[FFmpeg-devel] [PATCH 2/2] lavfi: EBU R.128 scanner.
Clément Bœsch
ubitux at gmail.com
Sat Sep 22 10:16:02 CEST 2012
TODO:
- lavfi minor bump
- Changelog
---
configure | 1 +
doc/filters.texi | 44 +++
libavfilter/Makefile | 1 +
libavfilter/af_ebur128.c | 689 +++++++++++++++++++++++++++++++++++++++++++++++
libavfilter/allfilters.c | 1 +
5 files changed, 736 insertions(+)
create mode 100644 libavfilter/af_ebur128.c
diff --git a/configure b/configure
index c001c5f..394ccf4 100755
--- a/configure
+++ b/configure
@@ -1900,6 +1900,7 @@ decimate_filter_deps="gpl avcodec"
delogo_filter_deps="gpl"
deshake_filter_deps="avcodec"
drawtext_filter_deps="libfreetype"
+ebur128_filter_deps="gpl"
flite_filter_deps="libflite"
frei0r_filter_deps="frei0r dlopen"
frei0r_filter_extralibs='$ldl'
diff --git a/doc/filters.texi b/doc/filters.texi
index e202d38..01f2778 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -4349,6 +4349,50 @@ setpts=PTS+10/TB
@end example
@end itemize
+ at section ebur128
+
+EBU R.128 scanner filter. This filter takes an audio stream as input and
+outputs it unchanged. By default, it logs a message at a frequency of 10Hz with
+the Momentary loudness (identified by @code{M}), Short-term loudness
+(@code{S}), Integrated loudness (@code{I}) and Loudness Range (@code{LRA}).
+
+The filter also has a video output (see the @var{video} option) with a real
+time graph to observe the loudness evolution. The graphic contains the logged
+message mentioned above, so it is not printed anymore when this option is set,
+unless the verbose logging is set. The main graphing area contains the
+short-term loudness (3 seconds of analysis), and the gauge on the right is for
+the momentary loudness (400 milliseconds).
+
+The filter accepts the following named parameters:
+
+ at table @option
+
+ at item video
+Activate the video output. The audio stream is passed unchanged whether this
+option is set or no. The video stream will appear in first position if
+activated. Default is @code{0}.
+
+ at item size
+Set the video size. This option is for video only. Default and minimum
+resolution is @code{640x480}.
+
+ at item meter
+Set the EBU scale meter. Default is @code{9}. Common values are @code{9} and
+ at code{18}, respectively for EBU scale meter +9 and EBU scale meter +18. Any
+other integer value between this range is allowed.
+
+ at end table
+
+Example of real-time graph using @command{ffplay}, with a EBU scale meter +18:
+ at example
+ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
+ at end example
+
+Run an analysis with @command{ffmpeg}:
+ at example
+ffmpeg -i input.mp3 -filter_complex ebur128 -f null -
+ at end example
+
@section settb, asettb
Set the timebase to use for the output frames timestamps.
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 82d39e4..690d529 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -64,6 +64,7 @@ OBJS-$(CONFIG_ATEMPO_FILTER) += af_atempo.o
OBJS-$(CONFIG_CHANNELMAP_FILTER) += af_channelmap.o
OBJS-$(CONFIG_CHANNELSPLIT_FILTER) += af_channelsplit.o
OBJS-$(CONFIG_EARWAX_FILTER) += af_earwax.o
+OBJS-$(CONFIG_EBUR128_FILTER) += af_ebur128.o
OBJS-$(CONFIG_JOIN_FILTER) += af_join.o
