pulseaudio/src/polyp/stream.c

/* $Id$ */

/***
  This file is part of polypaudio.
 
  polypaudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as published
  by the Free Software Foundation; either version 2 of the License,
  or (at your option) any later version.
 
  polypaudio 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 Lesser General Public License
  along with polypaudio; 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 <assert.h>
#include <string.h>
#include <stdio.h>
#include <string.h>

#include <polyp/def.h>
#include <polypcore/xmalloc.h>
#include <polypcore/pstream-util.h>
#include <polypcore/util.h>
#include <polypcore/log.h>
#include <polypcore/hashmap.h>

#include "internal.h"

#define LATENCY_IPOL_INTERVAL_USEC (10000L)

pa_stream *pa_stream_new(pa_context *c, const char *name, const pa_sample_spec *ss, const pa_channel_map *map) {
    pa_stream *s;
    int i;
    
    assert(c);

    PA_CHECK_VALIDITY_RETURN_NULL(c, ss && pa_sample_spec_valid(ss), PA_ERR_INVALID);
    PA_CHECK_VALIDITY_RETURN_NULL(c, !map || (pa_channel_map_valid(map) && map->channels == ss->channels), PA_ERR_INVALID);

    s = pa_xnew(pa_stream, 1);
    s->ref = 1;
    s->context = c;
    s->mainloop = c->mainloop;

    s->read_callback = NULL;
    s->read_userdata = NULL;
    s->write_callback = NULL;
    s->write_userdata = NULL;
    s->state_callback = NULL;
    s->state_userdata = NULL;
    s->overflow_callback = NULL;
    s->overflow_userdata = NULL;
    s->underflow_callback = NULL;
    s->underflow_userdata = NULL;

    s->direction = PA_STREAM_NODIRECTION;
    s->name = pa_xstrdup(name);
    s->sample_spec = *ss;
    s->flags = 0;

    if (map)
        s->channel_map = *map;
    else
        pa_channel_map_init_auto(&s->channel_map, ss->channels);
    
    s->channel = 0;
    s->channel_valid = 0;
    s->syncid = c->csyncid++;
    s->device_index = PA_INVALID_INDEX;
    s->requested_bytes = 0;
    s->state = PA_STREAM_UNCONNECTED;
    memset(&s->buffer_attr, 0, sizeof(s->buffer_attr));

    s->peek_memchunk.index = 0;
    s->peek_memchunk.length = 0;
    s->peek_memchunk.memblock = NULL;

    s->record_memblockq = NULL;

    s->previous_time = 0;
    s->timing_info_valid = 0;

    s->corked = 0;

    s->ipol_usec_valid = 0;
    s->ipol_timestamp.tv_sec = 0;
    s->ipol_timestamp.tv_usec = 0;
    s->ipol_event = NULL;
    s->ipol_requested = 0;

    for (i = 0; i < PA_MAX_LATENCY_CORRECTIONS; i++)
        s->latency_corrections[i].valid = 0;
    s->idx_latency_correction = 0;
    
    PA_LLIST_PREPEND(pa_stream, c->streams, s);

    /* The context and stream will point at each other. We cannot ref count
       both though since that will create a loop. */
    pa_context_ref(s->context);

    return s;
}

static void stream_free(pa_stream *s) {
    assert(s && s->context && !s->channel_valid);

    PA_LLIST_REMOVE(pa_stream, s->context->streams, s);

    pa_context_unref(s->context);

    if (s->ipol_event) {
        assert(s->mainloop);
        s->mainloop->time_free(s->ipol_event);
    }

    if (s->peek_memchunk.memblock)
        pa_memblock_unref(s->peek_memchunk.memblock);

    if (s->record_memblockq)
        pa_memblockq_free(s->record_memblockq);

    pa_xfree(s->name);
    pa_xfree(s);
}

void pa_stream_unref(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);

    if (--(s->ref) == 0)
        stream_free(s);
}

pa_stream* pa_stream_ref(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);
    
    s->ref++;
    return s;
}

pa_stream_state_t pa_stream_get_state(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);
    
    return s->state;
}

pa_context* pa_stream_get_context(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);
    
    return s->context;
}

uint32_t pa_stream_get_index(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);

    PA_CHECK_VALIDITY_RETURN_ANY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE, PA_INVALID_INDEX);
    
    return s->device_index;
}
    
void pa_stream_set_state(pa_stream *s, pa_stream_state_t st) {
    assert(s);
    assert(s->ref >= 1);

    if (s->state == st)
        return;
    
    pa_stream_ref(s);

    s->state = st;
    
    if ((st == PA_STREAM_FAILED || st == PA_STREAM_TERMINATED) && s->context) {
        /* Detach from context */
        
        if (s->channel_valid)
            pa_dynarray_put((s->direction == PA_STREAM_PLAYBACK) ? s->context->playback_streams : s->context->record_streams, s->channel, NULL);

        s->channel = 0;
        s->channel_valid = 0;

