FFmpeg tcp_nodelay & multiple_requests

[p2ndemic]

Hi, thanks for the best player in history 🚀. Also for the best guide I've ever come across 🎓 📖. I want to hug the people who write it 😻.

I had a lot of fun following it and creating my mpv config ✏️.

The only few questions I’d like to ask are about additional FFmpeg options.

I read the FFmpeg guide (it’s not as cool as yours) and want to enable a few additional flags, specifically tcp_nodelay and multiple_requests.

In mpv, there are two parameters through which these flags can be enabled:

stream-lavf-o-append=
demuxer-lavf-o-append=

Both parameters correctly accept these flags. I confirmed this by checking the mpv logs:

[   0.002][v][cplayer] Setting option 'stream-lavf-o-append' = 'tcp_nodelay=1' (flags = 4)
[   0.002][v][cplayer] Setting option 'stream-lavf-o-append' = 'multiple_requests=1' (flags = 4)
[   0.003][v][cplayer] Setting option 'demuxer-lavf-o-append' = 'http_persistent=true' (flags = 4)
[   0.003][v][cplayer] Setting option 'demuxer-lavf-o-append' = 'http_multiple=true' (flags = 4)
[   0.003][v][cplayer] Setting option 'demuxer-lavf-o-append' = 'fflags=+genpts' (flags = 4)
[   0.003][v][cplayer] Setting option 'demuxer-lavf-o-append' = 'err_detect=+ignore_err' (flags = 4)
[   0.003][v][cplayer] Setting option 'demuxer-lavf-o-append' = 'strict=-2' (flags = 4)
[   0.003][v][cplayer] Setting option 'demuxer-lavf-o-append' = 'tcp_nodelay=1' (flags = 4)
[   0.003][v][cplayer] Setting option 'demuxer-lavf-o-append' = 'multiple_requests=1' (flags = 4)

Question:
Which parameter should I tie these values to? stream-lavf-o or demuxer-lavf-o?

I think it’s stream-lavf-o, but just to be safe, I’d like to clarify with the professionals 🤓

Also, is it okay if I ask more questions if they come up?

Here's part of my config, just in case:

...

# ==========================
#  yt-dlp integration
# ==========================
ytdl=yes
script-opts=ytdl_hook-ytdl_path=yt-dlp,ytdl_hook-try_ytdl_first=yes,ytdl_hook-exclude="%.3gp$|%.avi$|%.flac$|%.flv$|%.m3u$|%.m3u8$|%.m4a$|%.m4v$|%.mka$|%.mkv$|%.mov$|%.MOV$|%.mp3$|%.mp4$|%.ogg$|%.ts$|%.vob$|%.VOB$|%.wav$|%.webm$|%.wmv$"
ytdl-raw-options=ignore-config=,config-location=$HOME/.config/mpv/mpv_yt-dlp.conf
ytdl-format=bestvideo*[height<=?1440]+bestaudio/best

# ==========================
#  Network
# ==========================
rtsp-transport=lavf                           # [default = tcp] | 'lavf': Leave the decision to libavformat
hls-bitrate=max                               # [default = max] | Pick the streams with the highest bitrate

#stream-buffer-size=128KiB                    # [default = 128KiB] | Size of the low level stream byte buffer. This is used as buffer between demuxer and low level I/O (e.g. sockets)
#demuxer-lavf-buffersize=32768                # [default = 32768] | Size of the stream read buffer allocated for libavformat in bytes. Lowering the size could lower latency. Libavformat might reallocate the buffer internally, or not fully use all of it

stream-lavf-o-append=tcp_nodelay=1            # [default = false] | (tcp | rtp) Set TCP_NODELAY to disable Nagle’s algorithm (Default: 0)
stream-lavf-o-append=multiple_requests=1      # [default = false] | (http | https) Use persistent connections if set to 1 (Default: 0)

demuxer-lavf-o-append=http_persistent=true    # (HLS muxer/demuxer | DASH muxer) Use multiple HTTP connections for fetching segments (HLS default: true | DASH default: false)
demuxer-lavf-o-append=http_multiple=true      # (HLS muxer/demuxer) Use multiple HTTP connections for downloading HTTP segments. Enabled by default for HTTP/1.1 servers (HLS default: auto)

demuxer-lavf-o-append=fflags=+genpts          # [default = n\a] | (AVFormatContext) Generate missing PTS if DTS is present
demuxer-lavf-o-append=err_detect=+ignore_err  # [default = crccheck] | (AVFormatContext) Set error detection flags (default: crccheck)
demuxer-lavf-o-append=strict=-1               # [default = 0] | '-1': allow 'unofficial' extensions | '-2': experimental | (AVFormatContext) How strictly to follow the standards (from INT_MIN to INT_MAX) (Default: 0 - normal)

# ==========================
#  Conditional auto profiles
# ==========================
#[online]
#profile-desc=online_stream
#profile-cond=demuxer_via_network
#stream-lavf-o-append=tcp_nodelay=1           # For example, to show how 'Conditional auto profiles work', set this flag for online streams

