/*****************************************************************************

 * flac.c: flac decoder/encoder module making use of libflac

 *****************************************************************************

 * Copyright (C) 1999-2001 VLC authors and VideoLAN

 *

 * Authors: Gildas Bazin <gbazin@videolan.org>

 *          Sigmund Augdal Helberg <dnumgis@videolan.org>

 *

 * This program 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.

 *

 * 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 Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public License

 * along with this program; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.

 *****************************************************************************/

/*****************************************************************************

 * Preamble

 *****************************************************************************/

/* workaround libflac overriding assert.h system header */

#define assert(x) do {} while(0)

#ifdef HAVE_CONFIG_H

# include "config.h"

#endif

#include <stdbit.h>

#include <vlc_common.h>

#include <vlc_plugin.h>

#include <vlc_codec.h>

#include <vlc_codecs.h>

#include <vlc_aout.h>

#ifdef _WIN32

# define FLAC__NO_DLL

#endif

#include <FLAC/stream_decoder.h>

#include <FLAC/stream_encoder.h>

#include <vlc_block_helper.h>

#include <vlc_bits.h>

#if defined(FLAC_API_VERSION_CURRENT) && FLAC_API_VERSION_CURRENT >= 8

#   define USE_NEW_FLAC_API

#endif

/*****************************************************************************

 * decoder_sys_t : FLAC decoder descriptor

 *****************************************************************************/

typedef struct

{

    /*

     * Input/Output properties

     */

    block_t *p_block;

    block_t *p_aout_buffer;

    date_t   end_date;

    /*

     * FLAC properties

     */

    FLAC__StreamDecoder *p_flac;

    FLAC__StreamMetadata_StreamInfo stream_info;

    uint8_t rgi_channels_reorder[AOUT_CHAN_MAX];

    bool b_stream_info;

} decoder_sys_t;

static const int pi_channels_maps[FLAC__MAX_CHANNELS + 1] =

{

    0,

    AOUT_CHAN_CENTER,

    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT,

    AOUT_CHAN_CENTER | AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT,

    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_REARLEFT

     | AOUT_CHAN_REARRIGHT,

    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER

     | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT,

    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER

     | AOUT_CHAN_REARLEFT | AOUT_CHAN_REARRIGHT | AOUT_CHAN_LFE,

    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER

     | AOUT_CHAN_REARCENTER | AOUT_CHAN_MIDDLELEFT| AOUT_CHAN_MIDDLERIGHT

     | AOUT_CHAN_LFE,

    AOUT_CHAN_LEFT | AOUT_CHAN_RIGHT | AOUT_CHAN_CENTER | AOUT_CHAN_REARLEFT

     | AOUT_CHAN_REARRIGHT | AOUT_CHAN_MIDDLELEFT | AOUT_CHAN_MIDDLERIGHT

     | AOUT_CHAN_LFE

};

/* XXX it supposes our internal format is WG4 */

static const uint8_t ppi_reorder[1+FLAC__MAX_CHANNELS][FLAC__MAX_CHANNELS] =

{

    { 0 },

    { 0, },

    { 0, 1 },

    { 0, 1, 2 },

    { 0, 1, 2, 3 },

    { 0, 1, 3, 4, 2 },

    { 0, 1, 4, 5, 2, 3 },

    { 0, 1, 5, 6, 4, 2, 3 },

    { 0, 1, 6, 7, 4, 5, 2, 3 },

};

/* Flac uses same order as waveformatex */

#define MAPPED_WFX_CHANNELS 9

static const uint32_t wfx_remapping[MAPPED_WFX_CHANNELS][2] =

{

    { WAVE_SPEAKER_FRONT_LEFT,              AOUT_CHAN_LEFT },

    { WAVE_SPEAKER_FRONT_RIGHT,             AOUT_CHAN_RIGHT },

    { WAVE_SPEAKER_FRONT_CENTER,            AOUT_CHAN_CENTER },

    { WAVE_SPEAKER_LOW_FREQUENCY,           AOUT_CHAN_LFE },

    { WAVE_SPEAKER_BACK_LEFT,               AOUT_CHAN_REARLEFT },

    { WAVE_SPEAKER_BACK_RIGHT,              AOUT_CHAN_REARRIGHT },

    { WAVE_SPEAKER_BACK_CENTER,             AOUT_CHAN_REARCENTER },

    { WAVE_SPEAKER_SIDE_LEFT,               AOUT_CHAN_MIDDLELEFT },

    { WAVE_SPEAKER_SIDE_RIGHT,              AOUT_CHAN_MIDDLERIGHT },

};

