From ed2a200d4b4a0651eb40bcfdd13a089f857fdfd8 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Jean-Fran=C3=A7ois=20DEL=20NERO?= Date: Mon, 20 Feb 2023 07:58:29 +0100 Subject: [PATCH] WIP: Composite video generator --- src/broadcast_tv/composite.c | 127 +++++++++++++++++++++++++++++++++++ src/broadcast_tv/composite.h | 57 ++++++++++++++++ 2 files changed, 184 insertions(+) create mode 100644 src/broadcast_tv/composite.c create mode 100644 src/broadcast_tv/composite.h diff --git a/src/broadcast_tv/composite.c b/src/broadcast_tv/composite.c new file mode 100644 index 0000000..40c2b22 --- /dev/null +++ b/src/broadcast_tv/composite.c @@ -0,0 +1,127 @@ +/////////////////////////////////////////////////////////////////////////////////// +//-------------------------------------------------------------------------------// +//-------------------------------------------------------------------------------// +//-----------H----H--X----X-----CCCCC----22222----0000-----0000------11----------// +//----------H----H----X-X-----C--------------2---0----0---0----0--1--1-----------// +//---------HHHHHH-----X------C----------22222---0----0---0----0-----1------------// +//--------H----H----X--X----C----------2-------0----0---0----0-----1-------------// +//-------H----H---X-----X---CCCCC-----222222----0000-----0000----1111------------// +//-------------------------------------------------------------------------------// +//----------------------------------------------------- http://hxc2001.free.fr --// +/////////////////////////////////////////////////////////////////////////////////// +// File : composite.c +// Contains: Composite video signal generator +// +// This file is part of rf-tools. +// +// Written by: Jean-François DEL NERO +// +// Copyright (C) 2023 Jean-François DEL NERO +// +// You are free to do what you want with this code. +// A credit is always appreciated if you use it into your product :) +// +// Change History (most recent first): +/////////////////////////////////////////////////////////////////////////////////// + +#include +#include +#include + +#include "composite.h" + +#define EQUALIZING_PULSE_LEN 2.35 +#define LINE_PULSE_LEN 4.7 +#define ASSERTED_LEVEL 10 +#define DEASSERTED_LEVEL 100 + +// PAL timings +pulses_state vertical_blanking[]= +{ + // First sequence of equalizing pulses + { 5, ASSERTED_LEVEL, DEASSERTED_LEVEL, EQUALIZING_PULSE_LEN/(double)1E6 ,((COMPOSITE_LINE_PERIOD_US/2)/(double)1E6),0}, + // Sequence of synchronizing pulses (Line 1 count) + { 5, ASSERTED_LEVEL, DEASSERTED_LEVEL, 27.3/(double)1E6 ,((COMPOSITE_LINE_PERIOD_US/2)/(double)1E6),0}, + // Duration of second sequence of equalizing pulses + { 5, ASSERTED_LEVEL, DEASSERTED_LEVEL, EQUALIZING_PULSE_LEN/(double)1E6 ,((COMPOSITE_LINE_PERIOD_US/2)/(double)1E6),0}, + + // Lines (6 > 310) + {305, ASSERTED_LEVEL, DEASSERTED_LEVEL, LINE_PULSE_LEN/(double)1E6 ,((COMPOSITE_LINE_PERIOD_US)/(double)1E6),0}, + + // First sequence of equalizing pulses + { 5, ASSERTED_LEVEL, DEASSERTED_LEVEL, EQUALIZING_PULSE_LEN/(double)1E6 ,((COMPOSITE_LINE_PERIOD_US/2)/(double)1E6),0}, + // Sequence of synchronizing pulses (Line 1 count) + { 5, ASSERTED_LEVEL, DEASSERTED_LEVEL, 27.3/(double)1E6 ,((COMPOSITE_LINE_PERIOD_US/2)/(double)1E6),0}, + // Duration of second sequence of equalizing pulses + { 5, ASSERTED_LEVEL, DEASSERTED_LEVEL, EQUALIZING_PULSE_LEN/(double)1E6 ,((COMPOSITE_LINE_PERIOD_US/2)/(double)1E6),0}, + + // -- end of line 318 + { 1, DEASSERTED_LEVEL, DEASSERTED_LEVEL, 0 ,(COMPOSITE_LINE_PERIOD_US/2)/(double)1E6,0}, + + // Lines (319 > 622) + {304, ASSERTED_LEVEL, DEASSERTED_LEVEL, LINE_PULSE_LEN/(double)1E6 ,(COMPOSITE_LINE_PERIOD_US)/(double)1E6,0}, + + // Line 623 - (half) + { 1, ASSERTED_LEVEL, DEASSERTED_LEVEL, LINE_PULSE_LEN/(double)1E6 ,((COMPOSITE_LINE_PERIOD_US)/2)/(double)1E6,0}, + + // End + { 0, 0, 0, 0 ,0,0} +}; + + +void init_composite(composite_state * state, int sample_rate, int x_res, int y_res) +{ + state->sample_period = (double)1 / (double)sample_rate; + + state->buf_x_res = x_res; + state->buf_y_res = y_res; + + state->video_buffer = malloc( x_res * y_res * sizeof(uint32_t) ); + if(state->video_buffer) + memset(state->video_buffer,0,x_res * y_res * sizeof(uint32_t) ); + + state->step_index = 0; + state->cur_state_time = 0; +} + +void gen_video_signal(composite_state * state, double * vid_signal, int buf_size) +{ + int i; + double value; + + value = 0; + i = 0; + while(i < buf_size) + { + if( state->cur_state_time >= vertical_blanking[state->step_index].total_duration) + { + state->cur_state_time = 0; + state->repeat_cnt++; + + if( state->repeat_cnt >= vertical_blanking[state->step_index].repeat ) + { + state->repeat_cnt = 0; + state->step_index++; + } + + if(!vertical_blanking[state->step_index].repeat) + { + state->step_index = 0; + } + } + + if( state->cur_state_time >= vertical_blanking[state->step_index].first_duration ) + { + value = vertical_blanking[state->step_index].end_val; + } + else + { + value = vertical_blanking[state->step_index].start_val; + } + + vid_signal[i] = value; + + state->cur_state_time += state->sample_period; + i++; + } +} diff --git a/src/broadcast_tv/composite.h b/src/broadcast_tv/composite.h new file mode 100644 index 0000000..3a7dac1 --- /dev/null +++ b/src/broadcast_tv/composite.h @@ -0,0 +1,57 @@ +/////////////////////////////////////////////////////////////////////////////////// +//-------------------------------------------------------------------------------// +//-------------------------------------------------------------------------------// +//-----------H----H--X----X-----CCCCC----22222----0000-----0000------11----------// +//----------H----H----X-X-----C--------------2---0----0---0----0--1--1-----------// +//---------HHHHHH-----X------C----------22222---0----0---0----0-----1------------// +//--------H----H----X--X----C----------2-------0----0---0----0-----1-------------// +//-------H----H---X-----X---CCCCC-----222222----0000-----0000----1111------------// +//-------------------------------------------------------------------------------// +//----------------------------------------------------- http://hxc2001.free.fr --// +/////////////////////////////////////////////////////////////////////////////////// +// File : composite.h +// Contains: Composite video signal generator +// +// This file is part of rf-tools. +// +// Written by: Jean-François DEL NERO +// +// Copyright (C) 2023 Jean-François DEL NERO +// +// You are free to do what you want with this code. +// A credit is always appreciated if you use it into your product :) +// +// Change History (most recent first): +/////////////////////////////////////////////////////////////////////////////////// + +#define COMPOSITE_LINE_PERIOD_US 64.0 + +typedef struct composite_state_ +{ + double sample_period; + + int buf_x_res; + int buf_y_res; + + uint32_t * video_buffer; + + int step_index; + int repeat_cnt; + + double cur_state_time; + +}composite_state; + +typedef struct pulses_state_ +{ + int repeat; + double start_val; + double end_val; + double first_duration; + double total_duration; + int type; +}pulses_state; + + +void init_composite(composite_state * state, int sample_rate, int x_res, int y_res); +void gen_video_signal(composite_state * state, double * vid_signal, int buf_size);