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/*
* Copyright (C) 2003-2015 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "config.h" /* must be first for large file support */
#include "OpusDecoderPlugin.h"
#include "OpusDomain.hxx"
#include "OpusHead.hxx"
#include "OpusTags.hxx"
#include "OggFind.hxx"
#include "OggSyncState.hxx"
#include "../DecoderAPI.hxx"
#include "OggCodec.hxx"
#include "tag/TagHandler.hxx"
#include "tag/TagBuilder.hxx"
#include "input/InputStream.hxx"
#include "util/Error.hxx"
#include "Log.hxx"
#include <opus.h>
#include <ogg/ogg.h>
#include <string.h>
#include <stdio.h>
static constexpr opus_int32 opus_sample_rate = 48000;
/**
* Allocate an output buffer for 16 bit PCM samples big enough to hold
* a quarter second, larger than 120ms required by libopus.
*/
static constexpr unsigned opus_output_buffer_frames = opus_sample_rate / 4;
gcc_pure
static bool
IsOpusHead(const ogg_packet &packet)
{
return packet.bytes >= 8 && memcmp(packet.packet, "OpusHead", 8) == 0;
}
gcc_pure
static bool
IsOpusTags(const ogg_packet &packet)
{
return packet.bytes >= 8 && memcmp(packet.packet, "OpusTags", 8) == 0;
}
static bool
mpd_opus_init(gcc_unused const config_param ¶m)
{
LogDebug(opus_domain, opus_get_version_string());
return true;
}
class MPDOpusDecoder {
Decoder &decoder;
InputStream &input_stream;
ogg_stream_state os;
OpusDecoder *opus_decoder;
opus_int16 *output_buffer;
/**
* If non-zero, then a previous Opus stream has been found
* already with this number of channels. If opus_decoder is
* nullptr, then its end-of-stream packet has been found
* already.
*/
unsigned previous_channels;
bool os_initialized;
int opus_serialno;
ogg_int64_t eos_granulepos;
size_t frame_size;
public:
MPDOpusDecoder(Decoder &_decoder,
InputStream &_input_stream)
:decoder(_decoder), input_stream(_input_stream),
opus_decoder(nullptr),
output_buffer(nullptr),
previous_channels(0),
os_initialized(false) {}
~MPDOpusDecoder();
bool ReadFirstPage(OggSyncState &oy);
bool ReadNextPage(OggSyncState &oy);
DecoderCommand HandlePackets();
DecoderCommand HandlePacket(const ogg_packet &packet);
DecoderCommand HandleBOS(const ogg_packet &packet);
DecoderCommand HandleEOS();
DecoderCommand HandleTags(const ogg_packet &packet);
DecoderCommand HandleAudio(const ogg_packet &packet);
bool Seek(OggSyncState &oy, uint64_t where_frame);
};
MPDOpusDecoder::~MPDOpusDecoder()
{
delete[] output_buffer;
if (opus_decoder != nullptr)
opus_decoder_destroy(opus_decoder);
if (os_initialized)
ogg_stream_clear(&os);
}
inline bool
MPDOpusDecoder::ReadFirstPage(OggSyncState &oy)
{
assert(!os_initialized);
if (!oy.ExpectFirstPage(os))
return false;
os_initialized = true;
return true;
}
inline bool
MPDOpusDecoder::ReadNextPage(OggSyncState &oy)
{
assert(os_initialized);
ogg_page page;
if (!oy.ExpectPage(page))
return false;
const auto page_serialno = ogg_page_serialno(&page);
if (page_serialno != os.serialno)
ogg_stream_reset_serialno(&os, page_serialno);
ogg_stream_pagein(&os, &page);
return true;
}
inline DecoderCommand
MPDOpusDecoder::HandlePackets()
{
ogg_packet packet;
while (ogg_stream_packetout(&os, &packet) == 1) {
auto cmd = HandlePacket(packet);
if (cmd != DecoderCommand::NONE)
return cmd;
}
return DecoderCommand::NONE;
}
inline DecoderCommand
MPDOpusDecoder::HandlePacket(const ogg_packet &packet)
{
if (packet.e_o_s)
return HandleEOS();
if (packet.b_o_s)
return HandleBOS(packet);
else if (opus_decoder == nullptr) {
LogDebug(opus_domain, "BOS packet expected");
return DecoderCommand::STOP;
}
if (IsOpusTags(packet))
return HandleTags(packet);
return HandleAudio(packet);
}
/**
* Load the end-of-stream packet and restore the previous file
* position.
*/
static bool
LoadEOSPacket(InputStream &is, Decoder *decoder, int serialno,
ogg_packet &packet)
{
if (!is.CheapSeeking())
/* we do this for local files only, because seeking
around remote files is expensive and not worth the
troubl */
return false;
const auto old_offset = is.GetOffset();
/* create temporary Ogg objects for seeking and parsing the
EOS packet */
OggSyncState oy(is, decoder);
ogg_stream_state os;
ogg_stream_init(&os, serialno);
bool result = OggSeekFindEOS(oy, os, packet, is);
ogg_stream_clear(&os);
/* restore the previous file position */
is.LockSeek(old_offset, IgnoreError());
return result;
}
/**
* Load the end-of-stream granulepos and restore the previous file
* position.
*
* @return -1 on error
*/
gcc_pure
static ogg_int64_t
LoadEOSGranulePos(InputStream &is, Decoder *decoder, int serialno)
{
ogg_packet packet;
if (!LoadEOSPacket(is, decoder, serialno, packet))
return -1;
return packet.granulepos;
}
inline DecoderCommand
MPDOpusDecoder::HandleBOS(const ogg_packet &packet)
{
assert(packet.b_o_s);
if (opus_decoder != nullptr || !IsOpusHead(packet)) {
LogDebug(opus_domain, "BOS packet must be OpusHead");
return DecoderCommand::STOP;
}
unsigned channels;
if (!ScanOpusHeader(packet.packet, packet.bytes, channels) ||
!audio_valid_channel_count(channels)) {
LogDebug(opus_domain, "Malformed BOS packet");
return DecoderCommand::STOP;
}
assert(opus_decoder == nullptr);
assert((previous_channels == 0) == (output_buffer == nullptr));
if (previous_channels != 0 && channels != previous_channels) {
FormatWarning(opus_domain,
"Next stream has different channels (%u -> %u)",
previous_channels, channels);
return DecoderCommand::STOP;
}
opus_serialno = os.serialno;
/* TODO: parse attributes from the OpusHead (sample rate,
channels, ...) */
int opus_error;
opus_decoder = opus_decoder_create(opus_sample_rate, channels,
&opus_error);
if (opus_decoder == nullptr) {
FormatError(opus_domain, "libopus error: %s",
opus_strerror(opus_error));
return DecoderCommand::STOP;
}
if (previous_channels != 0) {
/* decoder was already initialized by the previous
stream; skip the rest of this method */
LogDebug(opus_domain, "Found another stream");
return decoder_get_command(decoder);
}
eos_granulepos = LoadEOSGranulePos(input_stream, &decoder,
opus_serialno);
const auto duration = eos_granulepos >= 0
? SignedSongTime::FromScale<uint64_t>(eos_granulepos,
opus_sample_rate)
: SignedSongTime::Negative();
previous_channels = channels;
const AudioFormat audio_format(opus_sample_rate,
SampleFormat::S16, channels);
decoder_initialized(decoder, audio_format,
eos_granulepos > 0, duration);
frame_size = audio_format.GetFrameSize();
output_buffer = new opus_int16[opus_output_buffer_frames
* audio_format.channels];
return decoder_get_command(decoder);
}
inline DecoderCommand
MPDOpusDecoder::HandleEOS()
{
if (eos_granulepos < 0 && previous_channels != 0) {
/* allow chaining of (unseekable) streams */
assert(opus_decoder != nullptr);
assert(output_buffer != nullptr);
opus_decoder_destroy(opus_decoder);
opus_decoder = nullptr;
return decoder_get_command(decoder);
}
return DecoderCommand::STOP;
}
inline DecoderCommand
MPDOpusDecoder::HandleTags(const ogg_packet &packet)
{
ReplayGainInfo rgi;
rgi.Clear();
TagBuilder tag_builder;
DecoderCommand cmd;
if (ScanOpusTags(packet.packet, packet.bytes,
&rgi,
&add_tag_handler, &tag_builder) &&
!tag_builder.IsEmpty()) {
decoder_replay_gain(decoder, &rgi);
Tag tag = tag_builder.Commit();
cmd = decoder_tag(decoder, input_stream, std::move(tag));
} else
cmd = decoder_get_command(decoder);
return cmd;
}
inline DecoderCommand
MPDOpusDecoder::HandleAudio(const ogg_packet &packet)
{
assert(opus_decoder != nullptr);
int nframes = opus_decode(opus_decoder,
(const unsigned char*)packet.packet,
packet.bytes,
output_buffer, opus_output_buffer_frames,
0);
if (nframes < 0) {
FormatError(opus_domain, "libopus error: %s",
opus_strerror(nframes));
return DecoderCommand::STOP;
}
if (nframes > 0) {
const size_t nbytes = nframes * frame_size;
auto cmd = decoder_data(decoder, input_stream,
output_buffer, nbytes,
0);
if (cmd != DecoderCommand::NONE)
return cmd;
if (packet.granulepos > 0)
decoder_timestamp(decoder,
double(packet.granulepos)
/ opus_sample_rate);
}
return DecoderCommand::NONE;
}
bool
MPDOpusDecoder::Seek(OggSyncState &oy, uint64_t where_frame)
{
assert(eos_granulepos > 0);
assert(input_stream.IsSeekable());
assert(input_stream.KnownSize());
const ogg_int64_t where_granulepos(where_frame);
/* interpolate the file offset where we expect to find the
given granule position */
/* TODO: implement binary search */
offset_type offset(where_granulepos * input_stream.GetSize()
/ eos_granulepos);
return OggSeekPageAtOffset(oy, os, input_stream, offset);
}
static void
mpd_opus_stream_decode(Decoder &decoder,
InputStream &input_stream)
{
if (ogg_codec_detect(&decoder, input_stream) != OGG_CODEC_OPUS)
return;
/* rewind the stream, because ogg_codec_detect() has
moved it */
input_stream.LockRewind(IgnoreError());
MPDOpusDecoder d(decoder, input_stream);
OggSyncState oy(input_stream, &decoder);
if (!d.ReadFirstPage(oy))
return;
while (true) {
auto cmd = d.HandlePackets();
if (cmd == DecoderCommand::SEEK) {
if (d.Seek(oy, decoder_seek_where_frame(decoder)))
decoder_command_finished(decoder);
else
decoder_seek_error(decoder);
continue;
}
if (cmd != DecoderCommand::NONE)
break;
if (!d.ReadNextPage(oy))
break;
}
}
static bool
mpd_opus_scan_stream(InputStream &is,
const struct tag_handler *handler, void *handler_ctx)
{
OggSyncState oy(is);
ogg_stream_state os;
if (!oy.ExpectFirstPage(os))
return false;
/* read at most two more pages */
unsigned remaining_pages = 2;
bool result = false;
ogg_packet packet;
while (true) {
int r = ogg_stream_packetout(&os, &packet);
if (r < 0) {
result = false;
break;
}
if (r == 0) {
if (remaining_pages-- == 0)
break;
if (!oy.ExpectPageIn(os)) {
result = false;
break;
}
continue;
}
if (packet.b_o_s) {
if (!IsOpusHead(packet))
break;
unsigned channels;
if (!ScanOpusHeader(packet.packet, packet.bytes, channels) ||
!audio_valid_channel_count(channels)) {
result = false;
break;
}
result = true;
} else if (!result)
break;
else if (IsOpusTags(packet)) {
if (!ScanOpusTags(packet.packet, packet.bytes,
nullptr,
handler, handler_ctx))
result = false;
break;
}
}
if (packet.e_o_s || OggSeekFindEOS(oy, os, packet, is)) {
const auto duration =
SongTime::FromScale<uint64_t>(packet.granulepos,
opus_sample_rate);
tag_handler_invoke_duration(handler, handler_ctx, duration);
}
ogg_stream_clear(&os);
return result;
}
static const char *const opus_suffixes[] = {
"opus",
"ogg",
"oga",
nullptr
};
static const char *const opus_mime_types[] = {
/* the official MIME type (RFC 5334) */
"audio/ogg",
/* deprecated (RFC 5334) */
"application/ogg",
/* deprecated; from an early draft */
"audio/opus",
nullptr
};
const struct DecoderPlugin opus_decoder_plugin = {
"opus",
mpd_opus_init,
nullptr,
mpd_opus_stream_decode,
nullptr,
nullptr,
mpd_opus_scan_stream,
nullptr,
opus_suffixes,
opus_mime_types,
};
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