C++ put_bits_count函数代码示例

static int encode_superframe(AVCodecContext *avctx, AVPacket *avpkt,
                             const AVFrame *frame, int *got_packet_ptr)
{
    WMACodecContext *s = avctx->priv_data;
    int i, total_gain, ret, error;

    s->block_len_bits = s->frame_len_bits; // required by non variable block len
    s->block_len      = 1 << s->block_len_bits;

    ret = apply_window_and_mdct(avctx, frame);

    if (ret < 0)
        return ret;

    if (s->ms_stereo) {
        float a, b;
        int i;

        for (i = 0; i < s->block_len; i++) {
            a              = s->coefs[0][i] * 0.5;
            b              = s->coefs[1][i] * 0.5;
            s->coefs[0][i] = a + b;
            s->coefs[1][i] = a - b;
        }
    }

    if ((ret = ff_alloc_packet2(avctx, avpkt, 2 * MAX_CODED_SUPERFRAME_SIZE, 0)) < 0)
        return ret;

    total_gain = 128;
    for (i = 64; i; i >>= 1) {
        error = encode_frame(s, s->coefs, avpkt->data, avpkt->size,
                                 total_gain - i);
        if (error <= 0)
            total_gain -= i;
    }

    while(total_gain <= 128 && error > 0)
        error = encode_frame(s, s->coefs, avpkt->data, avpkt->size, total_gain++);
    if (error > 0) {
        av_log(avctx, AV_LOG_ERROR, "Invalid input data or requested bitrate too low, cannot encode\n");
        avpkt->size = 0;
        return AVERROR(EINVAL);
    }
    av_assert0((put_bits_count(&s->pb) & 7) == 0);
    i= avctx->block_align - (put_bits_count(&s->pb)+7)/8;
    av_assert0(i>=0);
    while(i--)
        put_bits(&s->pb, 8, 'N');

    flush_put_bits(&s->pb);
    av_assert0(put_bits_ptr(&s->pb) - s->pb.buf == avctx->block_align);

    if (frame->pts != AV_NOPTS_VALUE)
        avpkt->pts = frame->pts - ff_samples_to_time_base(avctx, avctx->initial_padding);

    avpkt->size     = avctx->block_align;
    *got_packet_ptr = 1;
    return 0;
}

int ff_copy_pce_data(PutBitContext *pb, GetBitContext *gb)
{
    int five_bit_ch, four_bit_ch, comment_size, bits;
    int offset = put_bits_count(pb);

    copy_bits(pb, gb, 10);                  //Tag, Object Type, Frequency
    five_bit_ch  = copy_bits(pb, gb, 4);    //Front
    five_bit_ch += copy_bits(pb, gb, 4);    //Side
    five_bit_ch += copy_bits(pb, gb, 4);    //Back
    four_bit_ch  = copy_bits(pb, gb, 2);    //LFE
    four_bit_ch += copy_bits(pb, gb, 3);    //Data
    five_bit_ch += copy_bits(pb, gb, 4);    //Coupling
    if (copy_bits(pb, gb, 1))               //Mono Mixdown
        copy_bits(pb, gb, 4);
    if (copy_bits(pb, gb, 1))               //Stereo Mixdown
        copy_bits(pb, gb, 4);
    if (copy_bits(pb, gb, 1))               //Matrix Mixdown
        copy_bits(pb, gb, 3);
    for (bits = five_bit_ch*5+four_bit_ch*4; bits > 16; bits -= 16)
        copy_bits(pb, gb, 16);
    if (bits)
        copy_bits(pb, gb, bits);
    align_put_bits(pb);
    align_get_bits(gb);
    comment_size = copy_bits(pb, gb, 8);
    for (; comment_size > 0; comment_size--)
        copy_bits(pb, gb, 8);

    return put_bits_count(pb) - offset;
}

static int encode_superframe(AVCodecContext *avctx,
                            unsigned char *buf, int buf_size, void *data){
    WMACodecContext *s = avctx->priv_data;
    short *samples = data;
    int i, total_gain;

    s->block_len_bits= s->frame_len_bits; //required by non variable block len
    s->block_len = 1 << s->block_len_bits;

    apply_window_and_mdct(avctx, samples, avctx->frame_size);

    if (s->ms_stereo) {
        float a, b;
        int i;

        for(i = 0; i < s->block_len; i++) {
            a = s->coefs[0][i]*0.5;
            b = s->coefs[1][i]*0.5;
            s->coefs[0][i] = a + b;
            s->coefs[1][i] = a - b;
        }
    }

