/*
  * Pulseaudio input
  * Copyright (c) 2011 Luca Barbato <lu_zero@gentoo.org>

  * Copyright 2004-2006 Lennart Poettering
  * Copyright (c) 2014 Michael Niedermayer <michaelni@gmx.at>

  *

  * This file is part of FFmpeg.

  *

  * FFmpeg 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 2.1 of the License, or (at your option) any later version.
  *

  * FFmpeg 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
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #include <pulse/rtclock.h>
 #include <pulse/error.h>

 
 #include "libavutil/internal.h"

 #include "libavutil/opt.h"

 #include "libavutil/time.h"

 
 #include "libavformat/avformat.h"
 #include "libavformat/internal.h"

 #include "pulse_audio_common.h"

 #include "timefilter.h"

 #define DEFAULT_CODEC_ID AV_NE(AV_CODEC_ID_PCM_S16BE, AV_CODEC_ID_PCM_S16LE)

 
 typedef struct PulseData {
     AVClass *class;
     char *server;
     char *name;
     char *stream_name;
     int  sample_rate;
     int  channels;
     int  frame_size;

     int  fragment_size;

 
     pa_threaded_mainloop *mainloop;
     pa_context *context;
     pa_stream *stream;
 
     TimeFilter *timefilter;
     int last_period;

     int wallclock;

 } PulseData;
 

 
 #define CHECK_SUCCESS_GOTO(rerror, expression, label)        \
     do {                                                        \
         if (!(expression)) {                                    \
             rerror = AVERROR_EXTERNAL;                          \
             goto label;                                         \
         }                                                       \

     } while (0)

 
 #define CHECK_DEAD_GOTO(p, rerror, label)                               \
     do {                                                                \
         if (!(p)->context || !PA_CONTEXT_IS_GOOD(pa_context_get_state((p)->context)) || \
             !(p)->stream || !PA_STREAM_IS_GOOD(pa_stream_get_state((p)->stream))) { \
             rerror = AVERROR_EXTERNAL;                                  \
             goto label;                                                 \
         }                                                               \

     } while (0)

 
 static void context_state_cb(pa_context *c, void *userdata) {
     PulseData *p = userdata;
 
     switch (pa_context_get_state(c)) {
         case PA_CONTEXT_READY:
         case PA_CONTEXT_TERMINATED:
         case PA_CONTEXT_FAILED:
             pa_threaded_mainloop_signal(p->mainloop, 0);
             break;
     }
 }
 
 static void stream_state_cb(pa_stream *s, void * userdata) {
     PulseData *p = userdata;
 
     switch (pa_stream_get_state(s)) {
         case PA_STREAM_READY:
         case PA_STREAM_FAILED:
         case PA_STREAM_TERMINATED:
             pa_threaded_mainloop_signal(p->mainloop, 0);
             break;
     }
 }
 
 static void stream_request_cb(pa_stream *s, size_t length, void *userdata) {
     PulseData *p = userdata;
 
     pa_threaded_mainloop_signal(p->mainloop, 0);
 }
 
 static void stream_latency_update_cb(pa_stream *s, void *userdata) {
     PulseData *p = userdata;
 
     pa_threaded_mainloop_signal(p->mainloop, 0);
 }
 
 static av_cold int pulse_close(AVFormatContext *s)
 {
     PulseData *pd = s->priv_data;
 
     if (pd->mainloop)
         pa_threaded_mainloop_stop(pd->mainloop);
 
     if (pd->stream)
         pa_stream_unref(pd->stream);
     pd->stream = NULL;
 
     if (pd->context) {
         pa_context_disconnect(pd->context);
         pa_context_unref(pd->context);
     }
     pd->context = NULL;
 
     if (pd->mainloop)
         pa_threaded_mainloop_free(pd->mainloop);
     pd->mainloop = NULL;
 
     ff_timefilter_destroy(pd->timefilter);
     pd->timefilter = NULL;
 
     return 0;
 }
 

 static av_cold int pulse_read_header(AVFormatContext *s)

