自学教程：C++ vlc_fourcc_GetCodec函数代码示例

static int transcode_video_encoder_open( sout_stream_t *p_stream,                                         sout_stream_id_t *id ){    sout_stream_sys_t *p_sys = p_stream->p_sys;    msg_Dbg( p_stream, "destination (after video filters) %ix%i",             id->p_encoder->fmt_in.video.i_width,             id->p_encoder->fmt_in.video.i_height );    id->p_encoder->p_module =        module_need( id->p_encoder, "encoder", p_sys->psz_venc, true );    if( !id->p_encoder->p_module )    {        msg_Err( p_stream, "cannot find video encoder (module:%s fourcc:%4.4s)",                 p_sys->psz_venc ? p_sys->psz_venc : "any",                 (char *)&p_sys->i_vcodec );        return VLC_EGENERIC;    }    id->p_encoder->fmt_in.video.i_chroma = id->p_encoder->fmt_in.i_codec;    /*  */    id->p_encoder->fmt_out.i_codec =        vlc_fourcc_GetCodec( VIDEO_ES, id->p_encoder->fmt_out.i_codec );    id->id = sout_StreamIdAdd( p_stream->p_next, &id->p_encoder->fmt_out );    if( !id->id )    {        msg_Err( p_stream, "cannot add this stream" );        return VLC_EGENERIC;    }    return VLC_SUCCESS;}

vlc_fourcc_t vlc_fourcc_GetCodecFromString( int i_cat, const char *psz_fourcc ){    if( !psz_fourcc || strlen(psz_fourcc) != 4 )        return 0;    return vlc_fourcc_GetCodec( i_cat,                                VLC_FOURCC( psz_fourcc[0], psz_fourcc[1],                                            psz_fourcc[2], psz_fourcc[3] ) );}

static const char *GetOmxAudioEncRole( vlc_fourcc_t i_fourcc ){    unsigned int i;    i_fourcc = vlc_fourcc_GetCodec( AUDIO_ES, i_fourcc );    for( i = 0; audio_enc_format_table[i].i_codec != 0; i++ )        if( audio_enc_format_table[i].i_fourcc == i_fourcc ) break;    return audio_enc_format_table[i].psz_role;}

bool es_format_IsSimilar( const es_format_t *p_fmt1, const es_format_t *p_fmt2 ){    if( p_fmt1->i_cat != p_fmt2->i_cat ||        vlc_fourcc_GetCodec( p_fmt1->i_cat, p_fmt1->i_codec ) !=        vlc_fourcc_GetCodec( p_fmt2->i_cat, p_fmt2->i_codec ) )        return false;    switch( p_fmt1->i_cat )    {    case AUDIO_ES:    {        audio_format_t a1 = p_fmt1->audio;        audio_format_t a2 = p_fmt2->audio;        if( a1.i_format && a2.i_format && a1.i_format != a2.i_format )            return false;        if( a1.i_rate != a2.i_rate ||            a1.i_physical_channels != a2.i_physical_channels ||            a1.i_original_channels != a2.i_original_channels )            return false;        return true;    }    case VIDEO_ES:    {        video_format_t v1 = p_fmt1->video;        video_format_t v2 = p_fmt2->video;        if( !v1.i_chroma )            v1.i_chroma = vlc_fourcc_GetCodec( p_fmt1->i_cat, p_fmt1->i_codec );        if( !v2.i_chroma )            v2.i_chroma = vlc_fourcc_GetCodec( p_fmt1->i_cat, p_fmt2->i_codec );        return video_format_IsSimilar( &p_fmt1->video, &p_fmt2->video );    }    case SPU_ES:    default:        return true;    }}

int GetOmxVideoFormat( vlc_fourcc_t i_fourcc,                       OMX_VIDEO_CODINGTYPE *pi_omx_codec,                       const char **ppsz_name ){    unsigned int i;    i_fourcc = vlc_fourcc_GetCodec( VIDEO_ES, i_fourcc );    for( i = 0; video_format_table[i].i_codec != 0; i++ )        if( video_format_table[i].i_fourcc == i_fourcc ) break;    if( pi_omx_codec ) *pi_omx_codec = video_format_table[i].i_codec;    if( ppsz_name ) *ppsz_name = vlc_fourcc_GetDescription( VIDEO_ES, i_fourcc );    return !!video_format_table[i].i_codec;}

