每帧后添加SEI消息

Question

我需要编写一个简单的编码器，在每个编码帧后添加一个 SEI 单元。

我查看了 BSAnalyzer，它看起来正是我需要的

SEI 在每一帧之后出现。但是当我在 ffmpeg 中播放文件时出现错误：

[NULL @ 000001cd901df1c0] SEI type 5 size 179843 truncated at 179776
[h264 @ 000001cd96eae780] SEI type 5 size 179843 truncated at 179774
[NULL @ 000001cd901df1c0] SEI type 5 size 179843 truncated at 179776
[h264 @ 000001cd970789c0] SEI type 5 size 179843 truncated at 179774
...and more

我写SEI的代码：

static const uint8_t START_MARKER[4] = {0x0, 0x0, 0x0, 0x1};
static const uint8_t UUID[16] = {
    0x81, 0x39, 0xe9, 0xbd, 0xa6, 0x09, 0x48, 0xb7,
    0x76, 0x2c, 0xc8, 0x20, 0xd9, 0x68, 0xcc, 0xcf};

static const uint8_t SEI_TYPE[1] = {0x06};
static const uint8_t PAYLOAD_TYPE[1] = {0x05};

int calc_sei_size(size_t user_data_size)
{
    int new_buffer_size = 0;
    new_buffer_size += sizeof(START_MARKER); // NAL marker
    new_buffer_size += sizeof(SEI_TYPE);     //+NAL type = 0x06
    new_buffer_size += sizeof(PAYLOAD_TYPE); //+PayloadType = 0x05

    int payload_size = user_data_size + sizeof(UUID); //user_data + uuid
    while (payload_size > 0xFF)
    {
        payload_size -= 0xFF;
        new_buffer_size++; // PayloadSize how FF while is more 255
    }
    new_buffer_size += 0xFF - payload_size; //+PayloadSize diff
    new_buffer_size += sizeof(UUID);        //+Uuid
    new_buffer_size += user_data_size;      //+userData
    return new_buffer_size;
}

void sei_write(uint8_t *user_data, size_t user_data_size)
{
    int newSize = calc_sei_size(user_data_size);
    uint8_t *buffer = (uint8_t *)calloc(sizeof(uint8_t), newSize);

    int offset = 0;
    memcpy(&buffer[offset], START_MARKER, sizeof(START_MARKER)); // copy start marker
    offset += sizeof(START_MARKER);
    memcpy(&buffer[offset], SEI_TYPE, sizeof(SEI_TYPE)); // copy SEI_TYPE
    offset += sizeof(SEI_TYPE);
    memcpy(&buffer[offset], PAYLOAD_TYPE, sizeof(PAYLOAD_TYPE)); // copy SEI_TYPE
    offset += sizeof(PAYLOAD_TYPE);

    int payload_size = user_data_size + sizeof(UUID);
    while (payload_size > 0xFF)
    {
        payload_size -= 0xFF;
        buffer[offset++] = 0xFF;
    }
    buffer[offset++] = 0xFF - payload_size;
    memcpy(&buffer[offset], UUID, sizeof(UUID)); // copy UUID
    offset += sizeof(UUID);
    memcpy(&buffer[offset], user_data, user_data_size); // copy user_data

    DoSomeWithBuffer(buffer, newSize)
}

Answer 1

试试这个

int calc_sei_size(size_t user_data_size) {
    int new_buffer_size = sizeof(START_MARKER) + sizeof(SEI_TYPE) + sizeof(PAYLOAD_TYPE);
    int payload_size = user_data_size + sizeof(UUID); // user_data + uuid

    new_buffer_size += payload_size; // Adding user_data and UUID size
    new_buffer_size += 1; // For the remaining size byte

    while (payload_size > 0xFF) {
        payload_size -= 0xFF;
        new_buffer_size++; // Adding a byte for each 0xFF byte
    }

    return new_buffer_size;
}

void sei_write(uint8_t *user_data, size_t user_data_size) {
    int newSize = calc_sei_size(user_data_size);
    uint8_t *buffer = (uint8_t *)calloc(sizeof(uint8_t), newSize);

    int offset = 0;
    memcpy(&buffer[offset], START_MARKER, sizeof(START_MARKER)); // copy start marker
    offset += sizeof(START_MARKER);
    memcpy(&buffer[offset], SEI_TYPE, sizeof(SEI_TYPE)); // copy SEI_TYPE
    offset += sizeof(SEI_TYPE);
    memcpy(&buffer[offset], PAYLOAD_TYPE, sizeof(PAYLOAD_TYPE)); // copy PAYLOAD_TYPE
    offset += sizeof(PAYLOAD_TYPE);

    int payload_size = user_data_size + sizeof(UUID);
    while (payload_size > 0xFF) {
        payload_size -= 0xFF;
        buffer[offset++] = 0xFF;
    }
    buffer[offset++] = payload_size; // Correctly write the remaining size

    memcpy(&buffer[offset], UUID, sizeof(UUID)); // copy UUID
    offset += sizeof(UUID);
    memcpy(&buffer[offset], user_data, user_data_size); // copy user_data

    DoSomeWithBuffer(buffer, newSize);

    free(buffer); // Don't forget to free the allocated memory
}