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

 * h26x.c : raw H264 and HEVC Video demuxers

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

 * Copyright (C) 2002-2004, 2014-2015 VLC authors and VideoLAN

 *

 * Authors: Laurent Aimar <fenrir@via.ecp.fr>

 *          Denis Charmet <typx@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

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

#ifdef HAVE_CONFIG_H

# include "config.h"

#endif

#include <vlc_common.h>

#include <vlc_plugin.h>

#include <vlc_demux.h>

#include <vlc_codec.h>

#include "../../packetizer/hevc_nal.h" /* definitions, inline helpers */

#include "../../packetizer/h264_nal.h" /* definitions, inline helpers */

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

 * Module descriptor

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

static int  OpenH264 ( vlc_object_t * );

static int  OpenHEVC ( vlc_object_t * );

static void Close( vlc_object_t * );

#define FPS_TEXT N_("Frames per Second")

#define FPS_LONGTEXT N_("Desired frame rate for the stream.")

vlc_module_begin ()

    set_shortname( "H264")

    set_subcategory( SUBCAT_INPUT_DEMUX )

    set_description( N_("H264 video demuxer" ) )

    set_capability( "demux", 8 )

    set_section( N_("H264 video demuxer" ), NULL )

    add_float( "h264-fps", 0.0, FPS_TEXT, FPS_LONGTEXT )

    set_callbacks( OpenH264, Close )

    add_shortcut( "h264" )

    add_file_extension("h264")

    add_submodule()

        set_shortname( "HEVC")

        set_subcategory( SUBCAT_INPUT_DEMUX )

        set_description( N_("HEVC/H.265 video demuxer" ) )

        set_capability( "demux", 8 )

        set_section( N_("HEVC/H.265 video demuxer" ), NULL )

        add_float( "hevc-fps", 0.0, FPS_TEXT, FPS_LONGTEXT )

        set_callbacks( OpenHEVC, Close )

        add_shortcut( "hevc", "h265" )

vlc_module_end ()

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

 * Local prototypes

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

typedef struct

{

    es_out_id_t *p_es;

    date_t      feed_dts;

    date_t      output_dts;

    unsigned    frame_rate_num;

    unsigned    frame_rate_den;

    decoder_t *p_packetizer;

} demux_sys_t;

static int Demux( demux_t * );

static int Control( demux_t *, int, va_list );

#define H26X_PACKET_SIZE 2048

#define H26X_PEEK_CHUNK  (H26X_PACKET_SIZE * 4)

#define H26X_MIN_PEEK    (4 + 7 + 10)

#define H26X_MAX_PEEK    (H26X_PEEK_CHUNK * 8) /* max data to check */

#define H26X_NAL_COUNT   8 /* max # or NAL to check */

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

 * Probing

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

typedef struct

{

    bool b_sps;

    bool b_pps;

    bool b_vps;

} hevc_probe_ctx_t;

typedef struct

{

    bool b_sps;

    bool b_pps;

} h264_probe_ctx_t;

static int ProbeHEVC( const uint8_t *p_peek, size_t i_peek, void *p_priv )

{

    hevc_probe_ctx_t *p_ctx = (hevc_probe_ctx_t *) p_priv;

    if( i_peek < 2 )

        return -1;

    if( p_peek[0] & 0x80 )

        return -1;

    const uint8_t i_type = hevc_getNALType( p_peek );

    const uint8_t i_layer = hevc_getNALLayer( p_peek );

   if ( i_type == HEVC_NAL_VPS ) /* VPS */

   {

       if( i_layer != 0 || i_peek < 6 ||

           p_peek[4] != 0xFF || p_peek[5] != 0xFF ) /* Check reserved bits */

           return -1;

       p_ctx->b_vps = true;

       return 0;

   }

   else if( i_type == HEVC_NAL_SPS )  /* SPS */

   {

       if( i_layer != 0 )

           return -1;

       p_ctx->b_sps = true;

       return 0;

   }

   else if( i_type == HEVC_NAL_PPS )  /* PPS */

   {

       if( i_layer != 0 )

           return -1;

       p_ctx->b_pps = true;

       return 0;

   }

   else if( i_type >= HEVC_NAL_BLA_W_LP && i_type <= HEVC_NAL_CRA ) /* Key Frame */

   {

        if( p_ctx->b_vps && p_ctx->b_sps && p_ctx->b_pps && i_layer == 0 )

            return 1;

   }

   else if( i_type == HEVC_NAL_AUD ) /* AU */

   {

        if( i_peek < H26X_MIN_PEEK ||

            p_peek[4] != 0 || p_peek[5] != 0 ) /* Must prefix another NAL */

            return -1;

