D++ (DPP)
C++ Discord API Bot Library
Streaming Ogg Opus file

This example shows how to stream an Ogg Opus file to a voice channel. This example requires some additional dependencies, namely libogg and opusfile.

#include <dpp/dpp.h>
#include <iomanip>
#include <sstream>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ogg/ogg.h>
#include <opus/opusfile.h>
int main(int argc, char const *argv[]) {
/* Load an ogg opus file into memory.
* The bot expects opus packets to be 2 channel stereo, 48000Hz.
*
* You may use ffmpeg to encode songs to ogg opus:
* ffmpeg -i /path/to/song -c:a libopus -ar 48000 -ac 2 -vn -b:a 96K /path/to/opus.ogg
*/
dpp::cluster bot("token");
/* The event is fired when someone issues your commands */
bot.on_slashcommand([&bot](const dpp::slashcommand_t& event) {
/* Check which command they ran */
if (event.command.get_command_name() == "join") {
/* Get the guild */
dpp::guild* g = dpp::find_guild(event.command.guild_id);
/* Attempt to connect to a voice channel, returns false if we fail to connect. */
if (!g->connect_member_voice(event.command.get_issuing_user().id)) {
event.reply("You don't seem to be in a voice channel!");
return;
}
/* Tell the user we joined their channel. */
event.reply("Joined your channel!");
} else if (event.command.get_command_name() == "play") {
/* Get the voice channel the bot is in, in this current guild. */
dpp::voiceconn* v = event.from->get_voice(event.command.guild_id);
/* If the voice channel was invalid, or there is an issue with it, then tell the user. */
if (!v || !v->voiceclient || !v->voiceclient->is_ready()) {
event.reply("There was an issue with getting the voice channel. Make sure I'm in a voice channel!");
return;
}
ogg_sync_state oy;
ogg_stream_state os;
ogg_page og;
ogg_packet op;
OpusHead header;
char *buffer;
FILE *fd;
fd = fopen("/path/to/opus.ogg", "rb");
fseek(fd, 0L, SEEK_END);
size_t sz = ftell(fd);
rewind(fd);
ogg_sync_init(&oy);
buffer = ogg_sync_buffer(&oy, sz);
fread(buffer, 1, sz, fd);
ogg_sync_wrote(&oy, sz);
if (ogg_sync_pageout(&oy, &og) != 1) {
fprintf(stderr,"Does not appear to be ogg stream.\n");
exit(1);
}
ogg_stream_init(&os, ogg_page_serialno(&og));
if (ogg_stream_pagein(&os,&og) < 0) {
fprintf(stderr,"Error reading initial page of ogg stream.\n");
exit(1);
}
if (ogg_stream_packetout(&os,&op) != 1) {
fprintf(stderr,"Error reading header packet of ogg stream.\n");
exit(1);
}
/* We must ensure that the ogg stream actually contains opus data */
if (!(op.bytes > 8 && !memcmp("OpusHead", op.packet, 8))) {
fprintf(stderr,"Not an ogg opus stream.\n");
exit(1);
}
/* Parse the header to get stream info */
int err = opus_head_parse(&header, op.packet, op.bytes);
if (err) {
fprintf(stderr,"Not a ogg opus stream\n");
exit(1);
}
/* Now we ensure the encoding is correct for Discord */
if (header.channel_count != 2 && header.input_sample_rate != 48000) {
fprintf(stderr,"Wrong encoding for Discord, must be 48000Hz sample rate with 2 channels.\n");
exit(1);
}
/* Now loop though all the pages and send the packets to the vc */
while (ogg_sync_pageout(&oy, &og) == 1) {
ogg_stream_init(&os, ogg_page_serialno(&og));
if(ogg_stream_pagein(&os,&og)<0) {
fprintf(stderr,"Error reading page of Ogg bitstream data.\n");
exit(1);
}
while (ogg_stream_packetout(&os,&op) != 0) {
/* Read remaining headers */
if (op.bytes > 8 && !memcmp("OpusHead", op.packet, 8)) {
int err = opus_head_parse(&header, op.packet, op.bytes);
if (err) {
fprintf(stderr,"Not a ogg opus stream\n");
exit(1);
}
if (header.channel_count != 2 && header.input_sample_rate != 48000) {
fprintf(stderr,"Wrong encoding for Discord, must be 48000Hz sample rate with 2 channels.\n");
exit(1);
}
continue;
}
/* Skip the opus tags */
if (op.bytes > 8 && !memcmp("OpusTags", op.packet, 8))
continue;
/* Send the audio */
int samples = opus_packet_get_samples_per_frame(op.packet, 48000);
v->voiceclient->send_audio_opus(op.packet, op.bytes, samples / 48);
}
}
/* Cleanup */
ogg_stream_clear(&os);
ogg_sync_clear(&oy);
event.reply("Finished playing the audio file!");
}
});
bot.on_ready([&bot](const dpp::ready_t & event) {
if (dpp::run_once<struct register_bot_commands>()) {
/* Create a new command. */
dpp::slashcommand joincommand("join", "Joins your voice channel.", bot.me.id);
dpp::slashcommand playcommand("play", "Plays an ogg file.", bot.me.id);
bot.global_bulk_command_create({ joincommand, playcommand });
}
});
/* Start bot */
bot.start(dpp::st_wait);
return 0;
}

You can compile this example using the following command

c++ /path/to/source.cc -ldpp -lopus -lopusfile -logg -I/usr/include/opus

Using liboggz

You can use liboggz to stream an Ogg Opus file to discord voice channel. liboggz provides higher level abstraction and useful APIs. Some features liboggz provides include: seeking and timestamp interpretation. Read more on the documentation.

