Controlling WS2812 LED with PWM and DMA - STM32F1 - stm32

Question

A try to controlling WS2812 LEDs using timer PWM and DMA. I almost succeeded but now I have a problem that I can't solve. As You can see on the image the first two LEDs glow green but another LEDs glow reed. But all of them should glow green.
![Link for image:] https://ibb.co/c2XEqS
I use Nucleo Board with STM32F1 microcontroller (64MHZ).
Timer initialization:
void Init_TIM4()
{
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
GPIO_InitTypeDef gpio;
GPIO_StructInit(&gpio);
gpio.GPIO_Mode = GPIO_Mode_AF_PP;
gpio.GPIO_Pin = GPIO_Pin_8;
gpio.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOB, &gpio);
TIM_TimeBaseInitTypeDef tim;
TIM_TimeBaseStructInit(&tim);
tim.TIM_CounterMode = TIM_CounterMode_Up;
tim.TIM_Period = 80;
tim.TIM_ClockDivision = 0;
TIM_TimeBaseInit(TIM4, &tim);
TIM_OCInitTypeDef channel;
TIM_OCStructInit(&channel);
channel.TIM_OCMode = TIM_OCMode_PWM1;
channel.TIM_OutputState = TIM_OutputState_Enable;
channel.TIM_Pulse = 0;
channel.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OC3Init(TIM4, &channel);
}
DMA and rest of code:
#define BUFFER_SIZE 25
volatile uint16_t src_buffer[BUFFER_SIZE] = {32, 32, 32, 32, 32, 32, 32, 32, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16, 16,0};
void send_data()
{
DMA_SetCurrDataCounter(DMA1_Channel1, BUFFER_SIZE);
DMA_Cmd(DMA1_Channel1, ENABLE);
TIM_Cmd(TIM4, ENABLE);
while(!DMA_GetFlagStatus(DMA1_FLAG_TC1));
TIM_Cmd(TIM4, DISABLE);
DMA_Cmd(DMA1_Channel1, DISABLE);
DMA_ClearFlag(DMA1_FLAG_TC1);
}
int main(void)
{
Init_TIM4();
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE);
DMA_InitTypeDef dma;
DMA_StructInit(&dma);
dma.DMA_PeripheralBaseAddr = (uint32_t)&TIM4->CCR3;
dma.DMA_PeripheralInc = DMA_PeripheralInc_Disable;
dma.DMA_MemoryBaseAddr = (uint32_t)src_buffer;
dma.DMA_MemoryInc = DMA_MemoryInc_Enable;
dma.DMA_BufferSize = BUFFER_SIZE;
dma.DMA_M2M = DMA_M2M_Disable;
dma.DMA_DIR = DMA_DIR_PeripheralDST;
dma.DMA_PeripheralDataSize = DMA_PeripheralDataSize_HalfWord;
dma.DMA_Mode = DMA_Mode_Normal;
dma.DMA_MemoryDataSize = DMA_MemoryDataSize_HalfWord;
DMA_Init(DMA1_Channel1, &dma);
TIM_DMACmd(TIM4, TIM_DMA_CC1, ENABLE);
for (int i = 0; i < 8; i++) {
send_data();
}
while(1)
{
}
}