int GetOmxAudioFormat( vlc_fourcc_t i_fourcc,                       OMX_AUDIO_CODINGTYPE *pi_omx_codec,                       const char **ppsz_name ){    unsigned int i;    i_fourcc = vlc_fourcc_GetCodec( AUDIO_ES, i_fourcc );    for( i = 0; audio_format_table[i].i_codec != 0; i++ )        if( audio_format_table[i].i_fourcc == i_fourcc ) break;    if( pi_omx_codec ) *pi_omx_codec = audio_format_table[i].i_codec;    if( ppsz_name ) *ppsz_name = vlc_fourcc_GetDescription( AUDIO_ES, i_fourcc );    return !!audio_format_table[i].i_codec;}

int GetOmxChromaFormat( vlc_fourcc_t i_fourcc,                        OMX_COLOR_FORMATTYPE *pi_omx_codec,                        const char **ppsz_name ){    unsigned int i;    i_fourcc = vlc_fourcc_GetCodec( VIDEO_ES, i_fourcc );    for( i = 0; chroma_format_table[i].i_codec != 0; i++ )        if( chroma_format_table[i].i_fourcc == i_fourcc ) break;    if( pi_omx_codec ) *pi_omx_codec = chroma_format_table[i].i_codec;    if( ppsz_name ) *ppsz_name = vlc_fourcc_GetDescription( VIDEO_ES, i_fourcc );    return !!chroma_format_table[i].i_codec;}

int GetFfmpegCodec( vlc_fourcc_t i_fourcc, int *pi_cat,                    unsigned *pi_ffmpeg_codec, const char **ppsz_name ){    i_fourcc = vlc_fourcc_GetCodec( UNKNOWN_ES, i_fourcc );    for( unsigned i = 0; i < codecs_count; i++ )    {        if( codecs_table[i].i_fourcc == i_fourcc )        {            if( pi_cat ) *pi_cat = codecs_table[i].i_cat;            if( pi_ffmpeg_codec ) *pi_ffmpeg_codec = codecs_table[i].i_codec;            if( ppsz_name ) *ppsz_name = vlc_fourcc_GetDescription( UNKNOWN_ES, i_fourcc );//char *)codecs_table[i].psz_name;            return true;        }    }    return false;}

/***************************************************************************** * aout_BitsPerSample : get the number of bits per sample *****************************************************************************/unsigned int aout_BitsPerSample( vlc_fourcc_t i_format ){    switch( vlc_fourcc_GetCodec( AUDIO_ES, i_format ) )    {    case VLC_CODEC_U8:    case VLC_CODEC_S8:    case VLC_CODEC_ALAW:    case VLC_CODEC_MULAW:        return 8;    case VLC_CODEC_U16L:    case VLC_CODEC_S16L:    case VLC_CODEC_U16B:    case VLC_CODEC_S16B:        return 16;    case VLC_CODEC_U24L:    case VLC_CODEC_S24L:    case VLC_CODEC_U24B:    case VLC_CODEC_S24B:        return 24;    case VLC_CODEC_S24L32:    case VLC_CODEC_S24B32:    case VLC_CODEC_U32L:    case VLC_CODEC_U32B:    case VLC_CODEC_S32L:    case VLC_CODEC_S32B:    case VLC_CODEC_F32L:    case VLC_CODEC_F32B:        return 32;    case VLC_CODEC_F64L:    case VLC_CODEC_F64B:        return 64;    default:        /* For these formats the caller has to indicate the parameters         * by hand. */        return 0;    }}

static int transcode_audio_initialize_encoder( sout_stream_id_t *id, sout_stream_t *p_stream ){    sout_stream_sys_t *p_sys = p_stream->p_sys;    /* Initialization of encoder format structures */    es_format_Init( &id->p_encoder->fmt_in, id->p_decoder->fmt_in.i_cat,                    id->p_decoder->fmt_out.i_codec );    id->p_encoder->fmt_in.audio.i_format = id->p_decoder->fmt_out.i_codec;    id->p_encoder->fmt_in.audio.i_rate = id->p_encoder->fmt_out.audio.i_rate;    id->p_encoder->fmt_in.audio.i_physical_channels =        id->p_encoder->fmt_out.audio.i_physical_channels;    aout_FormatPrepare( &id->p_encoder->fmt_in.audio );    id->p_encoder->p_cfg = p_stream->p_sys->p_audio_cfg;    id->p_encoder->p_module =        module_need( id->p_encoder, "encoder", p_sys->psz_aenc, true );    if( !id->p_encoder->p_module )    {        msg_Err( p_stream, "cannot find audio encoder (module:%s fourcc:%4.4s). Take a look few lines earlier to see possible reason.",                 p_sys->psz_aenc ? p_sys->psz_aenc : "any",                 (char *)&p_sys->i_acodec );        module_unneed( id->p_decoder, id->p_decoder->p_module );        id->p_decoder->p_module = NULL;        return VLC_EGENERIC;    }    id->p_encoder->fmt_out.i_codec =        vlc_fourcc_GetCodec( AUDIO_ES, id->p_encoder->fmt_out.i_codec );    /* Fix input format */    id->p_encoder->fmt_in.audio.i_format = id->p_encoder->fmt_in.i_codec;    if( !id->p_encoder->fmt_in.audio.i_physical_channels     || !id->p_encoder->fmt_in.audio.i_original_channels )    {        if( id->p_encoder->fmt_in.audio.i_channels < 6 )            id->p_encoder->fmt_in.audio.i_physical_channels =            id->p_encoder->fmt_in.audio.i_original_channels =                      pi_channels_maps[id->p_encoder->fmt_in.audio.i_channels];    }    aout_FormatPrepare( &id->p_encoder->fmt_in.audio );    return VLC_SUCCESS;}

