)[0]; + vector** buffer = (vector**)((void**)params)[1]; + unsigned* frameOffset = (unsigned*)((void**)params)[2], clockDivisor = (unsigned*)((void**)params)[3]; + bool* transmitting = (bool*)((void**)params)[4], restart = (bool*)((void**)params)[5]; + unsigned char dmaChannel = *(unsigned char*)((void**)params)[6]; + unsigned sampleRate = *(unsigned*)((void**)params)[7]; + unsigned long long current, start, playbackStart; - unsigned offset, length, temp; + unsigned offset, length, prevOffset; vector* frames = NULL; float* data; float value; + #ifndef NO_PREEMP float prevValue = 0.0; -#endif - - unsigned sampleRate = *(unsigned*)(params); - -#ifndef NO_PREEMP float preemp = 0.75 - 250000.0 / (float)(sampleRate * 75); #endif ACCESS(peripherals, GPIO_BASE) = (ACCESS(peripherals, GPIO_BASE) & 0xFFFF8FFF) | (0x01 << 14); ACCESS(peripherals, CLK0_BASE) = (0x5A << 24) | (0x01 << 9) | (0x01 << 4) | 0x06; - playbackStart = ACCESS64(peripherals, TCNT_BASE); - current = playbackStart; + current = ACCESS64(peripherals, TCNT_BASE); + playbackStart = current; - while (transmitting) { + while (*transmitting) { start = current; - while ((buffer == NULL) && transmitting) { + + while ((*buffer == NULL) && *transmitting) { usleep(1); current = ACCESS64(peripherals, TCNT_BASE); } - if (!transmitting) { + if (!*transmitting) { break; } - if (restart) { + if (*restart) { playbackStart = current; start = current; - restart = false; + *restart = false; } - frames = buffer; - frameOffset = (current - playbackStart) * (sampleRate) / 1000000; - buffer = NULL; + frames = *buffer; + *frameOffset = (current - playbackStart) * (sampleRate) / 1000000; + *buffer = NULL; + + offset = (current - start) * (sampleRate) / 1000000; length = frames->size(); data = &(*frames)[0]; - offset = 0; - while (true) { - temp = offset; if (offset >= length) { - offset -= length; break; } + prevOffset = offset; value = data[offset]; #ifndef NO_PREEMP @@ -251,8 +230,8 @@ void* Transmitter::transmit(void* params) value = (value < -1.0) ? -1.0 : ((value > 1.0) ? 1.0 : value); #endif - ACCESS(peripherals, CLK0DIV_BASE) = (0x5A << 24) | ((clockDivisor) - (int)(round(value * 16.0))); - while (temp >= offset) { + ACCESS(peripherals, CLK0DIV_BASE) = (0x5A << 24) | ((*clockDivisor) - (int)(round(value * 16.0))); + while (offset == prevOffset) { asm("nop"); current = ACCESS64(peripherals, TCNT_BASE); offset = (current - start) * (sampleRate) / 1000000; diff --git a/transmitter.h b/transmitter.h index be28727..66497d3 100644 --- a/transmitter.h +++ b/transmitter.h @@ -34,11 +34,7 @@ #ifndef TRANSMITTER_H #define TRANSMITTER_H -#include "error_reporter.h" -#include "audio_format.h" -#include - -using std::vector; +#include "wave_reader.h" #define BUFFER_TIME 1000000 @@ -48,21 +44,15 @@ class Transmitter { public: virtual ~Transmitter(); - - void play(string filename, double frequency, bool loop); - void stop(); - static Transmitter* getInstance(); + void play(WaveReader* reader, double frequency, unsigned char dmaChannel, bool loop); + void stop(); private: Transmitter(); - - bool forceStop, eof; - - static void* peripherals; - static vector* buffer; - static bool transmitting, restart; - static unsigned frameOffset, clockDivisor; static void* transmit(void* params); + + void* peripherals; + bool forceStop, transmitting; }; #endif // TRANSMITTER_H diff --git a/wave_reader.cpp b/wave_reader.cpp index 07de9e7..c06eac2 100644 --- a/wave_reader.cpp +++ b/wave_reader.cpp @@ -1,4 +1,4 @@ -#n/* +/* fm_transmitter - use Raspberry Pi as FM transmitter Copyright (c) 2018, Marcin Kondej @@ -34,16 +34,15 @@ #include "wave_reader.h" #include "error_reporter.h" #include -#include +#include #include #include -#include using std::ostringstream; using std::exception; WaveReader::WaveReader(string filename, bool &forceStop) : - filename(filename), currentFrameOffset(0), headerOffset(0) + filename(filename), headerOffset(0), currentFrameOffset(0) { char* headerData = (char*)((void*)&header); ostringstream oss; @@ -78,7 +77,7 @@ WaveReader::WaveReader(string filename, bool &forceStop) : throw ErrorReporter(oss.str()); } - readData(header.subchunk1Size, true, forceStop, headerData, headerOffset); + readData(header.subchunk1Size, true, forceStop, headerData); if ((header.audioFormat != WAVE_FORMAT_PCM) || (header.byteRate != (header.bitsPerSample >> 3) * header.channels * header.sampleRate) || @@ -172,7 +171,7 @@ vector* WaveReader::getFrames(unsigned frameCount, bool &forceStop) { bytesPerFrame = (header.bitsPerSample >> 3) * header.channels; bytesToRead = frameCount * bytesPerFrame; - bytesLeft = header.subchunk2Size - currentFrameOffse; + bytesLeft = header.subchunk2Size - currentFrameOffset; if (bytesToRead > bytesLeft) { bytesToRead = bytesLeft - bytesLeft % bytesPerFrame; frameCount = bytesToRead / bytesPerFrame; @@ -216,7 +215,7 @@ vector* WaveReader::getFrames(unsigned frameCount, bool &forceStop) { bool WaveReader::setFrameOffset(unsigned frameOffset) { if (fileDescriptor != STDIN_FILENO) { currentFrameOffset = frameOffset * (header.bitsPerSample >> 3) * header.channels; - if (lseek(fileDescriptor, dataOffset + currentFrameOffse, SEEK_SET) == -1) { + if (lseek(fileDescriptor, dataOffset + currentFrameOffset, SEEK_SET) == -1) { return false; } } @@ -228,11 +227,7 @@ string WaveReader::getFilename() return fileDescriptor != STDIN_FILENO ? filename : "STDIN"; } -AudioFormat* WaveReader::getFormat() +PCMWaveHeader WaveReader::getHeader() { - AudioFormat* format = new AudioFormat; - format->channels = header.channels; - format->sampleRate = header.sampleRate; - format->bitsPerSample = header.bitsPerSample; - return format; + return header; } diff --git a/wave_reader.h b/wave_reader.h index 46860a4..033b142 100644 --- a/wave_reader.h +++ b/wave_reader.h @@ -34,10 +34,9 @@ #ifndef WAVE_READER_H #define WAVE_READER_H +#include "pcm_wave_header.h" #include #include -#include "audio_format.h" -#include "pcm_wave_header.h" using std::vector; using std::string; @@ -47,18 +46,17 @@ class WaveReader public: WaveReader(string filename, bool &forceStop); virtual ~WaveReader(); - - AudioFormat* getFormat(); + string getFilename(); + PCMWaveHeader getHeader(); vector* getFrames(unsigned frameCount, bool &forceStop); bool setFrameOffset(unsigned frameOffset); private: + vector* readData(unsigned bytesToRead, bool headerBytes, bool &forceStop, char* headerData); + string filename; PCMWaveHeader header; unsigned dataOffset, headerOffset, currentFrameOffset; int fileDescriptor; - - vector* readData(unsigned bytesToRead, bool headerBytes, bool &forceStop, char* headerData); - string getFilename(); }; #endif // WAVE_READER_H