utils.c

播放H264文件的播放器

    s->release_buffer(s, &temp_pic); // Release old frame
    return 0;
}

int avcodec_default_execute(AVCodecContext *c, int (*func)(AVCodecContext *c2, void *arg2),void *arg, int *ret, int count, int size){
    int i;

    for(i=0; i<count; i++){
        int r= func(c, (char*)arg + i*size);
        if(ret) ret[i]= r;
    }
    return 0;
}

enum PixelFormat avcodec_default_get_format(struct AVCodecContext *s, const enum PixelFormat *fmt){
    while (*fmt != PIX_FMT_NONE && ff_is_hwaccel_pix_fmt(*fmt))
        ++fmt;
    return fmt[0];
}

void avcodec_get_frame_defaults(AVFrame *pic){
    memset(pic, 0, sizeof(AVFrame));

    pic->pts= AV_NOPTS_VALUE;
    pic->key_frame= 1;
}

AVFrame *avcodec_alloc_frame(void){
    AVFrame *pic= av_malloc(sizeof(AVFrame));

    if(pic==NULL) return NULL;

    avcodec_get_frame_defaults(pic);

    return pic;
}

int attribute_align_arg avcodec_open(AVCodecContext *avctx, AVCodec *codec)
{
    int ret= -1;

    entangled_thread_counter++;
    if(entangled_thread_counter != 1){
        av_log(avctx, AV_LOG_ERROR, "insufficient thread locking around avcodec_open/close()\n");
        goto end;
    }

    if(avctx->codec || !codec)
        goto end;

    if (codec->priv_data_size > 0) {
        avctx->priv_data = av_mallocz(codec->priv_data_size);
        if (!avctx->priv_data) {
            ret = AVERROR(ENOMEM);
            goto end;
        }
    } else {
        avctx->priv_data = NULL;
    }

    if(avctx->coded_width && avctx->coded_height)
        avcodec_set_dimensions(avctx, avctx->coded_width, avctx->coded_height);
    else if(avctx->width && avctx->height)
        avcodec_set_dimensions(avctx, avctx->width, avctx->height);

    if((avctx->coded_width||avctx->coded_height) && avcodec_check_dimensions(avctx,avctx->coded_width,avctx->coded_height)){
        av_freep(&avctx->priv_data);
        ret = AVERROR(EINVAL);
        goto end;
    }

    avctx->codec = codec;
    avctx->codec_id = codec->id;
    avctx->frame_number = 0;
    if(avctx->codec->init){
        ret = avctx->codec->init(avctx);
        if (ret < 0) {
            av_freep(&avctx->priv_data);
            avctx->codec= NULL;
            goto end;
        }
    }
    ret=0;
end:
    entangled_thread_counter--;
    return ret;
}

int attribute_align_arg avcodec_encode_audio(AVCodecContext *avctx, uint8_t *buf, int buf_size,
                         const short *samples)
{
    if(buf_size < FF_MIN_BUFFER_SIZE && 0){
        av_log(avctx, AV_LOG_ERROR, "buffer smaller than minimum size\n");
        return -1;
    }
    if((avctx->codec->capabilities & CODEC_CAP_DELAY) || samples){
        int ret = avctx->codec->encode(avctx, buf, buf_size, samples);
        avctx->frame_number++;
        return ret;
    }else
        return 0;
}

int attribute_align_arg avcodec_encode_video(AVCodecContext *avctx, uint8_t *buf, int buf_size,
                         const AVFrame *pict)
{
    if(buf_size < FF_MIN_BUFFER_SIZE){
        av_log(avctx, AV_LOG_ERROR, "buffer smaller than minimum size\n");
        return -1;
    }
    if(avcodec_check_dimensions(avctx,avctx->width,avctx->height))
        return -1;
    if((avctx->codec->capabilities & CODEC_CAP_DELAY) || pict){
        int ret = avctx->codec->encode(avctx, buf, buf_size, pict);
        avctx->frame_number++;
        emms_c(); //needed to avoid an emms_c() call before every return;

