一. 概述

总体来说比较简单这里就不详述了，参考官方文档即可《Video File Format Specification Version 10》，其中aac和h264的sequence header tag部分需要参考另外两分文档（这个在《Video File Format Specification Version 10》里有说明），这两份文档不太好找，找到的官方的还要收钱，我最终找到了一份.doc文档，其实这两个文档就介绍了一下两个结构体其他信息在这里没有什么参考价值，可以根据将h.264视频流封装成flv格式文件（二.开始动手）这篇文档中的两个图表来完成aac和h264的sequence header tag的填充。

我在github上找到了Akagi201写的代码，并在他的基础上进行了完善。aac编码部分在我的另外一片文章里面有讲述fdk-aac编码及mp4v2封装h264+aac[完整code]

flvmuxer实现了h264+aac的封装并在最后通过加入onMEtadata:duration这一scriptdata tag来告诉demuxer视频的时长。

二. 代码

以下部分是demo示例，详细代码请访问github:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <signal.h>
#include <stdint.h>
#include <pthread.h>
#include <errno.h>

#include "aacenc.h"
#include "flvmuxer.h"
#include "rts_middle_media.h"
#include <qcam_video_input.h>


/* XXX:WARNING the pcm period buf length should be the common factor of
 * the aac input pcm frame length, or the aac timestamp will be wrong
 * here the pcm period buf length == 1024 bytes,
 * and the aac input pcm frame length == 2048
 */


#define SPS_LEN		28
#define PPS_LEN		6
#define OUTFILE		"my.flv"

#define RES_720P
#ifdef RES_720P
#define RESOLUTION_720P QCAM_VIDEO_RES_720P
#define RES_WIDTH	1280
#define RES_HEIGHT	720
#endif

#define VIDEO_FPS		15
#define VIDEO_TIME_SCALE	90000
#define VIDEO_SAMPLE_DURATION	(VIDEO_TIME_SCALE / VIDEO_FPS)

#define AUDIO_SAMPLERATE	8000
#define AUDIO_CHANNELS		1
#define AUDIO_TIME_SCALE	(AUDIO_SAMPLERATE * AUDIO_CHANNELS)
/* (AUDIO_TIME_SCALE / AUDIO_FPS)audio_period_time = 64ms, fps = 15.625 */
#define AUDIO_SAMPLE_DURATION	512
#define AAC_BITRATE		16000


static const uint8_t sps_buf[SPS_LEN] = {0x27, 0x64, 0x00, 0x29, 0xac, 0x1a, 0xd0, 0x0a,
			0x00, 0xb7, 0x4d, 0xc0, 0x40, 0x40, 0x50, 0x00,
			0x00, 0x03, 0x00, 0x10, 0x00 ,0x00, 0x03, 0x01,
			0xe8, 0xf1 ,0x42, 0x2a};
static const uint8_t pps_buf[PPS_LEN] = {0x28, 0xee, 0x01, 0x34, 0x92, 0x24};
/*
static const uint8_t sps_buf[SPS_LEN + 4] = {0x00, 0x00, 0x00, 0x1c, 0x27, 0x64,
			0x00, 0x29, 0xac, 0x1a, 0xd0, 0x0a,
			0x00, 0xb7, 0x4d, 0xc0, 0x40, 0x40, 0x50, 0x00,
			0x00, 0x03, 0x00, 0x10, 0x00 ,0x00, 0x03, 0x01,
			0xe8, 0xf1 ,0x42, 0x2a};
static const uint8_t pps_buf[PPS_LEN + 4] = {0x00, 0x00, 0x00, 0x06, 0x28, 0xee,
			0x01, 0x04, 0x92, 0x24};
			*/
static int g_exit;
static HANDLE_AACENCODER aac_enc_hd;
static uint8_t aac_decoder_conf[64];
static int aac_decoder_conf_len;
static FILE *flv_hd;


void sig_handle(int sig)
{
	g_exit = 1;
}

void h264_cb(const struct timeval *tv, const void *data,
	const int len, const int keyframe)
{
	uint8_t *buf = NULL;
	int buf_len = 0;
	uint32_t timestamp = 0;
	int buf_payload_len = 0;

	timestamp = (tv->tv_sec * 1000) + (tv->tv_usec / 1000);

