High Definition Compatible Digital (HDCD) decoder filter, using libhdcd

Signed-off-by: Burt P <pburt0@gmail.com>
Signed-off-by: Diego Biurrun <diego@biurrun.de>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

Changelog

@@ -62,6 +62,7 @@ version <next>:
 - Intel QSV video scaling and deinterlacing filter
 - OpenH264 decoder wrapper
 - Removed the legacy X11 screen grabber, use XCB instead
+- HDCD decoding filter through libhdcd
 
 
 version 11:

configure

@@ -197,6 +197,7 @@ External library support:
   --enable-libfontconfig     font configuration and management
   --enable-libfreetype       font rendering
   --enable-libgsm            GSM audio encoding/decoding
+  --enable-libhdcd           HDCD decoding filter
   --enable-libilbc           ILBC audio encoding/decoding
   --enable-libkvazaar        HEVC video encoding
   --enable-libmp3lame        MP3 audio encoding
@@ -1270,6 +1271,7 @@ EXTERNAL_LIBRARY_LIST="
     libfontconfig
     libfreetype
     libgsm
+    libhdcd
     libilbc
     libkvazaar
     libmp3lame
@@ -2426,6 +2428,7 @@ frei0r_filter_deps="frei0r dlopen"
 frei0r_filter_extralibs='$ldl'
 frei0r_src_filter_deps="frei0r dlopen"
 frei0r_src_filter_extralibs='$ldl'
+hdcd_filter_deps="libhdcd"
 hqdn3d_filter_deps="gpl"
 interlace_filter_deps="gpl"
 ocv_filter_deps="libopencv"
@@ -4606,6 +4609,7 @@ enabled libfreetype       && require_pkg_config freetype2 "ft2build.h FT_FREETYP
 enabled libgsm            && { for gsm_hdr in "gsm.h" "gsm/gsm.h"; do
                                    check_lib "${gsm_hdr}" gsm_create -lgsm && break;
                                done || die "ERROR: libgsm not found"; }
+enabled libhdcd           && require_pkg_config libhdcd "hdcd/hdcd_simple.h" hdcd_new
 enabled libilbc           && require libilbc ilbc.h WebRtcIlbcfix_InitDecode -lilbc
 enabled libkvazaar        && require_pkg_config "kvazaar >= 0.8.1" kvazaar.h kvz_api_get
 enabled libmfx            && require_pkg_config libmfx "mfx/mfxvideo.h" MFXInit

doc/filters.texi

@@ -647,6 +647,53 @@ avconv -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
 out
 @end example
 
+@section hdcd
+
+Decodes High Definition Compatible Digital (HDCD) data. A 16-bit PCM stream with
+embedded HDCD codes is expanded into a 20-bit PCM stream.
+
+The filter supports the Peak Extend and Low-level Gain Adjustment features
+of HDCD, and detects the Transient Filter flag.
+
+@example
+avconv -i HDCD16.flac -af hdcd OUT24.flac
+@end example
+
+When using the filter with WAV, note that the default encoding for WAV is 16-bit,
+so the resulting 20-bit stream will be truncated back to 16-bit. Use something
+like @command{-acodec pcm_s24le} after the filter to get 24-bit PCM output.
+@example
+avconv -i HDCD16.wav -af hdcd OUT16.wav
+avconv -i HDCD16.wav -af hdcd -acodec pcm_s24le OUT24.wav
+@end example
+
+The filter accepts the following options:
+
+@table @option
+@item analyze_mode
+Replace audio with a solid tone and adjust the amplitude to signal some
+specific aspect of the decoding process. The output file can be loaded in
+an audio editor alongside the original to aid analysis.
+
+Modes are:
+@table @samp
+@item 0, off
+Disabled
+@item 1, lle
+Gain adjustment level at each sample
+@item 2, pe
+Samples where peak extend occurs
+@item 3, cdt
+Samples where the code detect timer is active
+@item 4, tgm
+Samples where the target gain does not match between channels
+@item 5, pel
+Any samples above peak extend level
+@item 6, ltgm
+Gain adjustment level at each sample, in each channel
+@end table
+@end table
+
 @section resample
 Convert the audio sample format, sample rate and channel layout. It is
 not meant to be used directly; it is inserted automatically by libavfilter

doc/general.texi

@@ -157,6 +157,15 @@ Go to @url{https://github.com/dekkers/libilbc} and follow the instructions for
 installing the library. Then pass @code{--enable-libilbc} to configure to
 enable it.
 