OBJS-$(CONFIG_PAN_FILTER) += af_pan.o
OBJS-$(CONFIG_RESAMPLE_FILTER) += af_resample.o
diff --git a/libavfilter/af_ebur128.c b/libavfilter/af_ebur128.c
new file mode 100644
index 0000000..c9cfd46
--- /dev/null
+++ b/libavfilter/af_ebur128.c
@@ -0,0 +1,689 @@
+/*
+ * Copyright (c) 2012 Clément Bœsch
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/**
+ * @file
+ * EBU R.128 implementation
+ * @see http://tech.ebu.ch/loudness
+ * @see https://www.youtube.com/watch?v=iuEtQqC-Sqo "EBU R128 Introduction - Florian Camerer"
+ * @todo implement start/stop/reset through filter command injection
+ * @todo support other frequencies to avoid resampling
+ */
+
+#include <math.h>
+
+#include "libavutil/audioconvert.h"
+#include "libavutil/avassert.h"
+#include "libavutil/avstring.h"
+#include "libavutil/xga_font_data.h"
+#include "libavutil/opt.h"
+#include "libavutil/timestamp.h"
+#include "audio.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+
+#define MAX_CHANNELS 63
+
+/* pre-filter coefficients */
+#define PRE_B0 1.53512485958697
+#define PRE_B1 -2.69169618940638
+#define PRE_B2 1.19839281085285
+#define PRE_A1 -1.69065929318241
+#define PRE_A2 0.73248077421585
+
+/* RLB-filter coefficients */
+#define RLB_B0 1.0
+#define RLB_B1 -2.0
+#define RLB_B2 1.0
+#define RLB_A1 -1.99004745483398
+#define RLB_A2 0.99007225036621
+
+#define ABS_THRES -70 ///< silence gate: we discard anything below this absolute (LUFS) threshold
+
+struct integrator {
+ double *cache[MAX_CHANNELS]; ///< window of filtered samples (N ms)
+ int cache_pos; ///< focus on the last added bin in the cache array
+ double sum[MAX_CHANNELS]; ///< sum of the last N ms filtered samples (cache content)
+
+ double sum_kept_powers; ///< sum of the powers (weighted sums) above absolute threshold
+ int nb_kept_powers; ///< number of sum above absolute threshold
+
+#define ABS_UP_THRES 10 ///< upper loud limit to consider (ABS_THRES being the minimum)
+#define HIST_GRAIN 100 ///< defines histogram precision
+#define HIST_SIZE ((ABS_UP_THRES - ABS_THRES) * HIST_GRAIN + 1)
+ int *powers_hist; ///< histogram of the powers, used to compute LRA and I
+};
+
+struct rect { int x, y, w, h; };
+
+typedef struct {
+ const AVClass *class; ///< AVClass context for log and options purpose
+
+ /* video */
+ int do_video; ///< 1 if video output enabled, 0 otherwise
+ int w, h; ///< size of the video output
+ struct rect text; ///< rectangle for the LU legend on the left
+ struct rect graph; ///< rectangle for the main graph in the center
+ struct rect gauge; ///< rectangle for the gauge on the right
+ AVFilterBufferRef *outpicref; ///< output picture reference, updated regularly
+ int meter; ///< select a EBU mode between +9 and +18
+ int scale_range; ///< the range of LU values according to the meter
+ int y_zero_lu; ///< the y value (pixel position) for 0 LU
+ int *y_line_ref; ///< y reference values for drawing the LU lines in the graph and the gauge
+
+ /* audio */
+ int nb_channels; ///< number of channels in the input
+ double *ch_weighting; ///< channel weighting mapping
+ int sample_count; ///< sample count used for refresh frequency, reset at refresh
+
+ /* Filter caches.