        /* We keep a ref as long as we're connected */
        pa_stream_unref(s);
    }

    if (s->state_callback)
        s->state_callback(s, s->state_userdata);

    pa_stream_unref(s);
}

void pa_command_stream_killed(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED uint32_t tag, pa_tagstruct *t, void *userdata) {
    pa_context *c = userdata;
    pa_stream *s;
    uint32_t channel;
    
    assert(pd);
    assert(command == PA_COMMAND_PLAYBACK_STREAM_KILLED || command == PA_COMMAND_RECORD_STREAM_KILLED);
    assert(t);
    assert(c);

    pa_context_ref(c);
    
    if (pa_tagstruct_getu32(t, &channel) < 0 ||
        !pa_tagstruct_eof(t)) {
        pa_context_fail(c, PA_ERR_PROTOCOL);
        goto finish;
    }
    
    if (!(s = pa_dynarray_get(command == PA_COMMAND_PLAYBACK_STREAM_KILLED ? c->playback_streams : c->record_streams, channel)))
        goto finish;

    pa_context_set_error(c, PA_ERR_KILLED);
    pa_stream_set_state(s, PA_STREAM_FAILED);

finish:
    pa_context_unref(c);
}

void pa_command_request(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED uint32_t tag, pa_tagstruct *t, void *userdata) {
    pa_stream *s;
    pa_context *c = userdata;
    uint32_t bytes, channel;
    
    assert(pd);
    assert(command == PA_COMMAND_REQUEST);
    assert(t);
    assert(c);

    pa_context_ref(c);
    
    if (pa_tagstruct_getu32(t, &channel) < 0 ||
        pa_tagstruct_getu32(t, &bytes) < 0 ||
        !pa_tagstruct_eof(t)) {
        pa_context_fail(c, PA_ERR_PROTOCOL);
        goto finish;
    }
    
    if (!(s = pa_dynarray_get(c->playback_streams, channel)))
        goto finish;

    if (s->state == PA_STREAM_READY) {
        s->requested_bytes += bytes;
        
        if (s->requested_bytes > 0 && s->write_callback)
            s->write_callback(s, s->requested_bytes, s->write_userdata);
    }

finish:
    pa_context_unref(c);
}

void pa_command_overflow_or_underflow(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED uint32_t tag, pa_tagstruct *t, void *userdata) {
    pa_stream *s;
    pa_context *c = userdata;
    uint32_t channel;

    assert(pd);
    assert(command == PA_COMMAND_OVERFLOW || command == PA_COMMAND_UNDERFLOW);
    assert(t);
    assert(c);

    pa_context_ref(c);
    
    if (pa_tagstruct_getu32(t, &channel) < 0 ||
        !pa_tagstruct_eof(t)) {
        pa_context_fail(c, PA_ERR_PROTOCOL);
        goto finish;
    }
    
    if (!(s = pa_dynarray_get(c->playback_streams, channel)))
        goto finish;

    if (s->state == PA_STREAM_READY) {

        if (command == PA_COMMAND_OVERFLOW) {
            if (s->overflow_callback)
                s->overflow_callback(s, s->overflow_userdata);
        } else if (command == PA_COMMAND_UNDERFLOW) {
            if (s->underflow_callback)
                s->underflow_callback(s, s->underflow_userdata);
        }
    }

finish:
    pa_context_unref(c);
}

static void ipol_callback(pa_mainloop_api *m, pa_time_event *e, PA_GCC_UNUSED const struct timeval *tv, void *userdata) {
    struct timeval next;
    pa_stream *s = userdata;

    pa_stream_ref(s);

/*     pa_log("requesting new ipol data"); */
    
    if (s->state == PA_STREAM_READY && !s->ipol_requested) {
        pa_operation *o;
        
        if ((o = pa_stream_update_timing_info(s, NULL, NULL))) {
            pa_operation_unref(o);
            s->ipol_requested = 1;
        }
    }
    
    pa_gettimeofday(&next);
    pa_timeval_add(&next, LATENCY_IPOL_INTERVAL_USEC);
    m->time_restart(e, &next);
    
    pa_stream_unref(s);
}


void pa_create_stream_callback(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED uint32_t tag, pa_tagstruct *t, void *userdata) {
    pa_stream *s = userdata;
    
    assert(pd);
    assert(t);
    assert(s);
    assert(s->state == PA_STREAM_CREATING);
        
    pa_stream_ref(s);
    
    if (command != PA_COMMAND_REPLY) {
        if (pa_context_handle_error(s->context, command, t) < 0)
            goto finish;
        
        pa_stream_set_state(s, PA_STREAM_FAILED);
        goto finish;
    }

    if (pa_tagstruct_getu32(t, &s->channel) < 0 ||
        ((s->direction != PA_STREAM_UPLOAD) && pa_tagstruct_getu32(t, &s->device_index) < 0) ||
        ((s->direction != PA_STREAM_RECORD) && pa_tagstruct_getu32(t, &s->requested_bytes) < 0) ||
        !pa_tagstruct_eof(t)) {
        pa_context_fail(s->context, PA_ERR_PROTOCOL);
        goto finish;
    }

    if (s->direction == PA_STREAM_RECORD) {
        assert(!s->record_memblockq);
        
        s->record_memblockq = pa_memblockq_new(
                0, 
                s->buffer_attr.maxlength,
                0,
                pa_frame_size(&s->sample_spec),
                1,
                0,
                NULL,
                s->context->memblock_stat);
    }

    s->channel_valid = 1;
    pa_dynarray_put((s->direction == PA_STREAM_RECORD) ? s->context->record_streams : s->context->playback_streams, s->channel, s);

