src/streamlit_app.py

import streamlit as st
import os

# Video directory
VIDEO_FOLDER = "./src/synthda_falling_realreal/"

# Set page layout
st.set_page_config(layout="wide")
st.title("AutoSynthDa Pose Interpolation Viewer")

st.markdown("""
### AutoSynthDa Interpolation Viewer

AutoSynthDa blends two input motion videos to **generate kinematically coherent, synthetic action videos**.  
Use the slider below to explore how the system interpolates motion from one video to another.  
Source: [github.com/nvidia/synthda](https://github.com/nvidia/synthda)
""")

# Slider instruction
st.markdown(
    '<p style="text-align:center;"><strong>Use the slider to control the interpolation between Input Video 1 (left) and Input Video 2 (right).</strong></p>',
    unsafe_allow_html=True
)

# Hide the orange filled track of the slider
st.markdown("""
    <style>
    /* Hide the filled track */
    .stSlider > div[data-baseweb="slider"] > div > div:nth-child(2) {
        background: transparent !important;
    }
    /* Optional: adjust track background to be subtle */
    .stSlider > div[data-baseweb="slider"] > div > div:first-child {
        background-color: #ccc !important;
    }
    </style>
""", unsafe_allow_html=True)

# Slider (starts at 0.5)
weight = st.slider("Interpolation Weight", 0.1, 0.9, 0.5, step=0.1)

# Filenames
filename_interp = f"videos_generated_{weight:.1f}.mp4"
filename_input1 = "videos_generated_0.0.mp4"
filename_input2 = "videos_generated_1.0.mp4"

# Full paths
video_interp = os.path.join(VIDEO_FOLDER, filename_interp)
video_input1 = os.path.join(VIDEO_FOLDER, filename_input1)
video_input2 = os.path.join(VIDEO_FOLDER, filename_input2)

# File checks
exists_interp = os.path.exists(video_interp)
exists_1 = os.path.exists(video_input1)
exists_2 = os.path.exists(video_input2)

# Interpolation status
if weight == 0.0:
    st.success("Showing Input Video 1 (no interpolation)")
elif weight == 1.0:
    st.success("Showing Input Video 2 (no interpolation)")
else:
    w2 = round(1.0 - weight, 1)
    st.info(
        f"Generated motion: {weight:.1f} from Input Video 1 + {w2:.1f} from Input Video 2"
    )

# Layout: 3 columns for videos
col1, col2, col3 = st.columns(3)

# Centered labels and video playback
with col1:
    st.markdown("<div style='text-align: center; font-weight: bold;'>Input Video 1</div>", unsafe_allow_html=True)
    if exists_1:
        st.video(video_input1)
    else:
        st.error("Video 1 not found")

with col2:
    st.markdown("<div style='text-align: center; font-weight: bold;'>Interpolated Video</div>", unsafe_allow_html=True)
    if exists_interp:
        st.video(video_interp)
    else:
        st.error("Interpolated video not found")

with col3:
    st.markdown("<div style='text-align: center; font-weight: bold;'>Input Video 2</div>", unsafe_allow_html=True)
    if exists_2:
        st.video(video_input2)
    else:
        st.error("Video 2 not found")