#if 1
    total_gain= 128;
    for(i=64; i; i>>=1){
        int error= encode_frame(s, s->coefs, buf, buf_size, total_gain-i);
        if(error<0)
            total_gain-= i;
    }
#else
    total_gain= 90;
    best= encode_frame(s, s->coefs, buf, buf_size, total_gain);
    for(i=32; i; i>>=1){
        int scoreL= encode_frame(s, s->coefs, buf, buf_size, total_gain-i);
        int scoreR= encode_frame(s, s->coefs, buf, buf_size, total_gain+i);
        av_log(NULL, AV_LOG_ERROR, "%d %d %d (%d)\n", scoreL, best, scoreR, total_gain);
        if(scoreL < FFMIN(best, scoreR)){
            best = scoreL;
            total_gain -= i;
        }else if(scoreR < best){
            best = scoreR;
            total_gain += i;
        }
    }
#endif

    encode_frame(s, s->coefs, buf, buf_size, total_gain);
    assert((put_bits_count(&s->pb) & 7) == 0);
    i= s->block_align - (put_bits_count(&s->pb)+7)/8;
    assert(i>=0);
    while(i--)
        put_bits(&s->pb, 8, 'N');

    flush_put_bits(&s->pb);
    return put_bits_ptr(&s->pb) - s->pb.buf;
}

static int cbs_jpeg_write_unit(CodedBitstreamContext *ctx,
                                CodedBitstreamUnit *unit)
{
    CodedBitstreamJPEGContext *priv = ctx->priv_data;
    PutBitContext pbc;
    int err;

    if (!priv->write_buffer) {
        // Initial write buffer size is 1MB.
        priv->write_buffer_size = 1024 * 1024;

    reallocate_and_try_again:
        err = av_reallocp(&priv->write_buffer, priv->write_buffer_size);
        if (err < 0) {
            av_log(ctx->log_ctx, AV_LOG_ERROR, "Unable to allocate a "
                   "sufficiently large write buffer (last attempt "
                   "%"SIZE_SPECIFIER" bytes).\n", priv->write_buffer_size);
            return err;
        }
    }

    init_put_bits(&pbc, priv->write_buffer, priv->write_buffer_size);

    if (unit->type == JPEG_MARKER_SOS)
        err = cbs_jpeg_write_scan(ctx, unit, &pbc);
    else
        err = cbs_jpeg_write_segment(ctx, unit, &pbc);

    if (err == AVERROR(ENOSPC)) {
        // Overflow.
        priv->write_buffer_size *= 2;
        goto reallocate_and_try_again;
    }
    if (err < 0) {
        // Write failed for some other reason.
        return err;
    }

    if (put_bits_count(&pbc) % 8)
        unit->data_bit_padding = 8 - put_bits_count(&pbc) % 8;
    else
        unit->data_bit_padding = 0;

    unit->data_size = (put_bits_count(&pbc) + 7) / 8;
    flush_put_bits(&pbc);

    err = ff_cbs_alloc_unit_data(ctx, unit, unit->data_size);
    if (err < 0)
        return err;

    memcpy(unit->data, priv->write_buffer, unit->data_size);

    return 0;
}

static void vaapi_encode_h264_write_sei(PutBitContext *pbc,
                                        VAAPIEncodeContext *ctx,
                                        VAAPIEncodePicture *pic)
{
    VAAPIEncodeH264Context *priv = ctx->priv_data;
    PutBitContext payload_bits;
    char payload[256];
    int payload_type, payload_size, i;
    void (*write_payload)(PutBitContext *pbc,
                          VAAPIEncodeContext *ctx,
                          VAAPIEncodePicture *pic) = NULL;