+@section libhdcd
+
+Libav can make use of the libhdcd library for High Definition Compatible
+Digital (HDCD) decoding via the @code{hdcd} filter.
+
+Go to @url{https://github.com/bp0/libhdcd} and follow the instructions for
+installing the library. Then pass @code{--enable-libhdcd} to configure to
+enable it.
+
 @section AviSynth
 
 Libav can read AviSynth scripts as input. To enable support you need a

libavfilter/Makefile

@@ -34,6 +34,7 @@ OBJS-$(CONFIG_BS2B_FILTER)                   += af_bs2b.o
 OBJS-$(CONFIG_CHANNELMAP_FILTER)             += af_channelmap.o
 OBJS-$(CONFIG_CHANNELSPLIT_FILTER)           += af_channelsplit.o
 OBJS-$(CONFIG_COMPAND_FILTER)                += af_compand.o
+OBJS-$(CONFIG_HDCD_FILTER)                   += af_hdcd.o
 OBJS-$(CONFIG_JOIN_FILTER)                   += af_join.o
 OBJS-$(CONFIG_RESAMPLE_FILTER)               += af_resample.o
 OBJS-$(CONFIG_VOLUME_FILTER)                 += af_volume.o

libavfilter/af_hdcd.c

+/*
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * HDCD decoding filter, using libhdcd
+ */
+
+#include <hdcd/hdcd_simple.h>
+
+#include "libavutil/channel_layout.h"
+#include "libavutil/opt.h"
+
+#include "audio.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+
+typedef struct HDCDContext {
+    const AVClass *class;
+
+    hdcd_simple *shdcd;
+
+    /* AVOption members */
+    /** analyze mode replaces the audio with a solid tone and adjusts
+     *  the amplitude to signal some specific aspect of the decoding
+     *  process. See docs or HDCD_ANA_* defines. */
+    int analyze_mode;
+    /* end AVOption members */
+} HDCDContext;
+
+#define OFFSET(x) offsetof(HDCDContext, x)
+#define A AV_OPT_FLAG_AUDIO_PARAM
+#define HDCD_ANA_MAX 6
+static const AVOption hdcd_options[] = {
+    { "analyze_mode",  "Replace audio with solid tone and signal some processing aspect in the amplitude.",
+      OFFSET(analyze_mode), AV_OPT_TYPE_INT, { .i64=HDCD_ANA_OFF }, 0, HDCD_ANA_MAX, A, "analyze_mode"},
+    { "off",  HDCD_ANA_OFF_DESC,  0, AV_OPT_TYPE_CONST, { .i64 = HDCD_ANA_OFF},  0, 0, A, "analyze_mode" },
+    { "lle",  HDCD_ANA_LLE_DESC,  0, AV_OPT_TYPE_CONST, { .i64 = HDCD_ANA_LLE},  0, 0, A, "analyze_mode" },
+    { "pe",   HDCD_ANA_PE_DESC,   0, AV_OPT_TYPE_CONST, { .i64 = HDCD_ANA_PE},   0, 0, A, "analyze_mode" },
+    { "cdt",  HDCD_ANA_CDT_DESC,  0, AV_OPT_TYPE_CONST, { .i64 = HDCD_ANA_CDT},  0, 0, A, "analyze_mode" },
+    { "tgm",  HDCD_ANA_TGM_DESC,  0, AV_OPT_TYPE_CONST, { .i64 = HDCD_ANA_TGM},  0, 0, A, "analyze_mode" },
+    { "pel",  HDCD_ANA_PEL_DESC,  0, AV_OPT_TYPE_CONST, { .i64 = HDCD_ANA_PEL},  0, 0, A, "analyze_mode" },
+    { "ltgm", HDCD_ANA_LTGM_DESC, 0, AV_OPT_TYPE_CONST, { .i64 = HDCD_ANA_LTGM}, 0, 0, A, "analyze_mode" },
+    { NULL }
+};
+
+static const AVClass hdcd_class = {
+    .class_name = "HDCD filter",
+    .item_name  = av_default_item_name,
+    .option     = hdcd_options,
+    .version    = LIBAVFILTER_VERSION_INT,
+};
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx = inlink->dst;
+    HDCDContext *s = ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[0];
+    AVFrame *out;
+    const int16_t *in_data;
+    int32_t *out_data;
+    int n, result;
+    int channel_count = av_get_channel_layout_nb_channels(in->channel_layout);
+
+    out = ff_get_audio_buffer(outlink, in->nb_samples);
+    if (!out) {
+        av_frame_free(&in);
+        return AVERROR(ENOMEM);
+    }
+    result = av_frame_copy_props(out, in);
+    if (result) {
+        av_frame_free(&out);
+        av_frame_free(&in);
+        return result;
+    }
+
+    in_data  = (int16_t *)in->data[0];