   }

   else if( i_type == HEVC_NAL_PREF_SEI ) /* Prefix SEI */

   {

       if( p_peek[2] == 0xFF ) /* empty SEI */

           return -1;

   }

   else

   {

       return -1; /* See 7.4.2.4.4 for sequence order */

   }

    return 0; /* Probe more */

}

static int ProbeH264( const uint8_t *p_peek, size_t i_peek, void *p_priv )

{

    h264_probe_ctx_t *p_ctx = (h264_probe_ctx_t *) p_priv;

    if( i_peek < 1 )

        return -1;

    const uint8_t i_nal_type = p_peek[0] & 0x1F;

    const uint8_t i_ref_idc = p_peek[0] & 0x60;

    if( (p_peek[0] & 0x80) ) /* reserved 0 */

        return -1;

    /* ( !i_ref_idc && (i_nal_type < 6 || i_nal_type == 7 || i_nal_type == 8) ) ||

       (  i_ref_idc && (i_nal_type == 6 || i_nal_type >= 9) ) */

    if( i_nal_type == H264_NAL_SPS )

    {

        if( i_ref_idc == 0 || i_peek < 3 ||

           (p_peek[2] & 0x03) /* reserved 0 bits */ )

            return -1;

        p_ctx->b_sps = true;

    }

    else if( i_nal_type == H264_NAL_PPS )

    {

        if( i_ref_idc == 0 )

            return -1;

        p_ctx->b_pps = true;

    }

    else if( i_nal_type == H264_NAL_SLICE_IDR )

    {

        if( i_ref_idc == 0 || ! p_ctx->b_pps || ! p_ctx->b_sps )

            return -1;

        else

            return 1;

    }

    else if( i_nal_type == H264_NAL_AU_DELIMITER )

    {

        if( i_ref_idc )

            return -1;

    }

    else if ( i_nal_type == H264_NAL_SEI )

    {

        if( i_ref_idc )

            return -1;

    }

     /* 7.4.1.1 */

    else if ( i_nal_type == H264_NAL_SPS_EXT ||

              i_nal_type == H264_NAL_SUBSET_SPS )

    {

        if( i_ref_idc == 0 || !p_ctx->b_sps )

            return -1;

    }

    else if( i_nal_type == H264_NAL_PREFIX )

    {

        if( i_ref_idc == 0 || !p_ctx->b_pps || !p_ctx->b_sps )

            return -1;

    }

    else return -1; /* see 7.4.1.2.3 for sequence */

    return 0;

}

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

 * Shared Open code

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

static inline bool check_Property( demux_t *p_demux, const char **pp_psz,

                                   bool(*pf_check)(demux_t *, const char *) )

{

    while( *pp_psz )

    {

        if( pf_check( p_demux, *pp_psz ) )

            return true;

        pp_psz++;

    }

    return false;

}

static int GenericOpen( demux_t *p_demux, const char *psz_module,

                        vlc_fourcc_t i_codec,

                        int(*pf_probe)(const uint8_t *, size_t, void *),

                        void *p_ctx,

                        const char **pp_psz_exts,

                        const char **pp_psz_mimes )

{

    demux_sys_t *p_sys;

    const uint8_t *p_peek;

    es_format_t fmt;

    uint8_t annexb_startcode[] = {0,0,0,1};

    int i_ret = 0;

    /* Restrict by type first */

    if( !p_demux->obj.force &&

        !check_Property( p_demux, pp_psz_exts, demux_IsPathExtension ) &&

        !check_Property( p_demux, pp_psz_mimes, demux_IsContentType ) )

    {

        return VLC_EGENERIC;

    }

    /* First check for first AnnexB header */

    if( vlc_stream_Peek( p_demux->s, &p_peek, H26X_MIN_PEEK ) == H26X_MIN_PEEK &&

       !memcmp( p_peek, annexb_startcode, 4 ) )

    {

        ssize_t i_peek = H26X_MIN_PEEK;

        size_t i_peek_target = H26X_MIN_PEEK;

        ssize_t i_probe_offset = 4;

        const uint8_t *p_probe = p_peek;

        bool b_synced = true;

        unsigned i_bitflow = 0;

        for( unsigned i=0; i<H26X_NAL_COUNT; i++ )

        {

            while( !b_synced )

            {

                if( i_probe_offset + H26X_MIN_PEEK >= i_peek &&

                    i_peek_target + H26X_PEEK_CHUNK <= H26X_MAX_PEEK )

                {

                    i_peek_target += H26X_PEEK_CHUNK;

                    i_peek = vlc_stream_Peek( p_demux->s, &p_peek, i_peek_target );

