Files
genode-world/src/app/audio_player/main.cc
Emery Hemingway 176a5c443c audio_player: consume and produce XSPF
Consume and produce playlists in the XML Shareable Playlist Format.

http://www.xspf.org
2019-02-22 17:01:48 +01:00

939 lines
22 KiB
C++

/*
* \brief Audio player
* \author Josef Soentgen
* \date 2015-11-19
*/
/*
* Copyright (C) 2015-2016 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
/* Genode includes */
#include <base/attached_rom_dataspace.h>
#include <libc/component.h>
#include <base/heap.h>
#include <base/sleep.h>
#include <os/reporter.h>
#include <util/retry.h>
#include <util/xml_node.h>
#include <audio_out_session/connection.h>
/* local includes */
#include <list.h>
#include <ring_buffer.h>
extern "C" {
/*
* UINT64_C is needed by libav headers
*
* Use the compiler's definition as fallback because the UINT64_C macro is only
* defined in <machine/_stdint.h> when used with C.
*/
#ifndef UINT64_C
#define UINT64_C(c) __UINT64_C(c)
#endif
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavutil/dict.h>
#include <libavutil/frame.h>
#include <libavutil/opt.h>
#include <libavresample/avresample.h>
#include <fcntl.h>
#include <unistd.h>
}; /* extern "C" */
namespace Audio_player {
class Output;
class Playlist;
class Decoder;
struct Main;
typedef Util::Ring_buffer<64 * 1024> Frame_data;
typedef Genode::String<1024> Path;
enum { LEFT, RIGHT, NUM_CHANNELS };
enum { AUDIO_OUT_PACKET_SIZE = Audio_out::PERIOD * NUM_CHANNELS * sizeof(float) };
enum { QUEUED_PACKET_THRESHOLD = 10 };
}
struct Audio_player::Output
{
Audio_out::Connection _left;
Audio_out::Connection _right;
Audio_out::Connection *_out[NUM_CHANNELS];
Audio_out::Packet *_alloc_position;
unsigned _packets_submitted = 0;
template <typename FUNC>
static void for_each_channel(FUNC const &func) {
for (int i = 0; i < Audio_player::NUM_CHANNELS; i++) func(i); }
/**
* Constructor
*
* \param sigh progress signal handler
*/
Output(Genode::Env &env,
Genode::Signal_context_capability sigh)
: _left(env, "left", true, true), _right(env, "right", false, false)
{
/*
* We only care about the left (first) channel and sync all other
* channels with it when needed
*/
_left.progress_sigh(sigh);
_out[LEFT] = &_left;
_out[RIGHT] = &_right;
}
void start()
{
for_each_channel([&] (int const i) { _out[i]->start(); });
}
void stop()
{
for_each_channel([&] (int const i) { _out[i]->stop(); });
_alloc_position = nullptr;
}
/**
* Return rounded estimate of packets per secound
*/
unsigned packets_per_sec() const { return Audio_out::SAMPLE_RATE / Audio_out::PERIOD; }
/**
* Return the size of one output frame
*/
size_t frame_size() const { return AUDIO_OUT_PACKET_SIZE; }
/**
* Return number of currently queued packets in Audio_out stream
*/
unsigned queued()
{
if (_alloc_position == nullptr) _alloc_position = _out[LEFT]->stream()->next();
unsigned const packet_pos = _out[LEFT]->stream()->packet_position(_alloc_position);
unsigned const play_pos = _out[LEFT]->stream()->pos();
unsigned const queued = packet_pos < play_pos
? ((Audio_out::QUEUE_SIZE + packet_pos) - play_pos)
: packet_pos - play_pos;
return queued;
}
/**
* Fetch decoded frames from frame data buffer and fill Audio_out packets
*/
void drain_buffer(Frame_data &frame_data)
{
if (_alloc_position == nullptr) _alloc_position = _out[LEFT]->stream()->next();