static const uint32_t wfx_chans_order[MAPPED_WFX_CHANNELS + 1] =

{

    AOUT_CHAN_LEFT,

    AOUT_CHAN_RIGHT,

    AOUT_CHAN_CENTER,

    AOUT_CHAN_LFE,

    AOUT_CHAN_REARLEFT,

    AOUT_CHAN_REARRIGHT,

    AOUT_CHAN_REARCENTER,

    AOUT_CHAN_MIDDLELEFT,

    AOUT_CHAN_MIDDLERIGHT,

    0

};

/*****************************************************************************

 * Local prototypes

 *****************************************************************************/

static int  OpenDecoder   ( vlc_object_t * );

static void CloseDecoder  ( vlc_object_t * );

#ifdef ENABLE_SOUT

static int OpenEncoder   ( vlc_object_t * );

static void CloseEncoder ( encoder_t * );

#endif

static int DecodeBlock( decoder_t *, block_t * );

static void Flush( decoder_t * );

/*****************************************************************************

 * Module descriptor

 *****************************************************************************/

vlc_module_begin ()

    set_subcategory( SUBCAT_INPUT_ACODEC )

    add_shortcut( "flac" )

    set_description( N_("Flac audio decoder") )

    set_capability( "audio decoder", 100 )

    set_callbacks( OpenDecoder, CloseDecoder )

#ifdef ENABLE_SOUT

    add_submodule ()

    add_shortcut( "flac" )

    set_description( N_("Flac audio encoder") )

    set_capability( "audio encoder", 100 )

    set_callback( OpenEncoder )

#endif

vlc_module_end ()

/*****************************************************************************

 * Interleave: helper function to interleave channels

 *****************************************************************************/

static void Interleave( int32_t *p_out, const int32_t * const *pp_in,

                        const uint8_t *restrict pi_index, unsigned i_nb_channels,

                        unsigned i_samples, unsigned bits )

{

    unsigned shift = 32 - bits;

    for( unsigned j = 0; j < i_samples; j++ )

        for( unsigned i = 0; i < i_nb_channels; i++ )

        {

            union { int32_t i; uint32_t u; } spl;

            spl.u = ((uint32_t)pp_in[pi_index[i]][j]) << shift;

            p_out[j * i_nb_channels + i] = spl.i;

        }

}

/*****************************************************************************

 * DecoderSetOutputFormat: helper function to convert and check frame format

 *****************************************************************************/

static int DecoderSetOutputFormat( unsigned i_channels, unsigned i_rate,

                                   unsigned i_streaminfo_rate,

                                   unsigned i_bitspersample,

                                   audio_format_t *fmt,

                                   uint8_t *pi_channels_reorder )

{

    if( i_channels == 0 || i_channels > FLAC__MAX_CHANNELS ||

        i_bitspersample == 0 || (i_rate == 0 && i_streaminfo_rate == 0) )

        return VLC_EGENERIC;

    fmt->i_channels = i_channels;

    fmt->i_rate = (i_rate > 0 ) ? i_rate : i_streaminfo_rate;

    fmt->i_physical_channels = pi_channels_maps[i_channels];

    memcpy( pi_channels_reorder, ppi_reorder[i_channels], i_channels );

    fmt->i_bitspersample = i_bitspersample;

    return VLC_SUCCESS;

}

/*****************************************************************************

 * DecoderWriteCallback: called by libflac to output decoded samples

 *****************************************************************************/

static FLAC__StreamDecoderWriteStatus

DecoderWriteCallback( const FLAC__StreamDecoder *decoder,

                      const FLAC__Frame *frame,

                      const FLAC__int32 *const buffer[], void *client_data )

{

    VLC_UNUSED(decoder);

    decoder_t *p_dec = (decoder_t *)client_data;

    decoder_sys_t *p_sys = p_dec->p_sys;

    if( DecoderSetOutputFormat( frame->header.channels,

                                frame->header.sample_rate,

                                p_sys->b_stream_info ? p_sys->stream_info.sample_rate : 0,

                                frame->header.bits_per_sample,

                                &p_dec->fmt_out.audio,

                                p_sys->rgi_channels_reorder ) )

        return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;

    if( p_sys->end_date.i_divider_num != p_dec->fmt_out.audio.i_rate )

