Cue Playback (Stream)

This tutorial shows how to play a cue in streaming mode by CRI Atom.

Files Needef for Playback

The files required for playing cues are ACF file (*.acf), ACB file (*.acb), AWB file (*.awb) and header files (*.h).
Those files are output of the Atom tool. For this tutorial, you can use the same data as the sample program and they are located:

Files related to this tutorial

	CRIWARE SDK common smpdata criatomex TutorialProject.acf tutorial_streaming.acb tutorial_streaming.h tutorial_streaming_streamfiles.awb
		: Sample data for tutorial
		: ACF file
		: ACB file
		: ACB header file
		: AWB file

Project File and Source Code

The project file and source codes are located at following folders.

Location of Tutorial source code

	CRIWARE SDK pc tutorials criatomex playback_cue_streaming pcvc playback_cue_streaming.sln playback_cue_streaming.vcxproj playback_cue_streaming.vcxproj.filters   playback_cue_streaming.c
		[Platform specific]
		: Tutorial program
		: Streaming playback tutorial
		: Project file folder
		: Visual Studio solution file
		: Visual Studio project file
		: Visual Studio filter file
		: Source code of Streaming playback

Program Flow

Program flow is as follows.
The different points from Cue Playback (Memory) are;
"3. Create D-BAS", "5. Allocate voice pool" and "7. Start playback".

1. Include header files
2. CRI Atom library initialization
3. Create D-BAS
4. Load necessary files
5. Allocate voice pool
6. Create AtomEx player
7. Start playback
8. Wait for playend and update internal state
9. Finalization
10. Verify playback
    

/* CRI SDK Header */
#include <cri_xpt.h>
 
/* CRI ADX Headers */
#include <cri_atom_ex.h>
#include <cri_atom_pc.h>
 
/* Header file for ACB file used in this tutorial */
 
#include  "../../../../common/smpdata/criatomex/tutorial_streaming.h"

/* Path string for data directory */
#define PATH                "..\\..\\..\\..\\..\\common\\smpdata\\criatomex\\"
 
/* File names for the sample */
#define ACF_FILE            "TutorialProject.acf"
#define ACB_FILE            "tutorial_streaming.acb"
#define AWB_FILE            "tutorial_streaming_streamfiles.awb"

/* main function */
CriSint32 main(CriSint32 argc, CriChar8 *argv[])
{
    CriAtomExStandardVoicePoolConfig voice_pool_config;
    CriAtomDbasId dbas_id;
    CriAtomExPlayerHn player;
    CriAtomExVoicePoolHn voice_pool;
    CriAtomExAcbHn acb_hn;
 
    UNUSED(argc);
    UNUSED(argv);
 
    /* Initialization (minimum) */
    tutorial_initialize();
 
    /* Registration of error callback function */
    criErr_SetCallback(tutorial_error_callback_func);
 
    /* Registration of memory allocator */
    criAtomEx_SetUserAllocator(tutorial_alloc, tutorial_free, NULL);
    
    /* Library initialization */
    criAtomEx_Initialize_PC(NULL, NULL, 0);
 
    /* D-BAS creation */
    dbas_id = criAtomDbas_Create(NULL, NULL, 0);
 
    /* Read and register ACF file */
    criAtomEx_RegisterAcfFile(NULL, PATH ACF_FILE, NULL, 0);
    
    /* Read ACB file and create ACB handle */
    acb_hn = criAtomExAcb_LoadAcbFile(
        NULL, PATH ACB_FILE, NULL, PATH AWB_FILE, NULL, 0);
 
    /* Allocate voice pool */
    criAtomExVoicePool_SetDefaultConfigForStandardVoicePool(&voice_pool_config);
    voice_pool_config.player_config.streaming_flag = CRI_TRUE;
    voice_pool = criAtomExVoicePool_AllocateStandardVoicePool(&voice_pool_config, NULL, 0);
    
    /* Create player */
    player = criAtomExPlayer_Create(NULL, NULL, 0);
 
    /* Specify Cue ID */
    criAtomExPlayer_SetCueId(player, acb_hn, CRI_TUTORIAL_STREAMING_MUSIC_TR);
    /* Start playback */
    criAtomExPlayer_Start(player);
 
    for(;;) {
        CriAtomExPlayerStatus explayer_status;
        tutorial_sleep(10);
        /* Execute server process */
        criAtomEx_ExecuteMain();
 