+ * The mult by 3 in the following is for X[i], X[i-1] and X[i-2] */
+ double x[MAX_CHANNELS * 3]; ///< 3 input samples cache for each channel
+ double y[MAX_CHANNELS * 3]; ///< 3 pre-filter samples cache for each channel
+ double z[MAX_CHANNELS * 3]; ///< 3 RLB-filter samples cache for each channel
+
+#define I400_BINS (48000 * 4 / 10)
+#define I3000_BINS (48000 * 3)
+ struct integrator i400; ///< 400ms integrator, used for Momentary loudness (M), and Integrated loudness (I)
+ struct integrator i3000; ///< 3s integrator, used for Short term loudness (S), and Loudness Range (LRA)
+} EBUR128Context;
+
+#define OFFSET(x) offsetof(EBUR128Context, x)
+#define A AV_OPT_FLAG_AUDIO_PARAM
+#define V AV_OPT_FLAG_VIDEO_PARAM
+#define F AV_OPT_FLAG_FILTERING_PARAM
+static const AVOption ebur128_options[] = {
+ { "video", "set video output", OFFSET(do_video), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, V|F },
+ { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0, V|F },
+ { "meter", "set scale meter (+9 to +18)", OFFSET(meter), AV_OPT_TYPE_INT, {.i64 = 9}, 9, 18, V|F },
+ { NULL },
+};
+
+AVFILTER_DEFINE_CLASS(ebur128);
+
+static const uint8_t graph_colors[] = {
+ 0xdd, 0x66, 0x66, // value above 0LU non reached
+ 0x66, 0x66, 0xdd, // value below 0LU non reached
+ 0x96, 0x33, 0x33, // value above 0LU reached
+ 0x33, 0x33, 0x96, // value below 0LU reached
+ 0xdd, 0x96, 0x96, // value above 0LU line non reached
+ 0x96, 0x96, 0xdd, // value below 0LU line non reached
+ 0xdd, 0x33, 0x33, // value above 0LU line reached
+ 0x33, 0x33, 0xdd, // value below 0LU line reached
+};
+
+static const uint8_t *get_graph_color(const EBUR128Context *ebur128, int v, int y)
+{
+ const int below0 = y > ebur128->y_zero_lu;
+ const int reached = y >= v;
+ const int line = ebur128->y_line_ref[y] || y == ebur128->y_zero_lu;
+ const int colorid = 4*line + 2*reached + below0;
+ return graph_colors + 3*colorid;
+}
+
+static inline int lu_to_y(const EBUR128Context *ebur128, double v)
+{
+ v += 2 * ebur128->meter; // make it in range [0;...]
+ v = av_clipf(v, 0, ebur128->scale_range); // make sure it's in the graph scale
+ v = ebur128->scale_range - v; // invert value (y=0 is on top)
+ return v * ebur128->graph.h / ebur128->scale_range; // rescale from scale range to px height
+}
+
+#define FONT8 0
+#define FONT16 1
+
+static const uint8_t font_colors[] = {
+ 0xdd, 0xdd, 0x00,
+ 0x00, 0x96, 0x96,
+};
+
+static void drawtext(AVFilterBufferRef *pic, int x, int y, int ftid, const uint8_t *color, const char *fmt, ...)
+{
+ int i;
+ char buf[128] = {0};
+ const uint8_t *font;
+ int font_height;
+ va_list vl;
+
+ if (ftid == FONT16) font = avpriv_vga16_font, font_height = 16;
+ else if (ftid == FONT8) font = avpriv_cga_font, font_height = 8;
+ else return;
+
+ va_start(vl, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, vl);
+ va_end(vl);
+
+ for (i = 0; buf[i]; i++) {
+ int char_y, mask;
+ uint8_t *p = pic->data[0] + y*pic->linesize[0] + (x + i*8)*3;
+
+ for (char_y = 0; char_y < font_height; char_y++) {
+ for (mask = 0x80; mask; mask >>= 1) {
+ if (font[buf[i] * font_height + char_y] & mask)
+ memcpy(p, color, 3);
+ else
+ memcpy(p, "\x00\x00\x00", 3);
+ p += 3;
+ }
+ p += pic->linesize[0] - 8*3;
+ }
+ }
+}
+
+static void drawline(AVFilterBufferRef *pic, int x, int y, int len, int step)