    {

        if( p_sys->end_date.i_divider_num > 0 )

            date_Change( &p_sys->end_date, p_dec->fmt_out.audio.i_rate, 1 );

        else

            date_Init( &p_sys->end_date, p_dec->fmt_out.audio.i_rate, 1 );

    }

    if( decoder_UpdateAudioFormat( p_dec ) )

        return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;

    if( date_Get( &p_sys->end_date ) == VLC_TICK_INVALID )

        return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;

    p_sys->p_aout_buffer =

        decoder_NewAudioBuffer( p_dec, frame->header.blocksize );

    if( p_sys->p_aout_buffer == NULL )

        return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;

    Interleave( (int32_t *)p_sys->p_aout_buffer->p_buffer, buffer,

                 p_sys->rgi_channels_reorder,

                 frame->header.channels, frame->header.blocksize,

                 frame->header.bits_per_sample );

    /* Date management (already done by packetizer) */

    p_sys->p_aout_buffer->i_pts = date_Get( &p_sys->end_date );

    p_sys->p_aout_buffer->i_length =

        date_Increment( &p_sys->end_date, frame->header.blocksize ) -

        p_sys->p_aout_buffer->i_pts;

    return FLAC__STREAM_DECODER_WRITE_STATUS_CONTINUE;

}

/*****************************************************************************

 * DecoderReadCallback: called by libflac when it needs more data

 *****************************************************************************/

static FLAC__StreamDecoderReadStatus

DecoderReadCallback( const FLAC__StreamDecoder *decoder, FLAC__byte buffer[],

                     size_t *bytes, void *client_data )

{

    VLC_UNUSED(decoder);

    decoder_t *p_dec = (decoder_t *)client_data;

    decoder_sys_t *p_sys = p_dec->p_sys;

    if( p_sys->p_block && p_sys->p_block->i_buffer )

    {

        *bytes = __MIN(*bytes, p_sys->p_block->i_buffer);

        memcpy( buffer, p_sys->p_block->p_buffer, *bytes );

        p_sys->p_block->i_buffer -= *bytes;

        p_sys->p_block->p_buffer += *bytes;

    }

    else

    {

        *bytes = 0;

        return FLAC__STREAM_DECODER_READ_STATUS_ABORT;

    }

    return FLAC__STREAM_DECODER_READ_STATUS_CONTINUE;

}

/*****************************************************************************

 * DecoderMetadataCallback: called by libflac to when it encounters metadata

 *****************************************************************************/

static void DecoderMetadataCallback( const FLAC__StreamDecoder *decoder,

                                     const FLAC__StreamMetadata *metadata,

                                     void *client_data )

{

    VLC_UNUSED(decoder);

    decoder_t *p_dec = (decoder_t *)client_data;

    decoder_sys_t *p_sys = p_dec->p_sys;

    switch(metadata->type)

    {

        case FLAC__METADATA_TYPE_STREAMINFO:

            /* Setup the format */

            DecoderSetOutputFormat( metadata->data.stream_info.channels,

                                    metadata->data.stream_info.sample_rate,

                                    metadata->data.stream_info.sample_rate,

                                    metadata->data.stream_info.bits_per_sample,

                                    &p_dec->fmt_out.audio, p_sys->rgi_channels_reorder );

            msg_Dbg( p_dec, "channels:%d samplerate:%d bitspersamples:%d",

                     p_dec->fmt_out.audio.i_channels, p_dec->fmt_out.audio.i_rate,

                     p_dec->fmt_out.audio.i_bitspersample );

            p_sys->b_stream_info = true;

            p_sys->stream_info = metadata->data.stream_info;

            date_Init( &p_sys->end_date, p_dec->fmt_out.audio.i_rate, 1 );

            break;

        case FLAC__METADATA_TYPE_VORBIS_COMMENT:

            for( FLAC__uint32 i=0; i<metadata->data.vorbis_comment.num_comments; i++ )

            {

                const FLAC__StreamMetadata_VorbisComment_Entry *comment =

                        &metadata->data.vorbis_comment.comments[i];

                /* Check for custom WAVEFORMATEX channel ordering */

                if( comment->length > 34 &&

                    !strncmp( "WAVEFORMATEXTENSIBLE_CHANNEL_MASK=", (char *) comment->entry, 34 ) )