 {
     PulseData *pd = s->priv_data;
     AVStream *st;

     char *device = NULL;

     int ret;

     enum AVCodecID codec_id =
         s->audio_codec_id == AV_CODEC_ID_NONE ? DEFAULT_CODEC_ID : s->audio_codec_id;

     const pa_sample_spec ss = { ff_codec_id_to_pulse_format(codec_id),

                                 pd->sample_rate,
                                 pd->channels };
 
     pa_buffer_attr attr = { -1 };
 
     st = avformat_new_stream(s, NULL);
 
     if (!st) {
         av_log(s, AV_LOG_ERROR, "Cannot add stream\n");
         return AVERROR(ENOMEM);
     }
 

     attr.fragsize = pd->fragment_size;
 

     if (s->filename[0] != '\0' && strcmp(s->filename, "default"))

         device = s->filename;

     if (!(pd->mainloop = pa_threaded_mainloop_new())) {
         pulse_close(s);
         return AVERROR_EXTERNAL;
     }
 
     if (!(pd->context = pa_context_new(pa_threaded_mainloop_get_api(pd->mainloop), pd->name))) {
         pulse_close(s);
         return AVERROR_EXTERNAL;
     }
 
     pa_context_set_state_callback(pd->context, context_state_cb, pd);
 
     if (pa_context_connect(pd->context, pd->server, 0, NULL) < 0) {
         pulse_close(s);
         return AVERROR(pa_context_errno(pd->context));
     }
 
     pa_threaded_mainloop_lock(pd->mainloop);

     if (pa_threaded_mainloop_start(pd->mainloop) < 0) {
         ret = -1;
         goto unlock_and_fail;

     }

 
     for (;;) {
         pa_context_state_t state;
 
         state = pa_context_get_state(pd->context);
 
         if (state == PA_CONTEXT_READY)
             break;
 
         if (!PA_CONTEXT_IS_GOOD(state)) {
             ret = AVERROR(pa_context_errno(pd->context));
             goto unlock_and_fail;
         }
 
         /* Wait until the context is ready */
         pa_threaded_mainloop_wait(pd->mainloop);
     }
 
     if (!(pd->stream = pa_stream_new(pd->context, pd->stream_name, &ss, NULL))) {
         ret = AVERROR(pa_context_errno(pd->context));
         goto unlock_and_fail;
     }
 
     pa_stream_set_state_callback(pd->stream, stream_state_cb, pd);
     pa_stream_set_read_callback(pd->stream, stream_request_cb, pd);
     pa_stream_set_write_callback(pd->stream, stream_request_cb, pd);
     pa_stream_set_latency_update_callback(pd->stream, stream_latency_update_cb, pd);
 
     ret = pa_stream_connect_record(pd->stream, device, &attr,
                                     PA_STREAM_INTERPOLATE_TIMING
                                     |PA_STREAM_ADJUST_LATENCY
                                     |PA_STREAM_AUTO_TIMING_UPDATE);
 
     if (ret < 0) {
         ret = AVERROR(pa_context_errno(pd->context));
         goto unlock_and_fail;
     }
 
     for (;;) {
         pa_stream_state_t state;
 
         state = pa_stream_get_state(pd->stream);
 
         if (state == PA_STREAM_READY)
             break;
 
         if (!PA_STREAM_IS_GOOD(state)) {
             ret = AVERROR(pa_context_errno(pd->context));
             goto unlock_and_fail;
         }
 
         /* Wait until the stream is ready */
         pa_threaded_mainloop_wait(pd->mainloop);
     }
 
     pa_threaded_mainloop_unlock(pd->mainloop);
 

     /* take real parameters */

     st->codecpar->codec_type  = AVMEDIA_TYPE_AUDIO;
     st->codecpar->codec_id    = codec_id;
     st->codecpar->sample_rate = pd->sample_rate;
     st->codecpar->channels    = pd->channels;

     avpriv_set_pts_info(st, 64, 1, 1000000);  /* 64 bits pts in us */

     pd->timefilter = ff_timefilter_new(1000000.0 / pd->sample_rate,
                                        1000, 1.5E-6);

     if (!pd->timefilter) {
         pulse_close(s);
         return AVERROR(ENOMEM);

     }
 

     return 0;

 
 unlock_and_fail:
     pa_threaded_mainloop_unlock(pd->mainloop);
 
     pulse_close(s);
     return ret;

 }
 
 static int pulse_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     PulseData *pd  = s->priv_data;

     int ret;
     size_t read_length;
     const void *read_data = NULL;
     int64_t dts;
     pa_usec_t latency;
     int negative;

     pa_threaded_mainloop_lock(pd->mainloop);

