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Rearrangements to the receive thread.

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Magnitude conversion now happens immediately when sample data is
received, so there is no risk of newly received data clobbering old
data under CPU overload.
This commit is contained in:
Oliver Jowett 2015-04-09 18:51:31 +01:00
parent e6c81251bf
commit 15ea5ba3da
11 changed files with 234 additions and 160 deletions
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35
dump1090.h
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@ -92,9 +92,10 @@
#define MODES_DEFAULT_FREQ 1090000000
#define MODES_DEFAULT_WIDTH 1000
#define MODES_DEFAULT_HEIGHT 700
#define MODES_ASYNC_BUF_NUMBER 16
#define MODES_ASYNC_BUF_SIZE (16*16384) // 256k
#define MODES_ASYNC_BUF_SAMPLES (MODES_ASYNC_BUF_SIZE / 2) // Each sample is 2 bytes
#define MODES_RTL_BUFFERS 15 // Number of RTL buffers
#define MODES_RTL_BUF_SIZE (16*16384) // 256k
#define MODES_MAG_BUF_SAMPLES (MODES_RTL_BUF_SIZE / 2) // Each sample is 2 bytes
#define MODES_MAG_BUFFERS 12 // Number of magnitude buffers (should be smaller than RTL_BUFFERS for flowcontrol to work)
#define MODES_AUTO_GAIN -100 // Use automatic gain
#define MODES_MAX_GAIN 999999 // Use max available gain
#define MODES_MSG_SQUELCH_DB 4.0 // Minimum SNR, in dB
@ -240,26 +241,29 @@ struct net_writer {
uint64_t lastWrite; // time of last write to clients
};
// Structure representing one magnitude buffer
struct mag_buf {
uint16_t *data; // Magnitude data. Starts with Modes.trailing_samples worth of overlap from the previous block
unsigned length; // Number of valid samples _after_ overlap. Total buffer length is buf->length + Modes.trailing_samples.
uint64_t sampleTimestamp; // Clock timestamp of the start of this block, 12MHz clock
struct timespec sysTimestamp; // Estimated system time at start of block
uint32_t dropped; // Number of dropped samples preceding this buffer
};
// Program global state
struct { // Internal state
pthread_t reader_thread;
pthread_mutex_t data_mutex; // Mutex to synchronize buffer access
pthread_cond_t data_cond; // Conditional variable associated
uint16_t *pData [MODES_ASYNC_BUF_NUMBER]; // Raw IQ sample buffers from RTL
struct timespec stSystemTimeRTL[MODES_ASYNC_BUF_NUMBER]; // System time when RTL passed us this block
int iDataIn; // Fifo input pointer
int iDataOut; // Fifo output pointer
int iDataReady; // Fifo content count
int iDataLost; // Count of missed buffers
struct timespec reader_cpu_accumulator; // CPU time used by the reader thread, copied out and reset by the main thread under the mutex
int trailing_samples;// extra trailing samples in magnitude buffer
struct mag_buf mag_buffers[MODES_MAG_BUFFERS]; // Converted magnitude buffers from RTL or file input
unsigned first_free_buffer; // Entry in mag_buffers that will next be filled with input.
unsigned first_filled_buffer; // Entry in mag_buffers that has valid data and will be demodulated next. If equal to next_free_buffer, there is no unprocessed data.
struct timespec reader_cpu_accumulator; // CPU time used by the reader thread, copied out and reset by the main thread under the mutex
unsigned trailing_samples; // extra trailing samples in magnitude buffers
uint16_t *pFileData; // Raw IQ samples buffer (from a File)
uint16_t *magnitude; // Magnitude vector
uint64_t timestampBlk; // Timestamp of the start of the current block
struct timespec stSystemTimeBlk; // System time when RTL passed us currently processing this block
int fd; // --ifile option file descriptor
uint16_t *maglut; // I/Q -> Magnitude lookup table
uint16_t *log10lut; // Magnitude -> log10 lookup table
@ -429,7 +433,6 @@ int scoreModesMessage(unsigned char *msg, int validbits);
int decodeModesMessage (struct modesMessage *mm, unsigned char *msg);
void displayModesMessage(struct modesMessage *mm);
void useModesMessage (struct modesMessage *mm);
void computeMagnitudeVector(uint16_t *pData);
//
// Functions exported from interactive.c
//