    /* We add an extra ref as long as we're connected (i.e. in the dynarray) */
    pa_stream_ref(s);

    if (s->direction != PA_STREAM_UPLOAD &&
        s->flags & PA_STREAM_INTERPOLATE_TIMING) {
        struct timeval tv;

        pa_gettimeofday(&tv);
        tv.tv_usec += LATENCY_IPOL_INTERVAL_USEC; /* every 100 ms */

        assert(!s->ipol_event);
        s->ipol_event = s->mainloop->time_new(s->mainloop, &tv, &ipol_callback, s);
    }

    pa_stream_set_state(s, PA_STREAM_READY);
    
    if (s->requested_bytes > 0 && s->ref > 1 && s->write_callback)
        s->write_callback(s, s->requested_bytes, s->write_userdata);

finish:
    pa_stream_unref(s);
}

static int create_stream(
        pa_stream_direction_t direction,
        pa_stream *s,
        const char *dev,
        const pa_buffer_attr *attr,
        pa_stream_flags_t flags,
        const pa_cvolume *volume,
        pa_stream *sync_stream) {
    
    pa_tagstruct *t;
    uint32_t tag;
    
    assert(s);
    assert(s->ref >= 1);
    
    PA_CHECK_VALIDITY(s->context, s->state == PA_STREAM_UNCONNECTED, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, !(flags & ~(PA_STREAM_START_CORKED|PA_STREAM_INTERPOLATE_TIMING)), PA_ERR_INVALID);
    PA_CHECK_VALIDITY(s->context, direction == PA_STREAM_PLAYBACK || flags == 0, PA_ERR_INVALID);
    PA_CHECK_VALIDITY(s->context, !volume || volume->channels == s->sample_spec.channels, PA_ERR_INVALID);
    PA_CHECK_VALIDITY(s->context, !sync_stream || (direction == PA_STREAM_PLAYBACK && sync_stream->direction == PA_STREAM_PLAYBACK), PA_ERR_INVALID);

    pa_stream_ref(s);

    s->direction = direction;
    s->flags = flags;
    
    if (sync_stream)
        s->syncid = sync_stream->syncid;
    
    if (attr)
        s->buffer_attr = *attr;
    else {
        /* half a second */
        s->buffer_attr.tlength = pa_bytes_per_second(&s->sample_spec)/2;
        s->buffer_attr.maxlength = (s->buffer_attr.tlength*3)/2;
        s->buffer_attr.minreq = s->buffer_attr.tlength/100;
        s->buffer_attr.prebuf = s->buffer_attr.tlength - s->buffer_attr.minreq;
        s->buffer_attr.fragsize = s->buffer_attr.tlength/100;
    }

    if (!dev)
        dev = s->direction == PA_STREAM_PLAYBACK ? s->context->conf->default_sink : s->context->conf->default_source;

    t = pa_tagstruct_command(
            s->context,
            s->direction == PA_STREAM_PLAYBACK ? PA_COMMAND_CREATE_PLAYBACK_STREAM : PA_COMMAND_CREATE_RECORD_STREAM,
            &tag);
    
    pa_tagstruct_put(
            t,
            PA_TAG_STRING, s->name,
            PA_TAG_SAMPLE_SPEC, &s->sample_spec,
            PA_TAG_CHANNEL_MAP, &s->channel_map,
            PA_TAG_U32, PA_INVALID_INDEX,
            PA_TAG_STRING, dev,
            PA_TAG_U32, s->buffer_attr.maxlength,
            PA_TAG_BOOLEAN, !!(flags & PA_STREAM_START_CORKED),
            PA_TAG_INVALID);
    
    if (s->direction == PA_STREAM_PLAYBACK) {
        pa_cvolume cv;

        pa_tagstruct_put(
                t,
                PA_TAG_U32, s->buffer_attr.tlength,
                PA_TAG_U32, s->buffer_attr.prebuf,
                PA_TAG_U32, s->buffer_attr.minreq,
                PA_TAG_U32, s->syncid,
                PA_TAG_INVALID);

        if (!volume)
            volume = pa_cvolume_reset(&cv, s->sample_spec.channels);
        
        pa_tagstruct_put_cvolume(t, volume);
    } else
        pa_tagstruct_putu32(t, s->buffer_attr.fragsize);

    pa_pstream_send_tagstruct(s->context->pstream, t);
    pa_pdispatch_register_reply(s->context->pdispatch, tag, DEFAULT_TIMEOUT, pa_create_stream_callback, s);

    pa_stream_set_state(s, PA_STREAM_CREATING);
    
    pa_stream_unref(s);
    return 0;
}

int pa_stream_connect_playback(
        pa_stream *s,
        const char *dev,
        const pa_buffer_attr *attr,
        pa_stream_flags_t flags,
        pa_cvolume *volume,
        pa_stream *sync_stream) {
    
    assert(s);
    assert(s->ref >= 1);
    
    return create_stream(PA_STREAM_PLAYBACK, s, dev, attr, flags, volume, sync_stream);
}

int pa_stream_connect_record(
        pa_stream *s,
        const char *dev,
        const pa_buffer_attr *attr,
        pa_stream_flags_t flags) {
    
    assert(s);
    assert(s->ref >= 1);

    return create_stream(PA_STREAM_RECORD, s, dev, attr, flags, NULL, NULL);
}

int pa_stream_write(
        pa_stream *s,
        const void *data,
        size_t length,
        void (*free_cb)(void *p),
        int64_t offset,
        pa_seek_mode_t seek) {
    
    pa_memchunk chunk;
    
    assert(s);
    assert(s->ref >= 1);
    assert(data);