                {

                    char *endptr = (char *) &comment->entry[34] + comment->length;

                    const uint32_t i_wfxmask = strtoul( (char *) &comment->entry[34], &endptr, 16 );

                    const unsigned i_wfxchannels = stdc_count_ones( i_wfxmask );

                    if( i_wfxchannels > 0 && i_wfxchannels <= AOUT_CHAN_MAX )

                    {

                        /* Create the vlc bitmap from wfx channels */

                        uint32_t i_vlcmask = 0;

                        for( uint32_t i_chan = 1; i_chan && i_chan <= i_wfxmask; i_chan <<= 1 )

                        {

                            if( (i_chan & i_wfxmask) == 0 )

                                continue;

                            for( size_t j=0; j<MAPPED_WFX_CHANNELS; j++ )

                            {

                                if( wfx_remapping[j][0] == i_chan )

                                    i_vlcmask |= wfx_remapping[j][1];

                            }

                        }

                        /* Check if we have the 1 to 1 mapping */

                        if( stdc_count_ones(i_vlcmask) != i_wfxchannels )

                        {

                            msg_Warn( p_dec, "Unsupported channel mask %x", i_wfxmask );

                            return;

                        }

                        /* Compute the remapping */

                        uint8_t neworder[AOUT_CHAN_MAX] = {0};

                        aout_CheckChannelReorder( wfx_chans_order, NULL,

                                                  i_vlcmask, neworder );

                        /* /!\ Invert our source/dest reordering,

                         * as Interleave() here works source indexes */

                        for( unsigned j=0; j<i_wfxchannels; j++ )

                            p_sys->rgi_channels_reorder[neworder[j]] = j;

                        p_dec->fmt_out.audio.i_physical_channels = i_vlcmask;

                        p_dec->fmt_out.audio.i_channels = i_wfxchannels;

                    }

                    break;

                }

            }

        default:

            break;

    }

}

/*****************************************************************************

 * DecoderErrorCallback: called when the libflac decoder encounters an error

 *****************************************************************************/

static void DecoderErrorCallback( const FLAC__StreamDecoder *decoder,

                                  FLAC__StreamDecoderErrorStatus status,

                                  void *client_data )

{

    VLC_UNUSED(decoder);

    decoder_t *p_dec = (decoder_t *)client_data;

    decoder_sys_t *p_sys = p_dec->p_sys;

    switch( status )

    {

    case FLAC__STREAM_DECODER_ERROR_STATUS_LOST_SYNC:

        msg_Warn( p_dec, "an error in the stream caused the decoder to "

                 "lose synchronization." );

        break;

    case FLAC__STREAM_DECODER_ERROR_STATUS_BAD_HEADER:

        msg_Err( p_dec, "the decoder encountered a corrupted frame header." );

        break;

    case FLAC__STREAM_DECODER_ERROR_STATUS_FRAME_CRC_MISMATCH:

        msg_Err( p_dec, "frame's data did not match the CRC in the "

                 "footer." );

        break;

    case FLAC__STREAM_DECODER_ERROR_STATUS_UNPARSEABLE_STREAM:

        msg_Err( p_dec, "The decoder encountered reserved fields in use in "

                 "the stream." );

        break;

    default:

        msg_Err( p_dec, "got decoder error: %d", status );

    }

    FLAC__stream_decoder_flush( p_sys->p_flac );

    return;

}

/*****************************************************************************

 * OpenDecoder: probe the decoder and return score

 *****************************************************************************/

static int OpenDecoder( vlc_object_t *p_this )

{

    decoder_t *p_dec = (decoder_t*)p_this;

    decoder_sys_t *p_sys;

    if( p_dec->fmt_in->i_codec != VLC_CODEC_FLAC )

    {

        return VLC_EGENERIC;

    }

    /* Allocate the memory needed to store the decoder's structure */

    if( ( p_dec->p_sys = p_sys = malloc(sizeof(*p_sys)) ) == NULL )

        return VLC_ENOMEM;

    /* Misc init */

    p_sys->b_stream_info = false;

    memset(p_sys->rgi_channels_reorder, 0, AOUT_CHAN_MAX);

    p_sys->p_block = NULL;

    /* Take care of flac init */

    if( !(p_sys->p_flac = FLAC__stream_decoder_new()) )

    {

        msg_Err( p_dec, "FLAC__stream_decoder_new() failed" );

        free( p_sys );

        return VLC_EGENERIC;

    }

    /* Enable STREAMINFO + COMMENTS */

    FLAC__stream_decoder_set_metadata_respond( p_sys->p_flac,

                                               FLAC__METADATA_TYPE_VORBIS_COMMENT );