        /* check the player status */
        explayer_status = criAtomExPlayer_GetStatus(player);
 
        /* Exit playback loop if the status is PLAYEND */
        if (explayer_status == CRIATOMEXPLAYER_STATUS_PLAYEND) {
            break;
        }
    }
    
    /* Destroy player handle */
    criAtomExPlayer_Destroy(player);
    
    /* Free voice pool */
    criAtomExVoicePool_Free(voice_pool);
 
    /* Release ACB handle */
    criAtomExAcb_Release(acb_hn);
 
    /* Unregister ACF */
    criAtomEx_UnregisterAcf();
 
    /* Destroy D-BAS */
    criAtomDbas_Destroy(dbas_id);
 
    /* Library Finalization */
    criAtomEx_Finalize_PC();
 
    /* Finalization (minimum) */
    tutorial_finalize();
 
    return 0;
}

Description of Program

Detail explanation for each step.

1. Include header files

/* CRI SDK Header */
#include <cri_xpt.h>
 
/* CRI ADX Headers */
#include <cri_atom_ex.h>
#include <cri_atom_pc.h>
 
/* Header file for ACB file used in this tutorial */
#include  "../../../../common/smpdata/criatomex/tutorial_streaming.h"

Include cri_xpt.h first, as it contains CRI specific type definitions.
Other header files have no restriction for their order.

cri_atom_ex.h contains API declaration of functions for CRI Atom.
It must be included.

tutorial_streaming.h contains cue information for ACB file and AWB file. Cue IDs for playback are defined in this header file.

2. CRI Atom library initialization

/* Registration of error callback function */
criErr_SetCallback(tutorial_error_callback_func);
 
/* Registration of memory allocator */
criAtomEx_SetUserAllocator(tutorial_alloc, tutorial_free, NULL);
 
/* Library initialization */
criAtomEx_Initialize_PC(NULL, NULL, 0);

Initialize CRI Atom Library.
In this tutorial, parameters for criAtomEx_Initialize_PC function are simplified.
The first argument of criAtomEx_Initialize_PC function is initialization parameter, but when it is NULL, the default setting is selected.
Second and third parameters are for specification of work area.
criAtomEx_Initialize_PC allocates work memory dynamically and internally when memory allocator function is set by criAtomEx_SetUserAllocator and NULL is passed as work area point and work memory size is 0 (zero).

3. Create D-BAS

/* D-BAS creation */
dbas_id = criAtomDbas_Create(NULL, NULL, 0);

For streaming playback, it is necessary to create D-BAS by calling criAtomDbas_Create.
In this tutorial, parameters for criAtomDbas_Create function are simplified.
The first argument of criAtomDbas_Create function is initialization parameter, but when it is NULL, the default setting is selected.
Second and third parameters are for specification of work area.
criAtomDbas_Create allocates work memory dynamically and internally when memory allocator function is set by criAtomEx_SetUserAllocator and NULL is passed as work area point and work memory size is 0 (zero).

The role of D-BAS is to manage streaming buffer for players.
Streaming buffer is divided into blocks and dynamically D-BAS assigns blocks needed to each player based on bitrate of each player.

Error handling is eliminated in this tutorial but return value verification should be recommended as criAtomDbas_Create may fail to allocate huge work memory.

[Note]
For current version, only one D-BAS can be created.
In the future, we are expecting more flexible feature such that application can assign different D-BAS for different player by creating multiple D-BASs.

4. Loading necessary files

/* Read and register ACF file */
criAtomEx_RegisterAcfFile(NULL, PATH ACF_FILE, NULL, 0);
 
/* Read ACB file and create ACB handle */
acb_hn = criAtomExAcb_LoadAcbFile(
    NULL, PATH ACB_FILE, NULL, PATH AWB_FILE, NULL, 0);

Read ACF file by calling criAtomEx_RegisterAcfFile function. This file is used for configuration of environment.
Then read ACB file by criAtomExAcb_LoadAcbFile. This function returns a ACB handle which is passed to player.
Both functions require work size as their arguments, but those are NULL and 0(zero) for simplification and work memory are allocated internally.

Both criAtomEx_RegisterAcfFile and criAtomExAcb_LoadAcbFile are synchronous functions.
After criAtomExAcb_LoadAcbFile successfully executed, ACB file loading should be completed and a valid ACB handle ( CriAtomExAcbHn ) should be returned.

