owntone-server/src/httpd_streaming.c
2019-09-22 23:08:35 +02:00

752 lines
22 KiB
C

/*
* Copyright (C) 2015 Espen Jürgensen <espenjurgensen@gmail.com>
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <fcntl.h>
#include <uninorm.h>
#include <unistd.h>
#include <pthread.h>
#include <event2/event.h>
#include "httpd_streaming.h"
#include "logger.h"
#include "conffile.h"
#include "transcode.h"
#include "player.h"
#include "listener.h"
#include "db.h"
/* httpd event base, from httpd.c */
extern struct event_base *evbase_httpd;
// Seconds between sending silence when player is idle
// (to prevent client from hanging up)
#define STREAMING_SILENCE_INTERVAL 1
// How many bytes we try to read at a time from the httpd pipe
#define STREAMING_READ_SIZE STOB(352, 16, 2)
#define STREAMING_MP3_SAMPLE_RATE 44100
#define STREAMING_MP3_BPS 16
#define STREAMING_MP3_CHANNELS 2
#define STREAMING_MP3_BIT_RATE 192000
// Linked list of mp3 streaming requests
struct streaming_session {
struct evhttp_request *req;
struct streaming_session *next;
bool require_icy; // Client requested icy meta
size_t bytes_sent; // Audio bytes sent since last metablock
};
static pthread_mutex_t streaming_sessions_lck;
static struct streaming_session *streaming_sessions;
// Means we're not able to encode to mp3
static bool streaming_not_supported;
// Interval for sending silence when playback is paused
static struct timeval streaming_silence_tv = { STREAMING_SILENCE_INTERVAL, 0 };
// Input buffer, output buffer and encoding ctx for transcode
static struct encode_ctx *streaming_encode_ctx;
static struct evbuffer *streaming_encoded_data;
static struct media_quality streaming_quality_in;
static struct media_quality streaming_quality_out = { STREAMING_MP3_SAMPLE_RATE, STREAMING_MP3_BPS, STREAMING_MP3_CHANNELS, STREAMING_MP3_BIT_RATE };
// Used for pushing events and data from the player
static struct event *streamingev;
static struct event *metaev;
static struct player_status streaming_player_status;
static int streaming_player_changed;
static int streaming_pipe[2];
static int streaming_meta[2];
#define STREAMING_ICY_METALEN_MAX 4080 // 255*16 incl header/footer (16bytes)
#define STREAMING_ICY_METATITLELEN_MAX 4064 // STREAMING_ICY_METALEN_MAX -16 (not incl header/footer)
/* As streaming quality goes up, we send more data to the remote client. With a
* smaller ICY_METAINT value we have to splice metadata more frequently - on
* some devices with small input buffers, a higher quality stream and low
* ICY_METAINT can lead to stuttering as observed on a Roku Soundbridge
*/
#define STREAMING_ICY_METAINT_DEFAULT 16384
static unsigned short streaming_icy_metaint = STREAMING_ICY_METAINT_DEFAULT;
static unsigned streaming_icy_clients;
static char *streaming_icy_title;
static void
streaming_close_cb(struct evhttp_connection *evcon, void *arg)
{
struct streaming_session *this;
struct streaming_session *session;
struct streaming_session *prev;
char *address;
ev_uint16_t port;
this = (struct streaming_session *)arg;
evhttp_connection_get_peer(evcon, &address, &port);
DPRINTF(E_INFO, L_STREAMING, "Stopping mp3 streaming to %s:%d\n", address, (int)port);
