libxvidff.c

ffmpeg的完整源代码和作者自己写的文档。不但有在Linux的工程哦

/*
 * Interface to xvidcore for mpeg4 encoding
 * Copyright (c) 2004 Adam Thayer <[e-mail]>
 *
 * 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 ([e-mail])
 */

#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 */
#if HAVE_ALTIVEC==1
extern int has_altivec(void);
#endif

/**
 * Structure for the private XviD context.
 * This stores all the private context for the codec.
 */
typedef 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 */
} xvid_context_t;

/**
 * Structure for the private first-pass plugin.
 */
typedef struct xvid_ff_pass1 {
    int     version;                /** XviD version */
    xvid_context_t *context;        /** Pointer to private context */
} xvid_ff_pass1_t;

/* 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
 */
int ff_xvid_encode_init(AVCodecContext *avctx)  {
    int xerr, i;
    int xvid_flags = avctx->flags;
    xvid_context_t *x = avctx->priv_data;
    uint16_t *intra, *inter;
    int fd;

    xvid_plugin_single_t single;
    xvid_ff_pass1_t 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( xvid_flags & CODEC_FLAG_TRELLIS_QUANT)
        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 */
#if HAVE_ALTIVEC==1
    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 or threads */
    xvid_enc_create.zones = NULL;
    xvid_enc_create.num_zones = 0;
    xvid_enc_create.num_threads = 0;

    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(xvid_ff_pass1_t));
        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;
    xvid_context_t *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;