#ifdef USE_NEW_FLAC_API

    if( FLAC__stream_decoder_init_stream( p_sys->p_flac,

                                          DecoderReadCallback,

                                          NULL,

                                          NULL,

                                          NULL,

                                          NULL,

                                          DecoderWriteCallback,

                                          DecoderMetadataCallback,

                                          DecoderErrorCallback,

                                          p_dec )

        != FLAC__STREAM_DECODER_INIT_STATUS_OK )

    {

        msg_Err( p_dec, "FLAC__stream_decoder_init_stream() failed" );

        FLAC__stream_decoder_delete( p_sys->p_flac );

        free( p_sys );

        return VLC_EGENERIC;

    }

#else

    FLAC__stream_decoder_set_read_callback( p_sys->p_flac,

                                            DecoderReadCallback );

    FLAC__stream_decoder_set_write_callback( p_sys->p_flac,

                                             DecoderWriteCallback );

    FLAC__stream_decoder_set_metadata_callback( p_sys->p_flac,

                                                DecoderMetadataCallback );

    FLAC__stream_decoder_set_error_callback( p_sys->p_flac,

                                             DecoderErrorCallback );

    FLAC__stream_decoder_set_client_data( p_sys->p_flac, p_dec );

    FLAC__stream_decoder_init( p_sys->p_flac );

#endif

    /* Set output properties */

    p_dec->fmt_out.i_codec = VLC_CODEC_S32N;

    /* Set callbacks */

    p_dec->pf_decode = DecodeBlock;

    p_dec->pf_flush  = Flush;

    return VLC_SUCCESS;

}

/*****************************************************************************

 * CloseDecoder: flac decoder destruction

 *****************************************************************************/

static void CloseDecoder( vlc_object_t *p_this )

{

    decoder_t *p_dec = (decoder_t *)p_this;

    decoder_sys_t *p_sys = p_dec->p_sys;

    FLAC__stream_decoder_finish( p_sys->p_flac );

    FLAC__stream_decoder_delete( p_sys->p_flac );

    if( p_sys->p_block )

        block_Release( p_sys->p_block );

    free( p_sys );

}

/*****************************************************************************

 * ProcessHeader: process Flac header.

 *****************************************************************************/

static void ProcessHeader( decoder_t *p_dec )

{

    decoder_sys_t *p_sys = p_dec->p_sys;

    if( !p_dec->fmt_in->i_extra )

        return;

    /* Decode STREAMINFO */

    msg_Dbg( p_dec, "decode STREAMINFO" );

    size_t i_extra = p_dec->fmt_in->i_extra;

    static const char header[4] = { 'f', 'L', 'a', 'C' };

    if( memcmp( p_dec->fmt_in->p_extra, header, 4 ) )

        i_extra += 8;

    p_sys->p_block = block_Alloc( i_extra );

    if( p_sys->p_block == NULL )

        return;

    uint8_t *p_data = p_sys->p_block->p_buffer;

    if( i_extra != p_dec->fmt_in->i_extra )

    {

        memcpy( p_data, header, 4);

        p_data[4] = 0x80 | 0; /* STREAMINFO faked as last block */

        p_data[5] = 0;

        p_data[6] = 0;

        p_data[7] = 34; /* block size */

        p_data += 8;

    }

    memcpy( p_data, p_dec->fmt_in->p_extra, p_dec->fmt_in->i_extra );

    FLAC__stream_decoder_process_until_end_of_metadata( p_sys->p_flac );

    msg_Dbg( p_dec, "STREAMINFO decoded" );

    block_Release( p_sys->p_block );

    p_sys->p_block = NULL;

}

/*****************************************************************************

 * decoder_state_error: print meaningful error messages

 *****************************************************************************/

static void decoder_state_error( decoder_t *p_dec,

                                 FLAC__StreamDecoderState state )

{

    switch ( state )

    {

    case FLAC__STREAM_DECODER_SEARCH_FOR_METADATA:

        msg_Dbg( p_dec, "the decoder is ready to search for metadata." );

        break;

    case FLAC__STREAM_DECODER_READ_METADATA:

        msg_Dbg( p_dec, "the decoder is ready to or is in the process of "

                 "reading metadata." );

        break;

    case FLAC__STREAM_DECODER_SEARCH_FOR_FRAME_SYNC:

        msg_Dbg( p_dec, "the decoder is ready to or is in the process of "