int GetVlcChromaSizes( vlc_fourcc_t i_fourcc,                       unsigned int width, unsigned int height,                       unsigned int *size, unsigned int *pitch,                       unsigned int *chroma_pitch_div ){    unsigned int i;    i_fourcc = vlc_fourcc_GetCodec( VIDEO_ES, i_fourcc );    for( i = 0; chroma_format_table[i].i_codec != 0; i++ )        if( chroma_format_table[i].i_fourcc == i_fourcc ) break;    /* Align on macroblock boundary */    width = (width + 15) & ~0xF;    height = (height + 15) & ~0xF;    if( size ) *size = width * height * chroma_format_table[i].i_size_mul / 2;    if( pitch ) *pitch = width * chroma_format_table[i].i_line_mul;    if( chroma_pitch_div )        *chroma_pitch_div = chroma_format_table[i].i_line_chroma_div;    return !!chroma_format_table[i].i_codec;}

vlc_fourcc_t vlc_fourcc_GetCodecAudio( vlc_fourcc_t i_fourcc, int i_bits ){    const int i_bytes = ( i_bits + 7 ) / 8;    if( i_fourcc == VLC_FOURCC( 'a', 'f', 'l', 't' ) )    {        switch( i_bytes )        {        case 4:            return VLC_CODEC_FL32;        case 8:            return VLC_CODEC_FL64;        default:            return 0;        }    }    else if( i_fourcc == VLC_FOURCC( 'a', 'r', 'a', 'w' ) ||             i_fourcc == VLC_FOURCC( 'p', 'c', 'm', ' ' ) )    {        switch( i_bytes )        {        case 1:            return VLC_CODEC_U8;        case 2:            return VLC_CODEC_S16L;        case 3:            return VLC_CODEC_S24L;            break;        case 4:            return VLC_CODEC_S32L;        default:            return 0;        }    }    else if( i_fourcc == VLC_FOURCC( 't', 'w', 'o', 's' ) )    {        switch( i_bytes )        {        case 1:            return VLC_CODEC_S8;        case 2:            return VLC_CODEC_S16B;        case 3:            return VLC_CODEC_S24B;        case 4:            return VLC_CODEC_S32B;        default:            return 0;        }    }    else if( i_fourcc == VLC_FOURCC( 's', 'o', 'w', 't' ) )    {        switch( i_bytes )        {        case 1:            return VLC_CODEC_S8;        case 2:            return VLC_CODEC_S16L;        case 3:            return VLC_CODEC_S24L;        case 4:            return VLC_CODEC_S32L;        default:            return 0;        }    }    else    {        return vlc_fourcc_GetCodec( AUDIO_ES, i_fourcc );    }}

