PeerStreamer

/*

 * Interface to xvidcore for mpeg4 encoding

 * Copyright (c) 2004 Adam Thayer <krevnik@comcast.net>

 *

 * 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

 */

/**

 * @file xvidmpeg4.c

 * Interface to xvidcore for MPEG-4 compliant encoding.

 * @author Adam Thayer (krevnik@comcast.net)

 */

#include <xvid.h>

#include <unistd.h>

#include "avcodec.h"

#include "libxvid_internal.h"

/**

 * Buffer management macros.

 */

#define BUFFER_SIZE                 1024

#define BUFFER_REMAINING(x)         (BUFFER_SIZE - strlen(x))

#define BUFFER_CAT(x)               (&((x)[strlen(x)]))

/* For PPC Use */

int has_altivec(void);

/**

 * Structure for the private Xvid context.

 * This stores all the private context for the codec.

 */

struct xvid_context {

    void *encoder_handle;          /** Handle for Xvid encoder */

    int xsize, ysize;              /** Frame size */

    int vop_flags;                 /** VOP flags for Xvid encoder */

    int vol_flags;                 /** VOL flags for Xvid encoder */

    int me_flags;                  /** Motion Estimation flags */

    int qscale;                    /** Do we use constant scale? */

    int quicktime_format;          /** Are we in a QT-based format? */

    AVFrame encoded_picture;       /** Encoded frame information */

    char *twopassbuffer;           /** Character buffer for two-pass */

    char *old_twopassbuffer;       /** Old character buffer (two-pass) */

    char *twopassfile;             /** second pass temp file name */

    unsigned char *intra_matrix;   /** P-Frame Quant Matrix */

    unsigned char *inter_matrix;   /** I-Frame Quant Matrix */

};

/**

 * Structure for the private first-pass plugin.

 */

struct xvid_ff_pass1 {

    int     version;                /** Xvid version */

    struct xvid_context *context;        /** Pointer to private context */

};

/* Prototypes - See function implementation for details */

int xvid_strip_vol_header(AVCodecContext *avctx, unsigned char *frame, unsigned int header_len, unsigned int frame_len);

int xvid_ff_2pass(void *ref, int opt, void *p1, void *p2);

void xvid_correct_framerate(AVCodecContext *avctx);

/**

 * Creates the private context for the encoder.

 * All buffers are allocated, settings are loaded from the user,

 * and the encoder context created.

 *

 * @param avctx AVCodecContext pointer to context

 * @return Returns 0 on success, -1 on failure

 */

av_cold int ff_xvid_encode_init(AVCodecContext *avctx)  {

    int xerr, i;

    int xvid_flags = avctx->flags;

    struct xvid_context *x = avctx->priv_data;

    uint16_t *intra, *inter;

    int fd;

    xvid_plugin_single_t single;

    struct xvid_ff_pass1 rc2pass1;

    xvid_plugin_2pass2_t rc2pass2;

    xvid_gbl_init_t xvid_gbl_init;

    xvid_enc_create_t xvid_enc_create;

    xvid_enc_plugin_t plugins[7];

    /* Bring in VOP flags from ffmpeg command-line */

    x->vop_flags = XVID_VOP_HALFPEL; /* Bare minimum quality */

    if( xvid_flags & CODEC_FLAG_4MV )

        x->vop_flags |= XVID_VOP_INTER4V; /* Level 3 */

    if( avctx->trellis

        )

        x->vop_flags |= XVID_VOP_TRELLISQUANT; /* Level 5 */

    if( xvid_flags & CODEC_FLAG_AC_PRED )

        x->vop_flags |= XVID_VOP_HQACPRED; /* Level 6 */

    if( xvid_flags & CODEC_FLAG_GRAY )

        x->vop_flags |= XVID_VOP_GREYSCALE;

    /* Decide which ME quality setting to use */

    x->me_flags = 0;

    switch( avctx->me_method ) {

       case ME_FULL:   /* Quality 6 */

           x->me_flags |=  XVID_ME_EXTSEARCH16

                       |   XVID_ME_EXTSEARCH8;

       case ME_EPZS:   /* Quality 4 */

           x->me_flags |=  XVID_ME_ADVANCEDDIAMOND8

                       |   XVID_ME_HALFPELREFINE8

                       |   XVID_ME_CHROMA_PVOP

                       |   XVID_ME_CHROMA_BVOP;

       case ME_LOG:    /* Quality 2 */

       case ME_PHODS:

       case ME_X1:

           x->me_flags |=  XVID_ME_ADVANCEDDIAMOND16

                       |   XVID_ME_HALFPELREFINE16;

       case ME_ZERO:   /* Quality 0 */

       default:

           break;

