[FFmpeg-cvslog] af_hdcd: add force_pe filter option
Burt P
git at videolan.org
Mon Aug 1 21:01:51 EEST 2016
ffmpeg | branch: master | Burt P <pburt0 at gmail.com> | Fri Jul 29 12:36:19 2016 -0500| [b90d0ab4be3d03400e25db5cc4e03126998a75dd] | committer: Michael Niedermayer
af_hdcd: add force_pe filter option
Used to attempt replication of some results from
http://www.audiomisc.co.uk/HFN/HDCD/Examined.html
May not be generally useful, defaults to off.
Signed-off-by: Burt P <pburt0 at gmail.com>
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=b90d0ab4be3d03400e25db5cc4e03126998a75dd
---
libavfilter/af_hdcd.c | 26 ++++++++++++++++++++++----
1 file changed, 22 insertions(+), 4 deletions(-)
diff --git a/libavfilter/af_hdcd.c b/libavfilter/af_hdcd.c
index 4a4c9c7..8e27d8a 100644
--- a/libavfilter/af_hdcd.c
+++ b/libavfilter/af_hdcd.c
@@ -867,6 +867,12 @@ typedef struct HDCDContext {
const AVClass *class;
hdcd_state_t state[2];
+ /* always extend peaks above -3dBFS even if PE isn't signaled
+ * -af hdcd=force_pe=0 for off
+ * -af hdcd=force_pe=1 for on
+ * default is off */
+ int force_pe;
+
AVFilterContext *fctx; /* filter context for logging errors */
int sample_count; /* used in error logging */
@@ -878,7 +884,10 @@ typedef struct HDCDContext {
float max_gain_adjustment; /* in dB, expected in the range -6.0 to 0.0 */
} HDCDContext;
+#define OFFSET(x) offsetof(HDCDContext, x)
static const AVOption hdcd_options[] = {
+ { "force_pe", "Always extend peaks above -3dBFS even when PE is not signaled.",
+ OFFSET(force_pe), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, 0 },
{NULL}
};
@@ -1093,14 +1102,21 @@ static int hdcd_envelope(int32_t *samples, int count, int stride, int gain, int
return gain;
}
+/* extract fields from control code */
+static void hdcd_control(HDCDContext *ctx, hdcd_state_t *state, int *peak_extend, int *target_gain)
+{
+ *peak_extend = (ctx->force_pe || state->control & 16);
+ *target_gain = (state->control & 15) << 7;
+}
+
static void hdcd_process(HDCDContext *ctx, hdcd_state_t *state, int32_t *samples, int count, int stride)
{
int32_t *samples_end = samples + count * stride;
int gain = state->running_gain;
- int peak_extend = (state->control & 16);
- int target_gain = (state->control & 15) << 7;
+ int peak_extend, target_gain;
int lead = 0;
+ hdcd_control(ctx, state, &peak_extend, &target_gain);
while (count > lead) {
int envelope_run;
int run;
@@ -1115,8 +1131,7 @@ static void hdcd_process(HDCDContext *ctx, hdcd_state_t *state, int32_t *samples
samples += envelope_run * stride;
count -= envelope_run;
lead = run - envelope_run;
- peak_extend = (state->control & 16);
- target_gain = (state->control & 15) << 7;
+ hdcd_control(ctx, state, &peak_extend, &target_gain);
}
if (lead > 0) {
av_assert0(samples + lead * stride <= samples_end);
@@ -1285,6 +1300,9 @@ static av_cold int init(AVFilterContext *ctx)
hdcd_reset(&s->state[c], 44100);
}
+ av_log(ctx, AV_LOG_VERBOSE, "Force PE: %s\n",
+ (s->force_pe) ? "on" : "off");
+
return 0;
}
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