int transcode_audio_new( sout_stream_t *p_stream,                                sout_stream_id_t *id ){    sout_stream_sys_t *p_sys = p_stream->p_sys;    audio_sample_format_t fmt_last;    /*     * Open decoder     */    /* Initialization of decoder structures */    id->p_decoder->fmt_out = id->p_decoder->fmt_in;    id->p_decoder->fmt_out.i_extra = 0;    id->p_decoder->fmt_out.p_extra = 0;    id->p_decoder->pf_decode_audio = NULL;    id->p_decoder->pf_aout_format_update = audio_update_format;    /* id->p_decoder->p_cfg = p_sys->p_audio_cfg; */    id->p_decoder->p_module =        module_need( id->p_decoder, "decoder", "$codec", false );    if( !id->p_decoder->p_module )    {        msg_Err( p_stream, "cannot find audio decoder" );        return VLC_EGENERIC;    }    /* decoders don't set audio.i_format, but audio filters use it */    id->p_decoder->fmt_out.audio.i_format = id->p_decoder->fmt_out.i_codec;    aout_FormatPrepare( &id->p_decoder->fmt_out.audio );    fmt_last = id->p_decoder->fmt_out.audio;    /* Fix AAC SBR changing number of channels and sampling rate */    if( !(id->p_decoder->fmt_in.i_codec == VLC_CODEC_MP4A &&        fmt_last.i_rate != id->p_encoder->fmt_in.audio.i_rate &&        fmt_last.i_channels != id->p_encoder->fmt_in.audio.i_channels) )        fmt_last.i_rate = id->p_decoder->fmt_in.audio.i_rate;    /*     * Open encoder     */    /* Initialization of encoder format structures */    es_format_Init( &id->p_encoder->fmt_in, id->p_decoder->fmt_in.i_cat,                    id->p_decoder->fmt_out.i_codec );    id->p_encoder->fmt_in.audio.i_format = id->p_decoder->fmt_out.i_codec;    id->p_encoder->fmt_in.audio.i_rate = id->p_encoder->fmt_out.audio.i_rate;    id->p_encoder->fmt_in.audio.i_physical_channels =        id->p_encoder->fmt_out.audio.i_physical_channels;    aout_FormatPrepare( &id->p_encoder->fmt_in.audio );    id->p_encoder->p_cfg = p_stream->p_sys->p_audio_cfg;    id->p_encoder->p_module =        module_need( id->p_encoder, "encoder", p_sys->psz_aenc, true );    if( !id->p_encoder->p_module )    {        msg_Err( p_stream, "cannot find audio encoder (module:%s fourcc:%4.4s). Take a look few lines earlier to see possible reason.",                 p_sys->psz_aenc ? p_sys->psz_aenc : "any",                 (char *)&p_sys->i_acodec );        module_unneed( id->p_decoder, id->p_decoder->p_module );        id->p_decoder->p_module = NULL;        return VLC_EGENERIC;    }    id->p_encoder->fmt_out.i_codec =        vlc_fourcc_GetCodec( AUDIO_ES, id->p_encoder->fmt_out.i_codec );    /* Fix input format */    id->p_encoder->fmt_in.audio.i_format = id->p_encoder->fmt_in.i_codec;    if( !id->p_encoder->fmt_in.audio.i_physical_channels     || !id->p_encoder->fmt_in.audio.i_original_channels )    {        if( id->p_encoder->fmt_in.audio.i_channels < 6 )            id->p_encoder->fmt_in.audio.i_physical_channels =            id->p_encoder->fmt_in.audio.i_original_channels =                      pi_channels_maps[id->p_encoder->fmt_in.audio.i_channels];    }    aout_FormatPrepare( &id->p_encoder->fmt_in.audio );    if( unlikely( transcode_audio_initialize_filters( p_stream, id, p_sys, &fmt_last ) != VLC_SUCCESS ) )        return VLC_EGENERIC;    return VLC_SUCCESS;}

void video_format_Setup( video_format_t *p_fmt, vlc_fourcc_t i_chroma,                         int i_width, int i_height,                         int i_sar_num, int i_sar_den ){    p_fmt->i_chroma         = vlc_fourcc_GetCodec( VIDEO_ES, i_chroma );    p_fmt->i_width          =    p_fmt->i_visible_width  = i_width;    p_fmt->i_height         =    p_fmt->i_visible_height = i_height;    p_fmt->i_x_offset       =    p_fmt->i_y_offset       = 0;    vlc_ureduce( &p_fmt->i_sar_num, &p_fmt->i_sar_den,                 i_sar_num, i_sar_den, 0 );    switch( p_fmt->i_chroma )    {    case VLC_CODEC_YUVA:        p_fmt->i_bits_per_pixel = 32;        break;    case VLC_CODEC_I444:    case VLC_CODEC_J444:        p_fmt->i_bits_per_pixel = 24;        break;    case VLC_CODEC_I422:    case VLC_CODEC_YUYV:    case VLC_CODEC_YVYU:    case VLC_CODEC_UYVY:    case VLC_CODEC_VYUY:    case VLC_CODEC_J422:        p_fmt->i_bits_per_pixel = 16;        break;    case VLC_CODEC_I440:    case VLC_CODEC_J440:        p_fmt->i_bits_per_pixel = 16;        break;    case VLC_CODEC_I411:    case VLC_CODEC_YV12:    case VLC_CODEC_I420:    case VLC_CODEC_J420:    case VLC_CODEC_MV12:        p_fmt->i_bits_per_pixel = 12;        break;    case VLC_CODEC_YV9:    case VLC_CODEC_I410:        p_fmt->i_bits_per_pixel = 9;        break;    case VLC_CODEC_Y211:        p_fmt->i_bits_per_pixel = 8;        break;    case VLC_CODEC_YUVP:        p_fmt->i_bits_per_pixel = 8;        break;    case VLC_CODEC_RGB32:    case VLC_CODEC_RGBA:        p_fmt->i_bits_per_pixel = 32;        break;    case VLC_CODEC_RGB24:        p_fmt->i_bits_per_pixel = 24;        break;    case VLC_CODEC_RGB15:    case VLC_CODEC_RGB16:        p_fmt->i_bits_per_pixel = 16;        break;    case VLC_CODEC_RGB8:        p_fmt->i_bits_per_pixel = 8;        break;    case VLC_CODEC_GREY:    case VLC_CODEC_RGBP:        p_fmt->i_bits_per_pixel = 8;        break;    default:        p_fmt->i_bits_per_pixel = 0;        break;    }}

