npv/clk/public/code.frag.c

   1 STATIC void npv_clk_init_once(void)
   2 {
   3         int r;
   4
   5         r = snd_pcm_status_malloc(&npv_clk_l.ref.status);
   6         if (r != 0)
   7                 npv_clk_fatal("alsa:unable to allocate an alsa status structure\n");
   8         r = snd_pcm_status_malloc(&npv_clk_l.now.status);
   9         if (r != 0)
  10                 npv_clk_fatal("alsa:unable to allocate an alsa status structure\n");
  11         /* we pre-allocate alsa pcm hw_params container */
  12         r = snd_pcm_hw_params_malloc(&npv_clk_pcm_hw_params_l);
  13         if (r < 0)
  14                 npv_clk_fatal("alsa:unable to allocate hardware parameters context\n");
  15         npv_clk_l.paused = false;
  16 }
  17 #define NO_REF_TIME_POINT 1
  18 STATIC u8 npv_clk_get_audio_filt_ts(s64 *ts)
  19 {
  20         int r;
  21         snd_pcm_audio_tstamp_config_t ac;
  22         snd_htimestamp_t hts;
  23         f64 now_ns;
  24         f64 ref_ns;
  25         f64 ref_status_ns;
  26         f64 ref_delay_frs_n;
  27         f64 ref_audio_filt_ts;
  28         avutil_rational_t audio_filt_tb;
  29         f64 audio_filt_tb_num;
  30         f64 audio_filt_tb_den;
  31         f64 audio_rate_num;
  32         unsigned int audio_rate_num_ui;
  33         f64 audio_rate_den;
  34         unsigned int audio_rate_den_ui;
  35         f64 written_frs_n;
  36         f64 now_audio_ts;
  37         f64 now_video_ts;
  38
  39         if (!npv_clk_l.ref_valid)
  40                 return NO_REF_TIME_POINT;
  41         if (!npv_clk_l.paused) {
  42                 memset(npv_clk_l.now.status, 0, snd_pcm_status_sizeof());
  43                 ac.report_delay = 0;
  44                 ac.type_requested = (unsigned int)npv_audio_selected_ts_type_p;
  45                 snd_pcm_status_set_audio_htstamp_config(npv_clk_l.now.status,
  46                                                                         &ac);
  47                 r = snd_pcm_status(npv_audio_pcm_p, npv_clk_l.now.status);
  48                 if (r < 0)
  49                         npv_clk_fatal("alsa:unable to sample timing information for 'now' time point\n");
  50         }
  51         snd_pcm_status_get_audio_htstamp(npv_clk_l.now.status, &hts);
  52         now_ns = (f64)hts.tv_sec * 1e9 + (f64)hts.tv_nsec;
  53
  54         snd_pcm_status_get_audio_htstamp(npv_clk_l.ref.status, &hts);
  55         ref_status_ns = (f64)hts.tv_sec * 1e9 + (f64)hts.tv_nsec;
  56
  57         ref_audio_filt_ts = (f64)npv_clk_l.ref.audio_filt_ts;
  58         ref_delay_frs_n = (f64)snd_pcm_status_get_delay(npv_clk_l.ref.status);
  59         /* we are writting the output of the filt to the audio pcm */
  60         audio_filt_tb = avfilter_bufsink_tb_get(npv_audio_filt_p.abufsink_ctx);
  61         audio_filt_tb_num = (f64)audio_filt_tb.num;
  62         audio_filt_tb_den = (f64)audio_filt_tb.den;
  63         /*--------------------------------------------------------------------*/
  64         r = snd_pcm_hw_params_current(npv_audio_pcm_p, npv_clk_pcm_hw_params_l);
  65         if (r != 0)
  66                 npv_clk_fatal("alsa:unable to get current hardware parameters\n");
  67         r = snd_pcm_hw_params_get_rate_numden(npv_clk_pcm_hw_params_l,
  68                                         &audio_rate_num_ui, &audio_rate_den_ui);
  69         if (r < 0)
  70                 npv_clk_fatal("alsa:unable to get exact rate\n");
  71         audio_rate_num = (f64)audio_rate_num_ui;
  72         audio_rate_den = (f64)audio_rate_den_ui;
  73         /*--------------------------------------------------------------------*/
  74         written_frs_n = (f64)npv_clk_l.ref.written_ufrs_n;
  75
  76         /* time translation */
  77         ref_ns = ref_status_ns + (ref_delay_frs_n - written_frs_n)
  78                                         * audio_rate_den * 1e9 / audio_rate_num;
  79         /* basic linear interpolation */
  80         now_audio_ts = audio_filt_tb_den * 1e-9 * (now_ns - ref_ns)
  81                                         / audio_filt_tb_num + ref_audio_filt_ts;
  82         *ts = (s64)lrint(now_audio_ts);
  83         return TS_RETURNED;
  84 }
  85 #undef NO_REF_TIME_POINT
  86 STATIC u8 npv_clk_get_video_st_ts(s64 *ts)
  87 {
  88         avutil_rational_t audio_filt_tb;
  89         s64 now_audio_filt_ts;
  90         u8 r;
  91
  92         audio_filt_tb = avfilter_bufsink_tb_get(npv_audio_filt_p.abufsink_ctx);
  93         r = npv_clk_get_audio_filt_ts(&now_audio_filt_ts);
  94         if (r != TS_RETURNED)
  95                 return r;
  96         *ts = avutil_rescale_q(now_audio_filt_ts, audio_filt_tb,
  97                                                         npv_video_st_p.tb);
  98         return TS_RETURNED;
  99 }
 100 STATIC void npv_clk_ref_time_point_update(s64 audio_filt_ts,
 101                                                 snd_pcm_ufrs_t written_ufrs_n)
 102 {
 103         int r;
 104         snd_pcm_audio_tstamp_config_t ac;
 105
 106         memset(npv_clk_l.ref.status, 0, snd_pcm_status_sizeof());
 107         ac.report_delay = 0;
 108         ac.type_requested = (unsigned int)npv_audio_selected_ts_type_p;
 109         snd_pcm_status_set_audio_htstamp_config(npv_clk_l.ref.status, &ac);
 110         r = snd_pcm_status(npv_audio_pcm_p, npv_clk_l.ref.status);
 111         if (r < 0)
 112                 npv_clk_fatal("unable to sample timing information for reference time point\n");
 113         npv_clk_l.ref.audio_filt_ts = audio_filt_ts;
 114         npv_clk_l.ref.written_ufrs_n = written_ufrs_n;
 115         npv_clk_l.ref_valid = true;
 116 }
 117 STATIC void npv_clk_invalidate(void)
 118 {
 119         npv_clk_l.ref_valid = false;
 120 }
 121 STATIC void npv_clk_pause(void)
 122 {
 123         int r;
 124         snd_pcm_audio_tstamp_config_t ac;
 125
 126         npv_clk_l.paused = true;
 127         memset(npv_clk_l.now.status, 0, snd_pcm_status_sizeof());
 128         ac.report_delay = 0;
 129         ac.type_requested = (unsigned int)npv_audio_selected_ts_type_p;
 130         snd_pcm_status_set_audio_htstamp_config(npv_clk_l.now.status, &ac);
 131         r = snd_pcm_status(npv_audio_pcm_p, npv_clk_l.now.status);
 132         if (r < 0)
 133                 npv_clk_fatal("alsa:unable to sample timing information for 'paused' time point\n");
 134 }
 135 STATIC void npv_clk_unpause(void)
 136 {
 137         npv_clk_l.paused = false;
 138         npv_clk_invalidate();
 139 }