FAQ Features and Fork Differences

FAQ — Features & Fork Differences

How this fork (gjrtimmer/jetson-ffmpeg) differs from upstream jocover and Keylost, and what is on the roadmap. The full provenance is in the Fork Analysis Results.

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Why this fork

• Widest FFmpeg matrix — 6.0 → 8.1 (v3.0.0+) with an idempotent, auto-detecting patcher and committed per-version patches. See Compatibility.
• Memory-safety and crash fixes ported and regression-guarded by a per-feature hardware test suite.
• Tag-driven releases with prebuilt artifacts — see Release Process and releases.

Fixed in this fork

Area	What changed	Issue
Decoder memory safety	Ported cgutman fixes: EOS deadlock, delete[] mismatch, uninitialized pointers, close-hang	#2
Undefined behavior	Missing return in decoder/encoder capture-loop callbacks (segfault on GCC 11+)	#3
Encoder keyframe flag	Honor V4L2 KeyFrame metadata — stop flagging every packet as a keyframe	#4
H.265 global header	GLOBAL_HEADER support + bounded SPS/PPS/VPS NAL scan (buffer-overread guard)	#5
glibc ≥ 2.34	Vendored patched NvV4l2ElementPlane — fixes pthread_join segfault	#6
4K I-frames	Enlarge + bounds-check + make decoder CHUNK_SIZE configurable	#7
Decoder crash on exit	Drain and clean up queued DMA buffers in teardown	#8
Decode performance	setMaxPerfMode, optional DPB disable, poc-type=2 (up to ~6×)	#9
Low-delay decode	Blocking wait in get_frame for AV_CODEC_FLAG_LOW_DELAY	#10
Configurable pools	frame_pool_size / packet_pool_size / chunk_size AVOptions	#11
Pixel formats	YUVJ420P acceptance, NV12 I/O, P010 10-bit decode, XRGB32 converter fix, insert_vui	#12
Codec flush	avcodec_flush_buffers for decoder and encoder	#16
RTSP / out-of-band SPS/PPS	Hardened extradata priming at decoder init (zero-frames fix)	#1
FFmpeg ≥ 6.1 SIGABRT	Decode callback returned EAGAIN on input-feed failure	#28
MJPEG decode	Hardware MJPEG decode via NvJPEGDecoder, baseline JPEG only	#18
MJPEG encode	Hardware MJPEG encode via NvJPEGEncoder (quality 1–100)	#19
Encoder level	Wire -level through to V4L2 setLevel for H.264 and H.265	#14
Encoder runtime control	Force IDR, dynamic bitrate, CABAC, AUD, lossless AVOptions, encoder flush	#13
Blocking encoder wait	-flags low_delay activates blocking get_packet, configurable wait_timeout	#31
Build system	CMake JP6 auto-detect, cross-compile sysroot, CPack .deb, pkg-config fix	#22
Stream dimension hints	Pre-allocate frame pool from container headers, reduce first-frame latency	—
Structured logging	NVMPI_LOG / NVMPI_LOG_SUB macros, compile-time threshold	—
FFmpeg 8.1	Support for FFmpeg 8.1 (libavcodec 62)	—

Roadmap / in progress

Area	Goal	Issue
JPEG zero-copy	decode→encode DMA-fd passthrough	#20
Zero-copy GPU pipeline	dlopen, DMA-BUF/DRM_PRIME, hwcontext_nvmpi, VIC scaling, CUDA interop	#21
Modern encode API	full send_frame/receive_packet with proper EOS drain	#15
AV1	hardware AV1 decode/encode on Orin-class modules	#23
Upstreaming	nvmpi codec support to FFmpeg mainline	#25

See all open issues for current status.