[FFmpeg-devel] [PATCH v2 3/3] avformat/movenccenc: add support for CENC AV1 encryption
James Almer
jamrial at gmail.com
Fri Mar 21 21:42:37 EET 2025
Signed-off-by: James Almer <jamrial at gmail.com>
---
configure | 2 +-
libavformat/Makefile | 1 +
libavformat/cbs.c | 10 ++
libavformat/cbs_av1.c | 6 ++
libavformat/movenc.c | 13 ++-
libavformat/movenccenc.c | 223 ++++++++++++++++++++++++++++++++++++++-
libavformat/movenccenc.h | 20 +++-
7 files changed, 269 insertions(+), 6 deletions(-)
create mode 100644 libavformat/cbs.c
create mode 100644 libavformat/cbs_av1.c
diff --git a/configure b/configure
index 14f7bcde0e..0f6b6c20fb 100755
--- a/configure
+++ b/configure
@@ -3689,7 +3689,7 @@ mlp_demuxer_select="mlp_parser"
mmf_muxer_select="riffenc"
mov_demuxer_select="iso_media riffdec"
mov_demuxer_suggest="iamfdec zlib"
-mov_muxer_select="iso_media iso_writer riffenc rtpenc_chain vp9_superframe_bsf aac_adtstoasc_bsf ac3_parser"
+mov_muxer_select="iso_media iso_writer riffenc rtpenc_chain vp9_superframe_bsf aac_adtstoasc_bsf ac3_parser cbs_av1"
mov_muxer_suggest="iamfenc"
mp3_demuxer_select="mpegaudio_parser"
mp3_muxer_select="mpegaudioheader"
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 7730e7c4e6..1e57ae7d8a 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -740,6 +740,7 @@ SHLIBOBJS-$(CONFIG_JNI) += ffjni.o
SHLIBOBJS-$(CONFIG_JPEGXL_ANIM_DEMUXER) += jpegxl_parse.o
SHLIBOBJS-$(CONFIG_MATROSKA_DEMUXER) += mpeg4audio_sample_rates.o
SHLIBOBJS-$(CONFIG_MOV_DEMUXER) += ac3_channel_layout_tab.o
+SHLIBOBJS-$(CONFIG_MOV_MUXER) += cbs.o cbs_av1.o
SHLIBOBJS-$(CONFIG_MP3_MUXER) += mpegaudiotabs.o
SHLIBOBJS-$(CONFIG_MXF_MUXER) += golomb_tab.o \
rangecoder_dec.o
diff --git a/libavformat/cbs.c b/libavformat/cbs.c
new file mode 100644
index 0000000000..9e970004ba
--- /dev/null
+++ b/libavformat/cbs.c
@@ -0,0 +1,10 @@
+#define CBS_WRITE 0
+#define CBS_TRACE 0
+#define CBS_H264 0
+#define CBS_H265 0
+#define CBS_H266 0
+#define CBS_JPEG 0
+#define CBS_MPEG2 0
+#define CBS_VP8 0
+#define CBS_VP9 0
+#include "libavcodec/cbs.c"
diff --git a/libavformat/cbs_av1.c b/libavformat/cbs_av1.c
new file mode 100644
index 0000000000..47a4d0c3a1
--- /dev/null
+++ b/libavformat/cbs_av1.c
@@ -0,0 +1,6 @@
+#define CBS_WRITE 0
+#define CBS_TRACE 0
+#define CBS_OBU_TILE_LIST 0
+#define CBS_OBU_METADATA 0
+#define CBS_OBU_PADDING 0
+#include "libavcodec/cbs_av1.c"
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index af013e1fc6..c60c46012f 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -6767,7 +6767,7 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
} else {
size = ff_vvc_annexb2mp4(pb, pkt->data, pkt->size, 0, NULL);
}
- } else if (par->codec_id == AV_CODEC_ID_AV1) {
+ } else if (par->codec_id == AV_CODEC_ID_AV1 && !trk->cenc.aes_ctr) {
if (trk->hint_track >= 0 && trk->hint_track < mov->nb_tracks) {
ret = ff_av1_filter_obus_buf(pkt->data, &reformatted_data,
&size, &offset);
@@ -6815,6 +6815,13 @@ int ff_mov_write_packet(AVFormatContext *s, AVPacket *pkt)
ret = ff_mov_cenc_avc_write_nal_units(s, &trk->cenc, nal_size_length, pb, pkt->data, size);
} else if(par->codec_id == AV_CODEC_ID_VVC) {
ret = AVERROR_PATCHWELCOME;
+ } else if(par->codec_id == AV_CODEC_ID_AV1) {
+ av_assert0(size == pkt->size);
+ ret = ff_mov_cenc_av1_write_obus(s, &trk->cenc, pb, pkt);
+ if (ret > 0) {
+ size = ret;
+ ret = 0;
+ }
} else {
