Multichannel-View

from flask import Flask, Response, request, stream_with_context
import subprocess
import time

app = Flask(__name__)

# === Configuration ===
CDVR_HOST = '192.168.0.13'        # IP address of the Channels DVR server
MULTICHANNEL_VIEW_PORT = 5001  # Port for running the Flask app
STARTUP_DELAY = 3              # Delay before FFmpeg starts, in seconds (adjust if streams are slow)
LABEL_FONT_SIZE = 36           # Font size for on-screen labels
LABEL_FADE_IN = 1              # seconds to fade in
LABEL_DISPLAY = 10             # how long label is fully visible
LABEL_FADE_OUT = 2             # seconds to fade out

# === Channel Number → Name Legend (editable by users) ===
CHANNEL_NAME_RAW = """
5.1=KTLA 5
9.1=KCAL 9
1000=CBS 2
1002=FOX 11
1003=KCAL 9
1084=FOX News
1141=MSNBC
1160=NewsNation
2137=FOX 11
5225=CNN
6985=ABC News
"""

def parse_channel_name_map(raw_text):
    mapping = {}
    for line in raw_text.strip().splitlines():
        if '=' in line:
            ch_num, ch_name = line.strip().split('=', 1)
            mapping[ch_num.strip()] = ch_name.strip()
    return mapping

CHANNEL_NAME_MAP = parse_channel_name_map(CHANNEL_NAME_RAW)

def build_input_urls(channels):
    return [f"http://{CDVR_HOST}:8089/devices/ANY/channels/{ch}/stream.mpg" for ch in channels]

@app.route('/combine')
def combine_streams():
    channels = request.args.getlist('ch')[:4]
    if not channels:
        return "No channels provided", 400

    urls = build_input_urls(channels)
    num_inputs = len(urls)

    ffmpeg_cmd = ['ffmpeg', '-hide_banner', '-loglevel', 'error']

    for url in urls:
        ffmpeg_cmd += ['-ss', '1', '-i', url]

    filter_parts = []
    for i, ch in enumerate(channels):
        label = CHANNEL_NAME_MAP.get(ch, f"CH {ch}")
        filter_parts.append(
            f"[{i}:v]scale=1280:720,fps=30000/1001,"
            f"drawtext=text='{label}':x=10:y=10:fontsize={LABEL_FONT_SIZE}:"
            f"fontcolor=white:box=1:[email protected]:"
            f"alpha='if(lt(t,{LABEL_FADE_IN}),t/{LABEL_FADE_IN},"
            f"if(lt(t,{LABEL_FADE_IN}+{LABEL_DISPLAY}),1,"
            f"if(lt(t,{LABEL_FADE_IN}+{LABEL_DISPLAY}+{LABEL_FADE_OUT}),"
            f"1-(t-{LABEL_FADE_IN}-{LABEL_DISPLAY})/{LABEL_FADE_OUT},0)))'[v{i}]"
        )
        ffmpeg_cmd += ['-map', f'{i}:a?']  # Optional audio mapping

    layout_map = {
        1: "[v0]xstack=inputs=1:layout=0_0[v]",
        2: "[v0][v1]xstack=inputs=2:layout=0_0|w0_0[v]",
        3: "[v0][v1][v2]xstack=inputs=3:layout=0_0|w0_0|0_h0[v]",
        4: "[v0][v1][v2][v3]xstack=inputs=4:layout=0_0|w0_0|0_h0|w0_h0[v]"
    }
    filter_parts.append(layout_map[num_inputs])
    filter_complex = ';'.join(filter_parts)

    ffmpeg_cmd += [
        '-filter_complex', filter_complex,
        '-map', '[v]',
        '-c:v', 'h264_videotoolbox',
        '-b:v', '5120k',
        '-f', 'mpegts',
        'pipe:1'
    ]

    def generate():
        time.sleep(STARTUP_DELAY)
        process = subprocess.Popen(ffmpeg_cmd, stdout=subprocess.PIPE)
        try:
            while True:
                chunk = process.stdout.read(1024 * 16)
                if not chunk:
                    break
                yield chunk
        finally:
            process.kill()

    return Response(stream_with_context(generate()), mimetype='video/MP2T')

if __name__ == '__main__':
    app.run(host='0.0.0.0', port=MULTICHANNEL_VIEW_PORT, debug=True)