utils.c

Trolltech公司发布的图形界面操作系统。可在qt-embedded-2.3.7平台上编译为嵌入式图形界面操作系统。

/*
 * utils for libavcodec
 * Copyright (c) 2001 Fabrice Bellard.
 *
 * This library 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 of the License, or (at your option) any later version.
 *
 * This library 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 library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"

void *av_mallocz(unsigned int size)
{
    void *ptr;
    ptr = av_malloc(size);
    if (!ptr)
        return NULL;
    memset(ptr, 0, size);
    return ptr;
}

/* cannot call it directly because of 'void **' casting is not automatic */
void __av_freep(void **ptr)
{
    av_free(*ptr);
    *ptr = NULL;
}

/* encoder management */
AVCodec *first_avcodec;

void register_avcodec(AVCodec *format)
{
    AVCodec **p;
    p = &first_avcodec;
    while (*p != NULL) p = &(*p)->next;
    *p = format;
    format->next = NULL;
}

void avcodec_get_context_defaults(AVCodecContext *s){
    s->bit_rate= 800*1000;
    s->bit_rate_tolerance= s->bit_rate*10;
    s->qmin= 2;
    s->qmax= 31;
    s->rc_eq= "tex^qComp";
    s->qcompress= 0.5;
    s->max_qdiff= 3;
    s->b_quant_factor=1.25;
    s->b_quant_offset=1.25;
    s->i_quant_factor=-0.8;
    s->i_quant_offset=0.0;
    s->error_concealment= 3;
    s->error_resilience= 1;
    s->workaround_bugs= FF_BUG_AUTODETECT;
    s->frame_rate = 25 * FRAME_RATE_BASE;
    s->gop_size= 50;
    s->me_method= ME_EPZS;
}

/**
 * allocates a AVCodecContext and set it to defaults.
 * this can be deallocated by simply calling free() 
 */
AVCodecContext *avcodec_alloc_context(void){
    AVCodecContext *avctx= av_mallocz(sizeof(AVCodecContext));
    
    if(avctx==NULL) return NULL;
    
    avcodec_get_context_defaults(avctx);
    
    return avctx;
}

int avcodec_open(AVCodecContext *avctx, AVCodec *codec)
{
    int ret;

    avctx->codec = codec;
    avctx->frame_number = 0;
    if (codec->priv_data_size > 0) {
        avctx->priv_data = av_mallocz(codec->priv_data_size);
        if (!avctx->priv_data) 
            return -ENOMEM;
    } else {
        avctx->priv_data = NULL;
    }
    ret = avctx->codec->init(avctx);
    if (ret < 0) {
        av_freep(&avctx->priv_data);
        return ret;
    }
    return 0;
}

int avcodec_encode_audio(AVCodecContext *avctx, UINT8 *buf, int buf_size, 
                         const short *samples)
{
    int ret;

    ret = avctx->codec->encode(avctx, buf, buf_size, (void *)samples);
    avctx->frame_number++;
    return ret;
}

int avcodec_encode_video(AVCodecContext *avctx, UINT8 *buf, int buf_size, 
                         const AVPicture *pict)
{
    int ret;

    ret = avctx->codec->encode(avctx, buf, buf_size, (void *)pict);
    
    emms_c(); //needed to avoid a emms_c() call before every return;

    avctx->frame_number++;
    return ret;
}

/* decode a frame. return -1 if error, otherwise return the number of
   bytes used. If no frame could be decompressed, *got_picture_ptr is
   zero. Otherwise, it is non zero */
int avcodec_decode_video(AVCodecContext *avctx, AVPicture *picture, 
                         int *got_picture_ptr,
                         UINT8 *buf, int buf_size)
{
    int ret;

    ret = avctx->codec->decode(avctx, picture, got_picture_ptr, 
                               buf, buf_size);

    emms_c(); //needed to avoid a emms_c() call before every return;

    if (*got_picture_ptr)                           
        avctx->frame_number++;
    return ret;
}

/* decode an audio frame. return -1 if error, otherwise return the
   *number of bytes used. If no frame could be decompressed,
   *frame_size_ptr is zero. Otherwise, it is the decompressed frame
   *size in BYTES. */
int avcodec_decode_audio(AVCodecContext *avctx, INT16 *samples, 
                         int *frame_size_ptr,
                         UINT8 *buf, int buf_size)
{
    int ret;

    ret = avctx->codec->decode(avctx, samples, frame_size_ptr, 
                               buf, buf_size);
    avctx->frame_number++;
    return ret;
}

int avcodec_close(AVCodecContext *avctx)
{
    if (avctx->codec->close)
        avctx->codec->close(avctx);
    av_freep(&avctx->priv_data);
    avctx->codec = NULL;
    return 0;
}