    PA_CHECK_VALIDITY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, s->direction == PA_STREAM_PLAYBACK || s->direction == PA_STREAM_UPLOAD, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, seek <= PA_SEEK_RELATIVE_END, PA_ERR_INVALID);
    PA_CHECK_VALIDITY(s->context, s->direction == PA_STREAM_PLAYBACK || (seek == PA_SEEK_RELATIVE && offset == 0), PA_ERR_INVALID);

    if (length <= 0)
        return 0;

    if (free_cb) 
        chunk.memblock = pa_memblock_new_user((void*) data, length, free_cb, 1, s->context->memblock_stat);
    else {
        chunk.memblock = pa_memblock_new(length, s->context->memblock_stat);
        memcpy(chunk.memblock->data, data, length);
    }
        
    chunk.index = 0;
    chunk.length = length;

    pa_pstream_send_memblock(s->context->pstream, s->channel, offset, seek, &chunk);
    pa_memblock_unref(chunk.memblock);
    
    if (length < s->requested_bytes)
        s->requested_bytes -= length;
    else
        s->requested_bytes = 0;

    if (s->direction == PA_STREAM_PLAYBACK) {
        /* Update latency request correction */
        if (s->latency_corrections[s->idx_latency_correction].valid) {
            
            if (seek == PA_SEEK_ABSOLUTE) {
                s->latency_corrections[s->idx_latency_correction].corrupt = 0;
                s->latency_corrections[s->idx_latency_correction].absolute = 1;
                s->latency_corrections[s->idx_latency_correction].value = offset + length;
            } else if (seek == PA_SEEK_RELATIVE) {
                if (!s->latency_corrections[s->idx_latency_correction].corrupt)
                    s->latency_corrections[s->idx_latency_correction].value += offset + length;
            } else
                s->latency_corrections[s->idx_latency_correction].corrupt = 1;
        }
        
        /* Update the write index in the already available latency data */
        if (s->timing_info_valid) {
            
            if (seek == PA_SEEK_ABSOLUTE) {
                s->timing_info.write_index_corrupt = 0;
                s->timing_info.write_index = offset + length;
            } else if (seek == PA_SEEK_RELATIVE) {
                if (!s->timing_info.write_index_corrupt)
                    s->timing_info.write_index += offset + length;
            } else
                s->timing_info.write_index_corrupt = 1;
        }
    }
    
    return 0;
}

int pa_stream_peek(pa_stream *s, const void **data, size_t *length) {
    assert(s);
    assert(s->ref >= 1);
    assert(data);
    assert(length);

    PA_CHECK_VALIDITY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, s->direction == PA_STREAM_RECORD, PA_ERR_BADSTATE);
    
    if (!s->peek_memchunk.memblock) {

        if (pa_memblockq_peek(s->record_memblockq, &s->peek_memchunk) < 0) {
            *data = NULL;
            *length = 0;
            return 0;
        }
    }

    *data = (const char*) s->peek_memchunk.memblock->data + s->peek_memchunk.index;
    *length = s->peek_memchunk.length;
    return 0;
}

int pa_stream_drop(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);

    PA_CHECK_VALIDITY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, s->direction == PA_STREAM_RECORD, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, s->peek_memchunk.memblock, PA_ERR_BADSTATE);
    
    pa_memblockq_drop(s->record_memblockq, &s->peek_memchunk, s->peek_memchunk.length);
    
    pa_memblock_unref(s->peek_memchunk.memblock);
    s->peek_memchunk.length = 0;
    s->peek_memchunk.index = 0;
    s->peek_memchunk.memblock = NULL;

    return 0;
}

size_t pa_stream_writable_size(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);

    PA_CHECK_VALIDITY_RETURN_ANY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE, (size_t) -1);
    PA_CHECK_VALIDITY_RETURN_ANY(s->context, s->direction == PA_STREAM_PLAYBACK, PA_ERR_BADSTATE, (size_t) -1);
    
    return s->requested_bytes;
}

size_t pa_stream_readable_size(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);

    PA_CHECK_VALIDITY_RETURN_ANY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE, (size_t) -1);
    PA_CHECK_VALIDITY_RETURN_ANY(s->context, s->direction == PA_STREAM_RECORD, PA_ERR_BADSTATE, (size_t) -1);

    return pa_memblockq_get_length(s->record_memblockq);
}

pa_operation * pa_stream_drain(pa_stream *s, pa_stream_success_cb_t cb, void *userdata) {
    pa_operation *o;
    pa_tagstruct *t;
    uint32_t tag;
    
    assert(s);
    assert(s->ref >= 1);

