tests/encoder.c

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include <ltcsmpte/ltcsmpte.h>
#include <tests.h>

int main(int argc, char **argv) 
{
        FILE* file;
        int length = 100 * 1000; // 100 seconds
        double framesPerSec = FRAME_RATE_NUM/(double)FRAME_RATE_DEN;
        int sampleRate = SAMPLE_RATE;
        int debuglevel = 1;

        char *filename = "output.raw";

        int total = 0;
        sample_t *buf;
        
        SMPTETime st;
        SMPTEEncoder *encoder;
        FrameRate *fps;

        if (argc > 1) {
                filename = argv[1];
                if (argc > 2) {
                        sscanf(argv[2], "%i", &sampleRate);
                }
                if (argc > 3) {
                        sscanf(argv[3], "%lf", &framesPerSec);
                }
                if (argc > 4) {
                        sscanf(argv[4], "%i", &length);
                }
        } else {
                printf("Usage: %s <filename> [sample rate [frame rate [duration in ms]]]\n", argv[0]);
                printf("The encoder creates " SAMPLE_TYPE " native endian raw audio at currently %i Hz sampling rate.\n", sampleRate);
                return -1;
        }
        
        
#ifdef ENABLE_DATE
        int i = 0;
        char timezone[6] = "+0100";
        // Copy the time zone info into the struct
        for (i = 0 ; i < sizeof(st.timezone) ; i++) st.timezone[i] = timezone[i];
        st.years =  8;
        st.months = 4;
        st.days =   7;
#endif

#if 0
        st.hours = 1;
        st.mins = 30;
        st.secs = 15;
        st.frame = 0;
#else
        st.hours = 0;
        st.mins = 0;
        st.secs = 0;
        st.frame = 0;
#endif
        
        fps = FR_create(1, 1, FRF_NONE);
        FR_setdbl(fps, framesPerSec, 1); // auto-detect drop-frames
        
        encoder = SMPTEEncoderCreate(sampleRate, fps);

        buf = calloc(SMPTEGetBuffersize(encoder), sizeof(sample_t));
        SMPTESetTime(encoder, &st);

        if (debuglevel > 1)
                printf("writing to: %s\n", filename);

        file = fopen(filename, "wb");
        //file = fdopen(fileno(stdout),"w");

        if (debuglevel > 0)
        {
                printf("samples are %s native endian\n", SAMPLE_TYPE);
                printf("sample rate = %i\n", sampleRate);
                printf("frames/sec = %.2lf\n", framesPerSec);
        }
        
        /* write 100 seconds of raw smpte audio */

        int start_time = SMPTEGetTimeInMillisecs(encoder);
        int current_time = start_time;
        int max_time = current_time + length;
        
//#define TRACK_SAMPLES_PER_FRAME
#ifdef TRACK_SAMPLES_PER_FRAME
        int samples_per_frame;
#endif

        int this_second_end = current_time + 1000;

        // FIXME: This currently overshoots the length set above for 29.97 df. 
        while (current_time < max_time)
        {
                
                int byteCnt;
                
#ifdef TRACK_SAMPLES_PER_FRAME
                samples_per_frame = 0;
#endif

                // encode and write each of the 80 LTC frame bits (10 bytes)
                for (byteCnt = 0 ; byteCnt < 10 ; byteCnt++)
                {
                        SMPTEEncode(encoder, byteCnt);
                        
                        // write to file
                        int len = SMPTEGetBuffer(encoder, buf);
                        
                        if (len > 0)
                        {
                                fwrite(buf, sizeof(sample_t), len, file);
                        }
                        

                        if (debuglevel > 4)
                        {
                                //printf("DEBUG: wrote %i samples.\n", len);
                                printf("DEBUG: wrote %lu bytes.\n", (unsigned long)len*sizeof(sample_t));
                        }
                        
#ifdef TRACK_SAMPLES_PER_FRAME
                        samples_per_frame += len;
#endif
                        
                }
                
                SMPTEEncIncrease(encoder);
                current_time = SMPTEGetTimeInMillisecs(encoder);
                
#ifdef TRACK_SAMPLES_PER_FRAME
                printf("DEBUG: current frame length: %i samples.\n", samples_per_frame);
#endif
                
                // every second...
                if (current_time >= this_second_end)
                {
                        if (debuglevel > 3)
                        {
                                printf("[%i]\n", SMPTEGetNsamples(encoder));
                        }
                        
                        total += SMPTEGetNsamples(encoder);
                        
                        SMPTESetNsamples(encoder, 0);
                        
                        this_second_end += 1000;
                        
                }
                
        }
        
        if (debuglevel > 0)
        {
                printf("DONE: wrote %.4f seconds == %i samples\n", (current_time-start_time)/1000.0, total);
        }
        
        fclose(file);

        FR_free(fps);
        SMPTEFreeEncoder(encoder);
        
        return 0;
}