while (frame_data.read_avail() > (AUDIO_OUT_PACKET_SIZE)) {
Audio_out::Packet *p[NUM_CHANNELS];
p[LEFT] = _out[LEFT]->stream()->next(_alloc_position);
unsigned const ppos = _out[LEFT]->stream()->packet_position(p[LEFT]);
p[RIGHT] = _out[RIGHT]->stream()->get(ppos);
float tmp[Audio_out::PERIOD * NUM_CHANNELS];
size_t const n = frame_data.read(tmp, sizeof(tmp));
if (n != sizeof(tmp)) {
Genode::warning("less frame data read than expected");
}
float *left_content = p[LEFT]->content();
float *right_content = p[RIGHT]->content();
for (unsigned i = 0; i < Audio_out::PERIOD; i++) {
left_content[i] = tmp[i * NUM_CHANNELS + LEFT];
right_content[i] = tmp[i * NUM_CHANNELS + RIGHT];
}
for_each_channel([&] (int const i) { _out[i]->submit(p[i]); });
_alloc_position = p[LEFT];
_packets_submitted++;
}
}
/**
* Return number of already submitted Audio_out packets
*/
unsigned packets_submitted() { return _packets_submitted; }
};
class Audio_player::Playlist
{
public:
struct Track : public Util::List<Track>::Element
{
Path path;
unsigned id = 0;
Track() { }
Track(char const *path, unsigned id) : path(path), id(id) { }
Track(Track const &track) : path(track.path), id(track.id) { }
bool valid() { return path.length(); }
};
template <typename FUNC>
void for_each_track(FUNC const &func) {
for (Track *t = _track_list.first(); t; t = t->next())
func(*t);
}
private:
Genode::Allocator &_alloc;
Util::List<Track> _track_list;
Track *_curr_track = nullptr;
typedef enum { MODE_ONCE, MODE_REPEAT } Mode;
Mode _mode;
void _insert(char const *path, unsigned id)
{
try {
Track *t = new (&_alloc) Track(path, id);
_track_list.append(t);
} catch (...) { Genode::warning("could not insert track"); }
}
void _remove_all()
{
while (Track *t = _track_list.first()) {
_track_list.remove(t);
Genode::destroy(&_alloc, t);
}
}
public:
Playlist(Genode::Allocator &alloc) : _alloc(alloc), _mode(MODE_ONCE) { }
~Playlist() { _remove_all(); }
/**
* Update playlist
*/
void update(Genode::Xml_node const &node)
{
using namespace Genode;
/* handle tracks */
_remove_all();
_curr_track = nullptr;
unsigned count = 0;
auto add_track = [&] (Xml_node const &track) {
try {
bool done = false;
auto try_location = [&] (Xml_node const &node) {
if (done) return;
typedef String<256> Location;
auto location = node.decoded_content<Location>();
char const *path = location.string();
auto _exists_file = [] (char const *path)
{
bool exists = false;
Libc::with_libc([&] () {
FILE *f = fopen(path, "r");
if (f != NULL) {
fclose(f);
exists = true;
}
});
return exists;
};
if (strcmp(path, "file://", 7) == 0) {
path += 7;
if (_exists_file(path)) {
_insert(path, ++count);
done = true;
}
} else
if (_exists_file(path)) {
_insert(path, ++count);
done = true;
}
};
track.for_each_sub_node("location", try_location);
} catch (...) { Genode::warning("invalid track node in playlist"); }
};
try {
Xml_node const track_list = node.sub_node("trackList");
track_list.for_each_sub_node("track", add_track);
} catch (...) { }
/* handle playlist mode */
_mode = MODE_ONCE;
try {
auto mode = node.attribute_value("mode", String<16>());
if (mode == "repeat") _mode = MODE_REPEAT;
} catch (...) { }
Genode::log("update playlist: ", count,
" tracks mode: ", _mode == MODE_ONCE ? "once" : "repeat");
}
/**