    }

    /* Decide how we should decide blocks */

    switch( avctx->mb_decision ) {

       case 2:

           x->vop_flags |= XVID_VOP_MODEDECISION_RD;

           x->me_flags |=  XVID_ME_HALFPELREFINE8_RD

                       |   XVID_ME_QUARTERPELREFINE8_RD

                       |   XVID_ME_EXTSEARCH_RD

                       |   XVID_ME_CHECKPREDICTION_RD;

       case 1:

           if( !(x->vop_flags & XVID_VOP_MODEDECISION_RD) )

               x->vop_flags |= XVID_VOP_FAST_MODEDECISION_RD;

           x->me_flags |=  XVID_ME_HALFPELREFINE16_RD

                       |   XVID_ME_QUARTERPELREFINE16_RD;

       default:

           break;

    }

    /* Bring in VOL flags from ffmpeg command-line */

    x->vol_flags = 0;

    if( xvid_flags & CODEC_FLAG_GMC ) {

        x->vol_flags |= XVID_VOL_GMC;

        x->me_flags |= XVID_ME_GME_REFINE;

    }

    if( xvid_flags & CODEC_FLAG_QPEL ) {

        x->vol_flags |= XVID_VOL_QUARTERPEL;

        x->me_flags |= XVID_ME_QUARTERPELREFINE16;

        if( x->vop_flags & XVID_VOP_INTER4V )

            x->me_flags |= XVID_ME_QUARTERPELREFINE8;

    }

    memset(&xvid_gbl_init, 0, sizeof(xvid_gbl_init));

    xvid_gbl_init.version = XVID_VERSION;

    xvid_gbl_init.debug = 0;

#ifdef ARCH_POWERPC

    /* Xvid's PPC support is borked, use libavcodec to detect */

#ifdef HAVE_ALTIVEC

    if( has_altivec() ) {

        xvid_gbl_init.cpu_flags = XVID_CPU_FORCE | XVID_CPU_ALTIVEC;

    } else

#endif

        xvid_gbl_init.cpu_flags = XVID_CPU_FORCE;

#else

    /* Xvid can detect on x86 */

    xvid_gbl_init.cpu_flags = 0;

#endif

    /* Initialize */

    xvid_global(NULL, XVID_GBL_INIT, &xvid_gbl_init, NULL);

    /* Create the encoder reference */

    memset(&xvid_enc_create, 0, sizeof(xvid_enc_create));

    xvid_enc_create.version = XVID_VERSION;

    /* Store the desired frame size */

    xvid_enc_create.width = x->xsize = avctx->width;

    xvid_enc_create.height = x->ysize = avctx->height;

    /* Xvid can determine the proper profile to use */

    /* xvid_enc_create.profile = XVID_PROFILE_S_L3; */

    /* We don't use zones */

    xvid_enc_create.zones = NULL;

    xvid_enc_create.num_zones = 0;

    xvid_enc_create.num_threads = avctx->thread_count;

    xvid_enc_create.plugins = plugins;

    xvid_enc_create.num_plugins = 0;

    /* Initialize Buffers */

    x->twopassbuffer = NULL;

    x->old_twopassbuffer = NULL;

    x->twopassfile = NULL;

    if( xvid_flags & CODEC_FLAG_PASS1 ) {

        memset(&rc2pass1, 0, sizeof(struct xvid_ff_pass1));

        rc2pass1.version = XVID_VERSION;

        rc2pass1.context = x;

        x->twopassbuffer = av_malloc(BUFFER_SIZE);

        x->old_twopassbuffer = av_malloc(BUFFER_SIZE);

        if( x->twopassbuffer == NULL || x->old_twopassbuffer == NULL ) {

            av_log(avctx, AV_LOG_ERROR,

                "Xvid: Cannot allocate 2-pass log buffers\n");

            return -1;

