utils.c

    ret = avctx->codec->decode(avctx, sub, got_sub_ptr,
                               (uint8_t *)buf, buf_size);
    if (*got_sub_ptr)
        avctx->frame_number++;
    return ret;
}

int avcodec_close(AVCodecContext *avctx)
{
    entangled_thread_counter++;
    if(entangled_thread_counter != 1){
        av_log(avctx, AV_LOG_ERROR, "insufficient thread locking around avcodec_open/close()\n");
        entangled_thread_counter--;
        return -1;
    }

    if (ENABLE_THREADS && avctx->thread_opaque)
        avcodec_thread_free(avctx);
    if (avctx->codec->close)
        avctx->codec->close(avctx);
    avcodec_default_free_buffers(avctx);
    av_freep(&avctx->priv_data);
    avctx->codec = NULL;
    entangled_thread_counter--;
    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;
}

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;
    AVRational display_aspect_ratio;

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

    if (p) {
        codec_name = p->name;
        if (!encode && enc->codec_id == CODEC_ID_MP3) {
            if (enc->sub_id == 2)
                codec_name = "mp2";
            else if (enc->sub_id == 1)
                codec_name = "mp1";
        }
    } else if (enc->codec_id == CODEC_ID_MPEG2TS) {
        /* fake mpeg2 transport stream codec (currently not
           registered) */
        codec_name = "mpeg2ts";
    } else if (enc->codec_name[0] != '\0') {
        codec_name = enc->codec_name;
    } else {
        /* output avi tags */
        if(   isprint(enc->codec_tag&0xFF) && isprint((enc->codec_tag>>8)&0xFF)
           && isprint((enc->codec_tag>>16)&0xFF) && isprint((enc->codec_tag>>24)&0xFF)){
            snprintf(buf1, sizeof(buf1), "%c%c%c%c / 0x%04X",
                     enc->codec_tag & 0xff,
                     (enc->codec_tag >> 8) & 0xff,
                     (enc->codec_tag >> 16) & 0xff,
                     (enc->codec_tag >> 24) & 0xff,
                      enc->codec_tag);
        } 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->mb_decision ? " (hq)" : "");
        if (enc->pix_fmt != PIX_FMT_NONE) {
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     ", %s",
                     avcodec_get_pix_fmt_name(enc->pix_fmt));
        }
        if (enc->width) {
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     ", %dx%d",
                     enc->width, enc->height);
            av_reduce(&display_aspect_ratio.num, &display_aspect_ratio.den,
                      enc->width*enc->sample_aspect_ratio.num,
                      enc->height*enc->sample_aspect_ratio.den,
                      1024*1024);
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     " [PAR %d:%d DAR %d:%d]",
                     enc->sample_aspect_ratio.num, enc->sample_aspect_ratio.den,
                     display_aspect_ratio.num, display_aspect_ratio.den);
            if(av_log_get_level() >= AV_LOG_DEBUG){
                int g= ff_gcd(enc->time_base.num, enc->time_base.den);
                snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     ", %d/%d",
                     enc->time_base.num/g, enc->time_base.den/g);
            }
        }
        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:
                snprintf(channels_str, sizeof(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_S32LE:
        case CODEC_ID_PCM_S32BE:
        case CODEC_ID_PCM_U32LE:
        case CODEC_ID_PCM_U32BE:
            bitrate = enc->sample_rate * enc->channels * 32;
            break;
        case CODEC_ID_PCM_S24LE:
        case CODEC_ID_PCM_S24BE:
        case CODEC_ID_PCM_U24LE:
        case CODEC_ID_PCM_U24BE:
        case CODEC_ID_PCM_S24DAUD:
            bitrate = enc->sample_rate * enc->channels * 24;
            break;
        case CODEC_ID_PCM_S16LE:
        case CODEC_ID_PCM_S16BE:
        case CODEC_ID_PCM_S16LE_PLANAR:
        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;
    case CODEC_TYPE_DATA:
        snprintf(buf, buf_size, "Data: %s", codec_name);
        bitrate = enc->bit_rate;
        break;
    case CODEC_TYPE_SUBTITLE:
        snprintf(buf, buf_size, "Subtitle: %s", codec_name);
        bitrate = enc->bit_rate;
        break;
    default:
        snprintf(buf, buf_size, "Invalid Codec type %d", enc->codec_type);
        return;
    }
    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);
    }
}

unsigned avcodec_version( void )
{
  return LIBAVCODEC_VERSION_INT;
}

unsigned avcodec_build( void )
{
  return LIBAVCODEC_BUILD;
}

static void init_crcs(void){
#if LIBAVUTIL_VERSION_INT  < (50<<16)
    av_crc04C11DB7= av_mallocz_static(sizeof(AVCRC) * 257);
    av_crc8005    = av_mallocz_static(sizeof(AVCRC) * 257);
    av_crc07      = av_mallocz_static(sizeof(AVCRC) * 257);
#endif
    av_crc_init(av_crc04C11DB7, 0, 32, AV_CRC_32_IEEE, sizeof(AVCRC)*257);
    av_crc_init(av_crc8005    , 0, 16, AV_CRC_16     , sizeof(AVCRC)*257);
    av_crc_init(av_crc07      , 0,  8, AV_CRC_8_ATM  , sizeof(AVCRC)*257);
}

void avcodec_init(void)
{
    static int inited = 0;

