/*****************************************************************************
 * input.c : internal management of input streams for the audio output
 *****************************************************************************
 * Copyright (C) 2002 VideoLAN
 * $Id: input.c,v 1.14 2002/09/27 23:38:04 massiot Exp $
 *
 * Authors: Christophe Massiot <massiot@via.ecp.fr>
 *
 * 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, USA.
 *****************************************************************************/

/*****************************************************************************
 * Preamble
 *****************************************************************************/
#include <stdlib.h>                            /* calloc(), malloc(), free() */
#include <string.h>

#include <vlc/vlc.h>

#ifdef HAVE_ALLOCA_H
#   include <alloca.h>
#endif

#include "audio_output.h"
#include "aout_internal.h"

/*****************************************************************************
 * aout_InputNew : allocate a new input and rework the filter pipeline
 *****************************************************************************/
int aout_InputNew( aout_instance_t * p_aout, aout_input_t * p_input )
{
    audio_sample_format_t intermediate_format;

    /* Prepare FIFO. */
    aout_FifoInit( p_aout, &p_input->fifo, p_aout->mixer.mixer.i_rate );
    p_input->p_first_byte_to_mix = NULL;

    /* Create filters. */
    memcpy( &intermediate_format, &p_aout->mixer.mixer,
            sizeof(audio_sample_format_t) );
    intermediate_format.i_rate = p_input->input.i_rate;
    if ( aout_FiltersCreatePipeline( p_aout, p_input->pp_filters,
                                     &p_input->i_nb_filters, &p_input->input,
                                     &intermediate_format ) < 0 )
    {
        msg_Err( p_aout, "couldn't set an input pipeline" );

        aout_FifoDestroy( p_aout, &p_input->fifo );
        p_input->b_error = 1;

        return -1;
    }

    /* Create resamplers. */
    intermediate_format.i_rate = (p_input->input.i_rate
                             * (100 + AOUT_MAX_RESAMPLING)) / 100;
    if ( intermediate_format.i_rate == p_aout->mixer.mixer.i_rate )
    {
        /* Just in case... */
        intermediate_format.i_rate++;
    }
    if ( aout_FiltersCreatePipeline( p_aout, p_input->pp_resamplers,
                                     &p_input->i_nb_resamplers,
                                     &intermediate_format,
                                     &p_aout->mixer.mixer ) < 0 )
    {
        msg_Err( p_aout, "couldn't set a resampler pipeline" );

        aout_FiltersDestroyPipeline( p_aout, p_input->pp_filters,
                                     p_input->i_nb_filters );
        aout_FifoDestroy( p_aout, &p_input->fifo );
        p_input->b_error = 1;

        return -1;
    }

    /* Prepare hints for the buffer allocator. */
    p_input->input_alloc.i_alloc_type = AOUT_ALLOC_HEAP;
    p_input->input_alloc.i_bytes_per_sec = -1;

    aout_FiltersHintBuffers( p_aout, p_input->pp_resamplers,
                             p_input->i_nb_resamplers,
                             &p_input->input_alloc );

    aout_FiltersHintBuffers( p_aout, p_input->pp_filters,
                             p_input->i_nb_filters,
                             &p_input->input_alloc );

    /* i_bytes_per_sec is still == -1 if no filters */
    p_input->input_alloc.i_bytes_per_sec = __MAX(
                                    p_input->input_alloc.i_bytes_per_sec,
                                    p_input->input.i_bytes_per_frame
                                     * p_input->input.i_rate
                                     / p_input->input.i_frame_length );
    /* Allocate in the heap, it is more convenient for the decoder. */
    p_input->input_alloc.i_alloc_type = AOUT_ALLOC_HEAP;

    p_input->b_error = 0;

    return 0;
}

/*****************************************************************************
 * aout_InputDelete : delete an input
 *****************************************************************************
 * This function must be entered with the mixer lock.
 *****************************************************************************/
int aout_InputDelete( aout_instance_t * p_aout, aout_input_t * p_input )
{
    if ( p_input->b_error ) return 0;

    aout_FiltersDestroyPipeline( p_aout, p_input->pp_filters,
                                 p_input->i_nb_filters );
    aout_FiltersDestroyPipeline( p_aout, p_input->pp_resamplers,
                                 p_input->i_nb_resamplers );
    aout_FifoDestroy( p_aout, &p_input->fifo );

    return 0;
}

/*****************************************************************************
 * aout_InputPlay : play a buffer
 *****************************************************************************
 * This function must be entered with the input lock.
 *****************************************************************************/
int aout_InputPlay( aout_instance_t * p_aout, aout_input_t * p_input,
                    aout_buffer_t * p_buffer )
{
    mtime_t start_date, duration;