#[local]
#profile-desc=local_file
#profile-cond=not demuxer_via_network
#stream-lavf-o-clr                            # '-clr' Suffix: Clear the option (remove all items). For example, to show how 'Conditional auto profiles work', remove all flags above for local files

# ==========================
#  Some experimental FFMPEG stuff
# ==========================

#demuxer-lavf-o-append=avioflags=+direct      # [default = 0] | (AVFormatContext) Reduce buffering. Allows avoiding the buffer when using avio read, write and seek functions (Default: 0)
#demuxer-lavf-o-append=fflags=+flush_packets+genpts+ignidx+discardcorrupt+fastseek+nobuffer # [default = n\a] | (AVFormatContext) These flags are provided as examples. Please read the documentation before using them
#demuxer-lavf-o-append=rtbufsize=8388608      # [default = 3041280] | '8388608': 8MiB | (AVFormatContext) Max memory used for buffering real-time frames (from 0 to INT_MAX) (Default: 3041280)
#demuxer-lavf-o-append=chunk_size=10485760    # [default = 0] | '10485760': 10MiB | (AVFormatContext) Size in bytes for each chunk (from 0 to 2.14748e+09) (Default: 0)
#demuxer-lavf-o-append=err_detect=+ignore_err # [default = crccheck] | (AVFormatContext) Set error detection flags (default: crccheck)
#demuxer-lavf-o-append=flush_packets=1        # [default = -1] | (AVFormatContext) Enable flushing of the I/O context after each packet (from -1 to 1) (Default: -1)
#demuxer-lavf-o-append=strict=-2              # [default = 0] | '-2': experimental | (AVFormatContext) How strictly to follow the standards (from INT_MIN to INT_MAX) (Default: 0 - normal)
#demuxer-lavf-o-append=avoid_negative_ts=2    # [default = -1] | '2': make_zero | (AVFormatContext) Shift timestamps so they start at 0 (from -1 to 2) (Default: -1 - auto)
#demuxer-lavf-o-append=ldash=true             # [default = false] | (DASH muxer) Enable Low-latency dash. Constrains the value of a few elements (Default: false)
#demuxer-lavf-o-append=lhls=true              # [default = false] | (DASH muxer) Enable Low-latency HLS(Experimental). Adds #EXT-X-PREFETCH tag with current segment's URI (Default: false)
#demuxer-lavf-o-append=streaming=true         # [default = false] | (DASH muxer) Enable/Disable Dash streaming mode of output. Each frame will be 'moof' fragment (Default: false)

#demuxer-lavf-o-append=http_persistent=true   # (HLS muxer/demuxer | DASH muxer) Use multiple HTTP connections for fetching segments (HLS default: true | DASH default: false)
#demuxer-lavf-o-append=http_multiple=true     # (HLS muxer/demuxer) Use multiple HTTP connections for downloading HTTP segments. Enabled by default for HTTP/1.1 servers (HLS default: auto)

#stream-lavf-o-append=tcp_nodelay=1           # [default = false] | (tcp | rtp) Set TCP_NODELAY to disable Nagle’s algorithm (Default: 0)
#stream-lavf-o-append=multiple_requests=1     # [default = false] | (http | https) Use persistent connections if set to 1 (Default: 0)
#stream-lavf-o-append=reconnect_on_http_error=4xx,5xx
#stream-lavf-o-append=reconnect_delay_max=30
#stream-lavf-o-append=reconnect_streamed=yes
#stream-lavf-o-append=reconnect_on_network_error=yes

# ==========================
#  mpv options
# ==========================
# mpv --list-options > ./mpv_all_options.txt
# mpv --show-profile && mpv --show-profile=high-quality
# mpv --vd=help && mpv --ad=help
# mpv --force-window --idle
# mpv --force-window --idle --msg-level=status=info --log-file=./mpv_logs.txt ./movie.mkv
# mpv --force-window --idle --msg-level=vo/gpu-next/libplacebo=info --log-file=./mpv_logs.txt ./movie.mkv
# mpv --force-window --idle --msg-level=ffmpeg=trace --log-file=./mpv_logs.txt ./movie.mkv

# ==========================
#  ffmpeg options
# ==========================
# ffmpeg -h full > ./ffmpeg_help_full.txt
# ffmpeg -muxers && ffmpeg -h muxer=dash && ffmpeg -h muxer=hls && ffmpeg -h muxer=rtsp
# ffmpeg -demuxers && ffmpeg -h demuxer=dash && ffmpeg -h demuxer=hls && ffmpeg -h demuxer=rtsp
# ffmpeg -protocols && ffmpeg -h protocol=tcp && ffmpeg -h protocol=udp && ffmpeg -h protocol=http
# ffmpeg -h full | sed -n '/AVFormatContext AVOptions:/,/AVIOContext AVOptions:/{/AVIOContext AVOptions:/!p}' | nano -
# ffmpeg -h full | awk '/AVFormatContext AVOptions:/ {flag=1} /AVIOContext AVOptions:/ {flag=0} flag' | nano -