        }

        x->twopassbuffer[0] = x->old_twopassbuffer[0] = 0;

        plugins[xvid_enc_create.num_plugins].func = xvid_ff_2pass;

        plugins[xvid_enc_create.num_plugins].param = &rc2pass1;

        xvid_enc_create.num_plugins++;

    } else if( xvid_flags & CODEC_FLAG_PASS2 ) {

        memset(&rc2pass2, 0, sizeof(xvid_plugin_2pass2_t));

        rc2pass2.version = XVID_VERSION;

        rc2pass2.bitrate = avctx->bit_rate;

        fd = av_tempfile("xvidff.", &(x->twopassfile));

        if( fd == -1 ) {

            av_log(avctx, AV_LOG_ERROR,

                "Xvid: Cannot write 2-pass pipe\n");

            return -1;

        }

        if( avctx->stats_in == NULL ) {

            av_log(avctx, AV_LOG_ERROR,

                "Xvid: No 2-pass information loaded for second pass\n");

            return -1;

        }

        if( strlen(avctx->stats_in) >

              write(fd, avctx->stats_in, strlen(avctx->stats_in)) ) {

            close(fd);

            av_log(avctx, AV_LOG_ERROR,

                "Xvid: Cannot write to 2-pass pipe\n");

            return -1;

        }

        close(fd);

        rc2pass2.filename = x->twopassfile;

        plugins[xvid_enc_create.num_plugins].func = xvid_plugin_2pass2;

        plugins[xvid_enc_create.num_plugins].param = &rc2pass2;

        xvid_enc_create.num_plugins++;

    } else if( !(xvid_flags & CODEC_FLAG_QSCALE) ) {

        /* Single Pass Bitrate Control! */

        memset(&single, 0, sizeof(xvid_plugin_single_t));

        single.version = XVID_VERSION;

        single.bitrate = avctx->bit_rate;

        plugins[xvid_enc_create.num_plugins].func = xvid_plugin_single;

        plugins[xvid_enc_create.num_plugins].param = &single;

        xvid_enc_create.num_plugins++;

    }

    /* Luminance Masking */

    if( 0.0 != avctx->lumi_masking ) {

        plugins[xvid_enc_create.num_plugins].func = xvid_plugin_lumimasking;

        plugins[xvid_enc_create.num_plugins].param = NULL;

        xvid_enc_create.num_plugins++;

    }

    /* Frame Rate and Key Frames */

    xvid_correct_framerate(avctx);

    xvid_enc_create.fincr = avctx->time_base.num;

    xvid_enc_create.fbase = avctx->time_base.den;

    if( avctx->gop_size > 0 )

        xvid_enc_create.max_key_interval = avctx->gop_size;

    else

        xvid_enc_create.max_key_interval = 240; /* Xvid's best default */

    /* Quants */

    if( xvid_flags & CODEC_FLAG_QSCALE ) x->qscale = 1;

    else x->qscale = 0;

    xvid_enc_create.min_quant[0] = avctx->qmin;

    xvid_enc_create.min_quant[1] = avctx->qmin;

    xvid_enc_create.min_quant[2] = avctx->qmin;

    xvid_enc_create.max_quant[0] = avctx->qmax;

    xvid_enc_create.max_quant[1] = avctx->qmax;

    xvid_enc_create.max_quant[2] = avctx->qmax;

    /* Quant Matrices */

    x->intra_matrix = x->inter_matrix = NULL;

    if( avctx->mpeg_quant )

       x->vol_flags |= XVID_VOL_MPEGQUANT;

    if( (avctx->intra_matrix || avctx->inter_matrix) ) {

       x->vol_flags |= XVID_VOL_MPEGQUANT;

       if( avctx->intra_matrix ) {

           intra = avctx->intra_matrix;

           x->intra_matrix = av_malloc(sizeof(unsigned char) * 64);

       } else

           intra = NULL;

       if( avctx->inter_matrix ) {

           inter = avctx->inter_matrix;

           x->inter_matrix = av_malloc(sizeof(unsigned char) * 64);

       } else

           inter = NULL;

       for( i = 0; i < 64; i++ ) {

           if( intra )

               x->intra_matrix[i] = (unsigned char)intra[i];

           if( inter )

               x->inter_matrix[i] = (unsigned char)inter[i];