    vaapi_encode_h264_write_nal_header(pbc, NAL_SEI, 0);

    for (payload_type = 0; payload_type < 64; payload_type++) {
        switch (payload_type) {
        case SEI_TYPE_BUFFERING_PERIOD:
            if (!priv->send_timing_sei ||
                pic->type != PICTURE_TYPE_IDR)
                continue;
            write_payload = &vaapi_encode_h264_write_buffering_period;
            break;
        case SEI_TYPE_PIC_TIMING:
            if (!priv->send_timing_sei)
                continue;
            write_payload = &vaapi_encode_h264_write_pic_timing;
            break;
        case SEI_TYPE_USER_DATA_UNREGISTERED:
            if (pic->encode_order != 0)
                continue;
            write_payload = &vaapi_encode_h264_write_identifier;
            break;
        default:
            continue;
        }

        init_put_bits(&payload_bits, payload, sizeof(payload));
        write_payload(&payload_bits, ctx, pic);
        if (put_bits_count(&payload_bits) & 7) {
            write_u(&payload_bits, 1, 1, bit_equal_to_one);
            while (put_bits_count(&payload_bits) & 7)
                write_u(&payload_bits, 1, 0, bit_equal_to_zero);
        }
        payload_size = put_bits_count(&payload_bits) / 8;
        flush_put_bits(&payload_bits);

        u(8, payload_type, last_payload_type_byte);
        u(8, payload_size, last_payload_size_byte);
        for (i = 0; i < payload_size; i++)
            u(8, payload[i] & 0xff, sei_payload);
    }

    vaapi_encode_h264_write_trailing_rbsp(pbc);
}

static int encode_frame(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
    ASV1Context * const a = avctx->priv_data;
    AVFrame *pict = data;
    AVFrame * const p= (AVFrame*)&a->picture;
    int size;
    int mb_x, mb_y;

    init_put_bits(&a->pb, buf, buf_size);
    
    *p = *pict;
    p->pict_type= I_TYPE;
    p->key_frame= 1;

    for(mb_y=0; mb_y<a->mb_height2; mb_y++){
        for(mb_x=0; mb_x<a->mb_width2; mb_x++){
            dct_get(a, mb_x, mb_y);
            encode_mb(a, a->block);
        }
    }

    if(a->mb_width2 != a->mb_width){
        mb_x= a->mb_width2;
        for(mb_y=0; mb_y<a->mb_height2; mb_y++){
            dct_get(a, mb_x, mb_y);
            encode_mb(a, a->block);
        }
    }

    if(a->mb_height2 != a->mb_height){
        mb_y= a->mb_height2;
        for(mb_x=0; mb_x<a->mb_width; mb_x++){
            dct_get(a, mb_x, mb_y);
            encode_mb(a, a->block);
        }
    }
    emms_c();
    
    align_put_bits(&a->pb);
    while(put_bits_count(&a->pb)&31)
        put_bits(&a->pb, 8, 0);
    
    size= put_bits_count(&a->pb)/32;
    
    if(avctx->codec_id == CODEC_ID_ASV1)
        a->dsp.bswap_buf((uint32_t*)buf, (uint32_t*)buf, size);
    else{
        int i;
        for(i=0; i<4*size; i++)
            buf[i]= reverse[ buf[i] ];
    }
    
    return size*4;
}

static int append_picture_header(const MPEG4PictureInfo *pic_info)
{
    MPEG4SliceInfo slice_info;
    uint8_t buf[32], buf_size;
    const uint8_t *slice_data;
    unsigned int slice_data_size;
    PutBitContext pb;
    int r;

    if (mpeg4_get_slice_info(0, &slice_info) < 0)
        return -1;

    int time_incr = 1 + ilog2(pic_info->vop_time_increment_resolution - 1);
    if (time_incr < 1)
        time_incr = 1;

