RTOS 多媒體編碼

介紹 FreeRTOS 下如何使用 xrecorder 的接口來(lái)開(kāi)發(fā)錄制應(yīng)用程序，方便錄制應(yīng)用開(kāi)發(fā)人員快速正確地開(kāi)發(fā)，以及錄制應(yīng)用測(cè)試人員如何根據(jù)該文檔對(duì)基于 xrecord 的錄制應(yīng)用進(jìn)行驗(yàn)證測(cè)試。

編碼支持情況

目前 RTOS 平臺(tái)多媒體編碼應(yīng)用支持的編碼格式分別為：pcm、amr、mp3、speex、opus。

其中 pcm、amr、mp3 可通過(guò) xrecorder 進(jìn)行編碼以及錄制；speex 和 opus 可通過(guò)第三方示例工程進(jìn)行編碼。

xrecorder 狀態(tài)圖

在這里插入圖片描述

這張狀態(tài)轉(zhuǎn)換圖清晰地描述了 xrecorder 的各個(gè)狀態(tài)，也列舉了主要的方法的調(diào)用時(shí)序，每種方法只能在一些特定的狀態(tài)下使用，否則會(huì)出錯(cuò)。

Init 狀態(tài)

Idle 狀態(tài)：當(dāng)調(diào)用 XRecordCreate() 創(chuàng)建一個(gè) xrecord 時(shí)，處于 idle 狀態(tài)。

Prepared 狀態(tài)

調(diào)用 XRecordPrepare() 函數(shù)并返回后，xrecorder 處于 Prepared 狀態(tài)。在這個(gè)狀態(tài)下說(shuō)明所有的資源都已經(jīng)就緒了，調(diào)用 XRecordStart() 函數(shù)就可以進(jìn)行錄制。

Started 狀態(tài)

xrecorder prepare 完成后，調(diào)用 XRecordStart() 進(jìn)行錄制，當(dāng)應(yīng)用開(kāi)始錄制后，xrecorder 就處于 Started 狀態(tài)，這表明 xrecorder 正在錄制文件。

Stopped 狀態(tài)

Started 狀態(tài)下均可調(diào)用 XrecordStop() 停止 xrecorder，而處于 Stop 狀態(tài)的 xrecorder 要想重新錄制，需要通過(guò) XRecorderPrepare() 回到先前的 Prepared 狀態(tài)重新開(kāi)始才可以。

Destroyed 狀態(tài)

通過(guò) XRecordDestroy() 的方法可以進(jìn)入 Destroyed 狀態(tài)，只要 xrecorder 不再被使用，就應(yīng)當(dāng)盡快將其 destroy 掉。

接口函數(shù)

創(chuàng)建一個(gè) XRecord

XRecord *XRecordCreate()

參數(shù)：

無(wú)

返回值：

無(wú)

設(shè)置錄制音頻的編碼格式

int XRecordSetAudioEncodeType(XRecord *p, XRECODER_AUDIO_ENCODE_TYPE type, XRecordConfig *config)

參數(shù)：

p: 通過(guò) XRecordCreate 創(chuàng)建的 XRecord 指針
type: 已支持的編碼格式
config: 上層應(yīng)用對(duì)音頻屬性的配置

返回值：

成功: 0; 失敗: ?1

獲取指針

獲取指向音頻設(shè)備管理模塊的指針，用于錄制音頻

void XRecordSetAudioCap(XRecord* p, const CaptureCtrl* audioSrc)

參數(shù)：

p: 通過(guò) XRecordCreate 創(chuàng)建的 XRecord 指針
audioSrc: 由上層應(yīng)用獲取的音頻設(shè)備管理模塊的指針

返回值：

無(wú)

audioSrc 可在上層應(yīng)用通過(guò)調(diào)用 cedarx 的音頻設(shè)備管理模塊的 RTCaptureDeviceCreate 來(lái)創(chuàng)建。

設(shè)置錄制后文件的保存的路徑

int XRecordSetDataDstUrl(XRecord* p, const char* pUrl, void* arg, const CdxKeyedVectorT* pHeaders)

參數(shù)：

p: 通過(guò) XRecordCreate 創(chuàng)建的 XRecord 指針
pUrl：url 地址

返回值：

成功：0；失?。?1

將 XRecord 置為準(zhǔn)備狀態(tài), 準(zhǔn)備 Muxer

int XRecordPrepare(XRecord* p)