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

    dsputil_static_init();
    init_crcs();
}

void avcodec_flush_buffers(AVCodecContext *avctx)
{
    if(avctx->codec->flush)
        avctx->codec->flush(avctx);
}

void avcodec_default_free_buffers(AVCodecContext *s){
    int i, j;

    if(s->internal_buffer==NULL) return;

    for(i=0; i<INTERNAL_BUFFER_SIZE; i++){
        InternalBuffer *buf= &((InternalBuffer*)s->internal_buffer)[i];
        for(j=0; j<4; j++){
            av_freep(&buf->base[j]);
            buf->data[j]= NULL;
        }
    }
    av_freep(&s->internal_buffer);

    s->internal_buffer_count=0;
}

char av_get_pict_type_char(int pict_type){
    switch(pict_type){
    case I_TYPE: return 'I';
    case P_TYPE: return 'P';
    case B_TYPE: return 'B';
    case S_TYPE: return 'S';
    case SI_TYPE:return 'i';
    case SP_TYPE:return 'p';
    default:     return '?';
    }
}

int av_get_bits_per_sample(enum CodecID codec_id){
    switch(codec_id){
    case CODEC_ID_ADPCM_SBPRO_2:
        return 2;
    case CODEC_ID_ADPCM_SBPRO_3:
        return 3;
    case CODEC_ID_ADPCM_SBPRO_4:
    case CODEC_ID_ADPCM_CT:
        return 4;
    case CODEC_ID_PCM_ALAW:
    case CODEC_ID_PCM_MULAW:
    case CODEC_ID_PCM_S8:
    case CODEC_ID_PCM_U8:
        return 8;
    case CODEC_ID_PCM_S16BE:
    case CODEC_ID_PCM_S16LE:
    case CODEC_ID_PCM_S16LE_PLANAR:
    case CODEC_ID_PCM_U16BE:
    case CODEC_ID_PCM_U16LE:
        return 16;
    case CODEC_ID_PCM_S24DAUD:
    case CODEC_ID_PCM_S24BE:
    case CODEC_ID_PCM_S24LE:
    case CODEC_ID_PCM_U24BE:
    case CODEC_ID_PCM_U24LE:
        return 24;
    case CODEC_ID_PCM_S32BE:
    case CODEC_ID_PCM_S32LE:
    case CODEC_ID_PCM_U32BE:
    case CODEC_ID_PCM_U32LE:
        return 32;
    default:
        return 0;
    }
}

int av_get_bits_per_sample_format(enum SampleFormat sample_fmt) {
    switch (sample_fmt) {
    case SAMPLE_FMT_U8:
        return 8;
    case SAMPLE_FMT_S16:
        return 16;
    case SAMPLE_FMT_S24:
        return 24;
    case SAMPLE_FMT_S32:
    case SAMPLE_FMT_FLT:
        return 32;
    default:
        return 0;
    }
}

#if !defined(HAVE_THREADS)
int avcodec_thread_init(AVCodecContext *s, int thread_count){
    return -1;
}
#endif

unsigned int av_xiphlacing(unsigned char *s, unsigned int v)
{
    unsigned int n = 0;

    while(v >= 0xff) {
        *s++ = 0xff;
        v -= 0xff;
        n++;
    }
    *s = v;
    n++;
    return n;
}

/* Wrapper to work around the lack of mkstemp() on mingw/cygin.
 * Also, tries to create file in /tmp first, if possible.
 * *prefix can be a character constant; *filename will be allocated internally.
 * Returns file descriptor of opened file (or -1 on error)
 * and opened file name in **filename. */
int av_tempfile(char *prefix, char **filename) {
    int fd=-1;
#if !defined(HAVE_MKSTEMP)
    *filename = tempnam(".", prefix);
#else
    size_t len = strlen(prefix) + 12; /* room for "/tmp/" and "XXXXXX\0" */
    *filename = av_malloc(len);
#endif
    /* -----common section-----*/
    if (*filename == NULL) {
        av_log(NULL, AV_LOG_ERROR, "ff_tempfile: Cannot allocate file name\n");
        return -1;
    }
#if !defined(HAVE_MKSTEMP)
    fd = open(*filename, O_RDWR | O_BINARY | O_CREAT, 0444);
#else
    snprintf(*filename, len, "/tmp/%sXXXXXX", prefix);
    fd = mkstemp(*filename);
    if (fd < 0) {
        snprintf(*filename, len, "./%sXXXXXX", prefix);
        fd = mkstemp(*filename);
    }
#endif
    /* -----common section-----*/
    if (fd < 0) {
        av_log(NULL, AV_LOG_ERROR, "ff_tempfile: Cannot open temporary file %s\n", *filename);
        return -1;
    }
    return fd; /* success */
}