+{
+ int i;
+ uint8_t *p = pic->data[0] + y*pic->linesize[0] + x*3;
+
+ for (i = 0; i < len; i++) {
+ memcpy(p, "\x00\xff\x00", 3);
+ p += step;
+ }
+}
+
+static int config_video_output(AVFilterLink *outlink)
+{
+ int i, x, y;
+ uint8_t *p;
+ AVFilterContext *ctx = outlink->src;
+ EBUR128Context *ebur128 = ctx->priv;
+ AVFilterBufferRef *outpicref;
+
+ if (ebur128->w < 640 || ebur128->h < 480) {
+ av_log(ctx, AV_LOG_ERROR, "Video size %dx%d is too small, "
+ "minimum size is 640x480\n", ebur128->w, ebur128->h);
+ return AVERROR(EINVAL);
+ }
+ outlink->w = ebur128->w;
+ outlink->h = ebur128->h;
+
+#define PAD 8
+
+ /* configure text area position and size */
+ ebur128->text.x = PAD;
+ ebur128->text.y = 40;
+ ebur128->text.w = 3 * 8; // 3 characters
+ ebur128->text.h = ebur128->h - PAD - ebur128->text.y;
+
+ /* configure gauge position and size */
+ ebur128->gauge.w = 20;
+ ebur128->gauge.h = ebur128->text.h;
+ ebur128->gauge.x = ebur128->w - PAD - ebur128->gauge.w;
+ ebur128->gauge.y = ebur128->text.y;
+
+ /* configure graph position and size */
+ ebur128->graph.x = ebur128->text.x + ebur128->text.w + PAD;
+ ebur128->graph.y = ebur128->gauge.y;
+ ebur128->graph.w = ebur128->gauge.x - ebur128->graph.x - PAD;
+ ebur128->graph.h = ebur128->gauge.h;
+
+ /* graph and gauge share the LU-to-pixel code */
+ av_assert0(ebur128->graph.h == ebur128->gauge.h);
+
+ /* prepare the initial picref buffer */
+ avfilter_unref_bufferp(&ebur128->outpicref);
+ ebur128->outpicref = outpicref =
+ ff_get_video_buffer(outlink, AV_PERM_WRITE|AV_PERM_PRESERVE|AV_PERM_REUSE2,
+ outlink->w, outlink->h);
+ if (!outpicref)
+ return AVERROR(ENOMEM);
+ outlink->sample_aspect_ratio = (AVRational){1,1};
+
+ /* init y references values (to draw LU lines) */
+ ebur128->y_line_ref = av_calloc(ebur128->graph.h + 1, sizeof(*ebur128->y_line_ref));
+ if (!ebur128->y_line_ref)
+ return AVERROR(ENOMEM);
+
+ /* black background */
+ memset(outpicref->data[0], 0, ebur128->h * outpicref->linesize[0]);
+
+ /* draw LU legends */
+ drawtext(outpicref, PAD, PAD+16, FONT8, font_colors+3, " LU");
+ for (i = ebur128->meter; i >= -ebur128->meter * 2; i--) {
+ y = lu_to_y(ebur128, i);
+ x = PAD + (i < 10 && i > -10) * 8;
+ ebur128->y_line_ref[y] = i;
+ y -= 4; // -4 to center vertically
+ drawtext(outpicref, x, y + ebur128->graph.y, FONT8, font_colors+3,
+ "%c%d", i < 0 ? '-' : i > 0 ? '+' : ' ', FFABS(i));
+ }
+
+ /* draw graph */
+ ebur128->y_zero_lu = lu_to_y(ebur128, 0);
+ p = outpicref->data[0] + ebur128->graph.y * outpicref->linesize[0]
+ + ebur128->graph.x * 3;
+ for (y = 0; y < ebur128->graph.h; y++) {
+ const uint8_t *c = get_graph_color(ebur128, INT_MAX, y);
+
+ for (x = 0; x < ebur128->graph.w; x++)
+ memcpy(p + x*3, c, 3);
+ p += outpicref->linesize[0];
+ }
+
+ /* draw fancy rectangles around the graph and the gauge */
+#define DRAW_RECT(r) do { \
+ drawline(outpicref, r.x, r.y - 1, r.w, 3); \
+ drawline(outpicref, r.x, r.y + r.h, r.w, 3); \
+ drawline(outpicref, r.x - 1, r.y, r.h, outpicref->linesize[0]); \
+ drawline(outpicref, r.x + r.w, r.y, r.h, outpicref->linesize[0]); \
+} while (0)
+ DRAW_RECT(ebur128->graph);
+ DRAW_RECT(ebur128->gauge);
+
+ return 0;
+}
+
+static int config_audio_output(AVFilterLink *outlink)
+{
+ int i;
+ AVFilterContext *ctx = outlink->src;