AVCodec *avcodec_find_encoder(enum CodecID id)
{
    AVCodec *p;
    p = first_avcodec;
    while (p) {
        if (p->encode != NULL && p->id == id)
            return p;
        p = p->next;
    }
    return NULL;
}

AVCodec *avcodec_find_encoder_by_name(const char *name)
{
    AVCodec *p;
    p = first_avcodec;
    while (p) {
        if (p->encode != NULL && strcmp(name,p->name) == 0)
            return p;
        p = p->next;
    }
    return NULL;
}

AVCodec *avcodec_find_decoder(enum CodecID id)
{
    AVCodec *p;
    p = first_avcodec;
    while (p) {
        if (p->decode != NULL && p->id == id)
            return p;
        p = p->next;
    }
    return NULL;
}

AVCodec *avcodec_find_decoder_by_name(const char *name)
{
    AVCodec *p;
    p = first_avcodec;
    while (p) {
        if (p->decode != NULL && strcmp(name,p->name) == 0)
            return p;
        p = p->next;
    }
    return NULL;
}

AVCodec *avcodec_find(enum CodecID id)
{
    AVCodec *p;
    p = first_avcodec;
    while (p) {
        if (p->id == id)
            return p;
        p = p->next;
    }
    return NULL;
}

const char *pix_fmt_str[] = {
    "yuv420p",
    "yuv422",
    "rgb24",
    "bgr24",
    "yuv422p",
    "yuv444p",
    "rgba32",
    "bgra32",
    "yuv410p",
    "yuv411p",
};

void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode)
{
    const char *codec_name;
    AVCodec *p;
    char buf1[32];
    char channels_str[100];
    int bitrate;

    if (encode)
        p = avcodec_find_encoder(enc->codec_id);
    else
        p = avcodec_find_decoder(enc->codec_id);

    if (p) {
        codec_name = p->name;
    } else if (enc->codec_name[0] != '\0') {
        codec_name = enc->codec_name;
    } else {
        /* output avi tags */
        if (enc->codec_type == CODEC_TYPE_VIDEO) {
            snprintf(buf1, sizeof(buf1), "%c%c%c%c", 
                     enc->codec_tag & 0xff,
                     (enc->codec_tag >> 8) & 0xff,
                     (enc->codec_tag >> 16) & 0xff,
                     (enc->codec_tag >> 24) & 0xff);
        } else {
            snprintf(buf1, sizeof(buf1), "0x%04x", enc->codec_tag);
        }
        codec_name = buf1;
    }

    switch(enc->codec_type) {
    case CODEC_TYPE_VIDEO:
        snprintf(buf, buf_size,
                 "Video: %s%s",
                 codec_name, enc->flags & CODEC_FLAG_HQ ? " (hq)" : "");
        if (enc->codec_id == CODEC_ID_RAWVIDEO) {
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     ", %s",
                     pix_fmt_str[enc->pix_fmt]);
        }
        if (enc->width) {
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     ", %dx%d, %0.2f fps",
                     enc->width, enc->height, 
                     (float)enc->frame_rate / FRAME_RATE_BASE);
        }
        if (encode) {
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     ", q=%d-%d", enc->qmin, enc->qmax);
        }
        bitrate = enc->bit_rate;
        break;
    case CODEC_TYPE_AUDIO:
        snprintf(buf, buf_size,
                 "Audio: %s",
                 codec_name);
        switch (enc->channels) {
            case 1:
                strcpy(channels_str, "mono");
                break;
            case 2:
                strcpy(channels_str, "stereo");
                break;
            case 6:
                strcpy(channels_str, "5:1");
                break;
            default:
                sprintf(channels_str, "%d channels", enc->channels);
                break;
        }
        if (enc->sample_rate) {
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     ", %d Hz, %s",
                     enc->sample_rate,
                     channels_str);
        }
        
