~ppsspp/ppsspp/ffmpeg-upstream

/*

 * 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

 * Interface to xvidcore for MPEG-4 compliant encoding.

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

 */

#include <xvid.h>

#include "libavutil/cpu.h"

#include "libavutil/file.h"

#include "libavutil/intreadwrite.h"

#include "libavutil/mathematics.h"

#include "avcodec.h"

#include "internal.h"

#include "libxvid.h"

#include "mpegvideo.h"

#if HAVE_UNISTD_H

#include <unistd.h>

#endif

#if HAVE_IO_H

#include <io.h>

#endif

/**

 * Buffer management macros.

 */

#define BUFFER_SIZE         1024

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

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

/**

 * Structure for the private Xvid context.

 * This stores all the private context for the codec.

 */

struct xvid_context {

    AVClass *class;

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

    int xsize;                     /**< Frame x size */

    int ysize;                     /**< Frame y 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? */

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

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

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

    int twopassfd;

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

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

    int lumi_aq;                   /**< Lumi masking as an aq method */

    int variance_aq;               /**< Variance adaptive quantization */

    int ssim;                      /**< SSIM information display mode */

    int ssim_acc;                  /**< SSIM accuracy. 0: accurate. 4: fast. */

    int gmc;

};

/**

 * Structure for the private first-pass plugin.

 */

struct xvid_ff_pass1 {

    int version;                    /**< Xvid version */

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

};

static int xvid_encode_close(AVCodecContext *avctx);

/*

 * 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.

 */

/**

 * Initialize 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)

        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;

}

/**

 * Destroy 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)

        ref->twopassbuffer[0] = 0;

    return 0;

}

/**

 * Enable 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;

}

/**

 * Capture statistic data and write 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;

    const char *frame_types = " ipbs";

    char frame_type;

    /* Quick bounds check */

    if (!log)

        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

 */

static 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;

    }

}

/**

 * 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

 */

static int xvid_strip_vol_header(AVCodecContext *avctx, AVPacket *pkt,

                                 unsigned int header_len,

                                 unsigned int frame_len)

{

    int vo_len = 0, i;

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

        if (pkt->data[i]     == 0x00 &&

            pkt->data[i + 1] == 0x00 &&

            pkt->data[i + 2] == 0x01 &&

            pkt->data[i + 3] == 0xB6) {

            vo_len = i;

            break;

        }

    }

    if (vo_len > 0) {

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

        if (!avctx->extradata) {

            avctx->extradata = av_malloc(vo_len);

            if (!avctx->extradata)

                return AVERROR(ENOMEM);

            memcpy(avctx->extradata, pkt->data, vo_len);

            avctx->extradata_size = vo_len;

        }

        /* Less dangerous now, memmove properly copies the two

         * chunks of overlapping data */

        memmove(pkt->data, &pkt->data[vo_len], frame_len - vo_len);

        pkt->size = frame_len - vo_len;

    }

    return 0;

}

/**

 * 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.

 */

static 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 = av_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 = av_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;

    }

}

static av_cold int xvid_encode_init(AVCodecContext *avctx)

{

    int xerr, i, ret = -1;

    int xvid_flags = avctx->flags;

    struct xvid_context *x = avctx->priv_data;

    uint16_t *intra, *inter;

    int fd;

    xvid_plugin_single_t      single          = { 0 };

    struct xvid_ff_pass1      rc2pass1        = { 0 };

    xvid_plugin_2pass2_t      rc2pass2        = { 0 };

    xvid_plugin_lumimasking_t masking_l       = { 0 }; /* For lumi masking */

    xvid_plugin_lumimasking_t masking_v       = { 0 }; /* For variance AQ */

    xvid_plugin_ssim_t        ssim            = { 0 };

    xvid_gbl_init_t           xvid_gbl_init   = { 0 };

    xvid_enc_create_t         xvid_enc_create = { 0 };

    xvid_enc_plugin_t         plugins[4];

    x->twopassfd = -1;

    /* 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 */

#if FF_API_GMC

    if (avctx->flags & CODEC_FLAG_GMC)

        x->gmc = 1;

#endif

    x->vol_flags = 0;

    if (x->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;

    }

    xvid_gbl_init.version   = XVID_VERSION;

    xvid_gbl_init.debug     = 0;

    xvid_gbl_init.cpu_flags = 0;

    /* Initialize */

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

    /* Create the encoder reference */

    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;

#if (XVID_VERSION <= 0x010303) && (XVID_VERSION >= 0x010300)

    /* workaround for a bug in libxvidcore */

    if (avctx->height <= 16) {

        if (avctx->thread_count < 2) {

            xvid_enc_create.num_threads = 0;

        } else {

            av_log(avctx, AV_LOG_ERROR,

                   "Too small height for threads > 1.");

            return AVERROR(EINVAL);

        }

    }

#endif

    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) {

        rc2pass1.version     = XVID_VERSION;

        rc2pass1.context     = x;

        x->twopassbuffer     = av_malloc(BUFFER_SIZE);

        x->old_twopassbuffer = av_malloc(BUFFER_SIZE);

        if (!x->twopassbuffer || !x->old_twopassbuffer) {

            av_log(avctx, AV_LOG_ERROR,

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

            return AVERROR(ENOMEM);

        }

        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) {

        rc2pass2.version = XVID_VERSION;

        rc2pass2.bitrate = avctx->bit_rate;

        fd = av_tempfile("xvidff.", &x->twopassfile, 0, avctx);

        if (fd < 0) {

            av_log(avctx, AV_LOG_ERROR, "Xvid: Cannot write 2-pass pipe\n");

            return fd;

