# Video Captioning Human labeling of videos is expensive and time-consuming. We adopt powerful image captioning models to generate captions for videos. Although GPT-4V achieves a better performance, its 20s/sample speed is too slow for us. As for our v1.2 model, we captioned our training videos with the [PLLaVA](https://github.com/magic-research/PLLaVA) model. PLLaVA performs highly competitively on multiple video-based text generation benchmarks including [MVbench](https://paperswithcode.com/sota/video-question-answering-on-mvbench?p=pllava-parameter-free-llava-extension-from-1). ## PLLaVA Captioning To balance captioning speed and performance, we chose the 13B version of PLLaVA configured with 2*2 spatial pooling. We feed it with 4 frames evenly extracted from the video. ### Installation Install the required dependancies by following our [installation instructions](../../docs/installation.md)'s "Data Dependencies" and "PLLaVA Captioning" sections. ### Usage Since PLLaVA is not fashioned as a package, we will use PYTHONPATH to use it. ```bash cd .. # step back to pllava_dir CUDA_VISIBLE_DEVICES=0,1,2,3,4,5,6,7 \ PYTHONPATH='$PYTHONPATH:OPEN_SORA_HOME/tools/caption/pllava_dir/PLLaVA' \ nohup python caption_pllava.py \ --pretrained_model_name_or_path PLLaVA/MODELS/pllava-13b \ --use_lora \ --lora_alpha 4 \ --num_frames 4 \ --weight_dir PLLaVA/MODELS/pllava-13b \ --csv_path meta.csv \ --pooling_shape 4-12-12 \ > pllava_caption.out 2>&1 & ``` ### PLLaVA vs. LLaVA In our previous releases, we used [LLaVA](#llava-captioning) for video captioning. Qualitatively speaking, we observe that PLLaVA has a somewhat higher chance of accurately capture the details in the video than LLaVA. See below for their comparison on a video sample.
LLaVA vs PLLaVA
| LLaVA | PLLaVA | |----------|----------| | The video is a close-up shot of two gold wedding rings. The rings are placed on a (black surface)✅, casting a soft shadow beneath them. The rings are positioned in such a way that (they are facing each other)❌, creating a mirror image effect. The rings are (identical in size and design)✅, suggesting they are a pair. The lighting in the video is soft and diffused, highlighting the gold color of the rings and creating a warm and inviting atmosphere. The overall style of the video is minimalist and elegant, focusing solely on the rings and their reflection. | The video shows a pair of gold wedding rings on a (reflective surface)✅. The rings are placed one on top of the other, with the top ring slightly tilted to the left. The rings have a (shiny, metallic finish)✅ and are the main focus of the image. The background is a gradient of dark to light gray, providing a neutral backdrop that highlights the rings. There are no texts or other objects in the image. The style of the video is a simple product display with a focus on the rings, likely intended for promotional or sales purposes. The lighting and shadows suggest a soft, even light source, (possibly a studio light)✅, which creates a reflective surface beneath the rings.| ## LLaVA Captioning We extract three frames from the video for captioning. With batch inference, we can achieve 10 times speedup. With approximately 720p resolution and 1 frames, the speed is 2~3 videos/s on 8 GPUs. If we resize the smaller side to 336, the speed can be 8 videos/s. In Open-Sora v1.1, to lower the cost, we use the 7B model. ### Installation Install the required dependancies by following our [installation instructions](../../docs/installation.md)'s "Data Dependencies" and "LLaVA Captioning" sections. ### Usage Prepare a csv file for processing. The csv file can be generated by `convert_dataset.py` according to its [documentation](/tools/datasets/README.md). Then, run the following command to generate captions for videos/images with Llava: ```bash # caption with mistral-7B torchrun --nproc_per_node 8 --standalone -m tools.caption.caption_llava DATA.csv --dp-size 8 --tp-size 1 --model-path liuhaotian/llava-v1.6-mistral-7b --prompt video # caption with llava-34B # NOTE: remember to enable flash attention for this model torchrun --nproc_per_node 8 --standalone -m tools.caption.caption_llava DATA.csv --dp-size 4 --tp-size 2 --model-path liuhaotian/llava-v1.6-34b --prompt image-3ex --flash-attention # we run this on 8xH800 GPUs torchrun --nproc_per_node 8 --standalone -m tools.caption.caption_llava DATA.csv --tp-size 2 --dp-size 4 --bs 16 # at least two 80G GPUs are required torchrun --nproc_per_node 2 --standalone -m tools.caption.caption_llava DATA.csv --tp-size 2 --dp-size 1 --bs 16 # can also caption images torchrun --nproc_per_node 2 --standalone -m tools.caption.caption_llava DATA.csv --tp-size 2 --dp-size 1 --bs 16 --prompt image-3ex ``` Please note that you should add the `--flash-attention` flag when running with Llama-based Llava models as it provides speedup but do turn it off for mistral-based ones. Reasons can be found in [this issue](https://discuss.huggingface.co/t/flash-attention-has-no-effect-on-inference/73453). After running the script, with `dp-size=N`, you will get `N` parts of csv files. Run the following command to merge them: ```bash python -m tools.datasets.datautil DATA_caption_part*.csv --output DATA_caption.csv ``` ### Resume Sometimes the process may be interrupted. We can resume the process by running the following command: ```bash # merge generated results python -m tools.datasets.datautil DATA_caption_part*.csv --output DATA_caption.csv # get the remaining videos python -m tools.datasets.datautil DATA.csv --difference DATA_caption.csv --output DATA_remaining.csv ``` Then use the output csv file to resume the process. ## GPT-4V Captioning Run the following command to generate captions for videos with GPT-4V: ```bash # output: DATA_caption.csv python -m tools.caption.caption_gpt4 DATA.csv --key $OPENAI_API_KEY ``` The cost is approximately $0.01 per video (3 frames per video). ## Camera Motion Detection Install required packages with `pip install -v .[data]` (See [installation.md](../../docs/installation.md)). Run the following command to classify camera motion: ```bash # output: meta_cmotion.csv python -m tools.caption.camera_motion.detect tools/caption/camera_motion/meta.csv ``` You may additionally specify `threshold` to indicate how "sensitive" the detection should be as below. For example `threshold = 0.2` means that the video is only counted as `tilt_up` when the pixels moved down by `>20%` of video height between the starting and ending frames. ```bash # output: meta_cmotion.csv python -m tools.caption.camera_motion.detect tools/caption/camera_motion/meta.csv --threshold 0.2 ``` Each video is classified according to 8 categories: `pan_right, pan_left, tilt_up, tilt_down, zoom_in, zoom_out, static, unclassified`. Categories of `tilt`, `pan` and `zoom` can overlap with each other.