    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->direction == PA_STREAM_PLAYBACK, PA_ERR_BADSTATE);

    o = pa_operation_new(s->context, s, (pa_operation_cb_t) cb, userdata);

    t = pa_tagstruct_command(s->context, PA_COMMAND_DRAIN_PLAYBACK_STREAM, &tag);
    pa_tagstruct_putu32(t, s->channel);
    pa_pstream_send_tagstruct(s->context->pstream, t);
    pa_pdispatch_register_reply(s->context->pdispatch, tag, DEFAULT_TIMEOUT, pa_stream_simple_ack_callback, o);

    return pa_operation_ref(o);
}

static void stream_get_timing_info_callback(pa_pdispatch *pd, uint32_t command, uint32_t tag, pa_tagstruct *t, void *userdata) {
    pa_operation *o = userdata;
    struct timeval local, remote, now;
    pa_timing_info *i;
    
    assert(pd);
    assert(o);
    assert(o->stream);
    assert(o->context);

    i = &o->stream->timing_info;
    o->stream->timing_info_valid = 0;
    i->write_index_corrupt = 0;

    if (command != PA_COMMAND_REPLY) {
        if (pa_context_handle_error(o->context, command, t) < 0)
            goto finish;

    } else if (pa_tagstruct_get_usec(t, &i->buffer_usec) < 0 ||
               pa_tagstruct_get_usec(t, &i->sink_usec) < 0 ||
               pa_tagstruct_get_usec(t, &i->source_usec) < 0 ||
               pa_tagstruct_get_boolean(t, &i->playing) < 0 ||
               pa_tagstruct_get_timeval(t, &local) < 0 ||
               pa_tagstruct_get_timeval(t, &remote) < 0 ||
               pa_tagstruct_gets64(t, &i->write_index) < 0 ||
               pa_tagstruct_gets64(t, &i->read_index) < 0 ||
               !pa_tagstruct_eof(t)) {
        pa_context_fail(o->context, PA_ERR_PROTOCOL);
        goto finish;
        
    } else {
        pa_gettimeofday(&now);
        
        if (pa_timeval_cmp(&local, &remote) <= 0 && pa_timeval_cmp(&remote, &now) <= 0) {
            /* local and remote seem to have synchronized clocks */
            
            if (o->stream->direction == PA_STREAM_PLAYBACK)
                i->transport_usec = pa_timeval_diff(&remote, &local);
            else
                i->transport_usec = pa_timeval_diff(&now, &remote);
            
            i->synchronized_clocks = 1;
            i->timestamp = remote;
        } else {
            /* clocks are not synchronized, let's estimate latency then */
            i->transport_usec = pa_timeval_diff(&now, &local)/2;
            i->synchronized_clocks = 0;
            i->timestamp = local;
            pa_timeval_add(&i->timestamp, i->transport_usec);
        }

        if (o->stream->direction == PA_STREAM_PLAYBACK) {
            /* Write index correction */

            int n, j;
            uint32_t ctag = tag;

            /* Go through the saved correction values and add up the total correction.*/
            
            for (n = 0, j = o->stream->idx_latency_correction;
                 n < PA_MAX_LATENCY_CORRECTIONS;
                 n++, j = (j + 1) % PA_MAX_LATENCY_CORRECTIONS) {

                /* Step over invalid data or out-of-date data */
                if (!o->stream->latency_corrections[j].valid ||
                    o->stream->latency_corrections[j].tag < ctag)
                    continue;

                /* Make sure that everything is in order */
                ctag = o->stream->latency_corrections[j].tag+1;

                /* Now fix the write index */
                if (o->stream->latency_corrections[j].corrupt) {
                    /* A corrupting seek was made */
                    i->write_index = 0;
                    i->write_index_corrupt = 1;
                } else if (o->stream->latency_corrections[j].absolute) {
                    /* An absolute seek was made */
                    i->write_index = o->stream->latency_corrections[j].value;
                    i->write_index_corrupt = 0;
                } else if (!i->write_index_corrupt) {
                    /* A relative seek was made */
                    i->write_index += o->stream->latency_corrections[j].value;
                }
            }
        }
        
        o->stream->timing_info_valid = 1;
        
        o->stream->ipol_timestamp = now;
        o->stream->ipol_usec_valid = 0;
    }

    /* Clear old correction entries */
    if (o->stream->direction == PA_STREAM_PLAYBACK) {
        int n;
        
        for (n = 0; n < PA_MAX_LATENCY_CORRECTIONS; n++) {
            if (!o->stream->latency_corrections[n].valid)
                continue;
            
            if (o->stream->latency_corrections[n].tag <= tag)
                o->stream->latency_corrections[n].valid = 0;
        }
    }

    if (o->callback) {
        pa_stream_success_cb_t cb = (pa_stream_success_cb_t) o->callback;
        cb(o->stream, o->stream->timing_info_valid, o->userdata);
    }
    
finish:

    pa_operation_done(o);
    pa_operation_unref(o);
}

pa_operation* pa_stream_update_timing_info(pa_stream *s, pa_stream_success_cb_t cb, void *userdata) {
    uint32_t tag;
    pa_operation *o;
    pa_tagstruct *t;
    struct timeval now;
    int cidx;
    
    assert(s);
    assert(s->ref >= 1);