    /* Reconstruct the VOP header */
    init_put_bits(&pb, buf, sizeof(buf));
    put_bits(&pb, 16, 0);                               /* vop header */
    put_bits(&pb, 16, VOP_STARTCODE);                   /* vop header */
    put_bits(&pb, 2, pic_info->vop_fields.bits.vop_coding_type);

    put_bits(&pb, 1, 0);
    put_bits(&pb, 1, 1);                                /* marker */
    put_bits(&pb, time_incr, 0);                        /* time increment */
    put_bits(&pb, 1, 1);                                /* marker */
    put_bits(&pb, 1, 1);                                /* vop coded */
    if (pic_info->vop_fields.bits.vop_coding_type == VOP_P_TYPE)
        put_bits(&pb, 1, pic_info->vop_fields.bits.vop_rounding_type);
    put_bits(&pb, 3, pic_info->vop_fields.bits.intra_dc_vlc_thr);
    if (pic_info->vol_fields.bits.interlaced) {
        put_bits(&pb, 1, pic_info->vop_fields.bits.top_field_first);
        put_bits(&pb, 1, pic_info->vop_fields.bits.alternate_vertical_scan_flag);
    }
    put_bits(&pb, pic_info->quant_precision, slice_info.quant_scale);
    if (pic_info->vop_fields.bits.vop_coding_type != VOP_I_TYPE)
        put_bits(&pb, 3, pic_info->vop_fcode_forward);
    if (pic_info->vop_fields.bits.vop_coding_type == VOP_B_TYPE)
        put_bits(&pb, 3, pic_info->vop_fcode_backward);

    /* Merge in bits from the first byte of the slice */
    if ((put_bits_count(&pb) % 8) != slice_info.macroblock_offset)
        return -1;
    if (mpeg4_get_slice_data(0, &slice_data, &slice_data_size) < 0)
        return -1;
    r = 8 - (put_bits_count(&pb) % 8);
    put_bits(&pb, r, slice_data[0] & ((1U << r) - 1));
    flush_put_bits(&pb);

    buf_size = put_bits_count(&pb) / 8;
    return vdpau_append_slice_data(buf, buf_size);
}

int avpriv_dca_convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst,
                             int max_size)
{
    uint32_t mrk;
    int i, tmp;
    PutBitContext pb;

    if ((unsigned) src_size > (unsigned) max_size)
        src_size = max_size;

    mrk = AV_RB32(src);
    switch (mrk) {
    case DCA_SYNCWORD_CORE_BE:
        memcpy(dst, src, src_size);
        return src_size;
    case DCA_SYNCWORD_CORE_LE:
        for (i = 0; i < (src_size + 1) >> 1; i++) {
            AV_WB16(dst, AV_RL16(src));
            src += 2;
            dst += 2;
        }
        return src_size;
    case DCA_SYNCWORD_CORE_14B_BE:
    case DCA_SYNCWORD_CORE_14B_LE:
        init_put_bits(&pb, dst, max_size);
        for (i = 0; i < (src_size + 1) >> 1; i++, src += 2) {
            tmp = ((mrk == DCA_SYNCWORD_CORE_14B_BE) ? AV_RB16(src) : AV_RL16(src)) & 0x3FFF;
            put_bits(&pb, 14, tmp);
        }
        flush_put_bits(&pb);
        return (put_bits_count(&pb) + 7) >> 3;
    default:
        return AVERROR_INVALIDDATA;
    }
}

size_t xau_pcm8m_encode( const sint8* pcm, size_t samples, void* buf, size_t bufsize )
{
	// check preconditions

	xau_codec_t codec;
	init_put_bits( &codec.pb, (uint8*)buf, bufsize );
	rice_init( codec.rice, PCM8M_K1, PCM8M_K2 );
	ppfilter_init( &codec.flt, PCM8M_SH );

	const sint8* p = pcm;
	for( size_t n = 0; n != samples; ++n ) {
		// a) skip sample diffing part as it seems hurting performance a lot on 8bit mode
		// *p -= prev / 2
		// b) apply polyphase filter
		sint32 tmp = ppfilter_encode( &codec.flt, *p++ );
		// c) skip median predictor part - also hurts performance on 8bps
		// *p -= PREDICTOR1( last, 4 );
		// d) encode the 'unsignificated' code
		rice_enc( &codec.pb, codec.rice, xbs_sign_pack( tmp ) );
	}
	align_put_bits( &codec.pb );
	uint32 written = put_bits_count( &codec.pb ) / 8;