ret = ff_mov_cenc_write_packet(&trk->cenc, pb, pkt->data, size);
}
@@ -8135,8 +8142,8 @@ static int mov_init(AVFormatContext *s)
if (mov->encryption_scheme == MOV_ENC_CENC_AES_CTR) {
ret = ff_mov_cenc_init(&track->cenc, mov->encryption_key,
(track->par->codec_id == AV_CODEC_ID_H264 || track->par->codec_id == AV_CODEC_ID_HEVC ||
- track->par->codec_id == AV_CODEC_ID_VVC),
- s->flags & AVFMT_FLAG_BITEXACT);
+ track->par->codec_id == AV_CODEC_ID_VVC || track->par->codec_id == AV_CODEC_ID_AV1),
+ track->par->codec_id, s->flags & AVFMT_FLAG_BITEXACT);
if (ret)
return ret;
}
diff --git a/libavformat/movenccenc.c b/libavformat/movenccenc.c
index f54d3bcbca..af801eb3a0 100644
--- a/libavformat/movenccenc.c
+++ b/libavformat/movenccenc.c
@@ -19,6 +19,9 @@
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "movenccenc.h"
+#include "libavcodec/av1_parse.h"
+#include "libavcodec/bytestream.h"
+#include "libavcodec/cbs_av1.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/mem.h"
#include "avio_internal.h"
@@ -280,6 +283,203 @@ int ff_mov_cenc_avc_write_nal_units(AVFormatContext *s, MOVMuxCencContext* ctx,
return 0;
}
+static int write_tiles(AVFormatContext *s, MOVMuxCencContext *ctx, AVIOContext *pb, AV1_OBU_Type type,
+ const AV1RawFrameHeader *frame_header, const uint8_t *fh_data, size_t fh_data_size,
+ const AV1RawTileGroup *tile_group)
+{
+ GetByteContext gb;
+ size_t tgh_data_size = tile_group->data_size;
+ int cur_tile_num = frame_header->tile_cols * frame_header->tile_rows;
+ int total = 0;
+
+ // Get the Frame Header size
+ if (type == AV1_OBU_FRAME)
+ fh_data_size -= tgh_data_size;
+ // Get the Tile Group Header size
+ tgh_data_size -= tile_group->tile_data.data_size;
+
+ if (ctx->tile_num < cur_tile_num) {
+ int ret = av_reallocp_array(&ctx->tile_group_sizes, cur_tile_num,
+ sizeof(*ctx->tile_group_sizes));
+ if (ret < 0) {
+ ctx->tile_num = 0;
+ return ret;
+ }
+ }
+ ctx->tile_num = cur_tile_num;
+
+ total = fh_data_size + tgh_data_size;
+ ctx->clear_bytes += total;
+
+ bytestream2_init(&gb, tile_group->tile_data.data, tile_group->tile_data.data_size);
+
+ // Build a table with block sizes for encrypted bytes and clear bytes
+ for (unsigned tile_num = tile_group->tg_start; tile_num <= tile_group->tg_end; tile_num++) {
+ uint32_t encrypted_bytes, tile_size_bytes, tile_size = 0;
+
+ if (tile_num == tile_group->tg_end) {
+ tile_size = bytestream2_get_bytes_left(&gb);
+ encrypted_bytes = tile_size & ~0xFU;
+ ctx->clear_bytes += tile_size & 0xFU;
+
+ ctx->tile_group_sizes[tile_num].encrypted_bytes = encrypted_bytes;
+ ctx->tile_group_sizes[tile_num].aux_clear_bytes = encrypted_bytes ? ctx->clear_bytes : 0;
+ ctx->tile_group_sizes[tile_num].write_clear_bytes = tile_size & 0xFU;
+
+ if (encrypted_bytes)
+ ctx->clear_bytes = 0;
+ total += tile_size;
+
+ break;
+ }
+
+ tile_size_bytes = frame_header->tile_size_bytes_minus1 + 1;
+ if (bytestream2_get_bytes_left(&gb) < tile_size_bytes)
+ return AVERROR_INVALIDDATA;
+
+ for (int i = 0; i < tile_size_bytes; i++)
+ tile_size |= bytestream2_get_byteu(&gb) << 8 * i;
+ if (bytestream2_get_bytes_left(&gb) <= tile_size)
+ return AVERROR_INVALIDDATA;
+ tile_size++;
+
+ // The spec requires encrypted bytes to be in blocks multiple of 16
+ encrypted_bytes = tile_size & ~0xFU;
+ ctx->clear_bytes += (tile_size & 0xFU) + tile_size_bytes;
+