    /* We don't care if someone changes the start date behind our back after
     * this. We'll deal with that when pushing the buffer, and compensate
     * with the next incoming buffer. */
    vlc_mutex_lock( &p_aout->input_fifos_lock );
    start_date = aout_FifoNextStart( p_aout, &p_input->fifo );
    vlc_mutex_unlock( &p_aout->input_fifos_lock );

    if ( start_date != 0 && start_date < mdate() )
    {
        /* The decoder is _very_ late. This can only happen if the user
         * pauses the stream (or if the decoder is buggy, which cannot
         * happen :). */
        msg_Warn( p_aout, "computed PTS is out of range (%lld), clearing out",
                  start_date );
        vlc_mutex_lock( &p_aout->mixer_lock );
        aout_FifoSet( p_aout, &p_input->fifo, 0 );
        vlc_mutex_unlock( &p_aout->mixer_lock );
        start_date = 0;
    } 

    if ( p_buffer->start_date < mdate() + AOUT_MIN_PREPARE_TIME )
    {
        /* The decoder gives us f*cked up PTS. It's its business, but we
         * can't present it anyway, so drop the buffer. */
        msg_Warn( p_aout, "PTS is out of range (%lld), dropping buffer",
                  mdate() - p_buffer->start_date );
        aout_BufferFree( p_buffer );

        vlc_mutex_unlock( &p_input->lock );
        return 0;
    }

    if ( start_date == 0 ) start_date = p_buffer->start_date;

    /* Run pre-filters. */
    aout_FiltersPlay( p_aout, p_input->pp_filters, p_input->i_nb_filters,
                      &p_buffer );

    if ( start_date < p_buffer->start_date - AOUT_PTS_TOLERANCE
          || start_date > p_buffer->start_date + AOUT_PTS_TOLERANCE )
    {
        /* Can happen in several circumstances :
         * 1. A problem at the input (clock drift)
         * 2. A small pause triggered by the user
         * 3. Some delay in the output stage, causing a loss of lip
         *    synchronization
         * Solution : resample the buffer to avoid a scratch.
         */
        int i_ratio;
        mtime_t old_duration;
        mtime_t drift = p_buffer->start_date - start_date;

        msg_Warn( p_aout, "buffer is %lld %s, resampling",
                         drift > 0 ? drift : -drift,
                         drift > 0 ? "in advance" : "late" );
        old_duration = p_buffer->end_date - p_buffer->start_date;
        duration = p_buffer->end_date - start_date;
        i_ratio = (duration * 100) / old_duration;
        /* If the ratio is too != 100, the sound quality will be awful. */
        if ( i_ratio < 100 - AOUT_MAX_RESAMPLING /* % */ )
        {
            duration = (old_duration * (100 - AOUT_MAX_RESAMPLING)) / 100;
        }
        if ( i_ratio > 100 + AOUT_MAX_RESAMPLING /* % */ )
        {
            duration = (old_duration * (100 + AOUT_MAX_RESAMPLING)) / 100;
        }
        p_input->pp_resamplers[0]->input.i_rate 
            = (p_input->input.i_rate * old_duration) / duration;

        aout_FiltersPlay( p_aout, p_input->pp_resamplers,
                          p_input->i_nb_resamplers,
                          &p_buffer );
    }
    else
    {
        duration = p_buffer->end_date - p_buffer->start_date;

        if ( p_input->input.i_rate != p_aout->mixer.mixer.i_rate )
        {
            /* Standard resampling is needed ! */
            p_input->pp_resamplers[0]->input.i_rate = p_input->input.i_rate;

            aout_FiltersPlay( p_aout, p_input->pp_resamplers,
                              p_input->i_nb_resamplers,
                              &p_buffer );
        }
    }

    /* Adding the start date will be managed by aout_FifoPush(). */
    p_buffer->start_date = start_date;
    p_buffer->end_date = start_date + duration;

    vlc_mutex_lock( &p_aout->input_fifos_lock );
    aout_FifoPush( p_aout, &p_input->fifo, p_buffer );
    vlc_mutex_unlock( &p_aout->input_fifos_lock );

    return 0;
}