+ EBUR128Context *ebur128 = ctx->priv;
+ const int nb_channels = av_get_channel_layout_nb_channels(outlink->channel_layout);
+
+#define BACK_MASK (AV_CH_BACK_LEFT |AV_CH_BACK_CENTER |AV_CH_BACK_RIGHT| \
+ AV_CH_TOP_BACK_LEFT|AV_CH_TOP_BACK_CENTER|AV_CH_TOP_BACK_RIGHT)
+
+ ebur128->nb_channels = nb_channels;
+ ebur128->ch_weighting = av_calloc(nb_channels, sizeof(*ebur128->ch_weighting));
+ if (!ebur128->ch_weighting)
+ return AVERROR(ENOMEM);
+
+ for (i = 0; i < nb_channels; i++) {
+
+ /* channel weighting */
+ if ((outlink->channel_layout & 1ULL<<i) == AV_CH_LOW_FREQUENCY)
+ continue;
+ if (outlink->channel_layout & 1ULL<<i & BACK_MASK)
+ ebur128->ch_weighting[i] = 1.41;
+ else
+ ebur128->ch_weighting[i] = 1.0;
+
+ /* bins buffer for the two integration window (400ms and 3s) */
+ ebur128->i400.cache[i] = av_calloc(I400_BINS, sizeof(*ebur128->i400.cache[0]));
+ ebur128->i3000.cache[i] = av_calloc(I3000_BINS, sizeof(*ebur128->i3000.cache[0]));
+ if (!ebur128->i400.cache[i] || !ebur128->i3000.cache[i])
+ return AVERROR(ENOMEM);
+ }
+
+ return 0;
+}
+
+static av_cold int init(AVFilterContext *ctx, const char *args)
+{
+ int ret;
+ EBUR128Context *ebur128 = ctx->priv;
+ AVFilterPad pad;
+
+ ebur128->class = &ebur128_class;
+ av_opt_set_defaults(ebur128);
+
+ if ((ret = av_set_options_string(ebur128, args, "=", ":")) < 0)
+ return ret;
+
+ // if meter is +9 scale, scale range is from -18 LU to +9 LU (or 3*9)
+ // if meter is +18 scale, scale range is from -36 LU to +18 LU (or 3*18)
+ ebur128->scale_range = 3 * ebur128->meter;
+
+ ebur128->i400.powers_hist = av_calloc(HIST_SIZE, sizeof(*ebur128->i400.powers_hist));
+ ebur128->i3000.powers_hist = av_calloc(HIST_SIZE, sizeof(*ebur128->i3000.powers_hist));
+
+ /* insert output pads */
+ if (ebur128->do_video) {
+ pad = (AVFilterPad){
+ .name = av_strdup("out0"),
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_video_output,
+ };
+ if (!pad.name)
+ return AVERROR(ENOMEM);
+ ff_insert_outpad(ctx, 0, &pad);
+ }
+ pad = (AVFilterPad){
+ .name = av_asprintf("out%d", ebur128->do_video),
+ .type = AVMEDIA_TYPE_AUDIO,
+ .config_props = config_audio_output,
+ };
+ if (!pad.name)
+ return AVERROR(ENOMEM);
+ ff_insert_outpad(ctx, ebur128->do_video, &pad);
+
+ /* summary */
+ av_log(ctx, AV_LOG_VERBOSE, "EBU +%d scale\n", ebur128->meter);
+
+ return 0;
+}
+
+#define HIST_POS(power) (int)(((power) - ABS_THRES) * HIST_GRAIN)
+#define HIST_POW(pos) ((double)(pos) / HIST_GRAIN + ABS_THRES)
+
+/* loudness and power should be set such as loudness = -0.691 +
+ * 10*log10(power), we just avoid doing that calculus two times */
+static int gate_update(struct integrator *integ, double power,
+ double loudness, int gate_thres)
+{
+ int ipower;
+ double relative_threshold;
+ int gate_hist_pos;
+
+ /* update powers histograms by incrementing current power count */
+ ipower = av_clip(HIST_POS(loudness), 0, HIST_SIZE - 1);
+ integ->powers_hist[ipower]++;
+
+ /* compute relative threshold and get its position in the histogram */
+ integ->sum_kept_powers += power;
+ integ->nb_kept_powers++;
+ relative_threshold = integ->sum_kept_powers / integ->nb_kept_powers;
+ relative_threshold = -0.691 + 10*log10(relative_threshold) + gate_thres;
+ gate_hist_pos = av_clip(HIST_POS(relative_threshold), 0, HIST_SIZE - 1);