* Return track with given id
*/
Track get_track(unsigned id)
{
for (Track *t = _track_list.first(); t; t = t->next())
if (t->id == id) {
_curr_track = t;
return *_curr_track;
}
return Track();
}
/**
* Return next track from playlist
*/
Track next_track()
{
_curr_track = _curr_track ? _curr_track->next()
: _track_list.first();
/* try to loop at the end of the playlist */
if (_curr_track == nullptr && _mode == MODE_REPEAT) {
_curr_track = _track_list.first();
}
return _curr_track ? *_curr_track : Track();
}
};
class Audio_player::Decoder
{
public:
/*
* Thrown as exception if the decoder could not be initialized
*/
struct Not_initialized { };
/*
* File_info contains metadata of the file that is currently decoded
*/
struct File_info : public Playlist::Track
{
typedef Genode::String<256> Artist;
typedef Genode::String<256> Album;
typedef Genode::String<256> Title;
typedef Genode::String<16> Track;
Artist artist;
Album album;
Title title;
Track track;
int64_t duration;
File_info(Playlist::Track const &playlist_track,
char const *artist, char const *album,
char const *title, char const *track,
int64_t duration)
:
Playlist::Track(playlist_track),
artist(artist), album(album), title(title), track(track),
duration(duration) { }
};
private:
AVFrame *_frame = nullptr;
AVFrame *_conv_frame = nullptr;
AVStream *_stream = nullptr;
AVFormatContext *_format_ctx = nullptr;
AVCodecContext *_codec_ctx = nullptr;
AVPacket _packet;
AVAudioResampleContext *_avr = nullptr;
unsigned _samples_decoded = 0;
Playlist::Track const &_track;
Genode::Constructible<File_info> _track_info;
void _close()
{
Libc::with_libc([&] () {
avformat_close_input(&_format_ctx);
av_free(_conv_frame);
av_free(_frame);
}); /* with_libc */
}
/**
* Initialize libav once before it gets used
*/
static void init()
{
static bool registered = false;
if (registered) { return; }
Libc::with_libc([&] () {
/* initialise libav first so that all decoders are present */
av_register_all();
/* make libav quiet so we do not need stderr access */
av_log_set_level(AV_LOG_QUIET);
}); /* with_libc */
registered = true;
}
public:
/*
* Constructor
*/
Decoder(Playlist::Track const &playlist_track)
: _track(playlist_track)
{
bool initialized = false;
Libc::with_libc([&] () {
Decoder::init();
_frame = av_frame_alloc();
if (!_frame) { return; }
_conv_frame = av_frame_alloc();
if (!_conv_frame) {
av_free(_frame);
return;
}
int err = 0;
err = avformat_open_input(&_format_ctx, _track.path.string(), NULL, NULL);
if (err != 0) {
Genode::error("could not open '", _track.path.string(), "'");
av_free(_conv_frame);
av_free(_frame);
return;
}
err = avformat_find_stream_info(_format_ctx, NULL);
if (err < 0) {
Genode::error("could not find the stream info");
_close();
return;
}
for (unsigned i = 0; i < _format_ctx->nb_streams; ++i)
if (_format_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
_stream = _format_ctx->streams[i];
break;
}
if (_stream == nullptr) {
Genode::error("could not find any audio stream");
_close();
return;
}
_codec_ctx = _stream->codec;
_codec_ctx->codec = avcodec_find_decoder(_codec_ctx->codec_id);
if (_codec_ctx->codec == NULL) {
Genode::error("could not find decoder");
_close();
return;
}
err = avcodec_open2(_codec_ctx, _codec_ctx->codec, NULL);
if (err != 0) {
Genode::error("could not open decoder");
