| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * Copyright (c) 2012 Nicolas George | ||
| 3 | * | ||
| 4 | * This file is part of FFmpeg. | ||
| 5 | * | ||
| 6 | * FFmpeg is free software; you can redistribute it and/or | ||
| 7 | * modify it under the terms of the GNU Lesser General Public License | ||
| 8 | * as published by the Free Software Foundation; either | ||
| 9 | * version 2.1 of the License, or (at your option) any later version. | ||
| 10 | * | ||
| 11 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| 14 | * GNU Lesser General Public License for more details. | ||
| 15 | * | ||
| 16 | * You should have received a copy of the GNU Lesser General Public License | ||
| 17 | * along with FFmpeg; if not, write to the Free Software Foundation, Inc., | ||
| 18 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 19 | */ | ||
| 20 | |||
| 21 | #include "libavutil/channel_layout.h" | ||
| 22 | #include "libavutil/avassert.h" | ||
| 23 | #include "audio.h" | ||
| 24 | #include "avfilter.h" | ||
| 25 | #include "filters.h" | ||
| 26 | |||
| 27 | typedef struct VolDetectContext { | ||
| 28 | /** | ||
| 29 | * Number of samples at each PCM value. | ||
| 30 | * histogram[0x8000 + i] is the number of samples at value i. | ||
| 31 | * The extra element is there for symmetry. | ||
| 32 | */ | ||
| 33 | uint64_t histogram[0x10001]; | ||
| 34 | } VolDetectContext; | ||
| 35 | |||
| 36 | ✗ | static int filter_frame(AVFilterLink *inlink, AVFrame *samples) | |
| 37 | { | ||
| 38 | ✗ | AVFilterContext *ctx = inlink->dst; | |
| 39 | ✗ | VolDetectContext *vd = ctx->priv; | |
| 40 | ✗ | int nb_samples = samples->nb_samples; | |
| 41 | ✗ | int nb_channels = samples->ch_layout.nb_channels; | |
| 42 | ✗ | int nb_planes = nb_channels; | |
| 43 | int plane, i; | ||
| 44 | int16_t *pcm; | ||
| 45 | |||
| 46 | ✗ | if (!av_sample_fmt_is_planar(samples->format)) { | |
| 47 | ✗ | nb_samples *= nb_channels; | |
| 48 | ✗ | nb_planes = 1; | |
| 49 | } | ||
| 50 | ✗ | for (plane = 0; plane < nb_planes; plane++) { | |
| 51 | ✗ | pcm = (int16_t *)samples->extended_data[plane]; | |
| 52 | ✗ | for (i = 0; i < nb_samples; i++) | |
| 53 | ✗ | vd->histogram[pcm[i] + 0x8000]++; | |
| 54 | } | ||
| 55 | |||
| 56 | ✗ | return ff_filter_frame(inlink->dst->outputs[0], samples); | |
| 57 | } | ||
| 58 | |||
| 59 | #define MAX_DB 91 | ||
| 60 | |||
| 61 | ✗ | static inline double logdb(uint64_t v) | |
| 62 | { | ||
| 63 | ✗ | double d = v / (double)(0x8000 * 0x8000); | |
| 64 | ✗ | if (!v) | |
| 65 | ✗ | return MAX_DB; | |
| 66 | ✗ | return -log10(d) * 10; | |
| 67 | } | ||
| 68 | |||
| 69 | ✗ | static void print_stats(AVFilterContext *ctx) | |
| 70 | { | ||
| 71 | ✗ | VolDetectContext *vd = ctx->priv; | |
| 72 | int i, max_volume, shift; | ||
