From 04f16811e1de827a0c90fabc0cae366ab9810035 Mon Sep 17 00:00:00 2001
From: Philipp Schafft <lion@lion.leolix.org>
Date: Wed, 16 Mar 2022 01:29:02 +0000
Subject: [PATCH] Feature: Report data from FLAC block STREAMINFO

---
 src/format_flac.c   | 25 +++++++++++++++++++++++++
 src/metadata_xiph.c | 13 +++++++++++++
 src/metadata_xiph.h |  1 +
 3 files changed, 39 insertions(+)

diff --git a/src/format_flac.c b/src/format_flac.c
index c88344bd..e8205420 100644
--- a/src/format_flac.c
+++ b/src/format_flac.c
@@ -127,11 +127,36 @@ static const char * flac_block_type_to_name(flac_block_type_t type)
     return "<unknown>";
 }
 
+static void flac_handle_block_streaminfo(format_plugin_t *plugin, ogg_state_t *ogg_info, ogg_codec_t *codec, const flac_block_t *block)
+{
+    uint32_t raw;
+    uint32_t sample_rate;
+    uint32_t channels;
+    uint32_t bits;
+
+    if (block->len != 34) {
+        ICECAST_LOG_ERROR("Can not parse FLAC header block STREAMINFO");
+        return;
+    }
+
+    raw = metadata_xiph_read_u32be_unaligned(block->data + 10);
+    sample_rate = ((raw >> 12) & 0xfffff) + 0;
+    channels    = ((raw >>  9) & 0x7    ) + 1;
+    bits        = ((raw >>  4) & 0x1F   ) + 1;
+
+    stats_event_args(ogg_info->mount, "audio_samplerate", "%ld", (long int)sample_rate);
+    stats_event_args(ogg_info->mount, "audio_channels", "%ld", (long int)channels);
+    stats_event_args(ogg_info->mount, "audio_bits", "%ld", (long int)bits);
+}
+
 static void flac_handle_block(format_plugin_t *plugin, ogg_state_t *ogg_info, ogg_codec_t *codec, const flac_block_t *block)
 {
     ICECAST_LOG_DEBUG("Found header of type %s%s with %zu bytes of data", flac_block_type_to_name(block->type), block->last ? "(last)" : "", block->len);
 
     switch (block->type) {
+        case FLAC_BLOCK_TYPE_STREAMINFO:
+            flac_handle_block_streaminfo(plugin, ogg_info, codec, block);
+            break;
         case FLAC_BLOCK_TYPE_VORBIS_COMMENT:
             vorbis_comment_clear(&plugin->vc);
             vorbis_comment_init(&plugin->vc);
diff --git a/src/metadata_xiph.c b/src/metadata_xiph.c
index beeec5b0..395f6542 100644
--- a/src/metadata_xiph.c
+++ b/src/metadata_xiph.c
@@ -18,6 +18,19 @@
 #include "logging.h"
 #define CATMODULE "metadata-xiph"
 
+uint32_t metadata_xiph_read_u32be_unaligned(const unsigned char *in)
+{
+    uint32_t ret = 0;
+    ret += in[0];
+    ret <<= 8;
+    ret += in[1];
+    ret <<= 8;
+    ret += in[2];
+    ret <<= 8;
+    ret += in[3];
+    return ret;
+}
+
 uint32_t metadata_xiph_read_u32le_unaligned(const unsigned char *in)
 {
     uint32_t ret = 0;
diff --git a/src/metadata_xiph.h b/src/metadata_xiph.h
index 3c1056b4..7127fdca 100644
--- a/src/metadata_xiph.h
+++ b/src/metadata_xiph.h
@@ -15,6 +15,7 @@
 
 #include <vorbis/codec.h>
 
+uint32_t metadata_xiph_read_u32be_unaligned(const unsigned char *in);
 uint32_t metadata_xiph_read_u32le_unaligned(const unsigned char *in);
 
 /* returns true if parsing was successful, *vc must be in inited state before and will be in inited state after (even when false is returned) */