Doom9's Forum - View Single Post - L-SMASH Source

sneaker_ger · 9th September 2019, 10:05

The PPS changes mid-stream (pic_init_qp_minus26 changes). Mkvmerge seems to detect this when doing a "full" remux (1. demux to ES. 2. mux ES) and prepends the SPS/PPS to every keyframe. In the original sample it is only prepended on an actual change compared to the prior keyframe. Since both frame #97 and #104 use the same pic_init_qp_minus26 frame #104 does not have this prepended PPS. Then decoder tries to use first/global pic_init_qp_minus26 and breaks.

9th September 2019, 10:05	#884 \| Link
sneaker_ger Registered User Join Date: Dec 2002 Posts: 5,181	The PPS changes mid-stream (pic_init_qp_minus26 changes). Mkvmerge seems to detect this when doing a "full" remux (1. demux to ES. 2. mux ES) and prepends the SPS/PPS to every keyframe. In the original sample it is only prepended on an actual change compared to the prior keyframe. Since both frame #97 and #104 use the same pic_init_qp_minus26 frame #104 does not have this prepended PPS. Then decoder tries to use first/global pic_init_qp_minus26 and breaks. Last edited by sneaker_ger; 9th September 2019 at 10:09.