+
+ return gate_hist_pos;
+}
+
+static int filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
+{
+ int i, ch;
+ AVFilterContext *ctx = inlink->dst;
+ EBUR128Context *ebur128 = ctx->priv;
+ const int nb_channels = ebur128->nb_channels;
+ const int nb_samples = insamples->audio->nb_samples;
+ const double *samples = (double *)insamples->data[0];
+ AVFilterBufferRef *pic = ebur128->outpicref;
+
+ for (i = 0; i < nb_samples; i++) {
+
+ const int bin_id_400 = ebur128->i400.cache_pos;
+ const int bin_id_3000 = ebur128->i3000.cache_pos;
+
+ if (++ebur128->i400.cache_pos == I400_BINS) ebur128->i400.cache_pos = 0;
+ if (++ebur128->i3000.cache_pos == I3000_BINS) ebur128->i3000.cache_pos = 0;
+
+ for (ch = 0; ch < nb_channels; ch++) {
+ double bin;
+
+ if (!ebur128->ch_weighting[ch])
+ continue;
+
+ /* Y[i] = X[i]*b0 + X[i-1]*b1 + X[i-2]*b2 - Y[i-1]*a1 - Y[i-2]*a2 */
+#define FILTER(Y, X, name) do { \
+ double *dst = ebur128->Y + ch*3; \
+ double *src = ebur128->X + ch*3; \
+ dst[2] = dst[1]; \
+ dst[1] = dst[0]; \
+ dst[0] = src[0]*name##_B0 + src[1]*name##_B1 + src[2]*name##_B2 \
+ - dst[1]*name##_A1 - dst[2]*name##_A2; \
+} while (0)
+
+ ebur128->x[ch * 3] = *samples++; // set X[i]
+
+ // TODO: merge both filters in one?
+ FILTER(y, x, PRE); // apply pre-filter
+ ebur128->x[ch * 3 + 2] = ebur128->x[ch * 3 + 1];
+ ebur128->x[ch * 3 + 1] = ebur128->x[ch * 3 ];
+ FILTER(z, y, RLB); // apply RLB-filter
+
+ bin = ebur128->z[ch * 3] * ebur128->z[ch * 3];
+
+ /* add the new value, and limit the sum to the cache size (400ms or 3s)
+ * by removing the oldest one */
+ ebur128->i400.sum [ch] = ebur128->i400.sum [ch] + bin - ebur128->i400.cache [ch][bin_id_400];
+ ebur128->i3000.sum[ch] = ebur128->i3000.sum[ch] + bin - ebur128->i3000.cache[ch][bin_id_3000];
+
+ /* override old cache entry with the new value */
+ ebur128->i400.cache [ch][bin_id_400 ] = bin;
+ ebur128->i3000.cache[ch][bin_id_3000] = bin;
+ }
+
+ /* For integrated loudness, gating blocks are 400ms long with 75%
+ * overlap (see BS.1770-2 p5), so a recomputation is needed each 100ms
+ * (4800 samples at 48kHz). */
+ if (++ebur128->sample_count == 4800) {
+ double loudness_400, loudness_3000;
+ double power_400 = 0, power_3000 = 0;
+ double integrated_loudness = 0;
+ double loudness_range = 0;
+
+ ebur128->sample_count = 0;
+
+#define COMPUTE_LOUDNESS(m, time) do { \
+ /* weighting sum of the last <time> ms */ \
+ for (ch = 0; ch < nb_channels; ch++) \
+ power_##time += ebur128->ch_weighting[ch] * ebur128->i##time.sum[ch]; \
+ power_##time /= I##time##_BINS; \
+ \
+ loudness_##time = -0.691 + 10*log10(power_##time); \
+} while (0)
+
+ COMPUTE_LOUDNESS(M, 400);
+ COMPUTE_LOUDNESS(S, 3000);
+
+ /* Integrated loudness */
+#define I_GATE_THRES -10 // initially defined to -8 LU in the first EBU standard
+
+ if (loudness_400 >= ABS_THRES) {
+ double integrated_sum = 0;
+ int nb_integrated = 0;
+ int gate_hist_pos = gate_update(&ebur128->i400, power_400,
+ loudness_400, I_GATE_THRES);
+
+ /* compute integrated loudness by summing the histogram values
+ * above the relative threshold */
+ for (i = gate_hist_pos; i < HIST_SIZE; i++) {
+ const int nb_v = ebur128->i400.powers_hist[i];
+ if (nb_v) {
+ nb_integrated += nb_v;
+ integrated_sum += nb_v * HIST_POW(i); // XXX: cache pow in histogram?