#include <dpp/dpp.h>
#include <iomanip>
#include <sstream>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <oggz/oggz.h>
int main() {
/* Load an ogg opus file into memory.
* The bot expects opus packets to be 2 channel stereo, 48000Hz.
*
* You may use ffmpeg to encode songs to ogg opus:
* ffmpeg -i /path/to/song -c:a libopus -ar 48000 -ac 2 -vn -b:a 96K /path/to/opus.ogg
*/
/* Setup the bot */
dpp::cluster bot("token");
/* The event is fired when someone issues your commands */
bot.on_slashcommand([&bot](const dpp::slashcommand_t& event) {
/* Check which command they ran */
if (event.command.get_command_name() == "join") {
/* Get the guild */
dpp::guild* g = dpp::find_guild(event.command.guild_id);
/* Attempt to connect to a voice channel, returns false if we fail to connect. */
if (!g->connect_member_voice(event.command.get_issuing_user().id)) {
event.reply("You don't seem to be in a voice channel!");
return;
}
/* Tell the user we joined their channel. */
event.reply("Joined your channel!");
} else if (event.command.get_command_name() == "play") {
/* Get the voice channel the bot is in, in this current guild. */
dpp::voiceconn* v = event.from->get_voice(event.command.guild_id);
/* If the voice channel was invalid, or there is an issue with it, then tell the user. */
if (!v || !v->voiceclient || !v->voiceclient->is_ready()) {
event.reply("There was an issue with getting the voice channel. Make sure I'm in a voice channel!");
return;
}
/* load the audio file with oggz */
OGGZ *track_og = oggz_open("/path/to/opus.ogg", OGGZ_READ);
/* If there was an issue reading the file, tell the user and stop */
if (!track_og) {
fprintf(stderr, "Error opening file\n");
event.reply("There was an issue opening the file!");
return;
}
/* set read callback, this callback will be called on packets with the serialno,
* -1 means every packet will be handled with this callback.
*/
oggz_set_read_callback(
track_og, -1,
[](OGGZ *oggz, oggz_packet *packet, long serialno,
void *user_data) {
dpp::voiceconn *voiceconn = (dpp::voiceconn *)user_data;
/* send the audio */
voiceconn->voiceclient->send_audio_opus(packet->op.packet,
packet->op.bytes);
/* make sure to always return 0 here, read more on oggz documentation */
return 0;
},
/* this will be the value of void *user_data */
(void *)v
);
// read loop
while (v && v->voiceclient && !v->voiceclient->terminating) {
/* you can tweak this to whatever. Here I use BUFSIZ, defined in
* stdio.h as 8192.
*/
static const constexpr long CHUNK_READ = BUFSIZ * 2;
const long read_bytes = oggz_read(track_og, CHUNK_READ);
/* break on eof */
if (!read_bytes) {
break;
}
}
/* Don't forget to free the memory */
oggz_close(track_og);
event.reply("Finished playing the audio file!");
}
});
bot.on_ready([&bot](const dpp::ready_t & event) {
if (dpp::run_once<struct register_bot_commands>()) {
/* Create a new command. */
dpp::slashcommand joincommand("join", "Joins your voice channel.", bot.me.id);
dpp::slashcommand playcommand("play", "Plays an ogg file.", bot.me.id);
bot.global_bulk_command_create({ joincommand, playcommand });
}
});
/* Start bot */
bot.start(dpp::st_wait);
return 0;
}

You can compile this example using the following command:

c++ /path/to/source.cc -ldpp -loggz
dpp::slashcommand_t
User has issued a slash command.
Definition: dispatcher.h:715
dpp::st_wait
@ st_wait
Wait forever on a condition variable. The cluster will spawn threads for each shard and start() will ...
Definition: cluster.h:101
dpp::unicode_emoji::v
constexpr const char v[]
Definition: unicode_emoji.h:1982
dpp::voiceconn
Represents a connection to a voice channel. A client can only connect to one voice channel per guild ...
Definition: discordclient.h:59
dpp::voiceconn::voiceclient
class discord_voice_client * voiceclient
voice websocket client
Definition: discordclient.h:88
dpp::discord_voice_client::send_audio_opus
discord_voice_client & send_audio_opus(uint8_t *opus_packet, const size_t length, uint64_t duration)
Send opus packets to the voice channel.
dpp::interaction_create_t::command
interaction command
command interaction
Definition: dispatcher.h:698
dpp::slashcommand
Represents an application command, created by your bot either globally, or on a guild.
Definition: appcommand.h:1358
dpp::utility::cout_logger
std::function< void(const dpp::log_t &)> DPP_EXPORT cout_logger()
Get a default logger that outputs to std::cout. e.g.
Definition: dispatcher.h:228
dpp::interaction::get_command_name
std::string get_command_name() const
Get the command name for a command interaction.
dpp::interaction_create_t::reply
void reply(command_completion_event_t callback=utility::log_error()) const
Acknowledge interaction without displaying a message to the user, for use with button and select menu...
dpp::unicode_emoji::rewind
constexpr const char rewind[]
Definition: unicode_emoji.h:5373
dpp::cluster
The cluster class represents a group of shards and a command queue for sending and receiving commands...
Definition: cluster.h:99
dpp::ready_t
Session ready.
Definition: dispatcher.h:981
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