From ad326379c6634505c9ebc46964057441761008bc Mon Sep 17 00:00:00 2001 From: Andriy Gelman Date: Thu, 5 Dec 2019 22:15:41 -0500 Subject: [PATCH] lavc/h2645_parse: Don't automatically remove nuh_layer_id > 0 packets HEVC standard supports multi-layer streams (ITU-T H.265 02/2018 Annex F). Each NAL unit belongs to a particular layer defined by nuh_layer_id in the header. Currently, all NAL units that do not belong to a base layer are automatically removed in ff_h2645_packet_split(). Some data may therefore be lost when future filters/decoders are designed to support multi-layer streams. A better approach is to forward nuh_layer_id > 0 packets and let blocks down the chain decide how to process them. The condition to remove packets has been moved to hevcdec and cbs. Found-by: Andreas Rheinhardt Signed-off-by: Andriy Gelman Signed-off-by: James Almer --- libavcodec/cbs_h2645.c | 3 +++ libavcodec/h2645_parse.c | 7 +++---- libavcodec/h2645_parse.h | 5 +++++ libavcodec/hevc_parse.c | 2 ++ libavcodec/hevc_parser.c | 3 +++ libavcodec/hevcdec.c | 2 +- 6 files changed, 17 insertions(+), 5 deletions(-) diff --git a/libavcodec/cbs_h2645.c b/libavcodec/cbs_h2645.c index ad8afa6d4a..5f1a20d427 100644 --- a/libavcodec/cbs_h2645.c +++ b/libavcodec/cbs_h2645.c @@ -565,6 +565,9 @@ static int cbs_h2645_fragment_add_nals(CodedBitstreamContext *ctx, AVBufferRef *ref; size_t size = nal->size; + if (nal->nuh_layer_id > 0) + continue; + // Remove trailing zeroes. while (size > 0 && nal->data[size - 1] == 0) --size; diff --git a/libavcodec/h2645_parse.c b/libavcodec/h2645_parse.c index 4808f79a67..0f3343004f 100644 --- a/libavcodec/h2645_parse.c +++ b/libavcodec/h2645_parse.c @@ -292,23 +292,22 @@ static int get_bit_length(H2645NAL *nal, int skip_trailing_zeros) static int hevc_parse_nal_header(H2645NAL *nal, void *logctx) { GetBitContext *gb = &nal->gb; - int nuh_layer_id; if (get_bits1(gb) != 0) return AVERROR_INVALIDDATA; nal->type = get_bits(gb, 6); - nuh_layer_id = get_bits(gb, 6); + nal->nuh_layer_id = get_bits(gb, 6); nal->temporal_id = get_bits(gb, 3) - 1; if (nal->temporal_id < 0) return AVERROR_INVALIDDATA; av_log(logctx, AV_LOG_DEBUG, "nal_unit_type: %d(%s), nuh_layer_id: %d, temporal_id: %d\n", - nal->type, hevc_nal_unit_name(nal->type), nuh_layer_id, nal->temporal_id); + nal->type, hevc_nal_unit_name(nal->type), nal->nuh_layer_id, nal->temporal_id); - return nuh_layer_id == 0; + return 1; } static int h264_parse_nal_header(H2645NAL *nal, void *logctx) diff --git a/libavcodec/h2645_parse.h b/libavcodec/h2645_parse.h index 2acf882d3d..3e47f86c53 100644 --- a/libavcodec/h2645_parse.h +++ b/libavcodec/h2645_parse.h @@ -56,6 +56,11 @@ typedef struct H2645NAL { */ int temporal_id; + /* + * HEVC only, identifier of layer to which nal unit belongs + */ + int nuh_layer_id; + int skipped_bytes; int skipped_bytes_pos_size; int *skipped_bytes_pos; diff --git a/libavcodec/hevc_parse.c b/libavcodec/hevc_parse.c index dddb293df6..29dfd479f3 100644 --- a/libavcodec/hevc_parse.c +++ b/libavcodec/hevc_parse.c @@ -37,6 +37,8 @@ static int hevc_decode_nal_units(const uint8_t *buf, int buf_size, HEVCParamSets for (i = 0; i < pkt.nb_nals; i++) { H2645NAL *nal = &pkt.nals[i]; + if (nal->nuh_layer_id > 0) + continue; /* ignore everything except parameter sets and VCL NALUs */ switch (nal->type) { diff --git a/libavcodec/hevc_parser.c b/libavcodec/hevc_parser.c index b444b99955..87d5dba4f5 100644 --- a/libavcodec/hevc_parser.c +++ b/libavcodec/hevc_parser.c @@ -202,6 +202,9 @@ static int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf, H2645NAL *nal = &ctx->pkt.nals[i]; GetBitContext *gb = &nal->gb; + if (nal->nuh_layer_id > 0) + continue; + switch (nal->type) { case HEVC_NAL_VPS: ff_hevc_decode_nal_vps(gb, avctx, ps); diff --git a/libavcodec/hevcdec.c b/libavcodec/hevcdec.c index 19b0cd815d..c74881e814 100644 --- a/libavcodec/hevcdec.c +++ b/libavcodec/hevcdec.c @@ -3077,7 +3077,7 @@ static int decode_nal_units(HEVCContext *s, const uint8_t *buf, int length) if (s->avctx->skip_frame >= AVDISCARD_ALL || (s->avctx->skip_frame >= AVDISCARD_NONREF - && ff_hevc_nal_is_nonref(nal->type))) + && ff_hevc_nal_is_nonref(nal->type)) || nal->nuh_layer_id > 0) continue; ret = decode_nal_unit(s, nal);