參數(shù)：

p：通過(guò) XRecordCreate 創(chuàng)建的 XRecord 指針

返回值：

成功：0；失?。?1

將 XRecord 置為啟動(dòng)狀態(tài)

int XRecordStart(XRecord* p)

參數(shù)：

p：通過(guò) XRecordCreate 創(chuàng)建的 XRecord 指針

返回值：

成功：0；失?。?1

將 XRecord 置為停止?fàn)顟B(tài)

int XRecordStop(XRecord* p)

參數(shù)：

p：通過(guò) XRecordCreate 創(chuàng)建的 XRecord 指針

返回值：

成功： 0；失?。?1

編碼數(shù)據(jù)入隊(duì)封裝

提供接口給下層編碼模塊，將編碼數(shù)據(jù)放進(jìn)緩存隊(duì)列中等待封裝

int onAudioDataEnc(XRecord* app, CdxMuxerPacketT* buff)

參數(shù)：

app: xrecorder 的環(huán)境句柄；
buff：編碼后的緩存數(shù)據(jù)

返回值：

成功： 0；失?。?1

銷(xiāo)毀一個(gè) XRecord

int XRecordDestroy(XRecord* p)

參數(shù)：

p：通過(guò) XRecordCreate 創(chuàng)建的 XRecord 指針

返回值：

成功： 0；失?。?1

XRecorder 開(kāi)發(fā)流程

XRecordCreate() //創(chuàng)建一個(gè)錄制應(yīng)用
XRecordSetAudioCap() //設(shè)置音頻采集設(shè)備；可先調(diào)用 RTCaptureDeviceCreate 創(chuàng)建。
XRecordSetDataDstUrl() //設(shè)置錄制后文件保存位置
XRecordSetAudioEncodeType() //設(shè)置音頻數(shù)據(jù)的編碼格式
XRecordPrepare() //設(shè)置 Muxer，讓 xrecorder 進(jìn)入準(zhǔn)備狀態(tài)
XRecordStart() //開(kāi)始錄制
XRecordStop() //停止錄制
XRecordDestroy() //當(dāng)不需要進(jìn)行錄制的時(shí)候，銷(xiāo)毀 xrecorder

注意事項(xiàng)

在調(diào)用 XRecordSetAudioCap 設(shè)置音頻采集設(shè)備之前，需先打開(kāi)音頻采集設(shè)備來(lái)獲取句柄。在 rtos 平臺(tái)可調(diào)用 libcedarx 提供的音頻采集設(shè)備控制模塊 rtosCaptureControl.c 中的 RTCaptureDeviceCreate 來(lái)創(chuàng)建句柄。
recorder 應(yīng)用未支持暫停錄制。
recorder 的錄制時(shí)長(zhǎng)為調(diào)用 XRecordStart 至調(diào)用 XRecordStop 之間的時(shí)長(zhǎng)來(lái)決定，因此上層應(yīng)用需要錄制指定時(shí)長(zhǎng)的音頻時(shí)，錄制的步驟應(yīng)為調(diào)用 XRecordStart，等待指定的時(shí)間，調(diào)用XRecordStop。

示例代碼

#include < stdio.h >
#include < stdlib.h >
#include < stdbool.h >
#include < string.h >
#include < aw_common.h >
#include < console.h >

#include "vfs.h"
#include "xrecord.h"

#define RECORDER_LOGD(msg, arg...)      printf("[RECORDER_DBG] < %s : %d > " msg "n", __func__, __LINE__, ##arg)
#define RECORDER_LOGI(msg, arg...)      printf("[RECORDER_INFO] < %s : %d > " msg "n", __func__, __LINE__, ##arg)
#define RECORDER_LOGW(msg, arg...)      printf("[RECORDER_WRN] < %s : %d > " msg "n", __func__, __LINE__, ##arg)
#define RECORDER_LOGE(msg, arg...)      printf("[RECORDER_ERR] < %s : %d > " msg "n", __func__, __LINE__, ##arg)

typedef struct recorder_base recorder_base;

typedef struct rec_cfg
{
    XRECODER_AUDIO_ENCODE_TYPE   type;
    int                 sample_rate;
    int                 chan_num;
    int                 bitrate;
    int                 sampler_bits;
} rec_cfg;

struct recorder_base
{
    int (*start)(recorder_base *base, const char *url, const rec_cfg *cfg);
    int (*stop)(recorder_base *base);
};

struct ExampleCustomerWriterImpl
{
    CdxWriterT base;
    vfs_file_t *vfs;
};

typedef struct recorder
{
    recorder_base base;
    XRecord *xrecorder;
    CaptureCtrl *cap;
} recorder;

recorder_base *recorder_create();
int recorder_destroy(recorder_base *base);