    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->direction != PA_STREAM_UPLOAD, PA_ERR_BADSTATE);

    if (s->direction == PA_STREAM_PLAYBACK) {
        /* Find a place to store the write_index correction data for this entry */
        cidx = (s->idx_latency_correction + 1) % PA_MAX_LATENCY_CORRECTIONS;
        
        /* Check if we could allocate a correction slot. If not, there are too many outstanding queries */
        PA_CHECK_VALIDITY_RETURN_NULL(s->context, !s->latency_corrections[cidx].valid, PA_ERR_INTERNAL);
    }
    
    o = pa_operation_new(s->context, s, (pa_operation_cb_t) cb, userdata);
    
    t = pa_tagstruct_command(
            s->context,
            s->direction == PA_STREAM_PLAYBACK ? PA_COMMAND_GET_PLAYBACK_LATENCY : PA_COMMAND_GET_RECORD_LATENCY,
            &tag);
    pa_tagstruct_putu32(t, s->channel);
    pa_tagstruct_put_timeval(t, pa_gettimeofday(&now));
    
    pa_pstream_send_tagstruct(s->context->pstream, t);
    pa_pdispatch_register_reply(s->context->pdispatch, tag, DEFAULT_TIMEOUT, stream_get_timing_info_callback, o);

    if (s->direction == PA_STREAM_PLAYBACK) {
        /* Fill in initial correction data */
        o->stream->idx_latency_correction = cidx;
        o->stream->latency_corrections[cidx].valid = 1;
        o->stream->latency_corrections[cidx].tag = tag;
        o->stream->latency_corrections[cidx].absolute = 0;
        o->stream->latency_corrections[cidx].value = 0;
        o->stream->latency_corrections[cidx].corrupt = 0;
    }
    
    return pa_operation_ref(o);
}

void pa_stream_disconnect_callback(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED uint32_t tag, pa_tagstruct *t, void *userdata) {
    pa_stream *s = userdata;
    
    assert(pd);
    assert(s);
    assert(s->ref >= 1);

    pa_stream_ref(s);

    if (command != PA_COMMAND_REPLY) {
        if (pa_context_handle_error(s->context, command, t) < 0)
            goto finish;

        pa_stream_set_state(s, PA_STREAM_FAILED);
        goto finish;
    } else if (!pa_tagstruct_eof(t)) {
        pa_context_fail(s->context, PA_ERR_PROTOCOL);
        goto finish;
    }

    pa_stream_set_state(s, PA_STREAM_TERMINATED);

finish:
    pa_stream_unref(s);
}

int pa_stream_disconnect(pa_stream *s) {
    pa_tagstruct *t;
    uint32_t tag;
    
    assert(s);
    assert(s->ref >= 1);

    PA_CHECK_VALIDITY(s->context, s->channel_valid, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, s->context->state == PA_CONTEXT_READY, PA_ERR_BADSTATE);

    pa_stream_ref(s);

    t = pa_tagstruct_command(
            s->context,
            s->direction == PA_STREAM_PLAYBACK ? PA_COMMAND_DELETE_PLAYBACK_STREAM :
            (s->direction == PA_STREAM_RECORD ? PA_COMMAND_DELETE_RECORD_STREAM : PA_COMMAND_DELETE_UPLOAD_STREAM),
            &tag);
    pa_tagstruct_putu32(t, s->channel);
    pa_pstream_send_tagstruct(s->context->pstream, t);
    pa_pdispatch_register_reply(s->context->pdispatch, tag, DEFAULT_TIMEOUT, pa_stream_disconnect_callback, s);

    pa_stream_unref(s);
    return 0;
}

void pa_stream_set_read_callback(pa_stream *s, pa_stream_request_cb_t cb, void *userdata) {
    assert(s);
    assert(s->ref >= 1);

    s->read_callback = cb;
    s->read_userdata = userdata;
}

void pa_stream_set_write_callback(pa_stream *s, pa_stream_request_cb_t cb, void *userdata) {
    assert(s);
    assert(s->ref >= 1);

    s->write_callback = cb;
    s->write_userdata = userdata;
}

void pa_stream_set_state_callback(pa_stream *s, pa_stream_notify_cb_t cb, void *userdata) {
    assert(s);
    assert(s->ref >= 1);

    s->state_callback = cb;
    s->state_userdata = userdata;
}

void pa_stream_set_overflow_callback(pa_stream *s, pa_stream_notify_cb_t cb, void *userdata) {
    assert(s);
    assert(s->ref >= 1);
    
    s->overflow_callback = cb;
    s->overflow_userdata = userdata;
}

void pa_stream_set_underflow_callback(pa_stream *s, pa_stream_notify_cb_t cb, void *userdata) {
    assert(s);
    assert(s->ref >= 1);
    
    s->underflow_callback = cb;
    s->underflow_userdata = userdata;
}

void pa_stream_simple_ack_callback(pa_pdispatch *pd, uint32_t command, PA_GCC_UNUSED uint32_t tag, pa_tagstruct *t, void *userdata) {
    pa_operation *o = userdata;
    int success = 1;
    
    assert(pd);
    assert(o);
    assert(o->context);
    assert(o->ref >= 1);

    if (command != PA_COMMAND_REPLY) {
        if (pa_context_handle_error(o->context, command, t) < 0)
            goto finish;

        success = 0;
    } else if (!pa_tagstruct_eof(t)) {
        pa_context_fail(o->context, PA_ERR_PROTOCOL);
        goto finish;
    }

    if (o->callback) {
        pa_stream_success_cb_t cb = (pa_stream_success_cb_t) o->callback;
        cb(o->stream, success, o->userdata);
    }

finish:
    pa_operation_done(o);
    pa_operation_unref(o);
}

pa_operation* pa_stream_cork(pa_stream *s, int b, pa_stream_success_cb_t cb, void *userdata) {
    pa_operation *o;
    pa_operation *lo;
    pa_tagstruct *t;
    uint32_t tag;
    
    assert(s);
    assert(s->ref >= 1);
    