       }

    }

    /* Misc Settings */

    xvid_enc_create.frame_drop_ratio = 0;

    xvid_enc_create.global = 0;

    if( xvid_flags & CODEC_FLAG_CLOSED_GOP )

        xvid_enc_create.global |= XVID_GLOBAL_CLOSED_GOP;

    /* Determines which codec mode we are operating in */

    avctx->extradata = NULL;

    avctx->extradata_size = 0;

    if( xvid_flags & CODEC_FLAG_GLOBAL_HEADER ) {

        /* In this case, we are claiming to be MPEG4 */

        x->quicktime_format = 1;

        avctx->codec_id = CODEC_ID_MPEG4;

    } else {

        /* We are claiming to be Xvid */

        x->quicktime_format = 0;

        if(!avctx->codec_tag)

            avctx->codec_tag = ff_get_fourcc("xvid");

    }

    /* Bframes */

    xvid_enc_create.max_bframes = avctx->max_b_frames;

    xvid_enc_create.bquant_offset = 100 * avctx->b_quant_offset;

    xvid_enc_create.bquant_ratio = 100 * avctx->b_quant_factor;

    if( avctx->max_b_frames > 0  && !x->quicktime_format ) xvid_enc_create.global |= XVID_GLOBAL_PACKED;

    /* Create encoder context */

    xerr = xvid_encore(NULL, XVID_ENC_CREATE, &xvid_enc_create, NULL);

    if( xerr ) {

        av_log(avctx, AV_LOG_ERROR, "Xvid: Could not create encoder reference\n");

        return -1;

    }

    x->encoder_handle = xvid_enc_create.handle;

    avctx->coded_frame = &x->encoded_picture;

    return 0;

}

/**

 * Encodes a single frame.

 *

 * @param avctx AVCodecContext pointer to context

 * @param frame Pointer to encoded frame buffer

 * @param buf_size Size of encoded frame buffer

 * @param data Pointer to AVFrame of unencoded frame

 * @return Returns 0 on success, -1 on failure

 */

int ff_xvid_encode_frame(AVCodecContext *avctx,

                         unsigned char *frame, int buf_size, void *data) {

    int xerr, i;

    char *tmp;

    struct xvid_context *x = avctx->priv_data;

    AVFrame *picture = data;

    AVFrame *p = &(x->encoded_picture);

    xvid_enc_frame_t xvid_enc_frame;

    xvid_enc_stats_t xvid_enc_stats;

    /* Start setting up the frame */

    memset(&xvid_enc_frame, 0, sizeof(xvid_enc_frame));

    xvid_enc_frame.version = XVID_VERSION;

    memset(&xvid_enc_stats, 0, sizeof(xvid_enc_stats));

    xvid_enc_stats.version = XVID_VERSION;

    *p = *picture;

    /* Let Xvid know where to put the frame. */

    xvid_enc_frame.bitstream = frame;

    xvid_enc_frame.length = buf_size;

    /* Initialize input image fields */

    if( avctx->pix_fmt != PIX_FMT_YUV420P ) {

        av_log(avctx, AV_LOG_ERROR, "Xvid: Color spaces other than 420p not supported\n");

        return -1;

    }

    xvid_enc_frame.input.csp = XVID_CSP_PLANAR; /* YUV420P */

    for( i = 0; i < 4; i++ ) {

        xvid_enc_frame.input.plane[i] = picture->data[i];

        xvid_enc_frame.input.stride[i] = picture->linesize[i];

    }

    /* Encoder Flags */

    xvid_enc_frame.vop_flags = x->vop_flags;

    xvid_enc_frame.vol_flags = x->vol_flags;

    xvid_enc_frame.motion = x->me_flags;

    xvid_enc_frame.type = XVID_TYPE_AUTO;

    /* Pixel aspect ratio setting */

    if (avctx->sample_aspect_ratio.num < 1 || avctx->sample_aspect_ratio.num > 255 ||

        avctx->sample_aspect_ratio.den < 1 || avctx->sample_aspect_ratio.den > 255) {

        av_log(avctx, AV_LOG_ERROR, "Invalid pixel aspect ratio %i/%i\n",

               avctx->sample_aspect_ratio.num, avctx->sample_aspect_ratio.den);

        return -1;