pthread_mutex_lock(&streaming_sessions_lck);
if (!streaming_sessions)
{
// This close comes during deinit() - we don't free `this` since it is
// already a dangling ptr (free'd in deinit()) at this stage
pthread_mutex_unlock(&streaming_sessions_lck);
return;
}
prev = NULL;
for (session = streaming_sessions; session; session = session->next)
{
if (session->req == this->req)
break;
prev = session;
}
if (!session)
{
DPRINTF(E_LOG, L_STREAMING, "Bug! Got a failure callback for an unknown stream (%s:%d)\n", address, (int)port);
free(this);
pthread_mutex_unlock(&streaming_sessions_lck);
return;
}
if (!prev)
streaming_sessions = session->next;
else
prev->next = session->next;
if (session->require_icy)
--streaming_icy_clients;
// Valgrind says libevent doesn't free the request on disconnect (even though it owns it - libevent bug?),
// so we do it with a reply end
evhttp_send_reply_end(session->req);
free(session);
if (!streaming_sessions)
{
DPRINTF(E_INFO, L_STREAMING, "No more clients, will stop streaming\n");
event_del(streamingev);
event_del(metaev);
}
pthread_mutex_unlock(&streaming_sessions_lck);
}
static void
streaming_end(void)
{
struct streaming_session *session;
struct evhttp_connection *evcon;
char *address;
ev_uint16_t port;
pthread_mutex_lock(&streaming_sessions_lck);
for (session = streaming_sessions; streaming_sessions; session = streaming_sessions)
{
evcon = evhttp_request_get_connection(session->req);
if (evcon)
{
evhttp_connection_set_closecb(evcon, NULL, NULL);
evhttp_connection_get_peer(evcon, &address, &port);
DPRINTF(E_INFO, L_STREAMING, "Force close stream to %s:%d\n", address, (int)port);
}
evhttp_send_reply_end(session->req);
streaming_sessions = session->next;
free(session);
}
pthread_mutex_unlock(&streaming_sessions_lck);
event_del(streamingev);
event_del(metaev);
}
static void
streaming_meta_cb(evutil_socket_t fd, short event, void *arg)
{
struct media_quality quality;
struct decode_ctx *decode_ctx;
int ret;
transcode_encode_cleanup(&streaming_encode_ctx);
ret = read(fd, &quality, sizeof(struct media_quality));
if (ret != sizeof(struct media_quality))
goto error;
decode_ctx = NULL;
if (quality.bits_per_sample == 16)
decode_ctx = transcode_decode_setup_raw(XCODE_PCM16, &quality);
else if (quality.bits_per_sample == 24)
decode_ctx = transcode_decode_setup_raw(XCODE_PCM24, &quality);
else if (quality.bits_per_sample == 32)
decode_ctx = transcode_decode_setup_raw(XCODE_PCM32, &quality);
if (!decode_ctx)
goto error;
streaming_encode_ctx = transcode_encode_setup(XCODE_MP3, &streaming_quality_out, decode_ctx, NULL, 0, 0);
transcode_decode_cleanup(&decode_ctx);
if (!streaming_encode_ctx)
{
DPRINTF(E_LOG, L_STREAMING, "Will not be able to stream MP3, libav does not support MP3 encoding: %d/%d/%d @ %d\n", streaming_quality_out.sample_rate, streaming_quality_out.bits_per_sample, streaming_quality_out.channels, streaming_quality_out.bit_rate);
streaming_not_supported = 1;
return;
}
streaming_quality_in = quality;
streaming_not_supported = 0;
return;
error:
DPRINTF(E_LOG, L_STREAMING, "Unknown or unsupported quality of input data (%d/%d/%d), cannot MP3 encode\n", quality.sample_rate, quality.bits_per_sample, quality.channels);
