[FFmpeg-soc] [soc] libavsequencer [PATCH 05/08] Instrument handling public API header file.

[Sebastian Vater]

Vitor Sessak a écrit :
> On 07/11/2010 10:07 PM, Sebastian Vater wrote:
>> /**
>>  * Envelope structure used by instruments to apply volume / panning
>>  * or pitch manipulation according to an user defined waveform.
>>  * New fields can be added to the end with minor version bumps.
>>  * Removal, reordering and changes to existing fields require a major
>>  * version bump.
>>  */
>> typedef struct AVSequencerEnvelope {
>
> Why not just
>
> typedef struct {
>
> ?

This is a point, where I'm not sure right now:
Is typedef struct { .. } AVSequencerEnevelope;

exactly the same as:

typedef struct AVSequencerEnvelope { .. } AVSequencerEnvelope;

If yes, then I would replace all typedef struct x { .. } with simply
typedef struct { .. } x;
>
>>     /** The actual node data of this envelope as signed 16-bit integer.
>
> The comment is cryptic for someone who doesn't know what the node data
> of the envelope might be.

Fixed.

>
>>        For a volume envelope, we have a default scale range of -32767
>>        to +32767, for panning envelopes the scale range is between -8191
>>        to +8191. For slide, vibrato, tremolo, pannolo (and their auto
>>        versions), the scale range is between -256 to +256.  */
>>     int16_t *data;
>> #define AVSEQ_ENVELOPE_SCALE_MAX        0x7FFF
>> #define AVSEQ_ENVELOPE_SCALE_INVALID   
>> ((FF_AVSEQ_ENVELOPE_SCALE_MAX) + 1)
>> #define AVSEQ_ENVELOPE_VOLUME_SCALE     0x7FFF
>> #define AVSEQ_ENVELOPE_PANNING_SCALE    0x1FFF
>> #define AVSEQ_ENVELOPE_SLIDE_SCALE      0x0100
>> #define AVSEQ_ENVELOPE_VIBRATO_SCALE    0x0100
>> #define AVSEQ_ENVELOPE_VIBRATO_SCALE    0x0100
>>
>>     /** The node points values or 0 if the envelope is empty.  */
>>     uint16_t *node_points;
>>
>>     /** Number of dragable nodes of this envelope (defaults to 12).  */
>>     uint16_t nodes;
>> #define AVSEQ_ENVELOPE_NODES    12
>>
>>     /** Number of envelope points, i.e. node data values which
>>        defaults to 64.  */
>>     uint16_t points;
>> #define AVSEQ_ENVELOPE_POINTS   64
>>
>>     /** Instrument envelope flags. Some sequencers feature
>>        loop points of various kinds, which have to be taken
>>        care specially in the internal playback engine.  */
>>     uint16_t flags;
>> #define AVSEQ_ENVELOPE_LOOP             0x0001 ///< Envelope uses
>> loop nodes
>> #define AVSEQ_ENVELOPE_SUSTAIN          0x0002 ///< Envelope uses
>> sustain nodes
>> #define AVSEQ_ENVELOPE_PINGPONG         0x0004 ///< Envelope loop is
>> in ping pong mode
>> #define AVSEQ_ENVELOPE_SUSTAIN_PINGPONG 0x0008 ///< Envelope sustain
>> loop is in ping pong mode
>>
>>     /** Envelope tempo in ticks (defaults to 1, i.e. change envelope
>>        at every frame / tick).  */
>>     uint16_t tempo;
>> #define AVSEQ_ENVELOPE_TEMPO    1
>>
>>     /** Envelope sustain loop start point.  */
>>     uint16_t sustain_start;
>>
>>     /** Envelope sustain loop end point.  */
>>     uint16_t sustain_end;
>
>>     /** Envelope sustain loop repeat counter for loop range.  */
>>     uint16_t sustain_count;
>>
>>     /** Envelope loop repeat start point.  */
>>     uint16_t loop_start;
>>
>>     /** Envelope loop repeat end point.  */
>>     uint16_t loop_end;
>>
>>     /** Envelope loop repeat counter for loop range.  */
>>     uint16_t loop_count;
>>
>>     /** Randomized lowest value allowed.  */
>>     int16_t value_min;
>>
>>     /** Randomized highest value allowed.  */
>>     int16_t value_max;
>>
>>     /** Array of pointers containing every unknown data field where
>>        the last element is indicated by a NULL pointer reference. The
>>        first 64-bit of the unknown data contains an unique identifier
>>        for this chunk and the second 64-bit data is actual unsigned
>>        length of the following raw data. Some formats are chunk based