    }

    xvid_enc_frame.par = XVID_PAR_EXT;

    xvid_enc_frame.par_width  = avctx->sample_aspect_ratio.num;

    xvid_enc_frame.par_height = avctx->sample_aspect_ratio.den;

    /* Quant Setting */

    if( x->qscale ) xvid_enc_frame.quant = picture->quality / FF_QP2LAMBDA;

    else xvid_enc_frame.quant = 0;

    /* Matrices */

    xvid_enc_frame.quant_intra_matrix = x->intra_matrix;

    xvid_enc_frame.quant_inter_matrix = x->inter_matrix;

    /* Encode */

    xerr = xvid_encore(x->encoder_handle, XVID_ENC_ENCODE,

        &xvid_enc_frame, &xvid_enc_stats);

    /* Two-pass log buffer swapping */

    avctx->stats_out = NULL;

    if( x->twopassbuffer ) {

        tmp = x->old_twopassbuffer;

        x->old_twopassbuffer = x->twopassbuffer;

        x->twopassbuffer = tmp;

        x->twopassbuffer[0] = 0;

        if( x->old_twopassbuffer[0] != 0 ) {

            avctx->stats_out = x->old_twopassbuffer;

        }

    }

    if( 0 <= xerr ) {

        p->quality = xvid_enc_stats.quant * FF_QP2LAMBDA;

        if( xvid_enc_stats.type == XVID_TYPE_PVOP )

            p->pict_type = FF_P_TYPE;

        else if( xvid_enc_stats.type == XVID_TYPE_BVOP )

            p->pict_type = FF_B_TYPE;

        else if( xvid_enc_stats.type == XVID_TYPE_SVOP )

            p->pict_type = FF_S_TYPE;

        else

            p->pict_type = FF_I_TYPE;

        if( xvid_enc_frame.out_flags & XVID_KEYFRAME ) {

            p->key_frame = 1;

            if( x->quicktime_format )

                return xvid_strip_vol_header(avctx, frame,

                    xvid_enc_stats.hlength, xerr);

         } else

            p->key_frame = 0;

        return xerr;

    } else {

        av_log(avctx, AV_LOG_ERROR, "Xvid: Encoding Error Occurred: %i\n", xerr);

        return -1;

    }

}

/**

 * Destroys the private context for the encoder.

 * All buffers are freed, and the Xvid encoder context is destroyed.

 *

 * @param avctx AVCodecContext pointer to context

 * @return Returns 0, success guaranteed

 */

av_cold int ff_xvid_encode_close(AVCodecContext *avctx) {

    struct xvid_context *x = avctx->priv_data;

    xvid_encore(x->encoder_handle, XVID_ENC_DESTROY, NULL, NULL);

    if( avctx->extradata != NULL )

        av_free(avctx->extradata);

    if( x->twopassbuffer != NULL ) {

        av_free(x->twopassbuffer);

        av_free(x->old_twopassbuffer);

    }

    if( x->twopassfile != NULL )

        av_free(x->twopassfile);

    if( x->intra_matrix != NULL )

        av_free(x->intra_matrix);

    if( x->inter_matrix != NULL )

        av_free(x->inter_matrix);

    return 0;

}

/**

 * Routine to create a global VO/VOL header for MP4 container.

 * What we do here is extract the header from the Xvid bitstream

 * as it is encoded. We also strip the repeated headers from the

 * bitstream when a global header is requested for MPEG-4 ISO

 * compliance.

 *

 * @param avctx AVCodecContext pointer to context

 * @param frame Pointer to encoded frame data

 * @param header_len Length of header to search

 * @param frame_len Length of encoded frame data

 * @return Returns new length of frame data

 */

int xvid_strip_vol_header(AVCodecContext *avctx,

                  unsigned char *frame,

                  unsigned int header_len,

                  unsigned int frame_len) {

    int vo_len = 0, i;

    for( i = 0; i < header_len - 3; i++ ) {

        if( frame[i] == 0x00 &&

            frame[i+1] == 0x00 &&

            frame[i+2] == 0x01 &&

            frame[i+3] == 0xB6 ) {

            vo_len = i;

            break;

        }

    }

    if( vo_len > 0 ) {

        /* We need to store the header, so extract it */

        if( avctx->extradata == NULL ) {

            avctx->extradata = av_malloc(vo_len);

            memcpy(avctx->extradata, frame, vo_len);

            avctx->extradata_size = vo_len;

        }

        /* Less dangerous now, memmove properly copies the two

           chunks of overlapping data */

        memmove(frame, &(frame[vo_len]), frame_len - vo_len);

        return frame_len - vo_len;

    } else

        return frame_len;

}

/**

 * Routine to correct a possibly erroneous framerate being fed to us.