+ ctx->tile_group_sizes[tile_num].encrypted_bytes = encrypted_bytes;
+ ctx->tile_group_sizes[tile_num].aux_clear_bytes = encrypted_bytes ? ctx->clear_bytes : 0;
+ ctx->tile_group_sizes[tile_num].write_clear_bytes = (tile_size & 0xFU) + tile_size_bytes;
+
+ if (encrypted_bytes)
+ ctx->clear_bytes = 0;
+
+ total += tile_size + tile_size_bytes;
+ bytestream2_skipu(&gb, tile_size);
+ }
+
+ bytestream2_init(&gb, tile_group->tile_data.data, tile_group->tile_data.data_size);
+
+ avio_write(pb, fh_data, fh_data_size);
+ avio_write(pb, tile_group->data, tgh_data_size);
+
+ for (unsigned tile_num = tile_group->tg_start; tile_num <= tile_group->tg_end; tile_num++) {
+ const struct MOVMuxCencAV1TGInfo *sizes = &ctx->tile_group_sizes[tile_num];
+
+ avio_write(pb, gb.buffer, sizes->write_clear_bytes);
+ bytestream2_skipu(&gb, sizes->write_clear_bytes);
+ mov_cenc_write_encrypted(ctx, pb, gb.buffer, sizes->encrypted_bytes);
+ bytestream2_skipu(&gb, sizes->encrypted_bytes);
+ if (sizes->encrypted_bytes) {
+ unsigned clear_bytes = sizes->aux_clear_bytes;
+ if (clear_bytes > UINT16_MAX) {
+ auxiliary_info_add_subsample(ctx, UINT16_MAX, 0);
+ clear_bytes -= UINT16_MAX;
+ }
+ auxiliary_info_add_subsample(ctx, clear_bytes, sizes->encrypted_bytes);
+ }
+ }
+
+ return total;
+}
+
+int ff_mov_cenc_av1_write_obus(AVFormatContext *s, MOVMuxCencContext* ctx,
+ AVIOContext *pb, const AVPacket *pkt)
+{
+ CodedBitstreamFragment *td = &ctx->temporal_unit;
+ const CodedBitstreamAV1Context *av1 = ctx->cbc->priv_data;
+ const AV1RawFrameHeader *frame_header = NULL;
+ const uint8_t *fh_data = NULL;
+ size_t fh_data_size;
+ int out_size = 0, ret;
+
+ ret = mov_cenc_start_packet(ctx);
+ if (ret) {
+ return ret;
+ }
+
+ ret = ff_cbs_read_packet(ctx->cbc, td, pkt);
+ if (ret < 0) {
+ av_log(s, AV_LOG_ERROR, "CENC-AV1: Failed to parse temporal unit.\n");
+ return ret;
+ }
+
+ if (!av1->sequence_header) {
+ av_log(s, AV_LOG_ERROR, "CENC-AV1: No sequence header available\n");
+ ret = AVERROR_INVALIDDATA;
+ goto end;
+ }
+
+ for (int i = 0; i < td->nb_units; i++) {
+ const CodedBitstreamUnit *unit = &td->units[i];
+ const AV1RawOBU *obu = unit->content;
+
+ switch (unit->type) {
+ case AV1_OBU_FRAME_HEADER:
+ if (!obu->obu.frame_header.show_existing_frame) {
+ frame_header = &obu->obu.frame_header;
+ fh_data = unit->data;
+ fh_data_size = unit->data_size;
+ break;
+ }
+ // fall-through
+ case AV1_OBU_SEQUENCE_HEADER:
+ case AV1_OBU_METADATA:
+ avio_write(pb, unit->data, unit->data_size);
+ ctx->clear_bytes += unit->data_size;
+ out_size += unit->data_size;
+ break;
+ case AV1_OBU_FRAME:
+ frame_header = &obu->obu.frame.header;
+ fh_data = unit->data;
+ fh_data_size = unit->data_size;
+ // fall-through
+ case AV1_OBU_TILE_GROUP:
+ {
+ const AV1RawTileGroup *tile_group;
+
+ if (!frame_header){
+ ret = AVERROR_INVALIDDATA;
+ goto end;
+ }
+
+ if (unit->type == AV1_OBU_FRAME)
+ tile_group = &obu->obu.frame.tile_group;
+ else
+ tile_group = &obu->obu.tile_group;
+
+ ret = write_tiles(s, ctx, pb, unit->type,
+ frame_header, fh_data, fh_data_size, tile_group);
+ if (ret < 0) {
+ av_log(s, AV_LOG_ERROR, "CENC-AV1: Failed to write tiles\n");
+ goto end;
+ }
+ av_assert0(ret == unit->data_size);
+ out_size += unit->data_size;
+ frame_header = NULL;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+
+ if (ctx->clear_bytes)
+ auxiliary_info_add_subsample(ctx, ctx->clear_bytes, 0);