    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->direction != PA_STREAM_UPLOAD, PA_ERR_BADSTATE);

    if (s->flags & PA_STREAM_INTERPOLATE_TIMING) {
        if (!s->corked && b) {
            /* Refresh the interpolated data just befor pausing */
            pa_stream_get_time(s, NULL);
        } else if (s->corked && !b)
            /* Unpausing */
            pa_gettimeofday(&s->ipol_timestamp);
    }

    s->corked = b;
    
    o = pa_operation_new(s->context, s, (pa_operation_cb_t) cb, userdata);

    t = pa_tagstruct_command(
            s->context,
            s->direction == PA_STREAM_PLAYBACK ? PA_COMMAND_CORK_PLAYBACK_STREAM : PA_COMMAND_CORK_RECORD_STREAM,
            &tag);
    pa_tagstruct_putu32(t, s->channel);
    pa_tagstruct_put_boolean(t, !!b);
    pa_pstream_send_tagstruct(s->context->pstream, t);
    pa_pdispatch_register_reply(s->context->pdispatch, tag, DEFAULT_TIMEOUT, pa_stream_simple_ack_callback, o);

    if ((lo = pa_stream_update_timing_info(s, NULL, NULL)))
        pa_operation_unref(lo);
    
    return pa_operation_ref(o);
}

static pa_operation* stream_send_simple_command(pa_stream *s, uint32_t command, pa_stream_success_cb_t cb, void *userdata) {
    pa_tagstruct *t;
    pa_operation *o;
    uint32_t tag;
    
    assert(s);
    assert(s->ref >= 1);

    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    
    o = pa_operation_new(s->context, s, (pa_operation_cb_t) cb, userdata);

    t = pa_tagstruct_command(s->context, command, &tag);
    pa_tagstruct_putu32(t, s->channel);
    pa_pstream_send_tagstruct(s->context->pstream, t);
    pa_pdispatch_register_reply(s->context->pdispatch, tag, DEFAULT_TIMEOUT, pa_stream_simple_ack_callback, o);

    return pa_operation_ref(o);
}

pa_operation* pa_stream_flush(pa_stream *s, pa_stream_success_cb_t cb, void *userdata) {
    pa_operation *o;

    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->direction != PA_STREAM_UPLOAD, PA_ERR_BADSTATE);
    
    if ((o = stream_send_simple_command(s, s->direction == PA_STREAM_PLAYBACK ? PA_COMMAND_FLUSH_PLAYBACK_STREAM : PA_COMMAND_FLUSH_RECORD_STREAM, cb, userdata))) {
        pa_operation *lo;

        if ((lo = pa_stream_update_timing_info(s, NULL, NULL)))
            pa_operation_unref(lo);
    }
    
    return o;
}

pa_operation* pa_stream_prebuf(pa_stream *s, pa_stream_success_cb_t cb, void *userdata) {
    pa_operation *o;

    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->direction == PA_STREAM_PLAYBACK, PA_ERR_BADSTATE);

    if ((o = stream_send_simple_command(s, PA_COMMAND_PREBUF_PLAYBACK_STREAM, cb, userdata))) {
        pa_operation *lo;

        if ((lo = pa_stream_update_timing_info(s, NULL, NULL)))
            pa_operation_unref(lo);
    }
    
    return o;
}

pa_operation* pa_stream_trigger(pa_stream *s, pa_stream_success_cb_t cb, void *userdata) {
    pa_operation *o;
    
    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->direction == PA_STREAM_PLAYBACK, PA_ERR_BADSTATE);

    if ((o = stream_send_simple_command(s, PA_COMMAND_TRIGGER_PLAYBACK_STREAM, cb, userdata))) {
        pa_operation *lo;

        if ((lo = pa_stream_update_timing_info(s, NULL, NULL)))
            pa_operation_unref(lo);
    }
    
    return o;
}

pa_operation* pa_stream_set_name(pa_stream *s, const char *name, pa_stream_success_cb_t cb, void *userdata) {
    pa_operation *o;
    pa_tagstruct *t;
    uint32_t tag;
    
    assert(s);
    assert(s->ref >= 1);
    assert(name);