 * Xvid currently chokes on framerates where the ticks per frame is

 * extremely large. This function works to correct problems in this area

 * by estimating a new framerate and taking the simpler fraction of

 * the two presented.

 *

 * @param avctx Context that contains the framerate to correct.

 */

void xvid_correct_framerate(AVCodecContext *avctx) {

    int frate, fbase;

    int est_frate, est_fbase;

    int gcd;

    float est_fps, fps;

    frate = avctx->time_base.den;

    fbase = avctx->time_base.num;

    gcd = ff_gcd(frate, fbase);

    if( gcd > 1 ) {

        frate /= gcd;

        fbase /= gcd;

    }

    if( frate <= 65000 && fbase <= 65000 ) {

        avctx->time_base.den = frate;

        avctx->time_base.num = fbase;

        return;

    }

    fps = (float)frate / (float)fbase;

    est_fps = roundf(fps * 1000.0) / 1000.0;

    est_frate = (int)est_fps;

    if( est_fps > (int)est_fps ) {

        est_frate = (est_frate + 1) * 1000;

        est_fbase = (int)roundf((float)est_frate / est_fps);

    } else

        est_fbase = 1;

    gcd = ff_gcd(est_frate, est_fbase);

    if( gcd > 1 ) {

        est_frate /= gcd;

        est_fbase /= gcd;

    }

    if( fbase > est_fbase ) {

        avctx->time_base.den = est_frate;

        avctx->time_base.num = est_fbase;

        av_log(avctx, AV_LOG_DEBUG,

            "Xvid: framerate re-estimated: %.2f, %.3f%% correction\n",

            est_fps, (((est_fps - fps)/fps) * 100.0));

    } else {

        avctx->time_base.den = frate;

        avctx->time_base.num = fbase;

    }

}

/*

 * Xvid 2-Pass Kludge Section

 *

 * Xvid's default 2-pass doesn't allow us to create data as we need to, so

 * this section spends time replacing the first pass plugin so we can write

 * statistic information as libavcodec requests in. We have another kludge

 * that allows us to pass data to the second pass in Xvid without a custom

 * rate-control plugin.

 */

/**

 * Initializes the two-pass plugin and context.

 *

 * @param param Input construction parameter structure

 * @param handle Private context handle

 * @return Returns XVID_ERR_xxxx on failure, or 0 on success.

 */

static int xvid_ff_2pass_create(xvid_plg_create_t * param,

                                void ** handle) {

    struct xvid_ff_pass1 *x = (struct xvid_ff_pass1 *)param->param;

    char *log = x->context->twopassbuffer;

    /* Do a quick bounds check */

    if( log == NULL )

        return XVID_ERR_FAIL;

    /* We use snprintf() */

    /* This is because we can safely prevent a buffer overflow */

    log[0] = 0;

    snprintf(log, BUFFER_REMAINING(log),

        "# ffmpeg 2-pass log file, using xvid codec\n");

    snprintf(BUFFER_CAT(log), BUFFER_REMAINING(log),

        "# Do not modify. libxvidcore version: %d.%d.%d\n\n",

        XVID_VERSION_MAJOR(XVID_VERSION),

        XVID_VERSION_MINOR(XVID_VERSION),

        XVID_VERSION_PATCH(XVID_VERSION));

    *handle = x->context;

    return 0;

}

/**

 * Destroys the two-pass plugin context.

 *

 * @param ref Context pointer for the plugin

 * @param param Destrooy context

 * @return Returns 0, success guaranteed

 */

static int xvid_ff_2pass_destroy(struct xvid_context *ref,

                                xvid_plg_destroy_t *param) {

    /* Currently cannot think of anything to do on destruction */

    /* Still, the framework should be here for reference/use */

    if( ref->twopassbuffer != NULL )

        ref->twopassbuffer[0] = 0;

    return 0;

}

/**

 * Enables fast encode mode during the first pass.

