1. libRTMP的包结构
typedef struct RTMPPacket
{
uint8_t m_headerType;
uint8_t m_packetType;
uint8_t m_hasAbsTimestamp;
int m_nChannel;
uint32_t m_nTimeStamp;
int32_t m_nInfoField2;
uint32_t m_nBodySize;
uint32_t m_nBytesRead;
RTMPChunk *m_chunk;
char *m_body;
} RTMPPacket;
packet->m_headerType: 可以定义如下:
#define RTMP_PACKET_SIZE_LARGE 0
#define RTMP_PACKET_SIZE_MEDIUM 1
#define RTMP_PACKET_SIZE_SMALL 2
#define RTMP_PACKET_SIZE_MINIMUM 3
一般定位为 RTMP_PACKET_SIZE_MEDIUM
packet->m_packetType: 音频、视频包类型
#define RTMP_PACKET_TYPE_AUDIO 0x08
#define RTMP_PACKET_TYPE_VIDEO 0x09
#define RTMP_PACKET_TYPE_INFO 0x12
还有其他更多类型,但一般都是 音频或视频
packet->m_hasAbsTimestamp: 是否使用绝对时间戳,一般定义为0。
packet->m_nChannel:音视频通道号码,音视频不要写错,
#define STREAM_CHANNEL_METADATA 0x03
#define STREAM_CHANNEL_VIDEO 0x04
#define STREAM_CHANNEL_AUDIO 0x05
packet->m_nTimeStamp:时间戳
一般视频时间戳可以从0开始计算,每帧时间戳 + 1000/fps (25fps每帧递增25;30fps递增33)
音频时间戳也可以从0开始计算,48K采样每帧递增21;44.1K采样每帧递增23。
packet->m_nInfoField2 = rtmp->m_stream_id
packet->m_nBodySize:数据包长度 = NALU包长度 + 包头长度
packet->m_nBytesRead:不用管
packet->m_chunk: 不用管
packet->m_body:包头数据 + NALU数据,其长度为packet->m_nBodySize。
2. 发送视频SPS,PPS包
int rtmp_write_video_header(RTMP *rtmp) {
int size = 10 + 3 + sps_pps.sps_length + 3 + sps_pps.pps_length;
RTMPPacket packet;
RTMPPacket_Reset(&packet);
RTMPPacket_Alloc(&packet, size);
unsigned char *body = packet.m_body;
int i = 0;
body[i++] = 0x17;
body[i++] = 0x00;
body[i++] = 0x00;
body[i++] = 0x00;
body[i++] = 0x00;
//AVCDecoderConfigurationRecord
body[i++] = 0x01;
body[i++] = sps_pps.sps_data[1];
body[i++] = sps_pps.sps_data[2];
body[i++] = sps_pps.sps_data[3];
body[i++] = 0xFF;
//sps
body[i++] = 0xE1;
body[i++] = (sps_pps.sps_length >> 8) & 0xFF;
body[i++] = sps_pps.sps_length & 0xFF;
memcpy(&body[i], sps_pps.sps_data, sps_pps.sps_length); // 复制sps数据
i += sps_pps.sps_length;
// pps
body[i++] = 0x01;
body[i++] = (sps_pps.pps_length >> 8) & 0xFF;
body[i++] = sps_pps.pps_length & 0xFF;
memcpy(&body[i], sps_pps.pps_data, sps_pps.pps_length); // 复制pps数据
i += sps_pps.pps_length;
packet->m_headerType = RTMP_PACKET_SIZE_MEDIUM;
packet->m_packetType = RTMP_PACKET_TYPE_VIDEO;
packet->m_hasAbsTimestamp = 0;
packet->m_nChannel = STREAM_CHANNEL_VIDEO;
packet->m_nTimeStamp = 0;
packet->m_nInfoField2 = rtmp->m_stream_id;
packet->m_nBodySize = size;
//调用发送接口
int nRet = RTMP_SendPacket(rtmp, packet, TRUE);
RTMPPacket_Free(&packet);
return nRet;
}
在最开始发送一次即可。
3. 发送视频数据包
int rtmp_write_video_frame(RTMP *rtmp, const BYTE *nalu_data, int slice_count, int nTimestamp){
int n;
int nRet =0;
int size = 0;
for(n=0; nm_stream_id;
packet.m_nBodySize = size;
for(n=0; n
4. 发送音频头包
int rtmp_write_audio_header(RTMP *rtmp){
RTMPPacket packet;
RTMPPacket_Reset(&packet);
RTMPPacket_Alloc(&packet, 4);
packet.m_body[0] = 0xAF; // MP3 AAC format 48000Hz
packet.m_body[1] = 0x00;
packet.m_body[2] = 0x11;
packet.m_body[3] = 0x90;//0x10修改为0x90,2016-1-19
packet.m_headerType = RTMP_PACKET_SIZE_MEDIUM;
packet.m_packetType = RTMP_PACKET_TYPE_AUDIO;
packet.m_hasAbsTimestamp = 0;
packet.m_nChannel = STREAM_CHANNEL_AUDIO;
packet.m_nTimeStamp = 0;
packet.m_nInfoField2 = rtmp->m_stream_id;
packet.m_nBodySize = 4;
//调用发送接口
int nRet = RTMP_SendPacket(rtmp, &packet, TRUE);
RTMPPacket_Free(&packet);//释放内存
return nRet;
}
在最开始发送一次即可。
5. 发送音频包
int rtmp_write_audio_data(RTMP *rtmp, const BYTE *nalu_data, int nalu_size, int audio_TimeStamp){
//rtmp包结构
int size = nalu_size + 2;
RTMPPacket packet;
RTMPPacket_Reset(&packet);
RTMPPacket_Alloc(&packet, size);
int i=0;
// MP3 AAC format 48000Hz
packet.m_body[i++] = 0xAF;
packet.m_body[i++] = 0x01;
memcpy(&packet.m_body[i], nalu_data, nalu_size);
packet.m_headerType = RTMP_PACKET_SIZE_MEDIUM;
packet.m_packetType = RTMP_PACKET_TYPE_AUDIO;
packet.m_hasAbsTimestamp = 0;
packet.m_nChannel = STREAM_CHANNEL_AUDIO;
packet.m_nTimeStamp = audio_TimeStamp;
packet.m_nInfoField2 = rtmp->m_stream_id;
packet.m_nBodySize = size;
//调用发送接口
int nRet = RTMP_SendPacket(rtmp, &packet, TRUE);
RTMPPacket_Free(&packet);//释放内存
return nRet;
}
6. 本地存储packet
int RTMP_SendPacket_wrap(RTMP_ *rtmp, RTMPPacket *packet, int queue){
#if OUTPUT_FLV
uint8_t data[] = {0x09,
0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00 };
if(packet->m_packetType == RTMP_PACKET_TYPE_VIDEO){
data[0] = 0x09;
} else if(packet->m_packetType == RTMP_PACKET_TYPE_AUDIO){
data[0] = 0x08;
}
int len = 0;
int_to_bytes(packet->m_nBodySize, &data[1], 3); // 3字节 包内容长度
int_to_bytes(packet->m_nTimeStamp, &data[4], 3); // 3字节 时间戳,没用第4字节,太长的文件会溢出
len += fwrite(data, 1, 11, flv_fp); // 写入包头11字节
len += fwrite(packet->m_body, 1, packet->m_nBodySize, flv_fp); // 写入数据包体
int_to_bytes(len, &data[0], 4); // 写入的总字节长度
fwrite(data, 1, 4, flv_fp); // 等于前Tag总长度
#endif
return RTMP_SendPacket(rtmp, packet, queue);
}