diff options
Diffstat (limited to 'src/sstv.c')
| -rw-r--r-- | src/sstv.c | 118 |
1 files changed, 118 insertions, 0 deletions
@@ -22,6 +22,12 @@ #define CYCbCr2B(Y, Cb, Cr) CLIP( Y + (116129 * Cb >> 16 ) - 226 ) /* + * Timings macros + */ +#define TIME_DESC_INIT(time_us, sample_rate) ((sstv_timing_desc_t){ (time_us), ((uint64_t)(time_us) * (uint64_t)(sample_rate)) }) +#define FREQ_DESC_INIT(freq, sample_rate) ((sstv_freq_desc_t){ (freq), ((((uint64_t)(freq)) << 32) / (uint64_t)(sample_rate)) }) + +/* * User-defined memory allocation functions */ sstv_malloc_t sstv_malloc_user = NULL; @@ -363,4 +369,116 @@ sstv_get_visp_code(sstv_mode_t mode) default: return 0; } +} + +sstv_error_t +sstv_get_mode_descriptor(sstv_mode_t mode, uint32_t sample_rate, sstv_mode_descriptor_t *desc) +{ + if (!desc) { + return SSTV_INTERNAL_ERROR; + } + + /* Common desc and frequencies */ + desc->leader_tone.time = TIME_DESC_INIT(300000, sample_rate); + desc->leader_tone.freq = FREQ_DESC_INIT(1900, sample_rate); + + desc->break_tone.time = TIME_DESC_INIT(10000, sample_rate); + desc->break_tone.freq = FREQ_DESC_INIT(1200, sample_rate); + + desc->vis.time = TIME_DESC_INIT(30000, sample_rate); + desc->vis.sep_freq = FREQ_DESC_INIT(1200, sample_rate); + desc->vis.low_freq = FREQ_DESC_INIT(1300, sample_rate); + desc->vis.high_freq = FREQ_DESC_INIT(1100, sample_rate); + + /* Mode frequencies */ + switch (mode) { + /* + * PD modes + */ + case SSTV_MODE_PD50: + case SSTV_MODE_PD90: + case SSTV_MODE_PD120: + case SSTV_MODE_PD160: + case SSTV_MODE_PD180: + case SSTV_MODE_PD240: + case SSTV_MODE_PD290: + desc->sync.freq = FREQ_DESC_INIT(1200, sample_rate); + desc->porch.freq = FREQ_DESC_INIT(1500, sample_rate); + desc->pixel.low_freq = FREQ_DESC_INIT(1500, sample_rate); + desc->pixel.bandwidth = FREQ_DESC_INIT(800, sample_rate); + break; + + /* + * invalid mode + */ + default: + return SSTV_BAD_MODE; + } + + /* Mode desc */ + switch (mode) { + /* + * PD modes + */ + case SSTV_MODE_PD50: + desc->sync.time = TIME_DESC_INIT(20000, sample_rate); + desc->porch.time = TIME_DESC_INIT(2080, sample_rate); + desc->pixel.time = TIME_DESC_INIT(286, sample_rate); + break; + + case SSTV_MODE_PD90: + desc->sync.time = TIME_DESC_INIT(20000, sample_rate); + desc->porch.time = TIME_DESC_INIT(2080, sample_rate); + desc->pixel.time = TIME_DESC_INIT(532, sample_rate); + break; + + case SSTV_MODE_PD120: + desc->sync.time = TIME_DESC_INIT(20000, sample_rate); + desc->porch.time = TIME_DESC_INIT(2080, sample_rate); + desc->pixel.time = TIME_DESC_INIT(190, sample_rate); + break; + + case SSTV_MODE_PD160: + desc->sync.time = TIME_DESC_INIT(20000, sample_rate); + desc->porch.time = TIME_DESC_INIT(2080, sample_rate); + desc->pixel.time = TIME_DESC_INIT(382, sample_rate); + break; + + case SSTV_MODE_PD180: + desc->sync.time = TIME_DESC_INIT(20000, sample_rate); + desc->porch.time = TIME_DESC_INIT(2080, sample_rate); + desc->pixel.time = TIME_DESC_INIT(286, sample_rate); + break; + + case SSTV_MODE_PD240: + desc->sync.time = TIME_DESC_INIT(20000, sample_rate); + desc->porch.time = TIME_DESC_INIT(2080, sample_rate); + desc->pixel.time = TIME_DESC_INIT(382, sample_rate); + break; + + case SSTV_MODE_PD290: + desc->sync.time = TIME_DESC_INIT(20000, sample_rate); + desc->porch.time = TIME_DESC_INIT(2080, sample_rate); + desc->pixel.time = TIME_DESC_INIT(286, sample_rate); + break; + + /* + * invalid mode + */ + default: + return SSTV_BAD_MODE; + } + + /* compute pixel value to delta phase lookup table */ + for (uint32_t i = 0; i < 256; i ++) { + uint64_t freq_t255 = + (uint64_t)desc->pixel.low_freq.hz * 255 + ((uint64_t)desc->pixel.bandwidth.hz * i); + + uint64_t dphase = (freq_t255 << 32) / ((uint64_t)(sample_rate) * 255); + + desc->pixel.val_phase_delta[i] = (uint32_t) dphase; + } + + /* all ok */ + return SSTV_OK; }
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