input_raw.cpp

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#include "stdafx.h"

enum {
    raw_bits_per_sample = 16,
    raw_channels = 2,
    raw_sample_rate = 44100,

    raw_bytes_per_sample = raw_bits_per_sample / 8,
    raw_total_sample_width = raw_bytes_per_sample * raw_channels,
};

// No inheritance. Our methods get called over input framework templates. See input_singletrack_impl for descriptions of what each method does.
class input_raw {
public:
    void open(service_ptr_t<file> p_filehint,const char * p_path,t_input_open_reason p_reason,abort_callback & p_abort) {
        if (p_reason == input_open_info_write) throw exception_io_unsupported_format();//our input does not support retagging.
        m_file = p_filehint;//p_filehint may be null, hence next line
        input_open_file_helper(m_file,p_path,p_reason,p_abort);//if m_file is null, opens file with appropriate privileges for our operation (read/write for writing tags, read-only otherwise).
    }

    void get_info(file_info & p_info,abort_callback & p_abort) {
        t_filesize size = m_file->get_size(p_abort);
        //note that the file size is not always known, for an example, live streams and alike have no defined size and filesize_invalid is returned
        if (size != filesize_invalid) {
            //file size is known, let's set length
            p_info.set_length(audio_math::samples_to_time( size / raw_total_sample_width, raw_sample_rate));
        }
        //note that the values below should be based on contents of the file itself, NOT on user-configurable variables for an example. To report info that changes independently from file contents, use get_dynamic_info/get_dynamic_info_track instead.
        p_info.info_set_int("samplerate",raw_sample_rate);
        p_info.info_set_int("channels",raw_channels);
        p_info.info_set_int("bitspersample",raw_bits_per_sample);
        p_info.info_set("encoding","lossless");
        p_info.info_set_bitrate((raw_bits_per_sample * raw_channels * raw_sample_rate + 500 /* rounding for bps to kbps*/ ) / 1000 /* bps to kbps */);
        
    }
    t_filestats get_file_stats(abort_callback & p_abort) {return m_file->get_stats(p_abort);}

    void decode_initialize(unsigned p_flags,abort_callback & p_abort) {
        m_file->reopen(p_abort);//equivalent to seek to zero, except it also works on nonseekable streams
    }
    bool decode_run(audio_chunk & p_chunk,abort_callback & p_abort) {
        enum {
            deltaread = 1024,
        };
        m_buffer.set_size(deltaread * raw_total_sample_width);
        t_size deltaread_done = m_file->read(m_buffer.get_ptr(),deltaread * raw_total_sample_width,p_abort) / raw_total_sample_width;
        if (deltaread_done == 0) return false;//EOF

        p_chunk.set_data_fixedpoint(m_buffer.get_ptr(),deltaread_done * raw_total_sample_width,raw_sample_rate,raw_channels,raw_bits_per_sample,audio_chunk::g_guess_channel_config(raw_channels));
        
        //processed successfully, no EOF
        return true;
    }
    void decode_seek(double p_seconds,abort_callback & p_abort) {
        m_file->ensure_seekable();//throw exceptions if someone called decode_seek() despite of our input having reported itself as nonseekable.
        // IMPORTANT: convert time to sample offset with proper rounding! audio_math::time_to_samples does this properly for you.
        t_filesize target = audio_math::time_to_samples(p_seconds,raw_sample_rate) * raw_total_sample_width;
        
        // get_size_ex fails (throws exceptions) if size is not known (where get_size would return filesize_invalid). Should never fail on seekable streams (if it does it's not our problem anymore).
        t_filesize max = m_file->get_size_ex(p_abort);
        if (target > max) target = max;//clip seek-past-eof attempts to legal range (next decode_run() call will just signal EOF).

        m_file->seek(target,p_abort);
    }
    bool decode_can_seek() {return m_file->can_seek();}
    bool decode_get_dynamic_info(file_info & p_out, double & p_timestamp_delta) {return false;} // deals with dynamic information such as VBR bitrates
    bool decode_get_dynamic_info_track(file_info & p_out, double & p_timestamp_delta) {return false;} // deals with dynamic information such as track changes in live streams
    void decode_on_idle(abort_callback & p_abort) {m_file->on_idle(p_abort);}

    void retag(const file_info & p_info,abort_callback & p_abort) {throw exception_io_unsupported_format();}
    
    static bool g_is_our_content_type(const char * p_content_type) {return false;} // match against supported mime types here
    static bool g_is_our_path(const char * p_path,const char * p_extension) {return stricmp_utf8(p_extension,"raw") == 0;}
public:
    service_ptr_t<file> m_file;
    pfc::array_t<t_uint8> m_buffer;
};

static input_singletrack_factory_t<input_raw> g_input_raw_factory;

// Declare .RAW as a supported file type to make it show in "open file" dialog etc.
DECLARE_FILE_TYPE("Raw files","*.RAW");