streaming_not_supported = 1;
streaming_end();
}
static int
encode_buffer(uint8_t *buffer, size_t size)
{
transcode_frame *frame;
int samples;
int ret;
if (streaming_not_supported)
{
DPRINTF(E_LOG, L_STREAMING, "Streaming unsupported\n");
return -1;
}
if (streaming_quality_in.channels == 0)
{
DPRINTF(E_LOG, L_STREAMING, "Streaming quality is zero (%d/%d/%d)\n", streaming_quality_in.sample_rate, streaming_quality_in.bits_per_sample, streaming_quality_in.channels);
return -1;
}
samples = BTOS(size, streaming_quality_in.bits_per_sample, streaming_quality_in.channels);
frame = transcode_frame_new(buffer, size, samples, &streaming_quality_in);
if (!frame)
{
DPRINTF(E_LOG, L_STREAMING, "Could not convert raw PCM to frame\n");
return -1;
}
ret = transcode_encode(streaming_encoded_data, streaming_encode_ctx, frame, 0);
transcode_frame_free(frame);
return ret;
}
/* We know that the icymeta is limited to 1+255*16 (ie 4081) bytes so caller must
* provide a buf of this size to avoid needless mallocs
*
* The icy meta block is defined by a single byte indicating how many double byte
* words used for the actual meta. Unused bytes are null padded
*
* https://stackoverflow.com/questions/4911062/pulling-track-info-from-an-audio-stream-using-php/4914538#4914538
* http://www.smackfu.com/stuff/programming/shoutcast.html
*/
static uint8_t *
streaming_icy_meta_create(uint8_t buf[STREAMING_ICY_METALEN_MAX+1], const char *title, unsigned *buflen)
{
unsigned titlelen = 0;
unsigned metalen = 0;
uint8_t no16s;
*buflen = 0;
if (title == NULL)
{
no16s = 0;
memcpy(buf, &no16s, 1);
*buflen = 1;
}
else
{
titlelen = strlen(title);
if (titlelen > STREAMING_ICY_METATITLELEN_MAX)
titlelen = STREAMING_ICY_METATITLELEN_MAX; // dont worry about the null byte
// [0] 1x byte N, indicate the total number of 16 bytes words required
// to represent the meta data
// [1..N] meta data book ended by "StreamTitle='" and "';"
//
// The '15' is strlen of StreamTitle=' + ';
no16s = (15 + titlelen)/16 +1;
metalen = 1 + no16s*16;
memset(buf, 0, metalen);
memcpy(buf, &no16s, 1);
memcpy(buf+1, (const uint8_t*)"StreamTitle='", 13);
memcpy(buf+14, title, titlelen);
memcpy(buf+14+titlelen, (const uint8_t*)"';", 2);
*buflen = metalen;
}
return buf;
}
static uint8_t *
streaming_icy_meta_splice(const uint8_t *data, size_t datalen, off_t offset, size_t *len)
{
uint8_t meta[STREAMING_ICY_METALEN_MAX+1]; // Buffer, of max sz, for the created icymeta
unsigned metalen; // How much of the buffer is in use
uint8_t *buf; // Client returned buffer; contains the audio (from data) spliced w/meta (from meta)
if (data == NULL || datalen == 0)
return NULL;
memset(meta, 0, sizeof(meta));
streaming_icy_meta_create(meta, streaming_icy_title, &metalen);
*len = datalen + metalen;
// DPRINTF(E_DBG, L_STREAMING, "splicing meta, audio block=%d bytes, offset=%d, metalen=%d new buflen=%d\n", datalen, offset, metalen, *len);
buf = malloc(*len);
memcpy(buf, data, offset);
memcpy(buf+offset, &meta[0], metalen);
memcpy(buf+offset+metalen, data+offset, datalen-offset);
return buf;