_close();
return;
}
_avr = avresample_alloc_context();
if (!_avr) {
_close();
return;
}
av_opt_set_int(_avr, "in_channel_layout", AV_CH_LAYOUT_STEREO, 0);
av_opt_set_int(_avr, "out_channel_layout", AV_CH_LAYOUT_STEREO, 0);
av_opt_set_int(_avr, "in_sample_rate", _codec_ctx->sample_rate, 0);
av_opt_set_int(_avr, "out_sample_rate", Audio_out::SAMPLE_RATE, 0);
av_opt_set_int(_avr, "in_sample_fmt", _codec_ctx->sample_fmt, 0);
av_opt_set_int(_avr, "out_sample_fmt", AV_SAMPLE_FMT_FLT, 0);
if (avresample_open(_avr) < 0) {
_close();
return;
}
_conv_frame->channel_layout = AV_CH_LAYOUT_STEREO;
_conv_frame->sample_rate = Audio_out::SAMPLE_RATE;
_conv_frame->format = AV_SAMPLE_FMT_FLT;
av_init_packet(&_packet);
/* extract metainformation */
bool const is_vorbis = _codec_ctx->codec_id == AV_CODEC_ID_VORBIS;
AVDictionary *md = is_vorbis ? _stream->metadata : _format_ctx->metadata;
int const flags = AV_DICT_IGNORE_SUFFIX;
AVDictionaryEntry *artist = av_dict_get(md, "artist", NULL, flags);
AVDictionaryEntry *album = av_dict_get(md, "album", NULL, flags);
AVDictionaryEntry *title = av_dict_get(md, "title", NULL, flags);
AVDictionaryEntry *track = av_dict_get(md, "track", NULL, flags);
_track_info.construct(_track,
artist ? artist->value : "",
album ? album->value : "",
title ? title->value : "",
track ? track->value : "",
_format_ctx->duration / 1000);
initialized = true;
}); /* with_libc */
if (!initialized) { throw Not_initialized(); }
}
/**
* Destructor
*/
~Decoder()
{
Libc::with_libc([&] () {
avresample_close(_avr);
avresample_free(&_avr);
avcodec_close(_codec_ctx);
avformat_close_input(&_format_ctx);
av_free(_conv_frame);
av_free(_frame);
}); /* with_libc */
}
/**
* Dump format information - needs <libc stderr="/dev/log"> configuration
*/
void dump_info() const
{
Libc::with_libc([&] () {
av_dump_format(_format_ctx, 0, _track.path.string(), 0);
}); /* with_libc */
}
/**
* Return metainformation of the file
*/
File_info const & file_info() const { return *_track_info; }
/**
* Return decoding progress in ms
*/
uint64_t progress() const
{
/*
* Until there is need for seeking support that is enough albeit
* inaccurate and do not get me started on the float abuse...
*
* XXX We could also count the Audio_out packets submitted per
* track to get a more accurate playback progress
* (see Out::packets_submitted()).
*/
return (float)_samples_decoded / _codec_ctx->sample_rate * 1000;
}
/**
* Fill frame data buffer with decoded frames
*
* \param frame_data reference to destination buffer
* \param min minimal number of bytes that have to be decoded at least
*/
int fill_buffer(Genode::Env &env, Frame_data &frame_data, size_t min)
{
size_t written = 0;
Libc::with_libc([&] {
while (written < min) {
if (av_read_frame(_format_ctx, &_packet) != 0) { break; }
if (_packet.stream_index == _stream->index) {
int finished = 0;
avcodec_decode_audio4(_codec_ctx, _frame, &finished, &_packet);
if (finished) {
/*
* We have to read all available samples, otherwise we
* end up leaking memory. Draining all available sample will
* lead to distorted audio; checking for > 64 works(tm) but
* we might still leak some memory (hopefully the song's duration
* is not too long.) FWIW, it seems to be happening only when
* resampling vorbis files with FLTP format.
