From faee5bbb78aa3a855fcecd49d111467dfbd40167 Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@musicpd.org>
Date: Wed, 1 Jul 2020 21:21:38 +0200
Subject: [PATCH] decoder/opus: implement End Trimming (RFC7845 4.4)
Closes https://github.com/MusicPlayerDaemon/MPD/issues/867
---
NEWS | 2 +-
src/decoder/plugins/OpusDecoderPlugin.cxx | 17 +++++++++++++++++
2 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/NEWS b/NEWS
index 0f86d2431..cfab38190 100644
--- a/NEWS
+++ b/NEWS
@@ -5,7 +5,7 @@ ver 0.21.25 (not yet released)
- file: detect premature end of file
- smbclient: don't send credentials to MPD clients
* decoder
- - opus: apply pre-skip
+ - opus: apply pre-skip and end trimming
- opus: fix memory leak
* output
- osx: improve sample rate selection
diff --git a/src/decoder/plugins/OpusDecoderPlugin.cxx b/src/decoder/plugins/OpusDecoderPlugin.cxx
index ed4ec3d01..fa448a2ff 100644
--- a/src/decoder/plugins/OpusDecoderPlugin.cxx
+++ b/src/decoder/plugins/OpusDecoderPlugin.cxx
@@ -286,6 +286,23 @@ MPDOpusDecoder::HandleAudio(const ogg_packet &packet)
AddGranulepos(skip);
skip = 0;
+ if (packet.e_o_s && packet.granulepos > 0 && granulepos >= 0) {
+ /* End Trimming (RFC7845 4.4): "The page with the 'end
+ of stream' flag set MAY have a granule position
+ that indicates the page contains less audio data
+ than would normally be returned by decoding up
+ through the final packet. This is used to end the
+ stream somewhere other than an even frame
+ boundary. [...] The remaining samples are
+ discarded. */
+ ogg_int64_t remaining = packet.granulepos - granulepos;
+ if (remaining <= 0)
+ return;
+
+ if (remaining < nframes)
+ nframes = remaining;
+ }
+
/* submit decoded samples to the DecoderClient */
const size_t nbytes = nframes * frame_size;
auto cmd = client.SubmitData(input_stream,