/* Example Customer Writer */
static int __CdxExampleConnect(CdxWriterT *writer)
{
    struct ExampleCustomerWriterImpl *impl;

    impl = (struct ExampleCustomerWriterImpl *)writer;

    vfs_unlink("data/record/2.amr");
    impl- >vfs = vfs_open("data/record/2.amr", VFS_RDWR | VFS_CREAT);
    if (impl- >vfs == NULL) {
        return -1;
    }

    return 0;
}

static int __CdxExampleRead(CdxWriterT *writer, void *buf, int size)
{
    return 0;
}

static int __CdxExampleWrite(CdxWriterT *writer, void *buf, int size)
{
    uint32_t write_len;
    struct ExampleCustomerWriterImpl *impl;

    impl = (struct ExampleCustomerWriterImpl *)writer;

    write_len = vfs_write(impl- >vfs, buf, size);

    return write_len;
}

static long __CdxExampleSeek(CdxWriterT *writer, long moffset, int mwhere)
{
    return 0;
}

static long __CdxExampleTell(CdxWriterT *writer)
{
    return 0;
}

static int __CdxExampleClose(CdxWriterT *writer)
{
    struct ExampleCustomerWriterImpl *impl;

    impl = (struct ExampleCustomerWriterImpl *)writer;

    vfs_close(impl- >vfs);
    free(impl);

    return 0;
}

static const struct CdxWriterOps exampleCustomerWriteOps =
{
    .cdxConnect   =  __CdxExampleConnect,
    .cdxRead      =  __CdxExampleRead,
    .cdxWrite     =  __CdxExampleWrite,
    .cdxSeek      =  __CdxExampleSeek,
    .cdxTell      =  __CdxExampleTell,
    .cdxClose     =  __CdxExampleClose
};

CdxWriterT *ExampleCustomerWriterCreat()
{
    struct ExampleCustomerWriterImpl *impl;

    impl = malloc(sizeof(*impl));
    if (impl == NULL) {
        printf("example customer writer create fail.n");
        return NULL;
    }

    memset(impl, 0, sizeof(*impl));

    impl- >base.ops = &exampleCustomerWriteOps;

    return &impl- >base;
}

/* Main App */
static void showHelp(){
    printf("n");
    printf("**************************n");
    printf("* This is a simple audio recoder, when it is started, you can input commands to telln");
    printf("* what you want it to do.n");
    printf("* Usage: n");
    printf("*   cedarx_record amr 10  : this means record 10s amr musicn");
    printf("*   cedarx_record pcm 10  : this means record 10s pcm musicn");
    printf("**************************n");
}

recorder *recorder_singleton = NULL;

static int record_start(recorder_base *base, const char *url, const rec_cfg *cfg)
{
    recorder *impl = container_of(base, recorder, base);

    XRecordConfig audioConfig;

    if (cfg- >type == XRECODER_AUDIO_ENCODE_PCM_TYPE)
    {
        audioConfig.nChan = cfg- >chan_num;
        audioConfig.nSamplerate = cfg- >sample_rate;
        audioConfig.nSamplerBits = cfg- >sampler_bits;
        audioConfig.nBitrate = cfg- >bitrate;
    }
    else if (cfg- >type == XRECODER_AUDIO_ENCODE_AMR_TYPE)
    {
        audioConfig.nChan = 1;
        audioConfig.nSamplerate = 8000;//amr-nb 8000Hz amr-wb 16000Hz
        audioConfig.nSamplerBits = 16;
        audioConfig.nBitrate = 12200;//amr-nb 12200  amr-wb 23850
    } else {
        audioConfig.nChan = cfg- >chan_num;
        audioConfig.nSamplerate = cfg- >sample_rate;
        audioConfig.nSamplerBits = cfg- >sampler_bits;
        audioConfig.nBitrate = cfg- >bitrate;
    }

