使用 g722 编解码器解码 PCM 音频数据

发布于 2024-12-09 14:35:45 字数 649 浏览 0 评论 0原文

我正在开发一个用于 VoIP 音频的通话录音机，音频是在 CISCO 环境中使用 g722 编解码器进行编码的。好吧，我已经从 RTP 帧中提取了数据，并且解码了这个 pcm 数据，如下所示：

unsigned int payloadSize = htons(udpHdr->len) - (CONSTANT::UDP_HDR_SIZE + CONSTANT::RTP_HDR_SIZE);
char * payload = (char*)rtpHdr + CONSTANT::RTP_HDR_SIZE;
  unsigned short m_payloadType = rtpHdr->pt;
//decode_state is initialize like :g722_decode_init(NULL, 64000, G722_SAMPLE_RATE_8000);
outBuffSize = g722_decode(decode_state, decompressed, (const uint8_t*)payload, payloadSize);

我将此解码数据存储在一个文件中（以及同一流的所有帧，等于 sscr），当尝试听到音频时，我只听到噪音。

我认为这个问题是针对CISCO使用的压缩算法的。

解码函数的行为是正确的。

有什么建议吗？

原文

I'm developing a call recorder for VoIP audio, the audio is encoded by using a g722 codec in a CISCO environment.
Well, I have extracted the data from the RTPs frames and I have decoded this pcm data as follow:

unsigned int payloadSize = htons(udpHdr->len) - (CONSTANT::UDP_HDR_SIZE + CONSTANT::RTP_HDR_SIZE);
char * payload = (char*)rtpHdr + CONSTANT::RTP_HDR_SIZE;
  unsigned short m_payloadType = rtpHdr->pt;
//decode_state is initialize like :g722_decode_init(NULL, 64000, G722_SAMPLE_RATE_8000);
outBuffSize = g722_decode(decode_state, decompressed, (const uint8_t*)payload, payloadSize);

I store in a file this decode data (and all frames of the same flow, equal sscr) and when try to hear the audio, I only hear noise.

I think this problem is for the compressed algorithm used CISCO.

The behaviour of the decoded function is correct.

Any suggestion?

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