From 9ff2ce59449ade100a5976bb9de3f0b9b6f41665 Mon Sep 17 00:00:00 2001
From: bnnm <bananaman255@gmail.com>
Date: Thu, 27 Dec 2018 16:51:27 +0100
Subject: [PATCH] Add name_offset/name_size option for TXTH

---
 doc/TXTH.md     | 16 ++++++++++++++--
 src/meta/txth.c | 18 ++++++++++++++++++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/doc/TXTH.md b/doc/TXTH.md
index f78dcf00..666da2f7 100644
--- a/doc/TXTH.md
+++ b/doc/TXTH.md
@@ -190,11 +190,23 @@ body_file = (filename)|*.(extension)|null
 
 # Subsongs [OPTIONAL]
 # Sets the number of subsongs in the file, adjusting reads per subsong N:
-# "value = @(offset) + subsong_offset*N". Mainly for bigfiles with consecutive
-# headers per subsong, set subsong_offset to 0 when done as it affects any reads.
+# "value = @(offset) + subsong_offset*N". (number) values aren't adjusted
+# as they are seen as constants.
+# Mainly for bigfiles with consecutive headers per subsong, set subsong_offset
+# to 0 when done as it affects any reads.
 # The current subsong number is handled externally by plugins or TXTP.
 subsong_count = (number)|(offset)|(field)
 subsong_offset = (number)|(offset)|(field)
+
+# Names [OPTIONAL]
+# Sets the name of the stream, most useful when used with subsongs.
+# TXTH will read a string at name_offset, with name_size characters.
+# name_size defaults to 0, which reads until null-terminator or a
+# non-ascii character.
+# name_offset can be a (number) value, but being an offset it's also
+# adjusted by subsong_offset.
+name_offset = (number)|(offset)|(field)
+name_size = (number)|(offset)|(field)
 ```
 
 ## Usages
diff --git a/src/meta/txth.c b/src/meta/txth.c
index 40165d5b..4dbb72a7 100644
--- a/src/meta/txth.c
+++ b/src/meta/txth.c
@@ -76,6 +76,10 @@ typedef struct {
     uint32_t subsong_count;
     uint32_t subsong_offset;
 
+    uint32_t name_offset_set;
+    uint32_t name_offset;
+    uint32_t name_size;
+
     /* original STREAMFILE and its type (may be an unsupported "base" file or a .txth) */
     STREAMFILE *streamFile;
     int streamfile_is_txth;
@@ -194,6 +198,10 @@ VGMSTREAM * init_vgmstream_txth(STREAMFILE *streamFile) {
     vgmstream->loop_end_sample = txth.loop_end_sample;
     vgmstream->num_streams = txth.subsong_count;
     vgmstream->stream_size = txth.data_size;
+    if (txth.name_offset_set) {
+        size_t name_size = txth.name_size ? txth.name_size + 1 : STREAM_NAME_SIZE;
+        read_string(vgmstream->stream_name,name_size, txth.name_offset,txth.streamHead);
+    }
 
     /* codec specific (taken from GENH with minimal changes) */
     switch (coding) {
@@ -720,6 +728,16 @@ static int parse_keyval(STREAMFILE * streamFile_, txth_header * txth, const char
     else if (0==strcmp(key,"subsong_offset")) {
         if (!parse_num(txth->streamHead,txth,val, &txth->subsong_offset)) goto fail;
     }
+    else if (0==strcmp(key,"name_offset")) {
+        if (!parse_num(txth->streamHead,txth,val, &txth->name_offset)) goto fail;
+        txth->name_offset_set = 1;
+        /* special subsong adjustment */
+        if (txth->subsong_offset)
+            txth->name_offset = txth->name_offset + txth->subsong_offset * (txth->target_subsong - 1);
+    }
+    else if (0==strcmp(key,"name_size")) {
+        if (!parse_num(txth->streamHead,txth,val, &txth->name_size)) goto fail;
+    }
     else if (0==strcmp(key,"header_file")) {
         if (txth->streamhead_opened) {
             close_streamfile(txth->streamHead);