    XRecordSetDataDstUrl(impl- >xrecorder, url, NULL, NULL);
    XRecordSetAudioEncodeType(impl- >xrecorder, cfg- >type, &audioConfig);

    XRecordPrepare(impl- >xrecorder);
    XRecordStart(impl- >xrecorder);
    RECORDER_LOGI("record start");
    return 0;
}

static int record_stop(recorder_base *base)
{
    recorder *impl = container_of(base, recorder, base);
    XRecordStop(impl- >xrecorder);
    return 0;
}

extern CaptureCtrl* RTCaptureDeviceCreate();

recorder_base *recorder_create()
{
    if (recorder_singleton != NULL)
        return &recorder_singleton- >base;

    recorder *impl = malloc(sizeof(*impl));
    if (impl == NULL)
        return NULL;
    memset(impl, 0, sizeof(*impl));

    impl- >xrecorder = XRecordCreate();
    if (impl- >xrecorder == NULL)
        goto failed;

    impl- >cap = (void *)(uintptr_t)RTCaptureDeviceCreate();
    if (impl- >cap == NULL)
        goto failed;
    XRecordSetAudioCap(impl- >xrecorder, impl- >cap);

    impl- >base.start = record_start;
    impl- >base.stop = record_stop;

    recorder_singleton = impl;

    return &impl- >base;

failed:
    RECORDER_LOGE("recorder create failed");
    if (impl- >xrecorder)
        XRecordDestroy(impl- >xrecorder);
    if (impl)
        free(impl);
    return NULL;
}

int recorder_destroy(recorder_base *base)
{
    recorder *impl = container_of(base, recorder, base);

    if (impl- >xrecorder) {
        XRecordDestroy(impl- >xrecorder);
    }

    free(impl);

    recorder_singleton = NULL;

    return 0;
}

static int cedarx_record_test(int argc, char **argv)
{
    recorder_base *recorder;
    rec_cfg cfg;
    char music_url[64];
    char file_url[64];
    CdxWriterT *writer;
    memset(file_url, 0, 64);
    if(argc == 3){
        if( !strncmp("amr", argv[1], sizeof("amr")-1) ){
            cfg.type = XRECODER_AUDIO_ENCODE_AMR_TYPE;
            snprintf(file_url, 64, "file://data/%ds.amr", atoi(argv[2]));
            cfg.sample_rate = 8000;//8000
            cfg.chan_num = 1;//1
            cfg.bitrate = 12200;
            cfg.sampler_bits = 16;
        }
        else if( !strncmp("pcm", argv[1], sizeof("pcm")-1) ){
            cfg.type = XRECODER_AUDIO_ENCODE_PCM_TYPE;
            snprintf(file_url, 64, "file://data/%ds.pcm", atoi(argv[2]));
            cfg.sample_rate = 8000;//8000
            cfg.chan_num = 1;//1
            cfg.bitrate = 12200;
            cfg.sampler_bits = 16;
        }
        else if( !strncmp("mp3", argv[1], sizeof("mp3")-1) ){
            cfg.type = XRECODER_AUDIO_ENCODE_MP3_TYPE;
            snprintf(file_url, 64, "file://data/%ds.mp3", atoi(argv[2]));
            cfg.sample_rate = 16000;
            cfg.chan_num = 1;
            cfg.bitrate = 32000;
            cfg.sampler_bits = 16;
        } else {
            printf("now support!n");
            return -1;
        }
    }else{
        printf("the parameter is error,usage is as following:n");
        showHelp();
        return -1;
    }

    recorder = recorder_create();
    if (recorder == NULL) {
        printf("recorder create fail, exitn");
        return -1;
    }

    printf("===start record %s now, last for %d s===n", argv[1], atoi(argv[2]));
    recorder- >start(recorder, file_url, &cfg);
    sleep(atoi(argv[2]));
    recorder- >stop(recorder);
    printf("record %s over.n", argv[1]);
exit:
    return recorder_destroy(recorder);
}

FINSH_FUNCTION_EXPORT_CMD(cedarx_record_test, cedarx_record, cedarx record test demo);

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