    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->direction != PA_STREAM_UPLOAD, PA_ERR_BADSTATE);

    o = pa_operation_new(s->context, s, (pa_operation_cb_t) cb, userdata);

    t = pa_tagstruct_command(
            s->context,
            s->direction == PA_STREAM_RECORD ? PA_COMMAND_SET_RECORD_STREAM_NAME : PA_COMMAND_SET_PLAYBACK_STREAM_NAME,
            &tag);
    pa_tagstruct_putu32(t, s->channel);
    pa_tagstruct_puts(t, name);
    pa_pstream_send_tagstruct(s->context->pstream, t);
    pa_pdispatch_register_reply(s->context->pdispatch, tag, DEFAULT_TIMEOUT, pa_stream_simple_ack_callback, o);

    return pa_operation_ref(o);
}

int pa_stream_get_time(pa_stream *s, pa_usec_t *r_usec) {
    pa_usec_t usec = 0;

    assert(s);
    assert(s->ref >= 1);

    PA_CHECK_VALIDITY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, s->direction != PA_STREAM_UPLOAD, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, s->timing_info_valid, PA_ERR_NODATA);

    if (s->flags & PA_STREAM_INTERPOLATE_TIMING && s->ipol_usec_valid )
        usec = s->ipol_usec;
    else {
        if (s->direction == PA_STREAM_PLAYBACK) {
            /* The last byte that was written into the output device
             * had this time value associated */
            usec = pa_bytes_to_usec(s->timing_info.read_index < 0 ? 0 : (uint64_t) s->timing_info.read_index, &s->sample_spec);
            
            /* Because the latency info took a little time to come
             * to us, we assume that the real output time is actually
             * a little ahead */
            usec += s->timing_info.transport_usec;
            
            /* However, the output device usually maintains a buffer
               too, hence the real sample currently played is a little
               back  */
            if (s->timing_info.sink_usec >= usec)
                usec = 0;
            else
                usec -= s->timing_info.sink_usec;
            
        } else if (s->direction == PA_STREAM_RECORD) {
            /* The last byte written into the server side queue had
             * this time value associated */
            usec = pa_bytes_to_usec(s->timing_info.write_index < 0 ? 0 : (uint64_t) s->timing_info.write_index, &s->sample_spec);
            
            /* Add transport latency */
            usec += s->timing_info.transport_usec;
            
            /* Add latency of data in device buffer */
            usec += s->timing_info.source_usec;
            
            /* If this is a monitor source, we need to correct the
             * time by the playback device buffer */
            if (s->timing_info.sink_usec >= usec)
                usec = 0;
            else
                usec -= s->timing_info.sink_usec;
        }

        if (s->flags & PA_STREAM_INTERPOLATE_TIMING) {
            s->ipol_usec_valid = 1;
            s->ipol_usec = usec;
        }
    }

    /* Interpolate if requested */
    if (s->flags & PA_STREAM_INTERPOLATE_TIMING) {

        /* We just add the time that passed since the latency info was
         * current */
        if (!s->corked) {
            struct timeval now;
            
            usec += pa_timeval_diff(pa_gettimeofday(&now), &s->ipol_timestamp);
            s->ipol_timestamp = now;
        }
    }

    /* Make sure the time runs monotonically */
    if (!(s->flags & PA_STREAM_NOT_MONOTONOUS)) {
        if (usec < s->previous_time)
            usec = s->previous_time;
        else
            s->previous_time = usec;
    }

    if (r_usec)
        *r_usec = usec;
    
    return 0;
}

static pa_usec_t time_counter_diff(pa_stream *s, pa_usec_t a, pa_usec_t b, int *negative) {
    assert(s);
    assert(s->ref >= 1);
    
    if (negative)
        *negative = 0;

    if (a >= b) 
        return a-b;
    else {
        if (negative && s->direction == PA_STREAM_RECORD) {
            *negative = 1;
            return b-a;
        } else
            return 0;
    }
}

int pa_stream_get_latency(pa_stream *s, pa_usec_t *r_usec, int *negative) {
    pa_usec_t t, c;
    int r;
    int64_t cindex;

    assert(s);
    assert(s->ref >= 1);
    assert(r_usec);

    PA_CHECK_VALIDITY(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, s->direction != PA_STREAM_UPLOAD, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY(s->context, s->timing_info_valid, PA_ERR_NODATA);
    PA_CHECK_VALIDITY(s->context, s->direction != PA_STREAM_PLAYBACK || !s->timing_info.write_index_corrupt, PA_ERR_NODATA);
    
    if ((r = pa_stream_get_time(s, &t)) < 0)
        return r;

    if (s->direction == PA_STREAM_PLAYBACK)
        cindex = s->timing_info.write_index;
    else
        cindex = s->timing_info.read_index;

    if (cindex < 0)
        cindex = 0;
    
    c = pa_bytes_to_usec(cindex, &s->sample_spec);

    if (s->direction == PA_STREAM_PLAYBACK)
        *r_usec = time_counter_diff(s, c, t, negative);
    else
        *r_usec = time_counter_diff(s, t, c, negative);

    return 0;
}

const pa_timing_info* pa_stream_get_timing_info(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);

    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->state == PA_STREAM_READY, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->direction != PA_STREAM_UPLOAD, PA_ERR_BADSTATE);
    PA_CHECK_VALIDITY_RETURN_NULL(s->context, s->timing_info_valid, PA_ERR_BADSTATE);

    return &s->timing_info;
}

const pa_sample_spec* pa_stream_get_sample_spec(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);

    return &s->sample_spec;
}

const pa_channel_map* pa_stream_get_channel_map(pa_stream *s) {
    assert(s);
    assert(s->ref >= 1);

    return &s->channel_map;
}