+ }
+ }
+ if (nb_integrated)
+ integrated_loudness = integrated_sum / nb_integrated;
+ }
+
+ /* LRA */
+#define LRA_GATE_THRES -20
+#define LRA_LOWER_PRC 10
+#define LRA_HIGHER_PRC 95
+
+ /* XXX: example code in EBU 3342 is ">=" but formula in BS.1770
+ * specs is ">" */
+ if (loudness_3000 >= ABS_THRES) {
+ int nb_powers = 0;
+ int gate_hist_pos = gate_update(&ebur128->i3000, power_3000,
+ loudness_3000, LRA_GATE_THRES);
+
+ for (i = gate_hist_pos; i < HIST_SIZE; i++)
+ nb_powers += ebur128->i3000.powers_hist[i];
+ if (nb_powers) {
+ int n, nb_pow;
+ double low_v = 0, high_v = 0;
+
+ /* get lower power to consider */
+ n = 0;
+ nb_pow = LRA_LOWER_PRC * nb_powers / 100. + 0.5;
+ for (i = gate_hist_pos; i < HIST_SIZE; i++) {
+ n += ebur128->i3000.powers_hist[i];
+ if (n >= nb_pow) {
+ low_v = HIST_POW(i);
+ break;
+ }
+ }
+
+ /* get higher power to consider */
+ n = nb_powers;
+ nb_pow = LRA_HIGHER_PRC * nb_powers / 100. + 0.5;
+ for (i = HIST_SIZE - 1; i >= 0; i--) {
+ n -= ebur128->i3000.powers_hist[i];
+ if (n < nb_pow) {
+ high_v = HIST_POW(i);
+ break;
+ }
+ }
+
+ // TODO: show low & high on the graph
+ loudness_range = high_v - low_v;
+ }
+ }
+
+#define LOG_FMT "M:%6.1f S:%6.1f I:%6.1f LUFS LRA:%6.1f LU"
+
+ /* push one video frame */
+ if (ebur128->do_video) {
+ int x, y;
+ uint8_t *p;
+ AVFilterLink *outlink = ctx->outputs[0];
+
+ const int y_loudness_lu_graph = lu_to_y(ebur128, loudness_3000 + 23);
+ const int y_loudness_lu_gauge = lu_to_y(ebur128, loudness_400 + 23);
+
+ /* draw the graph using the short-term loudness */
+ p = pic->data[0] + ebur128->graph.y*pic->linesize[0] + ebur128->graph.x*3;
+ for (y = 0; y < ebur128->graph.h; y++) {
+ const uint8_t *c = get_graph_color(ebur128, y_loudness_lu_graph, y);
+
+ memmove(p, p + 3, (ebur128->graph.w - 1) * 3);
+ memcpy(p + (ebur128->graph.w - 1) * 3, c, 3);
+ p += pic->linesize[0];
+ }
+
+ /* draw the gauge using the momentary loudness */
+ p = pic->data[0] + ebur128->gauge.y*pic->linesize[0] + ebur128->gauge.x*3;
+ for (y = 0; y < ebur128->gauge.h; y++) {
+ const uint8_t *c = get_graph_color(ebur128, y_loudness_lu_gauge, y);
+
+ for (x = 0; x < ebur128->gauge.w; x++)
+ memcpy(p + x*3, c, 3);
+ p += pic->linesize[0];
+ }
+
+ /* draw textual info */
+ drawtext(pic, PAD, PAD - PAD/2, FONT16, font_colors,
+ LOG_FMT " ", // padding to erase trailing characters
+ loudness_400, loudness_3000,
+ integrated_loudness, loudness_range);
+
+ /* set pts and push frame */
+ pic->pts = insamples->pts +
+ av_rescale_q(i, (AVRational){ 1, inlink->sample_rate },
+ outlink->time_base);
+ ff_start_frame(outlink, avfilter_ref_buffer(pic, ~AV_PERM_WRITE));
+ ff_draw_slice(outlink, 0, outlink->h, 1);
+ ff_end_frame(outlink);
+ }
+
+ av_log(ctx, ebur128->do_video ? AV_LOG_VERBOSE : AV_LOG_INFO,
+ LOG_FMT "\n", loudness_400, loudness_3000,
+ integrated_loudness, loudness_range);
+ }
+ }
+
+ return ff_filter_samples(ctx->outputs[ebur128->do_video], insamples);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ EBUR128Context *ebur128 = ctx->priv;
+ AVFilterFormats *formats;