+ ctx->clear_bytes = 0;
+
+ ret = mov_cenc_end_packet(ctx);
+ if (ret) {
+ ret = AVERROR_INVALIDDATA;
+ goto end;
+ }
+
+ ret = out_size;
+end:
+ ff_cbs_fragment_reset(td);
+ return ret;
+}
+
/* TODO: reuse this function from movenc.c */
static int64_t update_size(AVIOContext *pb, int64_t pos)
{
@@ -388,8 +588,16 @@ int ff_mov_cenc_write_sinf_tag(MOVTrack* track, AVIOContext *pb, uint8_t* kid)
return update_size(pb, pos);
}
+static const CodedBitstreamUnitType decompose_unit_types[] = {
+ AV1_OBU_TEMPORAL_DELIMITER,
+ AV1_OBU_SEQUENCE_HEADER,
+ AV1_OBU_FRAME_HEADER,
+ AV1_OBU_TILE_GROUP,
+ AV1_OBU_FRAME,
+};
+
int ff_mov_cenc_init(MOVMuxCencContext* ctx, uint8_t* encryption_key,
- int use_subsamples, int bitexact)
+ int use_subsamples, enum AVCodecID codec_id, int bitexact)
{
int ret;
@@ -409,6 +617,15 @@ int ff_mov_cenc_init(MOVMuxCencContext* ctx, uint8_t* encryption_key,
ctx->use_subsamples = use_subsamples;
+ if (codec_id == AV_CODEC_ID_AV1) {
+ ret = ff_cbs_init(&ctx->cbc, codec_id, NULL);
+ if (ret < 0)
+ return ret;
+
+ ctx->cbc->decompose_unit_types = decompose_unit_types;
+ ctx->cbc->nb_decompose_unit_types = FF_ARRAY_ELEMS(decompose_unit_types);
+ }
+
return 0;
}
@@ -417,4 +634,8 @@ void ff_mov_cenc_free(MOVMuxCencContext* ctx)
av_aes_ctr_free(ctx->aes_ctr);
av_freep(&ctx->auxiliary_info);
av_freep(&ctx->auxiliary_info_sizes);
+
+ av_freep(&ctx->tile_group_sizes);
+ ff_cbs_fragment_free(&ctx->temporal_unit);
+ ff_cbs_close(&ctx->cbc);
}
diff --git a/libavformat/movenccenc.h b/libavformat/movenccenc.h
index 7da5268090..722914dc1c 100644
--- a/libavformat/movenccenc.h
+++ b/libavformat/movenccenc.h
@@ -23,6 +23,7 @@
#define AVFORMAT_MOVENCCENC_H
#include "libavutil/aes_ctr.h"
+#include "libavcodec/cbs.h"
#include "avformat.h"
#include "avio.h"
@@ -30,6 +31,12 @@
struct MOVTrack;
+struct MOVMuxCencAV1TGInfo {
+ uint32_t encrypted_bytes;
+ uint32_t write_clear_bytes;
+ uint32_t aux_clear_bytes;
+};
+
typedef struct {
struct AVAESCTR* aes_ctr;
uint8_t* auxiliary_info;
@@ -43,6 +50,14 @@ typedef struct {
size_t auxiliary_info_subsample_start;
uint8_t* auxiliary_info_sizes;
size_t auxiliary_info_sizes_alloc_size;
+
+ /* AV1 */
+ struct MOVMuxCencAV1TGInfo *tile_group_sizes;
+ uint32_t clear_bytes;
+ int tile_num;
+ /* CBS */
+ CodedBitstreamContext *cbc;
+ CodedBitstreamFragment temporal_unit;
} MOVMuxCencContext;
/**
@@ -50,7 +65,8 @@ typedef struct {
* @param key encryption key, must have a length of AES_CTR_KEY_SIZE
* @param use_subsamples when enabled parts of a packet can be encrypted, otherwise the whole packet is encrypted
*/
-int ff_mov_cenc_init(MOVMuxCencContext* ctx, uint8_t* encryption_key, int use_subsamples, int bitexact);
+int ff_mov_cenc_init(MOVMuxCencContext* ctx, uint8_t* encryption_key, int use_subsamples,
+ enum AVCodecID codec_id, int bitexact);
/**
* Free a CENC context
@@ -73,6 +89,8 @@ int ff_mov_cenc_avc_parse_nal_units(MOVMuxCencContext* ctx, AVIOContext *pb, con
int ff_mov_cenc_avc_write_nal_units(AVFormatContext *s, MOVMuxCencContext* ctx, int nal_length_size,
AVIOContext *pb, const uint8_t *buf_in, int size);
+int ff_mov_cenc_av1_write_obus(AVFormatContext *s, MOVMuxCencContext* ctx,
+ AVIOContext *pb, const AVPacket *pkt);
/**
* Write the cenc atoms that should reside inside stbl
*/
--
2.48.1
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