typedef struct {
    const char *abbr;
    int width, height;
} VideoFrameSizeAbbr;

typedef struct {
    const char *abbr;
    int rate_num, rate_den;
} VideoFrameRateAbbr;

static VideoFrameSizeAbbr video_frame_size_abbrs[] = {
    { "ntsc",      720, 480 },
    { "pal",       720, 576 },
    { "qntsc",     352, 240 }, /* VCD compliant NTSC */
    { "qpal",      352, 288 }, /* VCD compliant PAL */
    { "sntsc",     640, 480 }, /* square pixel NTSC */
    { "spal",      768, 576 }, /* square pixel PAL */
    { "film",      352, 240 },
    { "ntsc-film", 352, 240 },
    { "sqcif",     128,  96 },
    { "qcif",      176, 144 },
    { "cif",       352, 288 },
    { "4cif",      704, 576 },
    { "qqvga",     160, 120 },
    { "qvga",      320, 240 },
    { "vga",       640, 480 },
    { "svga",      800, 600 },
    { "xga",      1024, 768 },
    { "uxga",     1600,1200 },
    { "qxga",     2048,1536 },
    { "sxga",     1280,1024 },
    { "qsxga",    2560,2048 },
    { "hsxga",    5120,4096 },
    { "wvga",      852, 480 },
    { "wxga",     1366, 768 },
    { "wsxga",    1600,1024 },
    { "wuxga",    1920,1200 },
    { "woxga",    2560,1600 },
    { "wqsxga",   3200,2048 },
    { "wquxga",   3840,2400 },
    { "whsxga",   6400,4096 },
    { "whuxga",   7680,4800 },
    { "cga",       320, 200 },
    { "ega",       640, 350 },
    { "hd480",     852, 480 },
    { "hd720",    1280, 720 },
    { "hd1080",   1920,1080 },
};

static VideoFrameRateAbbr video_frame_rate_abbrs[]= {
    { "ntsc",      30000, 1001 },
    { "pal",          25,    1 },
    { "qntsc",     30000, 1001 }, /* VCD compliant NTSC */
    { "qpal",         25,    1 }, /* VCD compliant PAL */
    { "sntsc",     30000, 1001 }, /* square pixel NTSC */
    { "spal",         25,    1 }, /* square pixel PAL */
    { "film",         24,    1 },
    { "ntsc-film", 24000, 1001 },
};

int av_parse_video_frame_size(int *width_ptr, int *height_ptr, const char *str)
{
    int i;
    int n = sizeof(video_frame_size_abbrs) / sizeof(VideoFrameSizeAbbr);
    const char *p;
    int frame_width = 0, frame_height = 0;

    for(i=0;i<n;i++) {
        if (!strcmp(video_frame_size_abbrs[i].abbr, str)) {
            frame_width = video_frame_size_abbrs[i].width;
            frame_height = video_frame_size_abbrs[i].height;
            break;
        }
    }
    if (i == n) {
        p = str;
        frame_width = strtol(p, (char **)&p, 10);
        if (*p)
            p++;
        frame_height = strtol(p, (char **)&p, 10);
    }
    if (frame_width <= 0 || frame_height <= 0)
        return -1;
    *width_ptr = frame_width;
    *height_ptr = frame_height;
    return 0;
}

int av_parse_video_frame_rate(AVRational *frame_rate, const char *arg)
{
    int i;
    int n = sizeof(video_frame_rate_abbrs) / sizeof(VideoFrameRateAbbr);
    char* cp;

    /* First, we check our abbreviation table */
    for (i = 0; i < n; ++i)
         if (!strcmp(video_frame_rate_abbrs[i].abbr, arg)) {
             frame_rate->num = video_frame_rate_abbrs[i].rate_num;
             frame_rate->den = video_frame_rate_abbrs[i].rate_den;
             return 0;
         }

    /* Then, we try to parse it as fraction */
    cp = strchr(arg, '/');
    if (!cp)
        cp = strchr(arg, ':');
    if (cp) {
        char* cpp;
        frame_rate->num = strtol(arg, &cpp, 10);
        if (cpp != arg || cpp == cp)
            frame_rate->den = strtol(cp+1, &cpp, 10);
        else
           frame_rate->num = 0;
    }
    else {
        /* Finally we give up and parse it as double */
        AVRational time_base = av_d2q(strtod(arg, 0), DEFAULT_FRAME_RATE_BASE);
        frame_rate->den = time_base.den;
        frame_rate->num = time_base.num;
    }
    if (!frame_rate->num || !frame_rate->den)
        return -1;
    else
        return 0;
}