}
static void
streaming_player_status_update()
{
unsigned x, y;
struct db_queue_item *queue_item = NULL;
struct player_status tmp;
tmp.id = streaming_player_status.id;
player_get_status(&streaming_player_status);
if (tmp.id != streaming_player_status.id && streaming_icy_clients)
{
free(streaming_icy_title);
if ( (queue_item = db_queue_fetch_byfileid(streaming_player_status.id)) == NULL)
{
streaming_icy_title = NULL;
}
else
{
x = strlen(queue_item->title);
y = strlen(queue_item->artist);
if (x && y)
{
streaming_icy_title = malloc(x+y+4);
snprintf(streaming_icy_title, x+y+4, "%s - %s", queue_item->title, queue_item->artist);
}
else
{
streaming_icy_title = strdup( x ? queue_item->title : queue_item->artist);
}
free_queue_item(queue_item, 0);
}
}
}
static void
streaming_send_cb(evutil_socket_t fd, short event, void *arg)
{
struct streaming_session *session;
struct evbuffer *evbuf;
uint8_t rawbuf[STREAMING_READ_SIZE];
uint8_t *buf;
uint8_t *splice_buf = NULL;
size_t splice_len;
size_t count;
int overflow;
int len;
int ret;
// Player wrote data to the pipe (EV_READ)
if (event & EV_READ)
{
while (1)
{
ret = read(fd, &rawbuf, sizeof(rawbuf));
if (ret <= 0)
break;
if (streaming_player_changed)
{
streaming_player_changed = 0;
streaming_player_status_update();
}
ret = encode_buffer(rawbuf, ret);
if (ret < 0)
return;
}
}
// Event timed out, let's see what the player is doing and send silence if it is paused
else
{
if (streaming_player_changed)
{
streaming_player_changed = 0;
streaming_player_status_update();
}
if (streaming_player_status.status != PLAY_PAUSED)
return;
memset(&rawbuf, 0, sizeof(rawbuf));
ret = encode_buffer(rawbuf, sizeof(rawbuf));
if (ret < 0)
return;
}
len = evbuffer_get_length(streaming_encoded_data);
if (len == 0)
return;
// Send data
evbuf = evbuffer_new();
pthread_mutex_lock(&streaming_sessions_lck);
for (session = streaming_sessions; session; session = session->next)
{
// Does this session want ICY meta data and is it time to send?
count = session->bytes_sent+len;
if (session->require_icy && count > streaming_icy_metaint)
{
overflow = count%streaming_icy_metaint;
buf = evbuffer_pullup(streaming_encoded_data, -1);
// DPRINTF(E_DBG, L_STREAMING, "session=%x sent=%ld len=%ld overflow=%ld\n", session, session->bytes_sent, len, overflow);
// Splice the 'icy title' in with the encoded audio data
splice_len = 0;
splice_buf = streaming_icy_meta_splice(buf, len, len-overflow, &splice_len);
evbuffer_add(evbuf, splice_buf, splice_len);
free(splice_buf);
splice_buf = NULL;
evhttp_send_reply_chunk(session->req, evbuf);
if (session->next == NULL)
{
// We're the last session, drop the contents of the encoded buffer
evbuffer_drain(streaming_encoded_data, len);
}
session->bytes_sent = overflow;
}
else
{
if (session->next)
{
buf = evbuffer_pullup(streaming_encoded_data, -1);
evbuffer_add(evbuf, buf, len);
evhttp_send_reply_chunk(session->req, evbuf);
}
else
{
evhttp_send_reply_chunk(session->req, streaming_encoded_data);
}
session->bytes_sent += len;
}
}
pthread_mutex_unlock(&streaming_sessions_lck);
evbuffer_free(evbuf);
}
// Thread: player (not fully thread safe, but hey...)
