From a84aeaea96a5e659b2a8ebe041cdd45c9f283c48 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fr=C3=A9d=C3=A9ric=20Mangano?= <frederic.mangano@u-psud.fr>
Date: Tue, 23 Feb 2016 14:23:27 +0100
Subject: [PATCH] implement most of ogg::Encoder

---
 src/actions.cc |  4 +--
 src/ogg.cc     | 71 +++++++++++++++++++++++++++++++++++++++++++++++++-
 src/ogg.h      | 11 +++++---
 3 files changed, 80 insertions(+), 6 deletions(-)

diff --git a/src/actions.cc b/src/actions.cc
index fa3c6a8..b5b365f 100644
--- a/src/actions.cc
+++ b/src/actions.cc
@@ -38,7 +38,7 @@ void opustags::edit_tags(ogg::Decoder &in, ogg::Encoder &out, TagsHandler &handl
                     s->downgrade();
                     out.write_raw_page(in.current_page);
                 } else {
-                    out.write_page(in.current_page);
+                    out.forward(*s);
                 }
                 break;
 
@@ -48,7 +48,7 @@ void opustags::edit_tags(ogg::Decoder &in, ogg::Encoder &out, TagsHandler &handl
                 break;
 
             case ogg::DATA_READY:
-                out.write_page(in.current_page);
+                out.forward(*s);
                 break;
 
             case ogg::RAW_READY:
diff --git a/src/ogg.cc b/src/ogg.cc
index 83ef006..f9b8198 100644
--- a/src/ogg.cc
+++ b/src/ogg.cc
@@ -42,7 +42,7 @@ bool ogg::Stream::page_in(ogg_page &og)
 bool ogg::Stream::handle_page()
 {
     ogg_packet op;
-    int rc = ogg_stream_packetout(&stream, &op);
+    int rc = ogg_stream_packetpeek(&stream, &op);
     if (rc < 0)
         throw std::runtime_error("ogg_stream_packetout failed");
     else if (rc == 0) // insufficient data
@@ -143,3 +143,72 @@ bool ogg::Decoder::buff()
     ogg_sync_wrote(&sync, input->gcount());
     return true;
 }
+
+////////////////////////////////////////////////////////////////////////////////
+// ogg::Encoder
+
+ogg::Encoder::Encoder(std::ostream *out)
+    : output(out)
+{
+    output->exceptions(std::ifstream::badbit);
+}
+
+ogg::Stream& ogg::Encoder::get_stream(int streamno)
+{
+    auto i = streams.find(streamno);
+    if (i == streams.end())
+        i = streams.emplace(streamno, Stream(streamno)).first;
+    return i->second;
+}
+
+void ogg::Encoder::forward(ogg::Stream &in)
+{
+    ogg::Stream *out = &get_stream(in.stream.serialno);
+    forward_stream(in, *out);
+    flush_stream(*out);
+}
+
+void ogg::Encoder::forward_stream(ogg::Stream &in, ogg::Stream &out)
+{
+    int rc;
+    ogg_packet op;
+    for (;;) {
+        rc = ogg_stream_packetout(&in.stream, &op);
+        if (rc < 0) {
+            throw std::runtime_error("ogg_stream_packetout failed");
+        } else if (rc == 0) {
+            break;
+        } else {
+            if (ogg_stream_packetin(&out.stream, &op) != 0)
+                throw std::runtime_error("ogg_stream_packetin failed");
+        }
+    }
+}
+void ogg::Encoder::flush_stream(ogg::Stream &out)
+{
+    ogg_page og;
+    if (ogg_stream_flush(&out.stream, &og))
+            write_raw_page(og);
+}
+
+void ogg::Encoder::write_raw_page(const ogg_page &og)
+{
+    output->write((const char*) og.header, og.header_len);
+    output->write((const char*) og.body, og.body_len);
+}
+
+void ogg::Encoder::write_tags(int streamno, const Tags&)
+{
+    ogg_packet op;
+    op.b_o_s = 0;
+    op.e_o_s = 0;
+    op.granulepos = 0;
+    op.packetno = 1; // TODO ensure it's not 2
+    // craft the tags
+    op.bytes = 0;
+
+    ogg::Stream *s = &streams.at(streamno); // assume it exists
+    if (ogg_stream_packetin(&s->stream, &op) != 0)
+        throw std::runtime_error("ogg_stream_packetin failed");
+    flush_stream(*s);
+}
diff --git a/src/ogg.h b/src/ogg.h
index d3125d8..21302ac 100644
--- a/src/ogg.h
+++ b/src/ogg.h
@@ -93,9 +93,9 @@ namespace ogg
     struct Encoder
     {
         Encoder(std::ostream*);
-        ~Encoder();
 
-        void write_page(const ogg_page&);
+        // Copy the input stream's current page.
+        void forward(Stream &in);
 
         // Write the page without even ensuring its page number is correct.
         // It would be an efficient way to copy a stream identically, and also
@@ -108,7 +108,12 @@ namespace ogg
 
         // We're gonna need some ogg_stream_state for adjusting the page
         // numbers and splitting large packets as it's gotta be done.
-        std::map<int, ogg_stream_state> streams;
+        std::map<int, Stream> streams;
+
+    private:
+        Stream& get_stream(int streamno);
+        void forward_stream(Stream &in, Stream &out);
+        void flush_stream(Stream &out);
     };
 }
 }