     CHECK_DEAD_GOTO(pd, ret, unlock_and_fail);

     while (!read_data) {
         int r;

         r = pa_stream_peek(pd->stream, &read_data, &read_length);
         CHECK_SUCCESS_GOTO(ret, r == 0, unlock_and_fail);
 
         if (read_length <= 0) {
             pa_threaded_mainloop_wait(pd->mainloop);
             CHECK_DEAD_GOTO(pd, ret, unlock_and_fail);
         } else if (!read_data) {
             /* There's a hole in the stream, skip it. We could generate
                 * silence, but that wouldn't work for compressed streams. */
             r = pa_stream_drop(pd->stream);
             CHECK_SUCCESS_GOTO(ret, r == 0, unlock_and_fail);

         }

     }

     if (av_new_packet(pkt, read_length) < 0) {
         ret = AVERROR(ENOMEM);
         goto unlock_and_fail;

     }
 

     dts = av_gettime();
     pa_operation_unref(pa_stream_update_timing_info(pd->stream, NULL, NULL));

     if (pa_stream_get_latency(pd->stream, &latency, &negative) >= 0) {
         enum AVCodecID codec_id =
             s->audio_codec_id == AV_CODEC_ID_NONE ? DEFAULT_CODEC_ID : s->audio_codec_id;
         int frame_size = ((av_get_bits_per_sample(codec_id) >> 3) * pd->channels);
         int frame_duration = read_length / frame_size;

         if (negative) {
             dts += latency;
         } else
             dts -= latency;

         if (pd->wallclock)
             pkt->pts = ff_timefilter_update(pd->timefilter, dts, pd->last_period);

 
         pd->last_period = frame_duration;
     } else {
         av_log(s, AV_LOG_WARNING, "pa_stream_get_latency() failed\n");
     }
 
     memcpy(pkt->data, read_data, read_length);
     pa_stream_drop(pd->stream);
 
     pa_threaded_mainloop_unlock(pd->mainloop);

     return 0;

 
 unlock_and_fail:
     pa_threaded_mainloop_unlock(pd->mainloop);
     return ret;

 }
 

 static int pulse_get_device_list(AVFormatContext *h, AVDeviceInfoList *device_list)
 {
     PulseData *s = h->priv_data;
     return ff_pulse_audio_get_devices(device_list, s->server, 0);
 }
 

 #define OFFSET(a) offsetof(PulseData, a)
 #define D AV_OPT_FLAG_DECODING_PARAM
 
 static const AVOption options[] = {

     { "server",        "set PulseAudio server",                             OFFSET(server),        AV_OPT_TYPE_STRING, {.str = NULL},     0, 0, D },
     { "name",          "set application name",                              OFFSET(name),          AV_OPT_TYPE_STRING, {.str = LIBAVFORMAT_IDENT},  0, 0, D },
     { "stream_name",   "set stream description",                            OFFSET(stream_name),   AV_OPT_TYPE_STRING, {.str = "record"}, 0, 0, D },
     { "sample_rate",   "set sample rate in Hz",                             OFFSET(sample_rate),   AV_OPT_TYPE_INT,    {.i64 = 48000},    1, INT_MAX, D },
     { "channels",      "set number of audio channels",                      OFFSET(channels),      AV_OPT_TYPE_INT,    {.i64 = 2},        1, INT_MAX, D },
     { "frame_size",    "set number of bytes per frame",                     OFFSET(frame_size),    AV_OPT_TYPE_INT,    {.i64 = 1024},     1, INT_MAX, D },
     { "fragment_size", "set buffering size, affects latency and cpu usage", OFFSET(fragment_size), AV_OPT_TYPE_INT,    {.i64 = -1},      -1, INT_MAX, D },

     { "wallclock",     "set the initial pts using the current time",     OFFSET(wallclock),     AV_OPT_TYPE_INT,    {.i64 = 1},       -1, 1, D },

     { NULL },
 };
 
 static const AVClass pulse_demuxer_class = {
     .class_name     = "Pulse demuxer",
     .item_name      = av_default_item_name,
     .option         = options,
     .version        = LIBAVUTIL_VERSION_INT,

     .category       = AV_CLASS_CATEGORY_DEVICE_AUDIO_INPUT,

 };
 
 AVInputFormat ff_pulse_demuxer = {
     .name           = "pulse",
     .long_name      = NULL_IF_CONFIG_SMALL("Pulse audio input"),
     .priv_data_size = sizeof(PulseData),
     .read_header    = pulse_read_header,
     .read_packet    = pulse_read_packet,
     .read_close     = pulse_close,

     .get_device_list = pulse_get_device_list,

     .flags          = AVFMT_NOFILE,
     .priv_class     = &pulse_demuxer_class,
 };