static void
player_change_cb(short event_mask)
{
streaming_player_changed = 1;
}
// Thread: player (also prone to race conditions, mostly during deinit)
void
streaming_write(struct output_buffer *obuf)
{
int ret;
// Explicit no-lock - let the write to pipes fail if during deinit
if (!streaming_sessions)
return;
if (!quality_is_equal(&obuf->data[0].quality, &streaming_quality_in))
{
ret = write(streaming_meta[1], &obuf->data[0].quality, sizeof(struct media_quality));
if (ret < 0)
{
if (errno == EBADF)
DPRINTF(E_LOG, L_STREAMING, "streaming pipe already closed\n");
else
DPRINTF(E_LOG, L_STREAMING, "Error writing to streaming pipe: %s\n", strerror(errno));
return;
}
}
ret = write(streaming_pipe[1], obuf->data[0].buffer, obuf->data[0].bufsize);
if (ret < 0)
{
if (errno == EAGAIN)
DPRINTF(E_WARN, L_STREAMING, "Streaming pipe full, skipping write\n");
else
{
if (errno == EBADF)
DPRINTF(E_LOG, L_STREAMING, "Streaming pipe already closed\n");
else
DPRINTF(E_LOG, L_STREAMING, "Error writing to streaming pipe: %s\n", strerror(errno));
}
}
}
int
streaming_request(struct evhttp_request *req, struct httpd_uri_parsed *uri_parsed)
{
struct streaming_session *session;
struct evhttp_connection *evcon;
struct evkeyvalq *output_headers;
cfg_t *lib;
const char *name;
char *address;
ev_uint16_t port;
const char *param;
bool require_icy = false;
char buf[9];
if (streaming_not_supported)
{
DPRINTF(E_LOG, L_STREAMING, "Got MP3 streaming request, but cannot encode to MP3\n");
evhttp_send_error(req, HTTP_NOTFOUND, "Not Found");
return -1;
}
evcon = evhttp_request_get_connection(req);
evhttp_connection_get_peer(evcon, &address, &port);
param = evhttp_find_header( evhttp_request_get_input_headers(req), "Icy-MetaData");
if (param && strcmp(param, "1") == 0)
require_icy = true;
DPRINTF(E_INFO, L_STREAMING, "Beginning mp3 streaming (with icy=%d, icy_metaint=%d) to %s:%d\n", require_icy, streaming_icy_metaint, address, (int)port);
lib = cfg_getsec(cfg, "library");
name = cfg_getstr(lib, "name");
output_headers = evhttp_request_get_output_headers(req);
evhttp_add_header(output_headers, "Content-Type", "audio/mpeg");
evhttp_add_header(output_headers, "Server", "forked-daapd/" VERSION);
evhttp_add_header(output_headers, "Cache-Control", "no-cache");
evhttp_add_header(output_headers, "Pragma", "no-cache");
evhttp_add_header(output_headers, "Expires", "Mon, 31 Aug 2015 06:00:00 GMT");
if (require_icy)
{
++streaming_icy_clients;
evhttp_add_header(output_headers, "icy-name", name);
snprintf(buf, sizeof(buf)-1, "%d", streaming_icy_metaint);
evhttp_add_header(output_headers, "icy-metaint", buf);
}
evhttp_add_header(output_headers, "Access-Control-Allow-Origin", "*");
evhttp_add_header(output_headers, "Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS");
evhttp_send_reply_start(req, HTTP_OK, "OK");
session = calloc(1, sizeof(struct streaming_session));
if (!session)
{
DPRINTF(E_LOG, L_STREAMING, "Out of memory for streaming request\n");
evhttp_send_error(req, HTTP_SERVUNAVAIL, "Internal Server Error");
return -1;
}
pthread_mutex_lock(&streaming_sessions_lck);
if (!streaming_sessions)
{
event_add(streamingev, &streaming_silence_tv);
event_add(metaev, NULL);
}
session->req = req;
session->next = streaming_sessions;
session->require_icy = require_icy;
session->bytes_sent = 0;
streaming_sessions = session;
pthread_mutex_unlock(&streaming_sessions_lck);
evhttp_connection_set_closecb(evcon, streaming_close_cb, session);
return 0;
}
int