                 "searching for the frame sync code." );

        break;

    case FLAC__STREAM_DECODER_READ_FRAME:

        msg_Dbg( p_dec, "the decoder is ready to or is in the process of "

                 "reading a frame." );

        break;

    case FLAC__STREAM_DECODER_END_OF_STREAM:

        msg_Dbg( p_dec, "the decoder has reached the end of the stream." );

        break;

#ifdef USE_NEW_FLAC_API

    case FLAC__STREAM_DECODER_OGG_ERROR:

        msg_Err( p_dec, "error occurred in the Ogg layer." );

        break;

    case FLAC__STREAM_DECODER_SEEK_ERROR:

        msg_Err( p_dec, "error occurred while seeking." );

        break;

#endif

    case FLAC__STREAM_DECODER_ABORTED:

        msg_Warn( p_dec, "the decoder was aborted by the read callback." );

        break;

#ifndef USE_NEW_FLAC_API

    case FLAC__STREAM_DECODER_UNPARSEABLE_STREAM:

        msg_Warn( p_dec, "the decoder encountered reserved fields in use "

                 "in the stream." );

        break;

#endif

    case FLAC__STREAM_DECODER_MEMORY_ALLOCATION_ERROR:

        msg_Err( p_dec, "error when allocating memory." );

        break;

#ifndef USE_NEW_FLAC_API

    case FLAC__STREAM_DECODER_ALREADY_INITIALIZED:

        msg_Err( p_dec, "FLAC__stream_decoder_init() was called when the "

                 "decoder was already initialized, usually because "

                 "FLAC__stream_decoder_finish() was not called." );

        break;

    case FLAC__STREAM_DECODER_INVALID_CALLBACK:

        msg_Err( p_dec, "FLAC__stream_decoder_init() was called without "

                 "all callbacks being set." );

        break;

#endif

    case FLAC__STREAM_DECODER_UNINITIALIZED:

        msg_Err( p_dec, "decoder in uninitialized state." );

        break;

    default:

        msg_Warn(p_dec, "unknown error" );

    }

}

/*****************************************************************************

 * Flush:

 *****************************************************************************/

static void Flush( decoder_t *p_dec )

{

    decoder_sys_t *p_sys = p_dec->p_sys;

    if( p_sys->b_stream_info )

        FLAC__stream_decoder_flush( p_sys->p_flac );

    date_Set( &p_sys->end_date, VLC_TICK_INVALID );

}

/****************************************************************************

 * DecodeBlock: the whole thing

 ****************************************************************************/

static int DecodeBlock( decoder_t *p_dec, block_t *p_block )

{

    decoder_sys_t *p_sys = p_dec->p_sys;

    if( p_block == NULL ) /* No Drain */

        return VLCDEC_SUCCESS;

    if( p_block->i_flags & (BLOCK_FLAG_DISCONTINUITY | BLOCK_FLAG_CORRUPTED) )

    {

        Flush( p_dec );

        if( p_block->i_flags & BLOCK_FLAG_CORRUPTED )

        {

            block_Release( p_block );

            return VLCDEC_SUCCESS;

        }

    }

    if( !p_sys->b_stream_info )

    {

        ProcessHeader( p_dec );

        if( !p_sys->b_stream_info )

        {

            block_Release( p_block );

            return VLCDEC_ECRITICAL;

        }

    }

    p_sys->p_block = p_block;

    if( p_sys->p_block->i_pts != VLC_TICK_INVALID &&

        p_sys->p_block->i_pts != date_Get( &p_sys->end_date ) )

        date_Set( &p_sys->end_date, p_sys->p_block->i_pts );

    p_sys->p_aout_buffer = 0;

    if( !FLAC__stream_decoder_process_single( p_sys->p_flac ) )

    {

        decoder_state_error( p_dec,

                             FLAC__stream_decoder_get_state( p_sys->p_flac ) );

        FLAC__stream_decoder_flush( p_sys->p_flac );

    }

    /* If the decoder is in the "aborted" state,

     * FLAC__stream_decoder_process_single() won't return an error. */

    switch ( FLAC__stream_decoder_get_state(p_sys->p_flac) )

    {

        case FLAC__STREAM_DECODER_ABORTED:

            FLAC__stream_decoder_flush( p_sys->p_flac );

            break;

        case FLAC__STREAM_DECODER_END_OF_STREAM:

