[FFmpeg-soc] [soc] libavsequencer [PATCH 02/08] Sub-song public API header file.

Vitor Sessak vitor1001 at gmail.com
Tue Jul 13 12:11:42 CEST 2010


On 07/11/2010 10:04 PM, Sebastian Vater wrote:
> Vitor Sessak a écrit :
>> On 07/07/2010 10:46 PM, Sebastian Vater wrote:
>>>
>>> diff --git a/libavsequencer/song.h b/libavsequencer/song.h
> /*
>  * AVSequencer sub-song management
>  * Copyright (c) 2010 Sebastian Vater <cdgs.basty at googlemail.com>
>  *
>  * This file is part of FFmpeg.
>  *
>  * FFmpeg is free software; you can redistribute it and/or
>  * modify it under the terms of the GNU Lesser General Public
>  * License as published by the Free Software Foundation; either
>  * version 2.1 of the License, or (at your option) any later version.
>  *
>  * FFmpeg is distributed in the hope that it will be useful,
>  * but WITHOUT ANY WARRANTY; without even the implied warranty of
>  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
>  * Lesser General Public License for more details.
>  *
>  * You should have received a copy of the GNU Lesser General Public
>  * License along with FFmpeg; if not, write to the Free Software
>  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
>  */
>
> #ifndef AVSEQUENCER_SONG_H
> #define AVSEQUENCER_SONG_H
>
> #include "libavformat/avformat.h"
> #include "libavsequencer/avsequencer.h"
> #include "libavsequencer/order.h"
> #include "libavsequencer/track.h"
> #include "libavsequencer/player.h"
>
> /**
>  * Sequencer song structure.
>  * 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 AVSequencerSong {
>     /** Metadata information: Original sub-song file name, sub-song
>      * title, song message, artist, genre, album, begin and finish
>      * date of composition and comment.  */
>     AVMetadata *metadata;

>     /** AVSequencerPlayerGlobals pointer to global channel data.  */
>     AVSequencerPlayerGlobals *global_data;
>
>     /** AVSequencerPlayerHostChannel pointer to host channel data.  */
>     AVSequencerPlayerHostChannel *channel_data;

Player?

>     /** AVSequencerOrderList pointer to list of order data.  */
>     AVSequencerOrderList *order_list;

Why not here an array of pointers like everywhere else?

>     /** Array of pointers containing all tracks for this sub-song.  */
>     AVSequencerTrack **track_list;
>
>     /** Duration of this sub-song, in AV_TIME_BASE fractional
>        seconds.  */
>     uint64_t duration;
>
>     /** Number of tracks attached to this sub-song.  */
>     uint16_t tracks;

>     /** Stack size, i.e. maximum recursion depth of GoSub command which
>        defaults to 4.  */
>     uint16_t gosub_stack_size;
> #define AVSEQ_SONG_GOSUB_STACK  4

Doesn't this depend on the player implementation? Or is it 
format-specific? Or is it read from the file?

>     /** Stack size, i.e. maximum recursion depth of the pattern loop
>        command, which defaults to 1 to imitate most trackers.  */
>     uint16_t loop_stack_size;
> #define AVSEQ_SONG_PATTERN_LOOP_STACK   1

Again, is this specified in the file?

>     /** Compatibility flags for playback. There are rare cases
>        where effect handling can not be mapped into internal
>        playback engine and have to be handled specially. For
>        each sub-song which needs this, this will define new
>        flags which tag the player to handle it to that special
>        way.  */
>     uint8_t compat_flags;
> #define AVSEQ_SONG_COMPAT_FLAG_SYNC             0x01 ///< Tracks are synchronous (linked together, pattern based)
> #define AVSEQ_SONG_COMPAT_FLAG_GLOBAL_LOOP      0x02 ///< Global pattern loop memory
> #define AVSEQ_SONG_COMPAT_FLAG_AMIGA_LIMITS     0x04 ///< Enforce AMIGA sound hardware limits (portamento)
> #define AVSEQ_SONG_COMPAT_FLAG_OLD_VOLUMES      0x08 ///< All volume related commands range from 0-64 instead of 0-255
> #define AVSEQ_SONG_COMPAT_FLAG_GLOBAL_NEW_ONLY  0x10 ///< Global volume/panning changes affect new notes only (S3M)
>
>     /** Song playback flags. Some sequencers use a totally
>        different timing scheme which has to be taken care
>        specially in the internal playback engine. Also
>        sequencers differ in how they handle slides.  */
>     uint8_t flags;
> #define AVSEQ_SONG_FLAG_LINEAR_FREQ_TABLE   0x01 ///< Use linear instead of Amiga frequency table
> #define AVSEQ_SONG_FLAG_SPD                 0x02 ///< Use SPD (OctaMED style) timing instead of BpM
> #define AVSEQ_SONG_FLAG_MONO                0x04 ///< Use mono instead of stereo output
> #define AVSEQ_SONG_FLAG_SURROUND            0x08 ///< Initial global surround instead of stereo panning
>
>     /** Maximum number of host channels, as edited in the track view.
>        to be allocated and usable for order list (defaults to 16).  */
>     uint16_t channels;
> #define AVSEQ_SONG_CHANNELS     16
> #define AVSEQ_SONG_CHANNELS_MIN 1
> #define AVSEQ_SONG_CHANNELS_MAX 256
>
>     /** Initial number of frames per row, i.e. sequencer tempo
>        (defaults to 6 as in most tracker formats).  */
>     uint16_t frames;
> #define AVSEQ_SONG_FRAMES   6
>
>     /** Initial speed multiplier, i.e. nominator which defaults
>        to disabled = 0.  */
>     uint8_t speed_mul;
> #define AVSEQ_SONG_SPEED_MUL    0
>
>     /** Initial speed divider, i.e. denominator which defaults
>        to disabled = 0.  */
>     uint8_t speed_div;
> #define AVSEQ_SONG_SPEED_DIV    0