streaming_is_request(const char *path)
{
char *ptr;
ptr = strrchr(path, '/');
if (ptr && (strcasecmp(ptr, "/stream.mp3") == 0))
return 1;
return 0;
}
int
streaming_init(void)
{
int ret;
cfg_t *cfgsec;
int val;
cfgsec = cfg_getsec(cfg, "streaming");
val = cfg_getint(cfgsec, "sample_rate");
// Validate against the variations of libmp3lame's supported sample rates: 32000/44100/48000
if (val % 11025 > 0 && val % 12000 > 0 && val % 8000 > 0)
DPRINTF(E_LOG, L_STREAMING, "Non standard streaming sample_rate=%d, defaulting\n", val);
else
streaming_quality_out.sample_rate = val;
val = cfg_getint(cfgsec, "bit_rate");
switch (val)
{
case 64:
case 96:
case 128:
case 192:
case 320:
streaming_quality_out.bit_rate = val*1000;
break;
default:
DPRINTF(E_LOG, L_STREAMING, "Unsuppported streaming bit_rate=%d, supports: 64/96/128/192/320, defaulting\n", val);
}
DPRINTF(E_INFO, L_STREAMING, "Streaming quality: %d/%d/%d @ %dkbps\n", streaming_quality_out.sample_rate, streaming_quality_out.bits_per_sample, streaming_quality_out.channels, streaming_quality_out.bit_rate/1000);
val = cfg_getint(cfgsec, "icy_metaint");
// Too low a value forces server to send more meta than data
if (val >= 4096 && val <= 131072)
streaming_icy_metaint = val;
else
DPRINTF(E_INFO, L_STREAMING, "Unsupported icy_metaint=%d, supported range: 4096..131072, defaulting to %d\n", val, streaming_icy_metaint);
pthread_mutex_init(&streaming_sessions_lck, NULL);
// Non-blocking because otherwise httpd and player thread may deadlock
#ifdef HAVE_PIPE2
ret = pipe2(streaming_pipe, O_CLOEXEC | O_NONBLOCK);
#else
if ( pipe(streaming_pipe) < 0 ||
fcntl(streaming_pipe[0], F_SETFL, O_CLOEXEC | O_NONBLOCK) < 0 ||
fcntl(streaming_pipe[1], F_SETFL, O_CLOEXEC | O_NONBLOCK) < 0 )
ret = -1;
else
ret = 0;
#endif
if (ret < 0)
{
DPRINTF(E_FATAL, L_STREAMING, "Could not create pipe: %s\n", strerror(errno));
goto error;
}
#ifdef HAVE_PIPE2
ret = pipe2(streaming_meta, O_CLOEXEC | O_NONBLOCK);
#else
if ( pipe(streaming_meta) < 0 ||
fcntl(streaming_meta[0], F_SETFL, O_CLOEXEC | O_NONBLOCK) < 0 ||
fcntl(streaming_meta[1], F_SETFL, O_CLOEXEC | O_NONBLOCK) < 0 )
ret = -1;
else
ret = 0;
#endif
if (ret < 0)
{
DPRINTF(E_FATAL, L_STREAMING, "Could not create pipe: %s\n", strerror(errno));
goto error;
}
// Listen to playback changes so we don't have to poll to check for pausing
ret = listener_add(player_change_cb, LISTENER_PLAYER);
if (ret < 0)
{
DPRINTF(E_FATAL, L_STREAMING, "Could not add listener\n");
goto error;
}
// Initialize buffer for encoded mp3 audio and event for pipe reading
CHECK_NULL(L_STREAMING, streaming_encoded_data = evbuffer_new());
CHECK_NULL(L_STREAMING, streamingev = event_new(evbase_httpd, streaming_pipe[0], EV_TIMEOUT | EV_READ | EV_PERSIST, streaming_send_cb, NULL));
CHECK_NULL(L_STREAMING, metaev = event_new(evbase_httpd, streaming_meta[0], EV_READ | EV_PERSIST, streaming_meta_cb, NULL));
streaming_icy_clients = 0;
streaming_icy_title = NULL;
return 0;
error:
close(streaming_pipe[0]);
close(streaming_pipe[1]);
close(streaming_meta[0]);
close(streaming_meta[1]);
return -1;
}
void
streaming_deinit(void)
{
streaming_end();
event_free(metaev);
event_free(streamingev);
streamingev = NULL;
listener_remove(player_change_cb);
close(streaming_pipe[0]);
close(streaming_pipe[1]);
close(streaming_meta[0]);
close(streaming_meta[1]);
transcode_encode_cleanup(&streaming_encode_ctx);
evbuffer_free(streaming_encoded_data);
free(streaming_icy_title);
pthread_mutex_destroy(&streaming_sessions_lck);
}