        return ret;
    }else
        return 0;
}

int avcodec_encode_subtitle(AVCodecContext *avctx, uint8_t *buf, int buf_size,
                            const AVSubtitle *sub)
{
    int ret;
    if(sub->start_display_time) {
        av_log(avctx, AV_LOG_ERROR, "start_display_time must be 0.\n");
        return -1;
    }
    if(sub->num_rects == 0 || !sub->rects)
        return -1;
    ret = avctx->codec->encode(avctx, buf, buf_size, sub);
    avctx->frame_number++;
    return ret;
}

int attribute_align_arg avcodec_decode_video(AVCodecContext *avctx, AVFrame *picture,
                         int *got_picture_ptr,
                         const uint8_t *buf, int buf_size)
{
    int ret;

    *got_picture_ptr= 0;
    if((avctx->coded_width||avctx->coded_height) && avcodec_check_dimensions(avctx,avctx->coded_width,avctx->coded_height))
        return -1;
    if((avctx->codec->capabilities & CODEC_CAP_DELAY) || buf_size){
        ret = avctx->codec->decode(avctx, picture, got_picture_ptr,
                                buf, buf_size);

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

        if (*got_picture_ptr)
            avctx->frame_number++;
    }else
        ret= 0;

    return ret;
}

int attribute_align_arg avcodec_decode_audio2(AVCodecContext *avctx, int16_t *samples,
                         int *frame_size_ptr,
                         const uint8_t *buf, int buf_size)
{
    int ret;

    if((avctx->codec->capabilities & CODEC_CAP_DELAY) || buf_size){
        //FIXME remove the check below _after_ ensuring that all audio check that the available space is enough
        if(*frame_size_ptr < AVCODEC_MAX_AUDIO_FRAME_SIZE){
            av_log(avctx, AV_LOG_ERROR, "buffer smaller than AVCODEC_MAX_AUDIO_FRAME_SIZE\n");
            return -1;
        }
        if(*frame_size_ptr < FF_MIN_BUFFER_SIZE ||
        *frame_size_ptr < avctx->channels * avctx->frame_size * sizeof(int16_t)){
            av_log(avctx, AV_LOG_ERROR, "buffer %d too small\n", *frame_size_ptr);
            return -1;
        }

        ret = avctx->codec->decode(avctx, samples, frame_size_ptr,
                                buf, buf_size);
        avctx->frame_number++;
    }else{
        ret= 0;
        *frame_size_ptr=0;
    }
    return ret;
}

int avcodec_decode_subtitle(AVCodecContext *avctx, AVSubtitle *sub,
                            int *got_sub_ptr,
                            const uint8_t *buf, int buf_size)
{
    int ret;

    *got_sub_ptr = 0;
    ret = avctx->codec->decode(avctx, sub, got_sub_ptr,
                               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 (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;
    if (!name)
        return NULL;
    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;
    if (!name)
        return NULL;
    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];
    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;
    } 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);
            if (enc->sample_aspect_ratio.num) {
                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= av_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);
        if (enc->sample_rate) {
            snprintf(buf + strlen(buf), buf_size - strlen(buf),
                     ", %d Hz", enc->sample_rate);
        }
                
        if (enc->sample_fmt != SAMPLE_FMT_NONE) {
            
        }

        /* for PCM codecs, compute bitrate directly */
        switch(enc->codec_id) {
        case CODEC_ID_PCM_F64BE:
        case CODEC_ID_PCM_F64LE:
            bitrate = enc->sample_rate * enc->channels * 64;
            break;
        case CODEC_ID_PCM_S32LE:
        case CODEC_ID_PCM_S32BE:
        case CODEC_ID_PCM_U32LE:
        case CODEC_ID_PCM_U32BE:
        case CODEC_ID_PCM_F32BE:
        case CODEC_ID_PCM_F32LE:
            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;