如何使用speex抖动缓冲区

我正在使用speex库对音频数据进行编码，解码和预处理。我认为speex库非常有用，但是当我使用speex 抖动缓冲区时，我遇到了一些问题。我使用多线程，一个线程将接收到的数据放入抖动缓冲区，另一个线程从活动抖动缓冲区获取数据，有时'gets'线程无法获得有效数据，特别是当速度比'把数据的线程。另外，我正在使用互斥锁来保护抖动缓冲区。如何使用speex抖动缓冲区

我不知道如何正确使用抖动缓冲区。我希望有一个人可以帮助我。

这是我的代码：

speex_jitter_buffer.h 

#include <speex/speex_jitter.h> 
#include <speex/speex.h> 

/** @defgroup SpeexJitter SpeexJitter: Adaptive jitter buffer specifically for Speex 
* This is the jitter buffer that reorders UDP/RTP packets and adjusts the buffer size 
* to maintain good quality and low latency. This is a simplified version that works only 
* with Speex, but is much easier to use. 
* @{ 
*/ 

/** Speex jitter-buffer state. Never use it directly! */ 
typedef struct SpeexJitter { 
    SpeexBits current_packet;   /**< Current Speex packet */ 
    int valid_bits;     /**< True if Speex bits are valid */ 
    JitterBuffer *packets;   /**< Generic jitter buffer state */ 
    void *dec;      /**< Pointer to Speex decoder */ 
    spx_int32_t frame_size;   /**< Frame size of Speex decoder */ 
} SpeexJitter; 

/** Initialise jitter buffer 
* 
* @param jitter State of the Speex jitter buffer 
* @param decoder Speex decoder to call 
* @param sampling_rate Sampling rate used by the decoder 
*/ 
void speex_jitter_init(SpeexJitter *jitter, void *decoder, int sampling_rate); 

/** Destroy jitter buffer */ 
void speex_jitter_destroy(SpeexJitter *jitter); 

/** Put one packet into the jitter buffer */ 
void speex_jitter_put(SpeexJitter *jitter, char *packet, int len, int timestamp); 

/** Get one packet from the jitter buffer */ 
void speex_jitter_get(SpeexJitter *jitter, spx_int16_t *out, int *start_offset); 

/** Get pointer timestamp of jitter buffer */ 
int speex_jitter_get_pointer_timestamp(SpeexJitter *jitter); 

#ifdef __cplusplus 
} 
#endif

speex_jitter_buffer.cpp

#include <speex/speex_jitter.h> 
#include "speex_jitter_buffer.h" 

#ifndef NULL 
#define NULL 0 
#endif 


void speex_jitter_init(SpeexJitter *jitter, void *decoder, int sampling_rate) 
{ 
    jitter->dec = decoder; 
    speex_decoder_ctl(decoder, SPEEX_GET_FRAME_SIZE, &jitter->frame_size); 

    jitter->packets = jitter_buffer_init(jitter->frame_size); 

    speex_bits_init(&jitter->current_packet); 
    jitter->valid_bits = 0; 

} 

void speex_jitter_destroy(SpeexJitter *jitter) 
{ 
    jitter_buffer_destroy(jitter->packets); 
    speex_bits_destroy(&jitter->current_packet); 
} 

void speex_jitter_put(SpeexJitter *jitter, char *packet, int len, int timestamp) 
{ 
    JitterBufferPacket p; 
    p.data = packet; 
    p.len = len; 
    p.timestamp = timestamp; 
    p.span = jitter->frame_size; 
    jitter_buffer_put(jitter->packets, &p); 
} 

void speex_jitter_get(SpeexJitter *jitter, spx_int16_t *out, int *current_timestamp) 
{ 
    int i; 
    int ret; 
    spx_int32_t activity; 
    char data[2048]; 
    JitterBufferPacket packet; 
    packet.data = data; 

    if (jitter->valid_bits) 
    { 
     /* Try decoding last received packet */ 
     ret = speex_decode_int(jitter->dec, &jitter->current_packet, out); 
     if (ret == 0) 
     { 
     jitter_buffer_tick(jitter->packets); 
     return; 
     } else { 
     jitter->valid_bits = 0; 
     } 
    } 

    ret = jitter_buffer_get(jitter->packets, &packet, jitter->frame_size, NULL); 

    if (ret != JITTER_BUFFER_OK) 
    { 
     /* No packet found */ 

     /*fprintf (stderr, "lost/late frame\n");*/ 
     /*Packet is late or lost*/ 
     speex_decode_int(jitter->dec, NULL, out); 
    } else { 
     speex_bits_read_from(&jitter->current_packet, packet.data, packet.len); 
     /* Decode packet */ 
     ret = speex_decode_int(jitter->dec, &jitter->current_packet, out); 
     if (ret == 0) 
     { 
     jitter->valid_bits = 1; 
     } else { 
     /* Error while decoding */ 
     for (i=0;i<jitter->frame_size;i++) 
      out[i]=0; 
     } 
    } 
    speex_decoder_ctl(jitter->dec, SPEEX_GET_ACTIVITY, &activity); 
    if (activity < 30) 
     jitter_buffer_update_delay(jitter->packets, &packet, NULL); 
    jitter_buffer_tick(jitter->packets); 
} 

int speex_jitter_get_pointer_timestamp(SpeexJitter *jitter) 
{ 
    return jitter_buffer_get_pointer_timestamp(jitter->packets); 
}

然后我用 “speex_jitter_buffer.h” 头文件。

的“把”线程代码：

m_jitter_mutex.lock(); 
speex_jitter_put(&jitter, recvBuf, payloadLength, timestamp); 
m_jitter_mutex.unlock();

的“得”线程代码：

while(true) 
{ 
    Sleep(20); 

    m_jitter_mutex.lock(); 
    speex_jitter_get(&jitter, (spx_int16_t*)pcm_short, NULL); 
    m_pOut->Play(pcm_char, pcm_data_length); // play the pcm data 
    m_jitter_mutex.lock(); 
}

我也想使用Speex库做回声消除，但我不知道如何准确地对待我们。非常感谢你。

来源

2012-03-06 Yinfei

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来源

2016-09-23 05:43:57 Romain

如何使用speex抖动缓冲区

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