# v4l2h264enc

Source: [https://docs.qualcomm.com/doc/80-70017-50SC/topic/v4l2h264enc.html](https://docs.qualcomm.com/doc/80-70017-50SC/topic/v4l2h264enc.html)

v4l2h264enc 插件使用 V4L2 API 对视频流进行编码。

- 该插件使用 H.264 视频编码器在支持的平台上提供硬件加速的 H.264 (MPEG-4 第 10 部分) 编码。
- 该插件基于[GstVideoEncoder](https://gstreamer.freedesktop.org/documentation/video/gstvideoencoder.html?gi-language=c)基类。

## 继承链

[GObject](https://docs.gtk.org/gobject/) → [GstObject](https://gstreamer.freedesktop.org/documentation/gstreamer/gstobject.html?gi-language=c) → [GstElement](https://gstreamer.freedesktop.org/documentation/gstreamer/gstelement.html?gi-language=c) → [GstVideoEncoder](https://gstreamer.freedesktop.org/documentation/video/gstvideoencoder.html?gi-language=c) → GstV4l2VideoEnc → v4l2h264enc

下表提供了有关 v4l2h264enc 的端口模板和组件属性的信息。有关用例信息，请参见[视频编码](https://docs.qualcomm.com/doc/80-70017-50SC/topic/camera-and-video-encode.html)和[基于切片的编码](https://docs.qualcomm.com/doc/80-70017-50SC/topic/camera-and-video-encode.html#slice-based-encoding)。

## 端口配置

| 端口名称 | 功能 | 功能 | 功能 |
| --- | --- | --- | --- |
| SINK 模板：'sink'<br><ul class="ul" id="v4l2h264enc__ul_q25_hrz_q1c"><br>                                    <li class="li"><em class="ph i">可用性：</em> 始终可用</li><br><br>                                    <li class="li"><em class="ph i">方向：</em> 接收端</li><br><br>                                </ul> | video/x-raw | format： | { (string)NV12, (string)NV21 } |
| SINK 模板：'sink'<br><ul class="ul" id="v4l2h264enc__ul_q25_hrz_q1c"><br>                                    <li class="li"><em class="ph i">可用性：</em> 始终可用</li><br><br>                                    <li class="li"><em class="ph i">方向：</em> 接收端</li><br><br>                                </ul> | video/x-raw | width: | [ 1, 32768 ] |
| SINK 模板：'sink'<br><ul class="ul" id="v4l2h264enc__ul_q25_hrz_q1c"><br>                                    <li class="li"><em class="ph i">可用性：</em> 始终可用</li><br><br>                                    <li class="li"><em class="ph i">方向：</em> 接收端</li><br><br>                                </ul> | video/x-raw | height: | [ 1, 32768 ] |
| SINK 模板：'sink'<br><ul class="ul" id="v4l2h264enc__ul_q25_hrz_q1c"><br>                                    <li class="li"><em class="ph i">可用性：</em> 始终可用</li><br><br>                                    <li class="li"><em class="ph i">方向：</em> 接收端</li><br><br>                                </ul> | video/x-raw | framerate： | [ 0/1, 2147483647/1 ] |
| SRC 模板：'src'<br><ul class="ul" id="v4l2h264enc__ul_r25_hrz_q1c"><br>                                    <li class="li"><em class="ph i">可用性：</em> 始终可用</li><br><br>                                    <li class="li"><em class="ph i">方向：</em> 发送</li><br><br>                                </ul> | video/x-h264 | alignment: | au |
| SRC 模板：'src'<br><ul class="ul" id="v4l2h264enc__ul_r25_hrz_q1c"><br>                                    <li class="li"><em class="ph i">可用性：</em> 始终可用</li><br><br>                                    <li class="li"><em class="ph i">方向：</em> 发送</li><br><br>                                </ul> | video/x-h264 | stream-format: | byte-stream |
| SRC 模板：'src'<br><ul class="ul" id="v4l2h264enc__ul_r25_hrz_q1c"><br>                                    <li class="li"><em class="ph i">可用性：</em> 始终可用</li><br><br>                                    <li class="li"><em class="ph i">方向：</em> 发送</li><br><br>                                </ul> | video/x-h264 | level: | { (string)1, (string)1b, (string)1.1, (string)1.2, (string)1.3, (string)2, (string)2.1, (string)2.2, (string)3, (string)3.1, (string)3.2, (string)4, (string)4.1, (string)4.2, (string)5, (string)5.1 } |
| SRC 模板：'src'<br><ul class="ul" id="v4l2h264enc__ul_r25_hrz_q1c"><br>                                    <li class="li"><em class="ph i">可用性：</em> 始终可用</li><br><br>                                    <li class="li"><em class="ph i">方向：</em> 发送</li><br><br>                                </ul> | video/x-h264 | profile: | { (string)baseline, (string)constrained-baseline, (string)main, (string)high, (string)constrained-high } |
|  |  |  |  |
|  |  |  |  |
|  |  |  |  |