            FLAC__stream_decoder_reset( p_sys->p_flac );

            break;

        default:

            break;

    }

    block_Release( p_sys->p_block );

    p_sys->p_block = NULL;

    if( p_sys->p_aout_buffer != NULL )

        decoder_QueueAudio( p_dec, p_sys->p_aout_buffer );

    return VLCDEC_SUCCESS;

}

#ifdef ENABLE_SOUT

/*****************************************************************************

 * encoder_sys_t : flac encoder descriptor

 *****************************************************************************/

typedef struct

{

    /*

     * Input properties

     */

    int i_headers;

    int i_samples_delay;

    FLAC__int32 *p_buffer;

    unsigned int i_buffer;

    block_t *p_chain;

    /*

     * FLAC properties

     */

    FLAC__StreamEncoder *p_flac;

    FLAC__StreamMetadata_StreamInfo stream_info;

    /*

     * Common properties

     */

    vlc_tick_t i_pts;

} encoder_sys_t;

#define STREAMINFO_SIZE 34

static block_t *Encode( encoder_t *, block_t * );

/*****************************************************************************

 * EncoderWriteCallback: called by libflac to output encoded samples

 *****************************************************************************/

static FLAC__StreamEncoderWriteStatus

EncoderWriteCallback( const FLAC__StreamEncoder *encoder,

                      const FLAC__byte buffer[],

                      size_t bytes, unsigned samples,

                      unsigned current_frame, void *client_data )

{

    VLC_UNUSED(encoder); VLC_UNUSED(current_frame);

    encoder_t *p_enc = (encoder_t *)client_data;

    encoder_sys_t *p_sys = p_enc->p_sys;

    block_t *p_block;

    if( samples == 0 )

    {

        if( p_sys->i_headers == 1 )

        {

            msg_Dbg( p_enc, "Writing STREAMINFO: %zu", bytes );

            /* Backup the STREAMINFO metadata block */

            p_enc->fmt_out.i_extra = STREAMINFO_SIZE + 8;

            p_enc->fmt_out.p_extra = xmalloc( STREAMINFO_SIZE + 8);

            memcpy(p_enc->fmt_out.p_extra, "fLaC", 4);

            memcpy((uint8_t*)p_enc->fmt_out.p_extra + 4, buffer, STREAMINFO_SIZE );

            /* Fake this as the last metadata block */

            ((uint8_t*)p_enc->fmt_out.p_extra)[4] |= 0x80;

        }

        p_sys->i_headers++;

        return FLAC__STREAM_ENCODER_WRITE_STATUS_OK;

    }

    p_block = block_Alloc( bytes );

    /* FLAC__STREAM_ENCODER_MEMORY_ALLOCATION_ERROR would be more appropriate

       but it's not the right type of enum */

    if( unlikely(p_block == NULL) )

        return FLAC__STREAM_ENCODER_WRITE_STATUS_FATAL_ERROR;

    memcpy( p_block->p_buffer, buffer, bytes );

    p_block->i_dts = p_block->i_pts = p_sys->i_pts;

    p_sys->i_samples_delay -= samples;

    p_block->i_length = vlc_tick_from_samples(samples, p_enc->fmt_in.audio.i_rate);

    /* Update pts */

    p_sys->i_pts += p_block->i_length;

    block_ChainAppend( &p_sys->p_chain, p_block );

    return FLAC__STREAM_ENCODER_WRITE_STATUS_OK;

}

/*****************************************************************************

 * EncoderMetadataCallback: called by libflac to output metadata

 *****************************************************************************/

static void EncoderMetadataCallback( const FLAC__StreamEncoder *encoder,

                                     const FLAC__StreamMetadata *metadata,

                                     void *client_data )

{

    VLC_UNUSED(encoder);

    encoder_t *p_enc = (encoder_t *)client_data;

    msg_Err( p_enc, "MetadataCallback: %i", metadata->type );

    return;

}

/*****************************************************************************

 * OpenEncoder: probe the encoder and return score

 *****************************************************************************/

static int OpenEncoder( vlc_object_t *p_this )

{

    encoder_t *p_enc = (encoder_t *)p_this;

    encoder_sys_t *p_sys;

    if( p_enc->fmt_out.i_codec != VLC_CODEC_FLAC &&

        !p_enc->obj.force )

    {

        return VLC_EGENERIC;