*/
AVFrame *in = _frame;
do {
if (avresample_convert_frame(_avr, _conv_frame, in) < 0) {
Genode::error("could not resample frame");
return 0;
}
void const *data = _conv_frame->extended_data[0];
size_t const bytes = _conv_frame->linesize[0];
size_t const s = 2 /* stereo */ * sizeof(float);
_samples_decoded += bytes / s;
written += frame_data.write(data, bytes);
in = nullptr;
} while (avresample_available(_avr) > 64);
}
}
av_free_packet(&_packet);
}
/* keep compiler for complaining b/c of lambda deduction */
return 0;
}); /* with_libc */
return written;
}
};
struct Audio_player::Main
{
Genode::Env &env;
Genode::Heap alloc { env.ram(), env.rm() } ;
void handle_progress();
Genode::Signal_handler<Main> progress_dispatcher = {
env.ep(), *this, &Main::handle_progress };
Output output { env, progress_dispatcher };
Frame_data frame_data;
Decoder *decoder = nullptr;
Playlist playlist { alloc };
Playlist::Track track;
void scan_playlist();
Genode::Reporter playlist_reporter { env, "playlist" };
bool report_playlist = false;
void handle_playlist();
Genode::Signal_handler<Main> playlist_dispatcher = {
env.ep(), *this, &Main::handle_playlist };
Genode::Attached_rom_dataspace playlist_rom { env, "playlist" };
bool is_paused = false;
bool is_stopped = false;
bool state_changed = false;
Genode::Reporter reporter { env, "current_track" };
unsigned report_progress_interval = 0; /* in Audio_out packets */
bool report_progress = false;
unsigned packet_count = 0;
void report_track(Decoder const *d);
Genode::Attached_rom_dataspace config_rom { env, "config" };
void handle_config();
Genode::Signal_handler<Main> config_dispatcher = {
env.ep(), *this, &Main::handle_config };
Main(Genode::Env &env) : env(env)
{
Genode::Signal_transmitter(config_dispatcher).submit();
config_rom.sigh(config_dispatcher);
Genode::Signal_transmitter(playlist_dispatcher).submit();
playlist_rom.sigh(playlist_dispatcher);
reporter.enabled(true);
playlist_reporter.enabled(true);
Genode::log("--- start Audio_player ---");
}
};
void Audio_player::Main::scan_playlist()
{
try {
Genode::Reporter::Xml_generator xml(playlist_reporter, [&] () {
xml.attribute("version", 1);
xml.attribute("xmlns", "http://xspf.org/ns/0/");
xml.node("trackList", [&] () {
playlist.for_each_track([&] (Playlist::Track const &t) {
Decoder d(t);
Decoder::File_info const &info = d.file_info();
xml.node("track", [&] () {
xml.node("location", [&] () {
xml.append_content(info.path); });
xml.node("title", [&] () {
xml.append_content(info.title); });
xml.node("creator", [&] () {
xml.append_content(info.artist); });
xml.node("album", [&] () {
xml.append_content(info.album); });
xml.node("duration", [&] () {
xml.append_content(
Genode::String<16>(info.duration)); });
});
});
});
});
} catch (...) { Genode::warning("could not report playlist"); }
}
void Audio_player::Main::handle_playlist()
{
playlist_rom.update();
if (!playlist_rom.valid()) { return; }
playlist.update(playlist_rom.xml());
track = playlist.next_track();
if (report_playlist) { scan_playlist(); }
/* trigger playback because playlist has changed */
handle_progress();
}
void Audio_player::Main::report_track(Decoder const *d)
{
try {
Genode::Reporter::Xml_generator xml(reporter, [&] () {
/*
* There is no valid decoder, create empty report to notify
* agents.
*/
if (d == nullptr) { return; }
Decoder::File_info const &info = d->file_info();
xml.attribute("id", info.id);
xml.attribute("path", info.path);
xml.attribute("artist", info.artist);
xml.attribute("album", info.album);
xml.attribute("title", info.title);
xml.attribute("track", info.track);
xml.attribute("progress", d->progress());
xml.attribute("duration", info.duration);
char const *s = "playing";
if (is_paused) { s = "paused"; }
if (is_stopped) { s = "stopped"; }
xml.attribute("state", s);
});
} catch (...) { Genode::warning("could not report current track"); }
}
void Audio_player::Main::handle_progress()
{
if (is_stopped) {
Genode::destroy(&alloc, decoder);
decoder = nullptr;
is_stopped = false;
report_track(nullptr);
}
if (is_paused) { return; }
/* do not bother, that is not the track you are looking for */
if (!track.valid()) { return; }
/* track is valid but there is no decoder yet */
if (decoder == nullptr) {
Genode::retry<Decoder::Not_initialized>(
[&] {
if (track.valid()) {
decoder = new (&alloc) Decoder(track);
report_track(decoder);
packet_count = 0;
}
},
[&] {
/* in case it did not work try next track */
track = playlist.next_track();
});
report_track(decoder);
}
/* update current track progress */
if (report_progress
&& decoder
&& (++packet_count == report_progress_interval)) {
report_track(decoder);
packet_count = 0;
}
/* only decode and play if we are below the threshold */
if (output.queued() < QUEUED_PACKET_THRESHOLD) {
if (decoder && frame_data.read_avail() <= output.frame_size()) {
size_t const req_size = output.frame_size();
int const n = decoder->fill_buffer(env, frame_data, req_size);
if (n == 0) {
Genode::destroy(&alloc, decoder);
decoder = nullptr;
track = playlist.next_track();
if (!track.valid()) {
Genode::warning("reached end of playlist");
report_track(nullptr);
}
}
}
if (frame_data.read_avail() >= AUDIO_OUT_PACKET_SIZE)
output.drain_buffer(frame_data);
}
}
void Audio_player::Main::handle_config()
{
config_rom.update();
if (!config_rom.valid()) { return; }
Genode::Xml_node config = config_rom.xml();
/* handle playlist scan request */
try {
config.attribute("scan_playlist").has_value("yes");
scan_playlist();
} catch (...) { }
/* handle state */
bool state_changed = false;
try {
static Genode::String<16> last_state { "-" };
Genode::String<16> state;
config.attribute("state").value(&state);
state_changed = state != last_state;
if (state_changed) {
if (state == "playing") {
is_paused = false;
output.start();
}
else if (state == "paused") {
is_paused = true;
output.stop();
}
else /*(state == "stopped")*/ {
Genode::error("state == stopped, should not happen");
is_stopped = true;
is_paused = true;
output.stop();
}
last_state = state;
}
report_track(decoder);
} catch (...) {
/* if there is no state attribute we are stopped */
Genode::warning("player state invalid, player is stopped");
is_stopped = true;
is_paused = true;
output.stop();
}
/* handle selected track */
try {
unsigned id = 0;
config.attribute("selected_track").value(&id);
if (id != track.id) { /* XXX what happens if the playlist changed? */
is_stopped = true; /* XXX do not abuse this flag */
track = playlist.get_track(id);
if (!track.valid()) {
Genode::error("invalid track ", id, " selected");
}
}
} catch (...) { }
/* handle progress report */
enum { DEFAULT_SEC = 5 };
try {
Genode::Xml_node node = config.sub_node("report");
report_progress = node.attribute_value("progress", false);
unsigned v = node.attribute_value<unsigned>("interval", DEFAULT_SEC);
report_progress_interval = output.packets_per_sec() * v;
report_playlist = node.attribute_value("playlist", false);
} catch (...) {
report_progress = false;
report_progress_interval = output.packets_per_sec() * DEFAULT_SEC;
report_playlist = false;
}
/* trigger playback because state might has changed */
if (state_changed) { handle_progress(); }
}
/***************
** Component **
***************/
void Libc::Component::construct(Libc::Env &env)
{
static Audio_player::Main main(env);
}