 *

 * @param ref Context pointer for the plugin

 * @param param Frame data

 * @return Returns 0, success guaranteed

 */

static int xvid_ff_2pass_before(struct xvid_context *ref,

                                xvid_plg_data_t *param) {

    int motion_remove;

    int motion_replacements;

    int vop_remove;

    /* Nothing to do here, result is changed too much */

    if( param->zone && param->zone->mode == XVID_ZONE_QUANT )

        return 0;

    /* We can implement a 'turbo' first pass mode here */

    param->quant = 2;

    /* Init values */

    motion_remove = ~XVID_ME_CHROMA_PVOP &

                    ~XVID_ME_CHROMA_BVOP &

                    ~XVID_ME_EXTSEARCH16 &

                    ~XVID_ME_ADVANCEDDIAMOND16;

    motion_replacements = XVID_ME_FAST_MODEINTERPOLATE |

                          XVID_ME_SKIP_DELTASEARCH |

                          XVID_ME_FASTREFINE16 |

                          XVID_ME_BFRAME_EARLYSTOP;

    vop_remove = ~XVID_VOP_MODEDECISION_RD &

                 ~XVID_VOP_FAST_MODEDECISION_RD &

                 ~XVID_VOP_TRELLISQUANT &

                 ~XVID_VOP_INTER4V &

                 ~XVID_VOP_HQACPRED;

    param->vol_flags &= ~XVID_VOL_GMC;

    param->vop_flags &= vop_remove;

    param->motion_flags &= motion_remove;

    param->motion_flags |= motion_replacements;

    return 0;

}

/**

 * Captures statistic data and writes it during first pass.

 *

 * @param ref Context pointer for the plugin

 * @param param Statistic data

 * @return Returns XVID_ERR_xxxx on failure, or 0 on success

 */

static int xvid_ff_2pass_after(struct xvid_context *ref,

                                xvid_plg_data_t *param) {

    char *log = ref->twopassbuffer;

    char *frame_types = " ipbs";

    char frame_type;

    /* Quick bounds check */

    if( log == NULL )

        return XVID_ERR_FAIL;

    /* Convert the type given to us into a character */

    if( param->type < 5 && param->type > 0 ) {

        frame_type = frame_types[param->type];

    } else {

        return XVID_ERR_FAIL;

    }

    snprintf(BUFFER_CAT(log), BUFFER_REMAINING(log),

        "%c %d %d %d %d %d %d\n",

        frame_type, param->stats.quant, param->stats.kblks, param->stats.mblks,

        param->stats.ublks, param->stats.length, param->stats.hlength);

    return 0;

}

/**

 * Dispatch function for our custom plugin.

 * This handles the dispatch for the Xvid plugin. It passes data

 * on to other functions for actual processing.

 *

 * @param ref Context pointer for the plugin

 * @param cmd The task given for us to complete

 * @param p1 First parameter (varies)

 * @param p2 Second parameter (varies)

 * @return Returns XVID_ERR_xxxx on failure, or 0 on success

 */

int xvid_ff_2pass(void *ref, int cmd, void *p1, void *p2) {

    switch( cmd ) {

        case XVID_PLG_INFO:

        case XVID_PLG_FRAME:

            return 0;

        case XVID_PLG_BEFORE:

            return xvid_ff_2pass_before(ref, p1);

        case XVID_PLG_CREATE:

            return xvid_ff_2pass_create(p1, p2);

        case XVID_PLG_AFTER:

            return xvid_ff_2pass_after(ref, p1);

        case XVID_PLG_DESTROY:

            return xvid_ff_2pass_destroy(ref, p1);

        default:

            return XVID_ERR_FAIL;

    }

}

/**

 * Xvid codec definition for libavcodec.

 */

AVCodec libxvid_encoder = {

    "libxvid",

    CODEC_TYPE_VIDEO,

    CODEC_ID_XVID,

    sizeof(struct xvid_context),

    ff_xvid_encode_init,

    ff_xvid_encode_frame,

    ff_xvid_encode_close,

    .pix_fmts= (enum PixelFormat[]){PIX_FMT_YUV420P, PIX_FMT_NONE},

    .long_name= NULL_IF_CONFIG_SMALL("libxvidcore MPEG-4 part 2"),

};