import (
"context"
"encoding/json"
"fmt"
"io"
"time"
aiplatform "cloud.google.com/go/aiplatform/apiv1beta1"
aiplatformpb "cloud.google.com/go/aiplatform/apiv1beta1/aiplatformpb"
"google.golang.org/api/option"
"google.golang.org/protobuf/encoding/protojson"
"google.golang.org/protobuf/types/known/structpb"
)
// generateForVideo shows how to use the multimodal model to generate embeddings for video input.
func generateForVideo(w io.Writer, project, location string) error {
// location = "us-central1"
// The default context timeout may be not enough to process a video input.
ctx, cancel := context.WithTimeout(context.Background(), 15*time.Second)
defer cancel()
apiEndpoint := fmt.Sprintf("%s-aiplatform.googleapis.com:443", location)
client, err := aiplatform.NewPredictionClient(ctx, option.WithEndpoint(apiEndpoint))
if err != nil {
return fmt.Errorf("failed to construct API client: %w", err)
}
defer client.Close()
model := "multimodalembedding@001"
endpoint := fmt.Sprintf("projects/%s/locations/%s/publishers/google/models/%s", project, location, model)
// This is the input to the model's prediction call. For schema, see:
// https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/multimodal-embeddings-api#request_body
instances, err := structpb.NewValue(map[string]any{
"video": map[string]any{
// Video input can be provided either as a Google Cloud Storage URI or as base64-encoded
// bytes using the "bytesBase64Encoded" field.
"gcsUri": "gs://cloud-samples-data/vertex-ai-vision/highway_vehicles.mp4",
"videoSegmentConfig": map[string]any{
"startOffsetSec": 1,
"endOffsetSec": 5,
},
},
})
if err != nil {
return fmt.Errorf("failed to construct request payload: %w", err)
}
req := &aiplatformpb.PredictRequest{
Endpoint: endpoint,
// The model supports only 1 instance per request.
Instances: []*structpb.Value{instances},
}
resp, err := client.Predict(ctx, req)
if err != nil {
return fmt.Errorf("failed to generate embeddings: %w", err)
}
instanceEmbeddingsJson, err := protojson.Marshal(resp.GetPredictions()[0])
if err != nil {
return fmt.Errorf("failed to convert protobuf value to JSON: %w", err)
}
// For response schema, see:
// https://cloud.google.com/vertex-ai/generative-ai/docs/model-reference/multimodal-embeddings-api#response-body
var instanceEmbeddings struct {
VideoEmbeddings []struct {
Embedding []float32 `json:"embedding"`
StartOffsetSec float64 `json:"startOffsetSec"`
EndOffsetSec float64 `json:"endOffsetSec"`
} `json:"videoEmbeddings"`
}
if err := json.Unmarshal(instanceEmbeddingsJson, &instanceEmbeddings); err != nil {
return fmt.Errorf("failed to unmarshal json: %w", err)
}
// Get the embedding for our single video segment (`.videoEmbeddings` object has one entry per
// each processed segment).
videoEmbedding := instanceEmbeddings.VideoEmbeddings[0]
fmt.Fprintf(w, "Video embedding (seconds: %.f-%.f; length=%d): %v\n",
videoEmbedding.StartOffsetSec,
videoEmbedding.EndOffsetSec,
len(videoEmbedding.Embedding),
videoEmbedding.Embedding,
)
// Example response:
// Video embedding (seconds: 1-5; length=1408): [-0.016427778 0.032878537 -0.030755188 ... ]
return nil
}