    }

    /* Allocate the memory needed to store the decoder's structure */

    if( ( p_sys = (encoder_sys_t *)malloc(sizeof(encoder_sys_t)) ) == NULL )

        return VLC_ENOMEM;

    p_enc->p_sys = p_sys;

    p_enc->fmt_out.i_codec = VLC_CODEC_FLAC;

    p_sys->i_headers = 0;

    p_sys->p_buffer = 0;

    p_sys->i_buffer = 0;

    p_sys->i_samples_delay = 0;

    /* Create flac encoder */

    if( !(p_sys->p_flac = FLAC__stream_encoder_new()) )

    {

        msg_Err( p_enc, "FLAC__stream_encoder_new() failed" );

        free( p_sys );

        return VLC_EGENERIC;

    }

    FLAC__stream_encoder_set_streamable_subset( p_sys->p_flac, 1 );

    FLAC__stream_encoder_set_channels( p_sys->p_flac,

                                       p_enc->fmt_in.audio.i_channels );

    FLAC__stream_encoder_set_sample_rate( p_sys->p_flac,

                                          p_enc->fmt_in.audio.i_rate );

    FLAC__stream_encoder_set_bits_per_sample( p_sys->p_flac, 16 );

    p_enc->fmt_in.i_codec = VLC_CODEC_S16N;

    /* Get and store the STREAMINFO metadata block as a p_extra */

    p_sys->p_chain = 0;

#ifdef USE_NEW_FLAC_API

    if( FLAC__stream_encoder_init_stream( p_sys->p_flac,

                                          EncoderWriteCallback,

                                          NULL,

                                          NULL,

                                          EncoderMetadataCallback,

                                          p_enc )

        != FLAC__STREAM_ENCODER_INIT_STATUS_OK )

    {

        msg_Err( p_enc, "FLAC__stream_encoder_init_stream() failed" );

        FLAC__stream_encoder_delete( p_sys->p_flac );

        free( p_sys );

        return VLC_EGENERIC;

    }

#else

    FLAC__stream_encoder_set_write_callback( p_sys->p_flac,

        EncoderWriteCallback );

    FLAC__stream_encoder_set_metadata_callback( p_sys->p_flac,

        EncoderMetadataCallback );

    FLAC__stream_encoder_set_client_data( p_sys->p_flac, p_enc );

    FLAC__stream_encoder_init( p_sys->p_flac );

#endif

    static const struct vlc_encoder_operations ops =

    {

        .close = CloseEncoder,

        .encode_audio = Encode,

    };

    p_enc->ops = &ops;

    return VLC_SUCCESS;

}

/****************************************************************************

 * Encode: the whole thing

 ****************************************************************************

 * This function spits out ogg packets.

 ****************************************************************************/

static block_t *Encode( encoder_t *p_enc, block_t *p_aout_buf )

{

    encoder_sys_t *p_sys = p_enc->p_sys;

    block_t *p_chain;

    /* FIXME: p_aout_buf is NULL when it's time to flush*/

    if( unlikely( !p_aout_buf ) ) return NULL;

    p_sys->i_pts = p_aout_buf->i_pts -

                vlc_tick_from_samples( p_sys->i_samples_delay,

                            p_enc->fmt_in.audio.i_rate );

    p_sys->i_samples_delay += p_aout_buf->i_nb_samples;

    /* Convert samples to FLAC__int32 */

    if( p_sys->i_buffer < p_aout_buf->i_buffer * sizeof(FLAC__int32) )

    {

        p_sys->p_buffer =

            xrealloc( p_sys->p_buffer, p_aout_buf->i_buffer * sizeof(FLAC__int32) );

        p_sys->i_buffer = p_aout_buf->i_buffer * 2;

    }

    for( unsigned i = 0 ; i < p_aout_buf->i_buffer / 2 ; i++ )

    {

        p_sys->p_buffer[i]= ((int16_t *)p_aout_buf->p_buffer)[i];

    }

    FLAC__stream_encoder_process_interleaved( p_sys->p_flac, p_sys->p_buffer,

                                              p_aout_buf->i_nb_samples );

    p_chain = p_sys->p_chain;

    p_sys->p_chain = 0;

    return p_chain;

}

/*****************************************************************************

 * CloseEncoder: encoder destruction

 *****************************************************************************/

static void CloseEncoder( encoder_t *p_enc )

{

    encoder_sys_t *p_sys = p_enc->p_sys;

    FLAC__stream_encoder_delete( p_sys->p_flac );

    free( p_sys->p_buffer );

    free( p_sys );

}

#endif