	/* strip sps/pps from I frame and
	 * replace NALU start flag '0x00/0x00/0x00/0x01' with
	 * the length of NALU in BIGENDIAN
	 */
	if (keyframe) {
		buf = (uint8_t *)data + SPS_LEN + PPS_LEN + 2 * 4;
		buf_len = len - SPS_LEN - PPS_LEN - 2 * 4;
	} else {
		buf = (uint8_t *)data;
	}
	buf_payload_len = buf_len - 4;
	buf[0] = buf_payload_len >> 24;
	buf[1] = buf_payload_len >> 16;
	buf[2] = buf_payload_len >> 8;
	buf[3] = buf_payload_len & 0xff;

	flv_write_avc_data_tag(flv_hd, buf, buf_len, timestamp, keyframe);
}

void audio_cb(const struct timeval *tv, const void *pcm_buf,
	const int pcm_len, const void *spk_buf)
{
	uint8_t *aac_buf = NULL;
	int aac_buf_len = 0;
	uint32_t timestamp = 0;

	timestamp = (tv->tv_sec * 1000) + (tv->tv_usec / 1000);

	aac_buf_len = aac_encode(aac_enc_hd, pcm_buf, pcm_len, &aac_buf);
	if (aac_buf_len == 0)
		return;

	flv_write_aac_data_tag(flv_hd, aac_buf, aac_buf_len, timestamp);
}

int main(int argc, char *argv[])
{
	int ret = 0;

	struct FLVProfile flv_profile = {
		.name = OUTFILE,
		.has_video = true,
		.has_audio = true,
		.sample_rate = AUDIO_SAMPLERATE,
		.channels = AUDIO_CHANNELS,
		.sps = sps_buf,
		.pps = pps_buf,
		.sps_len = SPS_LEN,
		.pps_len = PPS_LEN
	};

	QCamVideoInputChannel chn = {
		.channelId = 0,
		.res = RESOLUTION_720P,
		.fps = VIDEO_FPS,
		.bitrate = 1024,
		.gop = 1,
		.vbr = YSX_BITRATE_MODE_CBR,
		.cb = h264_cb
	};

	QCamVideoInputOSD osd_info = {
		.pic_enable = 0,
		.pic_path = "/usr/osd_char_lib/argb_2222",
		.pic_x = 200,
		.pic_y = 200,
		.time_enable = 1,
		.time_x = 100,
		.time_y  = 100
	};

	QCamAudioInputAttr_aec audio_in = {
		.sampleRate = AUDIO_SAMPLERATE,
		.sampleBit = 16,
		.volume = 95,
		.cb = audio_cb
	};

	signal(SIGTERM, sig_handle);
	signal(SIGINT, sig_handle);

	ret = create_aac_encoder(&aac_enc_hd,
				AUDIO_CHANNELS, AUDIO_SAMPLERATE, AAC_BITRATE,
				aac_decoder_conf, &aac_decoder_conf_len);
	if (ret < 0)
		goto exit;

	ret = create_flv_muxer(&flv_hd, &flv_profile);
	if (ret < 0)
		goto exit;

	QCamAV_Context_Init();

	ret = QCamVideoInput_Init();
	if (ret)
		goto out;

	ret = QCamVideoInput_AddChannel(chn);
	if (ret)
		goto out;

	ret = QCamVideoInput_SetOSD(chn.channelId, &osd_info);
	if (ret)
		goto out;

	ret = QCamAudioInputOpen_ysx(&audio_in);
	if (ret)
		goto out;

	ret = QCamVideoInput_Start();
	if (ret)
		goto out;

	ret = QCamAudioInputStart();
	if (ret)
		goto out;

	while (!g_exit)
		sleep(1);

out:
	QCamVideoInput_Uninit();
	QCamAudioInputStop();
	QCamAudioInputClose_ysx();

	QCamAV_Context_Release();

exit:
	destroy_aac_encoder(&aac_enc_hd);
	destroy_flv_muxer(flv_hd);
	return ret;

}

flv封装H264+AAC

一. 概述

二. 代码

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