>>        and can store information, which can't be handled by some
>>        other, in case of a transition the unknown data is kept as is.
>>        Some programs write editor settings for envelopes in those
>>        chunks, which then won't get lost in that case.  */
>>     uint8_t **unknown_data;
>> } AVSequencerEnvelope;
>>
>> /**
>>  * Keyboard definitions structure used by instruments to map
>>  * note to samples. C-0 is first key. B-9 is 120th key.
>>  * New fields can be added to the end with minor version bumps.
>>  * Removal, reordering and changes to existing fields require a major
>>  * version bump.
>>  */
>> typedef struct AVSequencerKeyboard {
>>     struct AVSequencerKeyboardEntry {
>>         /** Sample number for this keyboard note.  */
>>         uint16_t sample;
>>
>>         /** Octave value for this keyboard note.  */
>>         uint8_t octave;
>>
>>         /** Note value for this keyboard note.  */
>>         uint8_t note;
>>     } key[120];
>> } AVSequencerKeyboard;
>>
>> /**
>>  * Arpeggio data structure, This structure is actually for one tick
>>  * and therefore actually pointed as an array with the amount of
>>  * different ticks handled by the arpeggio control.
>>  * New fields can be added to the end with minor version bumps.
>>  * Removal, reordering and changes to existing fields require a major
>>  * version bump.
>>  */
>> typedef struct AVSequencerArpeggioData {
>>     /** Packed note or 0 if this is an arpeggio note.  */
>>     uint8_t tone;
>>
>>     /** Transpose for this arpeggio tick.  */
>>     int8_t transpose;
>>
>>     /** Instrument number to switch to or 0 for original instrument.  */
>>     uint16_t instrument;
>>
>>     /** The four effect command bytes which are executed.  */
>>     uint8_t command[4];
>>
>>     /** The four data word values of the four effect command bytes.  */
>>     uint16_t data[4];
>> } AVSequencerArpeggioData;
>>
>> /**
>>  * Arpeggio control envelope used by all instrumental stuff.
>>  * New fields can be added to the end with minor version bumps.
>>  * Removal, reordering and changes to existing fields require a major
>>  * version bump.
>>  */
>> typedef struct AVSequencerArpeggio {
>>     /** AVSequencerArpeggioData pointer to arpeggio data structure.  */
>>     AVSequencerArpeggioData *data;
>>
>>     /** Instrument arpeggio control flags. Some sequencers feature
>>        customized arpeggio command control.which have to be taken
>>        care specially in the internal playback engine.  */
>>     uint16_t flags;
>> #define AVSEQ_ARPEGGIO_FLAG_LOOP                0x0001   ///<
>> Arpeggio control is looped
>> #define AVSEQ_ARPEGGIO_FLAG_SUSTAIN             0x0002   ///<
>> Arpeggio control has a sustain loop
>> #define AVSEQ_ARPEGGIO_FLAG_PINGPONG            0x0004   ///<
>> Arpeggio control will be looped in ping pong mpde
>> #define AVSEQ_ARPEGGIO_FLAG_SUSTAIN_PINGPONG    0x0008   ///<
>> Arpeggio control will have sustain loop ping pong mode enabled
>>
>>     /** Number of arpeggio ticks handled by this arpeggio control
>>        (defaults to 3 points as in normal arpeggio command).  */
>>     uint16_t entries;
>> #define AVSEQ_ARPEGGIO_FLAG_ENTRIES 3
>>
>>     /** Sustain loop start tick of arpeggio control.  */
>>     uint16_t sustain_start;
>>
>>     /** Sustain loop end tick of arpeggio control.  */
>>     uint16_t sustain_end;
>>
>>     /** Sustain loop count number of how often to repeat loop
>>        of arpeggio control.  */
>>     uint16_t sustain_count;
>>
>>     /** Loop start tick of arpeggio control.  */
>>     uint16_t loop_start;
>>
>>     /** Loop end tick of arpeggio control.  */
>>     uint16_t loop_end;
>>
>>     /** Loop count number of how often to repeat loop of arpeggio
>>        control.  */
>>     uint16_t loop_count;
>
> This look repeated frequently. Why not a struct for loops?

That's a very good idea! Will fix this!

-- 

Best regards,
                   :-) Basty/CDGS (-: