utils.c

来自「linux下的MPEG1」· C语言 代码 · 共 1,355 行 · 第 1/5 页

        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);
        goto end;
    }

    avctx->codec = codec;
    avctx->codec_id = codec->id;
    avctx->frame_number = 0;
    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 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 then minimum size\n");
        return -1;
    }
    if((avctx->codec->capabilities & CODEC_CAP_DELAY) || samples){
        int ret = avctx->codec->encode(avctx, buf, buf_size, (void *)samples);
        avctx->frame_number++;
        return ret;
    }else
        return 0;
}

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

/**
 * decode a frame.
 * @param buf bitstream buffer, must be FF_INPUT_BUFFER_PADDING_SIZE larger then the actual read bytes
 * because some optimized bitstream readers read 32 or 64 bit at once and could read over the end
 * @param buf_size the size of the buffer in bytes
 * @param got_picture_ptr zero if no frame could be decompressed, Otherwise, it is non zero
 * @return -1 if error, otherwise return the number of
 * bytes used.
 */
int avcodec_decode_video(AVCodecContext *avctx, AVFrame *picture,
                         int *got_picture_ptr,
                         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;
}

/* 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_audio2(AVCodecContext *avctx, int16_t *samples,
                         int *frame_size_ptr,
                         uint8_t *buf, int buf_size)
{
    int ret;

    //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 then 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) ||
       *frame_size_ptr < buf_size){
        av_log(avctx, AV_LOG_ERROR, "buffer too small\n");
        return -1;
    }
    if((avctx->codec->capabilities & CODEC_CAP_DELAY) || buf_size){
        ret = avctx->codec->decode(avctx, samples, frame_size_ptr,
                                buf, buf_size);
        avctx->frame_number++;
    }else{
        ret= 0;
        *frame_size_ptr=0;
    }
    return ret;
}

#if LIBAVCODEC_VERSION_INT < ((52<<16)+(0<<8)+0)
int avcodec_decode_audio(AVCodecContext *avctx, int16_t *samples,
                         int *frame_size_ptr,
                         uint8_t *buf, int buf_size){
    *frame_size_ptr= AVCODEC_MAX_AUDIO_FRAME_SIZE;
    return avcodec_decode_audio2(avctx, samples, frame_size_ptr, buf, buf_size);
}
#endif


/* decode a subtitle message. return -1 if error, otherwise return the
   *number of bytes used. If no subtitle could be decompressed,
   *got_sub_ptr is zero. Otherwise, the subtitle is stored in *sub. */
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,
                               (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 (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;

    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;
    }