        /* for PCM codecs, compute bitrate directly */
        switch(enc->codec_id) {
        case CODEC_ID_PCM_S16LE:
        case CODEC_ID_PCM_S16BE:
        case CODEC_ID_PCM_U16LE:
        case CODEC_ID_PCM_U16BE:
            bitrate = enc->sample_rate * enc->channels * 16;
            break;
        case CODEC_ID_PCM_S8:
        case CODEC_ID_PCM_U8:
        case CODEC_ID_PCM_ALAW:
        case CODEC_ID_PCM_MULAW:
            bitrate = enc->sample_rate * enc->channels * 8;
            break;
        default:
            bitrate = enc->bit_rate;
            break;
        }
        break;
    default:
        av_abort();
    }
    if (encode) {
        if (enc->flags & CODEC_FLAG_PASS1)
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     ", pass 1");
        if (enc->flags & CODEC_FLAG_PASS2)
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     ", pass 2");
    }
    if (bitrate != 0) {
        snprintf(buf + strlen(buf), buf_size - strlen(buf), 
                 ", %d kb/s", bitrate / 1000);
    }
}

/* Picture field are filled with 'ptr' addresses */
void avpicture_fill(AVPicture *picture, UINT8 *ptr,
                    int pix_fmt, int width, int height)
{
    int size;

    size = width * height;
    switch(pix_fmt) {
    case PIX_FMT_YUV420P:
        picture->data[0] = ptr;
        picture->data[1] = picture->data[0] + size;
        picture->data[2] = picture->data[1] + size / 4;
        picture->linesize[0] = width;
        picture->linesize[1] = width / 2;
        picture->linesize[2] = width / 2;
        break;
    case PIX_FMT_YUV422P:
        picture->data[0] = ptr;
        picture->data[1] = picture->data[0] + size;
        picture->data[2] = picture->data[1] + size / 2;
        picture->linesize[0] = width;
        picture->linesize[1] = width / 2;
        picture->linesize[2] = width / 2;
        break;
    case PIX_FMT_YUV444P:
        picture->data[0] = ptr;
        picture->data[1] = picture->data[0] + size;
        picture->data[2] = picture->data[1] + size;
        picture->linesize[0] = width;
        picture->linesize[1] = width;
        picture->linesize[2] = width;
        break;
    case PIX_FMT_RGB24:
    case PIX_FMT_BGR24:
        picture->data[0] = ptr;
        picture->data[1] = NULL;
        picture->data[2] = NULL;
        picture->linesize[0] = width * 3;
        break;
    case PIX_FMT_RGBA32:
    case PIX_FMT_BGRA32:
        picture->data[0] = ptr;
        picture->data[1] = NULL;
        picture->data[2] = NULL;
        picture->linesize[0] = width * 4;
        break;
    case PIX_FMT_YUV422:
        picture->data[0] = ptr;
        picture->data[1] = NULL;
        picture->data[2] = NULL;
        picture->linesize[0] = width * 2;
        break;
    default:
        picture->data[0] = NULL;
        picture->data[1] = NULL;
        picture->data[2] = NULL;
        break;
    }
}

int avpicture_get_size(int pix_fmt, int width, int height)
{
    int size;

    size = width * height;
    switch(pix_fmt) {
    case PIX_FMT_YUV420P:
        size = (size * 3) / 2;
        break;
    case PIX_FMT_YUV422P:
        size = (size * 2);
        break;
    case PIX_FMT_YUV444P:
        size = (size * 3);
        break;
    case PIX_FMT_RGB24:
    case PIX_FMT_BGR24:
        size = (size * 3);
        break;
    case PIX_FMT_RGBA32:
    case PIX_FMT_BGRA32:
        size = (size * 4);
        break;
    case PIX_FMT_YUV422:
        size = (size * 2);
        break;
    default:
        size = -1;
        break;
    }
    return size;
}

unsigned avcodec_version( void )
{
  return LIBAVCODEC_VERSION_INT;
}

unsigned avcodec_build( void )
{
  return LIBAVCODEC_BUILD;
}

/* must be called before any other functions */
void avcodec_init(void)
{
    static int inited = 0;

    if (inited != 0)
	return;
    inited = 1;

    //dsputil_init();
}

/* this should be called after seeking and before trying to decode the next frame */
void avcodec_flush_buffers(AVCodecContext *avctx)
{
    MpegEncContext *s = avctx->priv_data;
    s->num_available_buffers=0;
}


static int raw_encode_init(AVCodecContext *s)
{
    return 0;
}

static int raw_decode_frame(AVCodecContext *avctx,
			    void *data, int *data_size,
			    UINT8 *buf, int buf_size)
{
    return -1;
}

static int raw_encode_frame(AVCodecContext *avctx,
			    unsigned char *frame, int buf_size, void *data)
{
    return -1;
}

AVCodec rawvideo_codec = {
    "rawvideo",
    CODEC_TYPE_VIDEO,
    CODEC_ID_RAWVIDEO,
    0,
    raw_encode_init,
    raw_encode_frame,
    NULL,
    raw_decode_frame,
};