Error handling is eliminated in this tutorial but return value verification should be recommended as both criAtomEx_RegisterAcfFile and criAtomExAcb_LoadAcbFile may fail with some reasons such as "file not found".

5. Allocate voice pool

/* Allocate voice pool */
criAtomExVoicePool_SetDefaultConfigForStandardVoicePool(&voice_pool_config);
voice_pool_config.player_config.streaming_flag = CRI_TRUE;
voice_pool = criAtomExVoicePool_AllocateStandardVoicePool(&voice_pool_config, NULL, 0);

Here Standard voice pool is allocated.

To play cue in streaming mode, it is necessary to set streaming_flag in voice pool configuration parameter, otherwise streaming buffer is not allocated to voice pool.

So in this tutorial, it is necessary to specify configuration parameter explicitly.

Initialize a variable with CriAtomExStandardVoicePoolConfig type by a macro, criAtomExVoicePool_SetDefaultConfigForStandardVoicePool.

Then modify parameters necessary. That is, player_config.streaming_flag in CriAtomExStandardVoicePoolConfig member is set to ::CRI_TRUE for streaming playback.
And pass this structure to criAtomExVoicePool_AllocateStandardVoicePool.

In the source code above, only configuration parameter is set explicitly.
Handling work memory is independent, so work memory parameters can be default, NULL and 0(zero) again.

6. Create AtomEx player

/* Create player */
player = criAtomExPlayer_Create(NULL, NULL, 0);

This code creates AtomEx player (in short we call it "player" simply here).

Again arguments are NULLs and 0 to specify default setting and the function returns a player handle ( CriAtomExPlayerHn ).
You can control AtomEx player through this handle.

For work memory, NULL and 0(zero) are specified in this tutorial to allocate work memory dynamically.

7. Start playback

/* Specify Cue ID */
criAtomExPlayer_SetCueId(player, acb_hn, CRI_TUTORIAL_STREAMING_MUSIC_TR);
/* Start playback */
criAtomExPlayer_Start(player);

Specifying Cue ID with criAtomExPlayer_SetCueId function, call criAtomExPlayer_Start start playback.
The second argument criAtomExPlayer_SetCueId is ACB handle that should have loaded and the third one is Cue ID (number) to be played.

The player start playback according to ACB handle and cue ID.
The sample cue ID, CRI_TUTORIAL_STREAMING_MUSIC_TR, is defined in tutorial_streaming.h.
CRI_TUTORIAL_STREAMING_MUSIC_TR is a streaming cue though it is not obvious in the cuesheet header file.

criAtomExPlayer_Start function starts playback with Atom player handle which is created by criAtomExPlayer_Create.

8. Waiting for play-end and updating internal state

/* Playback loop */
for(;;) {
    CriAtomExPlayerStatus explayer_status;
    tutorial_sleep(10);
    /* Execute server process */
    criAtomEx_ExecuteMain();
 
    /* check Ex player status */
    explayer_status = criAtomExPlayer_GetStatus(player);
 
    /* Exit playback loop if play-end */
    if (explayer_status == CRIATOMEXPLAYER_STATUS_PLAYEND) {
        break;
    }
}

criAtomExPlayer_GetStatus returns the player status and if it is play-end(CRIATOMEXPLAYER_STATUS_PLAYEND) then exit the loop.
In the playback loop, criAtomEx_ExecuteMain, the server process of CRI Atom, should be called for every V-sync, otherwise reading sound data may be delayed and it may result audio playback stuttering.

Also the status of player is updated by CRI Atom server process, so criAtomEx_ExecuteMain should be called for keep updating the status.

9. Finalization

/* Destroy Atom handle */
criAtomExPlayer_Destroy(player);
 
/* Free voice pool */
criAtomExVoicePool_Free(voice_pool);
 
/* Release ACB handle */
criAtomExAcb_Release(acb_hn);
 
/* Unregister ACF */
criAtomEx_UnregisterAcf();
 
/* Destroy D-BAS */
criAtomDbas_Destroy(dbas_id);
 
/* Finalize library */
criAtomEx_Finalize_PC();

At the termination of the application, each handles should be discarded through appropriate function, then all work area allocated dynamically are released in those functions.
Then lastly terminate the library by criAtomEx_Finalize_PC function.

10. Veryfy playback

Can you play the streaming sound of cue, can't you ?
You should hear a back ground music sound now.

Next:Error Handling