        }

        x->twopassfd = fd;

        if (!avctx->stats_in) {

            av_log(avctx, AV_LOG_ERROR,

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

            return AVERROR(EINVAL);

        }

        ret = write(fd, avctx->stats_in, strlen(avctx->stats_in));

        if (ret == -1)

            ret = AVERROR(errno);

        else if (strlen(avctx->stats_in) > ret) {

            av_log(avctx, AV_LOG_ERROR, "Xvid: Cannot write to 2-pass pipe\n");

            ret = AVERROR(EIO);

        }

        if (ret < 0)

            return ret;

        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! */

        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++;

    }

    if (avctx->lumi_masking != 0.0)

        x->lumi_aq = 1;

    /* Luminance Masking */

    if (x->lumi_aq) {

        masking_l.method                          = 0;

        plugins[xvid_enc_create.num_plugins].func = xvid_plugin_lumimasking;

        /* The old behavior is that when avctx->lumi_masking is specified,

         * plugins[...].param = NULL. Trying to keep the old behavior here. */

        plugins[xvid_enc_create.num_plugins].param =

            avctx->lumi_masking ? NULL : &masking_l;

        xvid_enc_create.num_plugins++;

    }

    /* Variance AQ */

    if (x->variance_aq) {

        masking_v.method                           = 1;

        plugins[xvid_enc_create.num_plugins].func  = xvid_plugin_lumimasking;

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

        xvid_enc_create.num_plugins++;

    }

    if (x->lumi_aq && x->variance_aq )

        av_log(avctx, AV_LOG_INFO,

               "Both lumi_aq and variance_aq are enabled. The resulting quality"

               "will be the worse one of the two effects made by the AQ.\n");

    /* SSIM */

    if (x->ssim) {

        plugins[xvid_enc_create.num_plugins].func  = xvid_plugin_ssim;

        ssim.b_printstat                           = x->ssim == 2;

        ssim.acc                                   = x->ssim_acc;

        ssim.cpu_flags                             = xvid_gbl_init.cpu_flags;

        ssim.b_visualize                           = 0;

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

        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);

            if (!x->intra_matrix)

                return AVERROR(ENOMEM);

        } else

            intra = NULL;

        if (avctx->inter_matrix) {

            inter           = avctx->inter_matrix;

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

            if (!x->inter_matrix)

                return AVERROR(ENOMEM);

        } 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     = AV_CODEC_ID_MPEG4;

    } else {

        /* We are claiming to be Xvid */

        x->quicktime_format = 0;

        if (!avctx->codec_tag)

            avctx->codec_tag = AV_RL32("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;

    av_assert0(xvid_enc_create.num_plugins + (!!x->ssim) + (!!x->variance_aq) + (!!x->lumi_aq) <= FF_ARRAY_ELEMS(plugins));

    /* 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 AVERROR_EXTERNAL;

    }

    x->encoder_handle  = xvid_enc_create.handle;

    avctx->coded_frame = av_frame_alloc();

    if (!avctx->coded_frame)

        return AVERROR(ENOMEM);

    return 0;

}

static int xvid_encode_frame(AVCodecContext *avctx, AVPacket *pkt,

                             const AVFrame *picture, int *got_packet)

{

    int xerr, i, ret, user_packet = !!pkt->data;

    struct xvid_context *x = avctx->priv_data;

    AVFrame *p             = avctx->coded_frame;

    int mb_width  = (avctx->width  + 15) / 16;

    int mb_height = (avctx->height + 15) / 16;

    char *tmp;

    xvid_enc_frame_t xvid_enc_frame = { 0 };

    xvid_enc_stats_t xvid_enc_stats = { 0 };

    if ((ret = ff_alloc_packet2(avctx, pkt, mb_width*(int64_t)mb_height*MAX_MB_BYTES + FF_MIN_BUFFER_SIZE)) < 0)

        return ret;

    /* Start setting up the frame */

    xvid_enc_frame.version = XVID_VERSION;

    xvid_enc_stats.version = XVID_VERSION;

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

    xvid_enc_frame.bitstream = pkt->data;

    xvid_enc_frame.length    = pkt->size;

    /* Initialize input image fields */

    if (avctx->pix_fmt != AV_PIX_FMT_YUV420P) {

        av_log(avctx, AV_LOG_ERROR,

               "Xvid: Color spaces other than 420P not supported\n");

        return AVERROR(EINVAL);

    }

    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      =

        picture->pict_type == AV_PICTURE_TYPE_I ? XVID_TYPE_IVOP :

        picture->pict_type == AV_PICTURE_TYPE_P ? XVID_TYPE_PVOP :

        picture->pict_type == AV_PICTURE_TYPE_B ? XVID_TYPE_BVOP :

                                                  XVID_TYPE_AUTO;

    /* Pixel aspect ratio setting */

    if (avctx->sample_aspect_ratio.num < 0 || avctx->sample_aspect_ratio.num > 255 ||

        avctx->sample_aspect_ratio.den < 0 || avctx->sample_aspect_ratio.den > 255) {

        av_log(avctx, AV_LOG_WARNING,

               "Invalid pixel aspect ratio %i/%i, limit is 255/255 reducing\n",

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

        av_reduce(&avctx->sample_aspect_ratio.num, &avctx->sample_aspect_ratio.den,

                   avctx->sample_aspect_ratio.num,  avctx->sample_aspect_ratio.den, 255);

    }

    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;

        }

    }