	// check for overruns
	return written;
}

static int vaapi_encode_h264_write_extra_header(AVCodecContext *avctx,
                                                VAAPIEncodePicture *pic,
                                                int index, int *type,
                                                char *data, size_t *data_len)
{
    VAAPIEncodeContext *ctx = avctx->priv_data;
    PutBitContext pbc;
    char tmp[256];
    size_t header_len;

    if (index == 0 && ctx->va_rc_mode == VA_RC_CBR) {
        *type = VAEncPackedHeaderH264_SEI;

        init_put_bits(&pbc, tmp, sizeof(tmp));
        vaapi_encode_h264_write_sei(&pbc, ctx, pic);
        header_len = put_bits_count(&pbc);
        flush_put_bits(&pbc);

        return ff_vaapi_encode_h26x_nal_unit_to_byte_stream(data, data_len,
                                                            tmp, header_len);

    } else {
        return AVERROR_EOF;
    }
}

static int encode_frame(AVCodecContext *avctx, unsigned char *buf,
                        int buf_size, void *data)
{
    PutBitContext pb;
    AVFrame *p = data;
    int x, y;

    p->pict_type = AV_PICTURE_TYPE_I;
    p->key_frame = 1;

    init_put_bits(&pb, buf, buf_size / 8);

    for (y = 0; y < avctx->height; y++) {
        uint8_t *luma = &p->data[0][y * p->linesize[0]];
        uint8_t *cb   = &p->data[1][y * p->linesize[1]];
        uint8_t *cr   = &p->data[2][y * p->linesize[2]];
        for (x = 0; x < avctx->width; x += 4) {
            put_bits(&pb, 5, luma[3] >> 3);
            put_bits(&pb, 5, luma[2] >> 3);
            put_bits(&pb, 5, luma[1] >> 3);
            put_bits(&pb, 5, luma[0] >> 3);
            luma += 4;
            put_bits(&pb, 6, *(cb++) >> 2);
            put_bits(&pb, 6, *(cr++) >> 2);
        }
    }

    flush_put_bits(&pb);

    return put_bits_count(&pb) / 8;
}

int ff_dca_convert_bitstream(const uint8_t *src, int src_size, uint8_t *dst,
                             int max_size)
{
    uint32_t mrk;
    int i, tmp;
    const uint16_t *ssrc = (const uint16_t *) src;
    uint16_t *sdst = (uint16_t *) dst;
    PutBitContext pb;

    if ((unsigned) src_size > (unsigned) max_size)
        src_size = max_size;

    mrk = AV_RB32(src);
    switch (mrk) {
    case DCA_MARKER_RAW_BE:
        memcpy(dst, src, src_size);
        return src_size;
    case DCA_MARKER_RAW_LE:
        for (i = 0; i < (src_size + 1) >> 1; i++)
            *sdst++ = av_bswap16(*ssrc++);
        return src_size;
    case DCA_MARKER_14B_BE:
    case DCA_MARKER_14B_LE:
        init_put_bits(&pb, dst, max_size);
        for (i = 0; i < (src_size + 1) >> 1; i++, src += 2) {
            tmp = ((mrk == DCA_MARKER_14B_BE) ? AV_RB16(src) : AV_RL16(src)) & 0x3FFF;
            put_bits(&pb, 14, tmp);
        }
        flush_put_bits(&pb);
        return (put_bits_count(&pb) + 7) >> 3;
    default:
        return AVERROR_INVALIDDATA;
    }
}

static int latm_read_audio_specific_config(GetBitContext *gb,
                                           PutBitContext *pb)
{
    int num_bits=0;
    int audio_object_type;