AVRational?

>     /** Initial MED style SPD speed (defaults to 33 as in
>        OctaMED Soundstudio).  */
>     uint16_t spd_speed;
> #define AVSEQ_SONG_SPD_SPEED    33
>
>     /** Initial number of rows per beat (defaults to 4 rows are a beat).  */
>     uint16_t bpm_tempo;
> #define AVSEQ_SONG_BPM_TEMPO    4
>
>     /** Initial beats per minute speed (defaults to 50 Hz => 125 BpM).  */
>     uint16_t bpm_speed;
> #define AVSEQ_SONG_BPM_SPEED    125

>     /** Minimum and lower limit of number of frames per row
>        (defaults to 1).  */
>     uint16_t frames_min;
> #define AVSEQ_SONG_FRAMES_MIN   1

Again, does this limit depend of the file format or is read directly 
from the file?

>     /** Maximum and upper limit of number of frames per row
>        (defaults to 255).  */
>     uint16_t frames_max;
> #define AVSEQ_SONG_FRAMES_MAX   255
>
>     /** Minimum and lower limit of MED style SPD timing values
>        (defaults to 1).  */
>     uint16_t spd_min;
> #define AVSEQ_SONG_SPD_MIN  1
>
>     /** Maximum and upper limit of MED style SPD timing values
>        (defaults to 255).  */
>     uint16_t spd_max;
> #define AVSEQ_SONG_SPD_MAX  255
>
>     /** Minimum and lower limit of rows per beat timing values
>        (defaults to 1).  */
>     uint16_t bpm_tempo_min;
> #define AVSEQ_SONG_BPM_TEMPO_MIN    1
>
>     /** Maximum and upper limit of rows per beat timing values
>        (defaults to 255).  */
>     uint16_t bpm_tempo_max;
> #define AVSEQ_SONG_BPM_TEMPO_MAX    255
>
>     /** Minimum and lower limit of beats per minute timing values
>        (defaults to 1).  */
>     uint16_t bpm_speed_min;
> #define AVSEQ_SONG_BPM_SPEED_MIN    1
>
>     /** Maximum and upper limit of beats per minute timing values
>        (defaults to 255).  */
>     uint16_t bpm_speed_max;
> #define AVSEQ_SONG_BPM_SPEED_MAX    255

Same for those.

>     /** Global volume of this sub-song. All other volume related
>        commands are scaled by this (defaults to 255 = no scaling).  */
>     uint8_t global_volume;
> #define AVSEQ_SONG_VOLUME   255
>
>     /** Global sub-volume of this sub-song. This is basically
>        volume divided by 256, but the sub-volume doesn't account
>        into actual mixer output (defaults to 0).  */
>     uint8_t global_sub_volume;
> #define AVSEQ_SONG_SUB_VOLUME   0
>
>     /** Global panning of this sub-song. All other panning related
>        commands are scaled by this stereo separation factor
>        (defaults to 0 which means full stereo separation).  */
>     uint8_t global_panning;
> #define AVSEQ_SONG_PANNING  0
>
>     /** Global sub-panning of this sub-song. This is basically
>        panning divided by 256, but the sub-panning doesn't account
>        into actual mixer output (defaults to 0).  */
>     uint8_t global_sub_panning;
> #define AVSEQ_SONG_SUB_PANNING  0

Again, a file can specify those, no? Or they are parameters for the player?

-Vitor


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