## 组件配置

Table : v4l2h264enc 的组件属性

| 属性 | 说明 |
| --- | --- |
| capture-io-mode | 采集 I/O 模式（匹配发送端）<br><ul class="ul" id="v4l2h264enc__ul_sq5_jrz_q1c"><br>                                    <li class="li">标志：可读、可写</li><br><br>                                    <li class="li">枚举“GstV4l2IOMode”；默认：0，“auto”<ul class="ul" id="v4l2h264enc__ul_h5x_krz_q1c"><br>                                            <li class="li"> (0): auto - GST_V4L2_IO_AUTO</li><br><br>                                            <li class="li"> (1): rw - GST_V4L2_IO_RW</li><br><br>                                            <li class="li"> (2): mmap - GST_V4L2_IO_MMAP</li><br><br>                                            <li class="li"> (3): userptr - GST_V4L2_IO_USERPTR</li><br><br>                                            <li class="li"> (4): dmabuf - GST_V4L2_IO_DMABUF</li><br><br>                                            <li class="li"> (5): dmabuf-import - GST_V4L2_IO_DMABUF_IMPORT</li><br><br>                                        </ul><br></li><br><br>                                </ul> |
| device | 设备位置<br><ul class="ul" id="v4l2h264enc__ul_tq5_jrz_q1c"><br>                                    <li class="li">标志：可读</li><br><br>                                    <li class="li">字符串。默认：“/dev/video1”</li><br><br>                                </ul> |
| device-fd | 设备的文件描述符<br><ul class="ul" id="v4l2h264enc__ul_uq5_jrz_q1c"><br>                                    <li class="li">标志：可读</li><br><br>                                    <li class="li">整型。范围：-1 - 2147483647；默认值：-1</li><br><br>                                </ul> |
| device-name | 设备名称<br><ul class="ul" id="v4l2h264enc__ul_vq5_jrz_q1c"><br>                                    <li class="li">标志：可读</li><br><br>                                    <li class="li">字符串。默认值：null</li><br><br>                                </ul> |
| extra-controls | 设备的额外 v4l2 控件 ID (CID)<br><ul class="ul" id="v4l2h264enc__ul_wq5_jrz_q1c"><br>                                    <li class="li">标志：可读、可写</li><br><br>                                    <li class="li">"GstStructure" 类型的装箱指针</li><br><br>                                </ul> |
| min-force-key-unit-interval | force-key-unit 请求之间的最小间隔（单位：纳秒）<br><ul class="ul" id="v4l2h264enc__ul_xq5_jrz_q1c"><br>                                    <li class="li">标志：可读、可写</li><br><br>                                    <li class="li">64 位无符号整型</li><br><br>                                    <li class="li">范围：0 - 18446744073709551615；默认：0</li><br><br>                                </ul> |
| name | 对象名称<br><ul class="ul" id="v4l2h264enc__ul_yq5_jrz_q1c"><br>                                    <li class="li">标志：可读、可写，0x2000</li><br><br>                                    <li class="li">字符串。默认：“v4l2h264enc0”</li><br><br>                                </ul> |
| output-io-mode | 输出侧 I/O 模式（匹配接收端）<br><ul class="ul" id="v4l2h264enc__ul_zq5_jrz_q1c"><br>                                    <li class="li">标志：可读、可写</li><br><br>                                    <li class="li"><br>                                        <p class="p">枚举 “GstV4l2IOMode” 默认： 0，“auto”</p><ul class="ul" id="v4l2h264enc__ul_j31_nrz_q1c"><br>                                            <li class="li"> (0): auto - GST_V4L2_IO_AUTO</li><br><br>                                            <li class="li"> (1): rw - GST_V4L2_IO_RW</li><br><br>                                            <li class="li"> (2): mmap - GST_V4L2_IO_MMAP</li><br><br>                                            <li class="li"> (3): userptr - GST_V4L2_IO_USERPTR</li><br><br>                                            <li class="li"> (4): dmabuf - GST_V4L2_IO_DMABUF</li><br><br>                                            <li class="li"> (5): dmabuf-import - GST_V4L2_IO_DMABUF_IMPORT</li><br><br>                                        </ul><br><br>                                    </li><br><br>                                </ul> |
| parent | 对象的父级<br><ul class="ul" id="v4l2h264enc__ul_ar5_jrz_q1c"><br>                                    <li class="li">标志：可读、可写，0x2000</li><br><br>                                    <li class="li">"GstObject" 类型的对象</li><br><br>                                </ul> |
| qos | 处理下游的服务质量事件<br><ul class="ul" id="v4l2h264enc__ul_br5_jrz_q1c"><br>                                    <li class="li">标志：可读、可写</li><br><br>                                    <li class="li">Boolean。默认值：true</li><br><br>                                </ul> |