+ AVFilterChannelLayouts *layouts;
+ AVFilterLink *inlink = ctx->inputs[0];
+ AVFilterLink *outlink = ctx->outputs[0];
+
+ static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_DBL, -1 };
+ static const int input_srate[] = {48000, -1}; // ITU-R BS.1770 provides coeff only for 48kHz
+ static const enum PixelFormat pix_fmts[] = { PIX_FMT_RGB24, -1 };
+
+ /* set input audio formats */
+ formats = ff_make_format_list(sample_fmts);
+ if (!formats)
+ return AVERROR(ENOMEM);
+ ff_formats_ref(formats, &inlink->out_formats);
+
+ layouts = ff_all_channel_layouts();
+ if (!layouts)
+ return AVERROR(ENOMEM);
+ ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts);
+
+ formats = ff_make_format_list(input_srate);
+ if (!formats)
+ return AVERROR(ENOMEM);
+ ff_formats_ref(formats, &inlink->out_samplerates);
+
+ /* set optional output video format */
+ if (ebur128->do_video) {
+ formats = ff_make_format_list(pix_fmts);
+ if (!formats)
+ return AVERROR(ENOMEM);
+ ff_formats_ref(formats, &outlink->in_formats);
+ outlink = ctx->outputs[1];
+ }
+
+ /* set audio output formats (same as input since it's just a passthrough) */
+ formats = ff_make_format_list(sample_fmts);
+ if (!formats)
+ return AVERROR(ENOMEM);
+ ff_formats_ref(formats, &outlink->in_formats);
+
+ layouts = ff_all_channel_layouts();
+ if (!layouts)
+ return AVERROR(ENOMEM);
+ ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts);
+
+ formats = ff_make_format_list(input_srate);
+ if (!formats)
+ return AVERROR(ENOMEM);
+ ff_formats_ref(formats, &outlink->in_samplerates);
+
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ int i;
+ EBUR128Context *ebur128 = ctx->priv;
+
+ av_freep(&ebur128->y_line_ref);
+ av_freep(&ebur128->ch_weighting);
+ av_freep(&ebur128->i400.powers_hist);
+ av_freep(&ebur128->i3000.powers_hist);
+ for (i = 0; i < ebur128->nb_channels; i++) {
+ av_freep(&ebur128->i400.cache[i]);
+ av_freep(&ebur128->i3000.cache[i]);
+ }
+ for (i = 0; i < ctx->nb_outputs; i++)
+ av_freep(&ctx->output_pads[i].name);
+ avfilter_unref_bufferp(&ebur128->outpicref);
+}
+
+AVFilter avfilter_af_ebur128 = {
+ .name = "ebur128",
+ .description = NULL_IF_CONFIG_SMALL("EBU R.128 scanner."),
+ .priv_size = sizeof(EBUR128Context),
+ .init = init,
+ .uninit = uninit,
+ .query_formats = query_formats,
+
+ .inputs = (const AVFilterPad[]) {
+ { .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .get_audio_buffer = ff_null_get_audio_buffer,
+ .filter_samples = filter_samples, },
+ { .name = NULL }
+ },
+ .outputs = (const AVFilterPad[]) { { .name = NULL } },
+};
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index 6842ec9..6214c12 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -53,6 +53,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (CHANNELMAP, channelmap, af);
REGISTER_FILTER (CHANNELSPLIT,channelsplit,af);
REGISTER_FILTER (EARWAX, earwax, af);
+ REGISTER_FILTER (EBUR128, ebur128, af);
REGISTER_FILTER (JOIN, join, af);
REGISTER_FILTER (PAN, pan, af);
REGISTER_FILTER (SILENCEDETECT, silencedetect, af);
--
1.7.12.1
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