static int SetOutputType(decoder_t *p_dec, DWORD stream_id, IMFMediaType **result){    decoder_sys_t *p_sys = p_dec->p_sys;    HRESULT hr;    *result = NULL;    IMFMediaType *output_media_type = NULL;    /*     * Enumerate available output types. The list is ordered by     * preference thus we will use the first one unless YV12/I420 is     * available for video or float32 for audio.     */    int output_type_index = 0;    bool found = false;    for (int i = 0; !found; ++i)    {        hr = IMFTransform_GetOutputAvailableType(p_sys->mft, stream_id, i, &output_media_type);        if (hr == MF_E_NO_MORE_TYPES)            break;        else if (hr == MF_E_TRANSFORM_TYPE_NOT_SET)        {            /* The input type must be set before setting the output type for this MFT. */            return VLC_SUCCESS;        }        else if (FAILED(hr))            goto error;        GUID subtype;        hr = IMFMediaType_GetGUID(output_media_type, &MF_MT_SUBTYPE, &subtype);        if (FAILED(hr))            goto error;        if (p_dec->fmt_in.i_cat == VIDEO_ES)        {            if (IsEqualGUID(&subtype, &MFVideoFormat_YV12) || IsEqualGUID(&subtype, &MFVideoFormat_I420))                found = true;        }        else        {            UINT32 bits_per_sample;            hr = IMFMediaType_GetUINT32(output_media_type, &MF_MT_AUDIO_BITS_PER_SAMPLE, &bits_per_sample);            if (FAILED(hr))                continue;            if (bits_per_sample == 32 && IsEqualGUID(&subtype, &MFAudioFormat_Float))                found = true;        }        if (found)            output_type_index = i;        IMFMediaType_Release(output_media_type);        output_media_type = NULL;    }    /*     * It's not an error if we don't find the output type we were     * looking for, in this case we use the first available type which     * is the "preferred" output type for this MFT.     */    hr = IMFTransform_GetOutputAvailableType(p_sys->mft, stream_id, output_type_index, &output_media_type);    if (FAILED(hr))        goto error;    hr = IMFTransform_SetOutputType(p_sys->mft, stream_id, output_media_type, 0);    if (FAILED(hr))        goto error;    GUID subtype;    hr = IMFMediaType_GetGUID(output_media_type, &MF_MT_SUBTYPE, &subtype);    if (FAILED(hr))        goto error;    if (p_dec->fmt_in.i_cat == VIDEO_ES)    {        video_format_Copy( &p_dec->fmt_out.video, &p_dec->fmt_in.video );        p_dec->fmt_out.i_codec = vlc_fourcc_GetCodec(p_dec->fmt_in.i_cat, subtype.Data1);    }    else    {        p_dec->fmt_out.audio = p_dec->fmt_in.audio;        UINT32 bitspersample = 0;        hr = IMFMediaType_GetUINT32(output_media_type, &MF_MT_AUDIO_BITS_PER_SAMPLE, &bitspersample);        if (SUCCEEDED(hr) && bitspersample)            p_dec->fmt_out.audio.i_bitspersample = bitspersample;        UINT32 channels = 0;        hr = IMFMediaType_GetUINT32(output_media_type, &MF_MT_AUDIO_NUM_CHANNELS, &channels);        if (SUCCEEDED(hr) && channels)            p_dec->fmt_out.audio.i_channels = channels;        UINT32 rate = 0;        hr = IMFMediaType_GetUINT32(output_media_type, &MF_MT_AUDIO_SAMPLES_PER_SECOND, &rate);        if (SUCCEEDED(hr) && rate)            p_dec->fmt_out.audio.i_rate = rate;        vlc_fourcc_t fourcc;        wf_tag_to_fourcc(subtype.Data1, &fourcc, NULL);//.........这里部分代码省略.........