Table : v4l2ctl extra-controls – 用户控件

| 控件名称 | 控件类型 | 参数 |
| --- | --- | --- |
| horizontal\_flip | Boolean | <ul class="ul" id="v4l2h264enc__ul_ts2_ljc_fbc"><br>                                    <li class="li">值=0；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| vertical\_flip | Boolean | <ul class="ul" id="v4l2h264enc__ul_us2_ljc_fbc"><br>                                    <li class="li">值=0；这是默认值</li><br><br>                                    <li class="li">flags= execute-on-write</li><br><br>                                </ul> |
| rotate | 整型 | <ul class="ul" id="v4l2h264enc__ul_vs2_ljc_fbc"><br>                                    <li class="li">最小值=0 </li><br><br>                                    <li class="li">最大值=270 </li><br><br>                                    <li class="li">步长=90 </li><br><br>                                    <li class="li">值=0；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write and modify-layout</li><br><br>                                </ul> |

Table : v4l2ctl extra-controls – 编解码控件

| 控件名称 | 控件类型 | 参数 |
| --- | --- | --- |
| video\_b\_frames | 整型 | <ul class="ul" id="v4l2h264enc__ul_p4d_tjc_fbc"><br>                                    <li class="li">最小值=0 </li><br><br>                                    <li class="li">最大值=7 </li><br><br>                                    <li class="li">step=1<ul class="ul" id="v4l2h264enc__ul_q4d_tjc_fbc"><br>                                            <li class="li">值=0；这是默认值</li><br><br>                                            <li class="li">flags=update and execute-on-write</li><br><br>                                        </ul><br></li><br><br>                                </ul> |
| video\_gop\_size | 整型 | <ul class="ul" id="v4l2h264enc__ul_r4d_tjc_fbc"><br>                                    <li class="li">最小值=0 </li><br><br>                                    <li class="li">最大值=2147483647 </li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">value=59；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| video\_bitrate\_mode | 菜单 | <ul class="ul" id="v4l2h264enc__ul_t4d_tjc_fbc"><br>                                    <li class="li">最小值=0 </li><br><br>                                    <li class="li">最大值=3 </li><br><br>                                    <li class="li">value=0：可变比特率<ul class="ul" id="v4l2h264enc__ul_s4d_tjc_fbc"><br>                                            <li class="li">0：可变码率；这是默认值 </li><br><br>                                            <li class="li">1：恒定比特率</li><br><br>                                            <li class="li">3：最大比特率</li><br><br>                                        </ul><br></li><br><br>                                    <li class="li">flags=update, execute-on-write</li><br><br>                                </ul> |
| video\_bitrate | 整型 | <ul class="ul" id="v4l2h264enc__ul_v4d_tjc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">最大值=100000000</li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">value=20000000 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                    <li class="li"> </li><br><br>                                </ul> |
| frame\_level\_rate\_control\_enable | 整型 | <ul class="ul" id="v4l2h264enc__ul_x4d_tjc_fbc"><br>                                    <li class="li">值=1；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| maximum\_bytes\_in\_a\_slice | 整型 | <ul class="ul" id="v4l2h264enc__ul_y4d_tjc_fbc"><br>                                    <li class="li">最小值=512 </li><br><br>                                    <li class="li">最大值=12500000 </li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">值 =512；这是默认值。</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| number\_of\_mbs\_in\_a\_slice | 整型 | <ul class="ul" id="v4l2h264enc__ul_z4d_tjc_fbc"><br>                                    <li class="li">min=1 </li><br><br>                                    <li class="li">最大值=36864 </li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">值=1；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| slice\_partitioning\_method | 菜单 | <ul class="ul" id="v4l2h264enc__ul_bpd_tjc_fbc"><br>                                    <li class="li">最小值=0 </li><br><br>                                    <li class="li">最大值=2 </li><br><br>                                    <li class="li">value=0: Single<ul class="ul" id="v4l2h264enc__ul_apd_tjc_fbc"><br>                                            <li class="li">0：单个；这是默认值</li><br><br>                                            <li class="li">1：最大宏块</li><br><br>                                            <li class="li">2：最大字节数</li><br><br>                                        </ul><br></li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| ltr\_count | 整型 | <ul class="ul" id="v4l2h264enc__ul_cpd_tjc_fbc"><br>                                    <li class="li">最小值=0 </li><br><br>                                    <li class="li">最大值=2 </li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">值=0；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| frame\_ltr\_index | 整型 | <ul class="ul" id="v4l2h264enc__ul_dpd_tjc_fbc"><br>                                    <li class="li">最小值=-1 </li><br><br>                                    <li class="li">最大值=1 </li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">值 =-1；这是默认值。</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| use\_ltr\_frames | 位掩码 | <ul class="ul" id="v4l2h264enc__ul_epd_tjc_fbc"><br>                                    <li class="li">max=0x00000003 </li><br><br>                                    <li class="li">default=0x00000000 </li><br><br>                                    <li class="li">value=0</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| intra\_refresh\_period | 整型 | <ul class="ul" id="v4l2h264enc__ul_fpd_tjc_fbc"><br>                                    <li class="li">最小值=0 </li><br><br>                                    <li class="li">最大值=2147483647 </li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">值=0；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| intra\_refresh\_period\_type | 菜单 | <ul class="ul" id="v4l2h264enc__ul_hpd_tjc_fbc"><br>                                    <li class="li">最小值=0 </li><br><br>                                    <li class="li">最大值=1 </li><br><br>                                    <li class="li">value=0<ul class="ul" id="v4l2h264enc__ul_gpd_tjc_fbc"><br>                                            <li class="li">0：随机；这是默认值</li><br><br>                                            <li class="li">1: Cyclic</li><br><br>                                        </ul><br></li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |

Table : v4l2ctl extra-controls – H.264 codec 控件

| 控件名称 | 控件类型 | 参数 |
| --- | --- | --- |
| h264\_i\_frame\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_j3w_jkc_fbc"><br>                                    <li class="li">min=1 </li><br><br>                                    <li class="li">max=51 </li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">值=20；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_p\_frame\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_k3w_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">max=51 </li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">值=20；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_b\_frame\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_l3w_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">max=51</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=20；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_minimum\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_m3w_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">max=51</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=1；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_maximum\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_n3w_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">max=51</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">value=51；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_entropy\_mode | 菜单 | <ul class="ul" id="v4l2h264enc__ul_p3w_jkc_fbc"><br>                                    <li class="li">最小值=0</li><br><br>                                    <li class="li">最大值=1</li><br><br>                                    <li class="li">value=1 (CABAC)<ul class="ul" id="v4l2h264enc__ul_o3w_jkc_fbc"><br>                                            <li class="li">0：CAVLC</li><br><br>                                            <li class="li">1：CABAC；这是默认值</li><br><br>                                        </ul><br></li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_level | 菜单 | <ul class="ul" id="v4l2h264enc__ul_r3w_jkc_fbc"><br>                                    <li class="li">最小值=0</li><br><br>                                    <li class="li">最大值=15</li><br><br>                                    <li class="li">值 =15 (5.1)<ul class="ul" id="v4l2h264enc__ul_q3w_jkc_fbc"><br>                                            <li class="li">0:1</li><br><br>                                            <li class="li">1: 1b</li><br><br>                                            <li class="li">2: 1.1</li><br><br>                                            <li class="li">3: 1.2</li><br><br>                                            <li class="li">4: 1.3</li><br><br>                                            <li class="li">5: 2</li><br><br>                                            <li class="li">6: 2.1</li><br><br>                                            <li class="li">7: 2.2</li><br><br>                                            <li class="li">8: 3</li><br><br>                                            <li class="li">9: 3.1</li><br><br>                                            <li class="li">10: 3.2</li><br><br>                                            <li class="li">11: 4</li><br><br>                                            <li class="li">12: 4.1</li><br><br>                                            <li class="li">13: 4.2</li><br><br>                                            <li class="li">14: 5</li><br><br>                                            <li class="li">15：5.1；这是默认值</li><br><br>                                        </ul><br></li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_profile | 菜单 | <ul class="ul" id="v4l2h264enc__ul_t3w_jkc_fbc"><br>                                    <li class="li">最小值=0</li><br><br>                                    <li class="li">最大值=17 </li><br><br>                                    <li class="li">value=4（高）<ul class="ul" id="v4l2h264enc__ul_s3w_jkc_fbc"><br>                                            <li class="li">0: 基线</li><br><br>                                            <li class="li">1：受约束基准</li><br><br>                                            <li class="li">2: 主机</li><br><br>                                            <li class="li">4：高；这是默认值</li><br><br>                                            <li class="li">17：受约束高</li><br><br>                                        </ul><br></li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| enable\_h264\_hierarchical\_coding | 整型 | <ul class="ul" id="v4l2h264enc__ul_u3w_jkc_fbc"><br>                                    <li class="li">最小值=0</li><br><br>                                    <li class="li">最大值=1</li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">值=0；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_hierarchical\_coding\_type | 菜单 | <ul class="ul" id="v4l2h264enc__ul_w3w_jkc_fbc"><br>                                    <li class="li">最小值=0</li><br><br>                                    <li class="li">最大值=1</li><br><br>                                    <li class="li">value =1<ul class="ul" id="v4l2h264enc__ul_v3w_jkc_fbc"><br>                                            <li class="li">0：层次编码 B</li><br><br>                                            <li class="li">1：Hier Coding P；这是默认值</li><br><br>                                        </ul><br></li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_number\_of\_hc\_layers | 整型 | <ul class="ul" id="v4l2h264enc__ul_x3w_jkc_fbc"><br>                                    <li class="li">最小值=0</li><br><br>                                    <li class="li">最大值=5</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=0；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_i\_frame\_minimum\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_y3w_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">max=51</li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">值=1；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_i\_frame\_maximum\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_z3w_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">max=51</li><br><br>                                    <li class="li">step=1 </li><br><br>                                    <li class="li">value=51；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_p\_frame\_minimum\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_ajw_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">max=51</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=1；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_p\_frame\_maximum\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_bjw_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">max=51</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">value=51；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_b\_frame\_minimum\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_cjw_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">max=51</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=1；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_b\_frame\_maximum\_qp\_value | 整型 | <ul class="ul" id="v4l2h264enc__ul_djw_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">max=51</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">value=51；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_hierarchical\_lay\_0\_bitrate | 整型 | <ul class="ul" id="v4l2h264enc__ul_ejw_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">最大值=100000000</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=20000000；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_hierarchical\_lay\_1\_bitrate | 整型 | <ul class="ul" id="v4l2h264enc__ul_fjw_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">最大值=100000000</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=20000000；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_hierarchical\_lay\_2\_bitrate | 整型 | <ul class="ul" id="v4l2h264enc__ul_gjw_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">最大值=100000000</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=20000000；这是默认值 </li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_hierarchical\_lay\_3\_bitrate | 整型 | <ul class="ul" id="v4l2h264enc__ul_hjw_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">最大值=100000000</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=20000000；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_hierarchical\_lay\_4\_bitrate | 整型 | <ul class="ul" id="v4l2h264enc__ul_ijw_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">最大值=100000000</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=20000000；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |
| h264\_hierarchical\_lay\_5\_bitrate | 整型 | <ul class="ul" id="v4l2h264enc__ul_jjw_jkc_fbc"><br>                                    <li class="li">min=1</li><br><br>                                    <li class="li">最大值=100000000</li><br><br>                                    <li class="li">step=1</li><br><br>                                    <li class="li">值=20000000；这是默认值</li><br><br>                                    <li class="li">flags=execute-on-write</li><br><br>                                </ul> |

**上一级主题：** [显示、摄像头、编码和解码插件](https://docs.qualcomm.com/doc/80-70017-50SC/topic/display-plugins.html)

Last Published: Nov 11, 2025

[Previous Topic
v4l2h265dec](https://docs.qualcomm.com/bundle/publicresource/80-70017-50SC/topics/v4l2h265dec.md) [Next Topic
v4l2h265enc](https://docs.qualcomm.com/bundle/publicresource/80-70017-50SC/topics/v4l2h265enc.md)