    MPEG4AudioConfig b, *c;
    c = &b;

    c->sbr = -1;

    audio_object_type = copy_bits(pb, gb, 5);
    if (audio_object_type == AOT_ESCAPE) {
        audio_object_type = AOT_ESCAPE + copy_bits(pb, gb, 6) + 1;
    }
    c->object_type = audio_object_type;

    c->sampling_index = copy_bits(pb, gb, 4);
    c->sample_rate = ff_mpeg4audio_sample_rates[c->sampling_index];
    if (c->sampling_index == 0x0f) {
        c->sample_rate = copy_bits(pb, gb, 24);
    }
    c->chan_config = copy_bits(pb, gb, 4);

    if (c->chan_config < FF_ARRAY_ELEMS(ff_mpeg4audio_channels))
        c->channels = ff_mpeg4audio_channels[c->chan_config];

    if (audio_object_type == AOT_AAC_MAIN ||
        audio_object_type == AOT_AAC_LC ||
        audio_object_type == AOT_AAC_SSR ||
        audio_object_type == AOT_AAC_LTP ||
        audio_object_type == AOT_AAC_SCALABLE ||
        audio_object_type == AOT_TWINVQ) {
        latm_read_ga_specific_config(audio_object_type, c, gb, pb);
    } else if (audio_object_type == AOT_SBR) {
        c->sbr = 1;
        c->ext_sampling_index = copy_bits(pb, gb, 4);
        c->ext_sample_rate = ff_mpeg4audio_sample_rates[c->ext_sampling_index];
        if (c->ext_sampling_index == 0x0f) {
            c->ext_sample_rate = copy_bits(pb, gb, 24);
        }
        c->object_type = copy_bits(pb, gb, 5);
    } else if (audio_object_type >= AOT_ER_AAC_LC) {
        latm_read_ga_specific_config(audio_object_type, c, gb, pb);
        copy_bits(pb, gb, 2);                   // epConfig
    }

    if (c->sbr == -1 && c->sample_rate <= 24000)
        c->sample_rate *= 2;

    // count the extradata
    num_bits = put_bits_count(pb);

    flush_put_bits(pb);
    return num_bits;
}

void ff_copy_bits(PutBitContext *pb, const uint8_t *src, int length)
{
    int words= length>>4;
    int bits= length&15;
    int i;

    if(length==0) return;

    if(words < 16 || put_bits_count(pb)&7){
        for(i=0; i<words; i++) put_bits(pb, 16, AV_RB16(src + 2*i));
    }else{
        for(i=0; put_bits_count(pb)&31; i++)
            put_bits(pb, 8, src[i]);
        flush_put_bits(pb);
        memcpy(put_bits_ptr(pb), src+i, 2*words-i);
        skip_put_bytes(pb, 2*words-i);
    }

    put_bits(pb, bits, AV_RB16(src + 2*words)>>(16-bits));
}

static int vaapi_encode_h264_write_sequence_header(AVCodecContext *avctx,
                                                   char *data, size_t *data_len)
{
    VAAPIEncodeContext *ctx = avctx->priv_data;
    PutBitContext pbc;
    char tmp[256];
    int err;
    size_t nal_len, bit_len, bit_pos, next_len;

    bit_len = *data_len;
    bit_pos = 0;

    init_put_bits(&pbc, tmp, sizeof(tmp));
    vaapi_encode_h264_write_sps(&pbc, ctx);
    nal_len = put_bits_count(&pbc);
    flush_put_bits(&pbc);

    next_len = bit_len - bit_pos;
    err = ff_vaapi_encode_h26x_nal_unit_to_byte_stream(data + bit_pos / 8,
                                                       &next_len,
                                                       tmp, nal_len);
    if (err < 0)
        return err;
    bit_pos += next_len;

    init_put_bits(&pbc, tmp, sizeof(tmp));
    vaapi_encode_h264_write_pps(&pbc, ctx);
    nal_len = put_bits_count(&pbc);
    flush_put_bits(&pbc);

    next_len = bit_len - bit_pos;
    err = ff_vaapi_encode_h26x_nal_unit_to_byte_stream(data + bit_pos / 8,
                                                       &next_len,
                                                       tmp, nal_len);
    if (err < 0)
        return err;
    bit_pos += next_len;

    *data_len = bit_pos;
    return 0;
}