| 73 | ✗ | uint64_t nb_samples = 0, power = 0, nb_samples_shift = 0, sum = 0; | |
| 74 | ✗ | uint64_t histdb[MAX_DB + 1] = { 0 }; | |
| 75 | |||
| 76 | ✗ | for (i = 0; i < 0x10000; i++) | |
| 77 | ✗ | nb_samples += vd->histogram[i]; | |
| 78 | ✗ | av_log(ctx, AV_LOG_INFO, "n_samples: %"PRId64"\n", nb_samples); | |
| 79 | ✗ | if (!nb_samples) | |
| 80 | ✗ | return; | |
| 81 | |||
| 82 | /* If nb_samples > 1<<34, there is a risk of overflow in the | ||
| 83 | multiplication or the sum: shift all histogram values to avoid that. | ||
| 84 | The total number of samples must be recomputed to avoid rounding | ||
| 85 | errors. */ | ||
| 86 | ✗ | shift = av_log2(nb_samples >> 33); | |
| 87 | ✗ | for (i = 0; i < 0x10000; i++) { | |
| 88 | ✗ | nb_samples_shift += vd->histogram[i] >> shift; | |
| 89 | ✗ | power += (i - 0x8000) * (i - 0x8000) * (vd->histogram[i] >> shift); | |
| 90 | } | ||
| 91 | ✗ | if (!nb_samples_shift) | |
| 92 | ✗ | return; | |
| 93 | ✗ | power = (power + nb_samples_shift / 2) / nb_samples_shift; | |
| 94 | ✗ | av_assert0(power <= 0x8000 * 0x8000); | |
| 95 | ✗ | av_log(ctx, AV_LOG_INFO, "mean_volume: %.1f dB\n", -logdb(power)); | |
| 96 | |||
| 97 | ✗ | max_volume = 0x8000; | |
| 98 | ✗ | while (max_volume > 0 && !vd->histogram[0x8000 + max_volume] && | |
| 99 | ✗ | !vd->histogram[0x8000 - max_volume]) | |
| 100 | ✗ | max_volume--; | |
| 101 | ✗ | av_log(ctx, AV_LOG_INFO, "max_volume: %.1f dB\n", -logdb(max_volume * max_volume)); | |
| 102 | |||
| 103 | ✗ | for (i = 0; i < 0x10000; i++) | |
| 104 | ✗ | histdb[(int)logdb((i - 0x8000) * (i - 0x8000))] += vd->histogram[i]; | |
| 105 | ✗ | for (i = 0; i <= MAX_DB && !histdb[i]; i++); | |
| 106 | ✗ | for (; i <= MAX_DB && sum < nb_samples / 1000; i++) { | |
| 107 | ✗ | av_log(ctx, AV_LOG_INFO, "histogram_%ddb: %"PRId64"\n", i, histdb[i]); | |
| 108 | ✗ | sum += histdb[i]; | |
| 109 | } | ||
| 110 | } | ||
| 111 | |||
| 112 | ✗ | static av_cold void uninit(AVFilterContext *ctx) | |
| 113 | { | ||
| 114 | ✗ | print_stats(ctx); | |
| 115 | ✗ | } | |
| 116 | |||
| 117 | static const AVFilterPad volumedetect_inputs[] = { | ||
| 118 | { | ||
| 119 | .name = "default", | ||
| 120 | .type = AVMEDIA_TYPE_AUDIO, | ||
| 121 | .filter_frame = filter_frame, | ||
| 122 | }, | ||
| 123 | }; | ||
| 124 | |||
| 125 | const AVFilter ff_af_volumedetect = { | ||
| 126 | .name = "volumedetect", | ||
| 127 | .description = NULL_IF_CONFIG_SMALL("Detect audio volume."), | ||
| 128 | .priv_size = sizeof(VolDetectContext), | ||
| 129 | .uninit = uninit, | ||
| 130 | .flags = AVFILTER_FLAG_METADATA_ONLY, | ||
| 131 | FILTER_INPUTS(volumedetect_inputs), | ||
| 132 | FILTER_OUTPUTS(ff_audio_default_filterpad), | ||
| 133 | FILTER_SAMPLEFMTS(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S16P), | ||
| 134 | }; | ||
| 135 |