[FFmpeg-devel] [PATCH 5/5] af_hdcd: tweak hdcd_analyze_prepare() a bit

[Burt P.]

applied

On Mon, Sep 5, 2016 at 6:18 AM, Burt P <pburt0 at gmail.com> wrote:
> * use the actual sample rate
> * use a more sensible frequency for the tone
> * update fate test result
>
> Signed-off-by: Burt P <pburt0 at gmail.com>
> ---
>  libavfilter/af_hdcd.c       | 9 ++++++---
>  tests/fate/filter-audio.mak | 2 +-
>  2 files changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/libavfilter/af_hdcd.c b/libavfilter/af_hdcd.c
> index 1487a0b..fde6b7b 100644
> --- a/libavfilter/af_hdcd.c
> +++ b/libavfilter/af_hdcd.c
> @@ -871,6 +871,7 @@ typedef struct {
>       *  a code. -1 for timer never set. */
>      int count_sustain_expired;
>
> +    int rate;                   /**< sampling rate */
>      int _ana_snb;               /**< used in the analyze mode tone generator */
>  } hdcd_state;
>
> @@ -1026,6 +1027,7 @@ static void hdcd_reset(hdcd_state *state, unsigned rate, unsigned cdt_ms)
>      state->max_gain = 0;
>      state->count_sustain_expired = -1;
>
> +    state->rate = rate;
>      state->_ana_snb = 0;
>  }
>
> @@ -1297,7 +1299,8 @@ static int hdcd_scan_stereo(HDCDContext *ctx, const int32_t *samples, int max)
>
>  /** replace audio with solid tone, but save LSBs */
>  static void hdcd_analyze_prepare(hdcd_state *state, int32_t *samples, int count, int stride) {
> -    int n;
> +    int n, f = 300;
> +    int so = state->rate / f;
>      for (n = 0; n < count * stride; n += stride) {
>          /* in analyze mode, the audio is replaced by a solid tone, and
>           * amplitude is changed to signal when the specified feature is
> @@ -1306,9 +1309,9 @@ static void hdcd_analyze_prepare(hdcd_state *state, int32_t *samples, int count,
>           * bit 1: Original sample was above PE level */
>          int32_t save = (abs(samples[n]) - PEAK_EXT_LEVEL >= 0) ? 2 : 0; /* above PE level */
>          save |= samples[n] & 1;                      /* save LSB for HDCD packets */
> -        samples[n] = TONEGEN16(state->_ana_snb, 277.18, 44100, 0.1);
> +        samples[n] = TONEGEN16(state->_ana_snb, f, state->rate, 0.1);
>          samples[n] = (samples[n] | 3) ^ ((~save) & 3);
> -        if (++state->_ana_snb > 0x3fffffff) state->_ana_snb = 0;
> +        if (++state->_ana_snb > so) state->_ana_snb = 0;
>      }
>  }
>
> diff --git a/tests/fate/filter-audio.mak b/tests/fate/filter-audio.mak
> index 2066fa9..cf92ef6 100644
> --- a/tests/fate/filter-audio.mak
> +++ b/tests/fate/filter-audio.mak
> @@ -242,7 +242,7 @@ FATE_AFILTER_SAMPLES-$(call FILTERDEMDECENCMUX, HDCD, FLAC, FLAC, PCM_S24LE, PCM
>  fate-filter-hdcd-analyze: SRC = $(TARGET_SAMPLES)/filter/hdcd.flac
>  fate-filter-hdcd-analyze: CMD = md5 -i $(SRC) -af hdcd=analyze_mode=pe -f s24le
>  fate-filter-hdcd-analyze: CMP = oneline
> -fate-filter-hdcd-analyze: REF = 81a4f00f85a585bc0198e9a0670a8cde
> +fate-filter-hdcd-analyze: REF = 6e39dc4629c1e84321c0d8bc069b42f6
>
>  FATE_AFILTER_SAMPLES-$(call FILTERDEMDECENCMUX, HDCD, FLAC, FLAC, PCM_S24LE, PCM_S24LE) += fate-filter-hdcd-false-positive
>  fate-filter-hdcd-false-positive: SRC = $(TARGET_SAMPLES)/filter/hdcd-false-positive.flac
> --
> 2.7.4
>



-- 
Burt