                }

                if( i_probe_offset + H26X_MIN_PEEK >= i_peek )

                    break;

                p_probe = &p_peek[i_probe_offset];

                i_bitflow = (i_bitflow << 1) | (!p_probe[0]);

                /* Check for annexB */

                if( p_probe[0] == 0x01 && ((i_bitflow & 0x06) == 0x06) )

                    b_synced = true;

                i_probe_offset++;

            }

            if( b_synced )

            {

                p_probe = &p_peek[i_probe_offset];

                i_ret = pf_probe( p_probe, (size_t)(i_peek - i_probe_offset), p_ctx );

            }

            if( i_ret != 0 )

                break;

            i_probe_offset += 4;

            b_synced = false;

        }

    }

    if( i_ret < 1 )

    {

        if( !p_demux->obj.force )

        {

            msg_Warn( p_demux, "%s module discarded (no startcode)", psz_module );

            return VLC_EGENERIC;

        }

        msg_Err( p_demux, "this doesn't look like a %s ES stream, "

                 "continuing anyway", psz_module );

    }

    p_demux->pf_demux  = Demux;

    p_demux->pf_control= Control;

    p_demux->p_sys     = p_sys = malloc( sizeof( demux_sys_t ) );

    p_sys->p_es        = NULL;

    p_sys->frame_rate_num = 0;

    p_sys->frame_rate_den = 0;

    float f_fps = 0;

    char *psz_fpsvar;

    if( asprintf( &psz_fpsvar, "%s-fps", psz_module ) != -1 )

    {

        f_fps = var_CreateGetFloat( p_demux, psz_fpsvar );

        free( psz_fpsvar );

    }

    if( f_fps )

    {

        if ( f_fps < 0.001f ) f_fps = 0.001f;

        p_sys->frame_rate_den = 1000;

        p_sys->frame_rate_num = 2000 * f_fps;

        date_Init( &p_sys->feed_dts, p_sys->frame_rate_num, p_sys->frame_rate_den );

    }

    else

        date_Init( &p_sys->feed_dts, 25000, 1000 );

    date_Set( &p_sys->feed_dts, VLC_TICK_0 );

    p_sys->output_dts = p_sys->feed_dts;

    /* Load the mpegvideo packetizer */

    es_format_Init( &fmt, VIDEO_ES, i_codec );

    if( f_fps )

    {

        fmt.video.i_frame_rate = p_sys->feed_dts.i_divider_num;

        fmt.video.i_frame_rate_base = p_sys->feed_dts.i_divider_den;

    }

    p_sys->p_packetizer = demux_PacketizerNew( VLC_OBJECT(p_demux), &fmt, psz_module );

    if( !p_sys->p_packetizer )

    {

        free( p_sys );

        return VLC_EGENERIC;

    }

    return VLC_SUCCESS;

}

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

 * Open: initializes demux structures

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

static int OpenH264( vlc_object_t * p_this )

{

    h264_probe_ctx_t ctx = { 0, 0 };

    const char *rgi_psz_ext[] = { ".h264", ".264", ".bin", ".bit", ".raw", NULL };

    const char *rgi_psz_mime[] = { "video/H264", "video/h264", "video/avc", NULL };

    return GenericOpen( (demux_t*)p_this, "h264", VLC_CODEC_H264, ProbeH264,

                        &ctx, rgi_psz_ext, rgi_psz_mime );

}

static int OpenHEVC( vlc_object_t * p_this )

{

    hevc_probe_ctx_t ctx = { 0, 0, 0 };

    const char *rgi_psz_ext[] = { ".h265", ".265", ".hevc", ".bin", ".bit", ".raw", NULL };

    const char *rgi_psz_mime[] = { "video/h265", "video/hevc", "video/HEVC", NULL };

    return GenericOpen( (demux_t*)p_this, "hevc", VLC_CODEC_HEVC, ProbeHEVC,

                        &ctx, rgi_psz_ext, rgi_psz_mime );

}

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

 * Close: frees unused data

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

static void Close( vlc_object_t * p_this )

{

    demux_t     *p_demux = (demux_t*)p_this;

    demux_sys_t *p_sys = p_demux->p_sys;

    demux_PacketizerDestroy( p_sys->p_packetizer );

    free( p_sys );

}

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

 * Demux: reads and demuxes data packets

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

 * Returns -1 in case of error, 0 in case of EOF, 1 otherwise

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

static int Demux( demux_t *p_demux)