+    out_data = (int32_t *)out->data[0];
+    for (n = 0; n < in->nb_samples * channel_count; n++)
+        out_data[n] = in_data[n];
+
+    hdcd_process(s->shdcd, out_data, in->nb_samples);
+
+    av_frame_free(&in);
+    return ff_filter_frame(outlink, out);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    AVFilterFormats *in_formats, *out_formats, *sample_rates = NULL;
+    AVFilterChannelLayouts *layouts = NULL;
+    AVFilterLink *inlink  = ctx->inputs[0];
+    AVFilterLink *outlink = ctx->outputs[0];
+
+    static const enum AVSampleFormat sample_fmts_in[] = {
+        AV_SAMPLE_FMT_S16,
+        AV_SAMPLE_FMT_NONE
+    };
+    static const enum AVSampleFormat sample_fmts_out[] = {
+        AV_SAMPLE_FMT_S32,
+        AV_SAMPLE_FMT_NONE
+    };
+
+    ff_add_channel_layout(&layouts, AV_CH_LAYOUT_STEREO);
+
+    ff_set_common_channel_layouts(ctx, layouts);
+
+    in_formats  = ff_make_format_list(sample_fmts_in);
+    out_formats = ff_make_format_list(sample_fmts_out);
+    if (!in_formats || !out_formats)
+        return AVERROR(ENOMEM);
+
+    ff_formats_ref(in_formats, &inlink->out_formats);
+    ff_formats_ref(out_formats, &outlink->in_formats);
+
+    ff_add_format(&sample_rates, 44100);
+    ff_set_common_samplerates(ctx, sample_rates);
+    return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    HDCDContext *s = ctx->priv;
+    char detect_str[256] = "";
+
+    /* log the HDCD decode information */
+    hdcd_detect_str(s->shdcd, detect_str, sizeof(detect_str));
+    av_log(ctx, AV_LOG_INFO, "%s\n", detect_str);
+
+    hdcd_free(s->shdcd);
+}
+
+/** callback for error logging */
+static void af_hdcd_log(const void *priv, const char *fmt, va_list args)
+{
+    av_vlog((AVFilterContext *)priv, AV_LOG_VERBOSE, fmt, args);
+}
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    HDCDContext *s = ctx->priv;
+
+    s->shdcd = hdcd_new();
+    hdcd_logger_attach(s->shdcd, af_hdcd_log, ctx);
+
+    if (s->analyze_mode)
+        hdcd_analyze_mode(s->shdcd, s->analyze_mode);
+    av_log(ctx, AV_LOG_VERBOSE, "Analyze mode: [%d] %s\n",
+           s->analyze_mode, hdcd_str_analyze_mode_desc(s->analyze_mode));
+
+    return 0;
+}
+
+static const AVFilterPad avfilter_af_hdcd_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_AUDIO,
+        .filter_frame = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad avfilter_af_hdcd_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_AUDIO,
+    },
+    { NULL }
+};
+
+AVFilter ff_af_hdcd = {
+    .name          = "hdcd",
+    .description   = NULL_IF_CONFIG_SMALL("Apply High Definition Compatible Digital (HDCD) decoding."),
+    .priv_size     = sizeof(HDCDContext),
+    .priv_class    = &hdcd_class,
+    .init          = init,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+    .inputs        = avfilter_af_hdcd_inputs,
+    .outputs       = avfilter_af_hdcd_outputs,
+};

libavfilter/allfilters.c

@@ -57,6 +57,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(CHANNELMAP,     channelmap,     af);
     REGISTER_FILTER(CHANNELSPLIT,   channelsplit,   af);
     REGISTER_FILTER(COMPAND,        compand,        af);
+    REGISTER_FILTER(HDCD,           hdcd,           af);
     REGISTER_FILTER(JOIN,           join,           af);
     REGISTER_FILTER(RESAMPLE,       resample,       af);
     REGISTER_FILTER(VOLUME,         volume,         af);

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  6
-#define LIBAVFILTER_VERSION_MINOR  6
+#define LIBAVFILTER_VERSION_MINOR  7
 #define LIBAVFILTER_VERSION_MICRO  0
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \