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/*
* Copyright (C) 2003-2012 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 "OggUtil.hxx"
#include "OggFind.hxx"
#include "OggSyncState.hxx"
#include "DecoderAPI.hxx"
#include "OggCodec.hxx"
#include "CheckAudioFormat.hxx"
#include "tag/TagHandler.hxx"
#include "tag/TagBuilder.hxx"
#include "InputStream.hxx"
#include "util/Error.hxx"
#include "Log.hxx"
#include <opus.h>
#include <ogg/ogg.h>
#include <glib.h>
#include <stdio.h>
#include <string.h>
static const opus_int32 opus_sample_rate = 48000;
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 {
struct decoder *decoder;
struct input_stream *input_stream;
ogg_stream_state os;
OpusDecoder *opus_decoder;
opus_int16 *output_buffer;
unsigned output_size;
bool os_initialized;
bool found_opus;
int opus_serialno;
size_t frame_size;
public:
MPDOpusDecoder(struct decoder *_decoder,
struct input_stream *_input_stream)
:decoder(_decoder), input_stream(_input_stream),
opus_decoder(nullptr),
output_buffer(nullptr), output_size(0),
os_initialized(false), found_opus(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 HandleTags(const ogg_packet &packet);
DecoderCommand HandleAudio(const ogg_packet &packet);
};
MPDOpusDecoder::~MPDOpusDecoder()
{
g_free(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 DecoderCommand::STOP;
if (packet.b_o_s)
return HandleBOS(packet);
else if (!found_opus)
return DecoderCommand::STOP;
if (IsOpusTags(packet))
return HandleTags(packet);
return HandleAudio(packet);
}
inline DecoderCommand
MPDOpusDecoder::HandleBOS(const ogg_packet &packet)
{
assert(packet.b_o_s);
if (found_opus || !IsOpusHead(packet))
return DecoderCommand::STOP;
unsigned channels;
if (!ScanOpusHeader(packet.packet, packet.bytes, channels) ||
!audio_valid_channel_count(channels))
return DecoderCommand::STOP;
assert(opus_decoder == nullptr);
assert(output_buffer == nullptr);
opus_serialno = os.serialno;
found_opus = true;
/* 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;
}
const AudioFormat audio_format(opus_sample_rate,
SampleFormat::S16, channels);
decoder_initialized(decoder, audio_format, false, -1);
frame_size = audio_format.GetFrameSize();
/* allocate an output buffer for 16 bit PCM samples big enough
to hold a quarter second, larger than 120ms required by
libopus */
output_size = audio_format.sample_rate / 4;
output_buffer = (opus_int16 *)
g_malloc(sizeof(*output_buffer) * output_size *
audio_format.channels);
return decoder_get_command(decoder);
}
inline DecoderCommand
MPDOpusDecoder::HandleTags(const ogg_packet &packet)
{
TagBuilder tag_builder;
DecoderCommand cmd;
if (ScanOpusTags(packet.packet, packet.bytes,
&add_tag_handler, &tag_builder) &&
!tag_builder.IsEmpty()) {
Tag tag;
tag_builder.Commit(tag);
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, output_size,
0);
if (nframes < 0) {
LogError(opus_domain, 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;
}
return DecoderCommand::NONE;
}
static void
mpd_opus_stream_decode(struct decoder *decoder,
struct input_stream *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->LockSeek(0, SEEK_SET, 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::NONE)
break;
if (!d.ReadNextPage(oy))
break;
}
}
static bool
SeekFindEOS(OggSyncState &oy, ogg_stream_state &os, ogg_packet &packet,
input_stream *is)
{
if (is->size > 0 && is->size - is->offset < 65536)
return OggFindEOS(oy, os, packet);
if (!is->CheapSeeking())
return false;
oy.Reset();
Error error;
return is->LockSeek(-65536, SEEK_END, error) &&
oy.ExpectPageSeekIn(os) &&
OggFindEOS(oy, os, packet);
}
static bool
mpd_opus_scan_stream(struct input_stream *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,
handler, handler_ctx))
result = false;
break;
}
}
if (packet.e_o_s || SeekFindEOS(oy, os, packet, is))
tag_handler_invoke_duration(handler, handler_ctx,
packet.granulepos / opus_sample_rate);
ogg_stream_clear(&os);
return result;
}
static const char *const opus_suffixes[] = {
"opus",
"ogg",
"oga",
nullptr
};
static const char *const opus_mime_types[] = {
"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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