{

    demux_sys_t *p_sys = p_demux->p_sys;

    block_t *p_block_in, *p_block_out;

    bool b_eof = false;

    p_block_in = vlc_stream_Block( p_demux->s, H26X_PACKET_SIZE );

    if( p_block_in == NULL )

    {

        b_eof = true;

    }

    else

    {

        p_block_in->i_dts = date_Get( &p_sys->feed_dts );

    }

    while( (p_block_out = p_sys->p_packetizer->pf_packetize( p_sys->p_packetizer,

                                                             p_block_in ? &p_block_in : NULL )) )

    {

        while( p_block_out )

        {

            block_t *p_next = p_block_out->p_next;

            p_block_out->p_next = NULL;

            if( p_sys->p_packetizer->fmt_out.video.i_frame_rate_base &&

                p_sys->p_packetizer->fmt_out.video.i_frame_rate_base != p_sys->frame_rate_den &&

                p_sys->p_packetizer->fmt_out.video.i_frame_rate &&

                p_sys->p_packetizer->fmt_out.video.i_frame_rate_base != p_sys->frame_rate_num )

            {

                p_sys->frame_rate_num = p_sys->p_packetizer->fmt_out.video.i_frame_rate;

                p_sys->frame_rate_den = p_sys->p_packetizer->fmt_out.video.i_frame_rate_base;

                date_Change( &p_sys->feed_dts, 2 * p_sys->frame_rate_num, p_sys->frame_rate_den );

                date_Change( &p_sys->output_dts, 2 * p_sys->frame_rate_num, p_sys->frame_rate_den );

                msg_Dbg( p_demux, "using %.2f fps", (double) p_sys->frame_rate_num / p_sys->frame_rate_den );

            }

            /* we only want to use the pts-dts offset and length from packetizer */

            vlc_tick_t dtsdiff = p_block_out->i_pts > p_block_out->i_dts

                               ? p_block_out->i_pts - p_block_out->i_dts

                               : 0;

            /* Always start frame N=1 so we get PCR on N=0 */

            date_t dtsdate = p_sys->output_dts;

            vlc_tick_t dts = date_Increment( &dtsdate, 2 );

            p_block_out->i_dts = dts;

            if( p_block_out->i_pts != VLC_TICK_INVALID )

                p_block_out->i_pts = dts + dtsdiff;

            if( p_block_in )

            {

                p_block_in->i_dts = date_Get( &p_sys->feed_dts );

                p_block_in->i_pts = VLC_TICK_INVALID;

            }

            if( p_sys->p_es == NULL )

            {

                p_sys->p_packetizer->fmt_out.b_packetized = true;

                p_sys->p_packetizer->fmt_out.i_id = 0;

                p_sys->p_es = es_out_Add( p_demux->out, &p_sys->p_packetizer->fmt_out );

                if( !p_sys->p_es )

                {

                    block_ChainRelease( p_block_out );

                    return VLC_DEMUXER_EOF;

                }

            }

            /* h264 packetizer does merge multiple NAL into AU, but slice flag persists */

            bool frame = p_block_out->i_flags & BLOCK_FLAG_TYPE_MASK;

            const vlc_tick_t i_frame_length = p_block_out->i_length;

            /* first output */

            if( date_Get( &p_sys->output_dts ) == VLC_TICK_0 )

                es_out_SetPCR( p_demux->out, date_Get( &p_sys->output_dts ) );

            es_out_Send( p_demux->out, p_sys->p_es, p_block_out );

            vlc_tick_t pcr = b_eof ? dts : date_Get( &p_sys->output_dts );

            if( frame )

            {

                unsigned i_nb_fields;

                if( i_frame_length > 0 )

                {

                    i_nb_fields = round( (double)i_frame_length * 2 * p_sys->frame_rate_num /

                                  ( p_sys->frame_rate_den * CLOCK_FREQ ) );

                }

                else i_nb_fields = 2;

                if( i_nb_fields <= 6 ) /* in the legit range */

                {

                    date_Increment( &p_sys->output_dts, i_nb_fields );

                }

            }

            es_out_SetPCR( p_demux->out, pcr );

            p_block_out = p_next;

        }

    }

    return (b_eof) ? VLC_DEMUXER_EOF : VLC_DEMUXER_SUCCESS;

}

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

 * Control:

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

static int Control( demux_t *p_demux, int i_query, va_list args )

{

    /* demux_sys_t *p_sys  = p_demux->p_sys; */

    /* FIXME calculate the bitrate */

    if( i_query == DEMUX_SET_TIME )

        return VLC_EGENERIC;

    else

        return demux_vaControlHelper( p_demux->s,

                                       0, -1,

                                       0, 1, i_query, args );

}