On 11/11/2019 4:28 PM, Andreas Rheinhardt wrote:
> James Almer:
>> Signed-off-by: James Almer <jamr...@gmail.com>
>> ---
>> configure | 1 +
>> libavformat/Makefile | 1 +
>> libavformat/allformats.c | 1 +
>> libavformat/obu.c | 276 +++++++++++++++++++++++++++++++++++++++
>> 4 files changed, 279 insertions(+)
>> create mode 100644 libavformat/obu.c
>>
>> diff --git a/configure b/configure
>> index 70f60997c1..a8dbba879d 100755
>> --- a/configure
>> +++ b/configure
>> @@ -3293,6 +3293,7 @@ mxf_d10_muxer_select="mxf_muxer"
>> mxf_opatom_muxer_select="mxf_muxer"
>> nut_muxer_select="riffenc"
>> nuv_demuxer_select="riffdec"
>> +obu_demuxer_select="av1_frame_merge_bsf"
>> oga_muxer_select="ogg_muxer"
>> ogg_demuxer_select="dirac_parse"
>> ogv_muxer_select="ogg_muxer"
>> diff --git a/libavformat/Makefile b/libavformat/Makefile
>> index 8251f8f657..9057d0358a 100644
>> --- a/libavformat/Makefile
>> +++ b/libavformat/Makefile
>> @@ -350,6 +350,7 @@ OBJS-$(CONFIG_NULL_MUXER) += nullenc.o
>> OBJS-$(CONFIG_NUT_DEMUXER) += nutdec.o nut.o isom.o
>> OBJS-$(CONFIG_NUT_MUXER) += nutenc.o nut.o
>> OBJS-$(CONFIG_NUV_DEMUXER) += nuv.o
>> +OBJS-$(CONFIG_OBU_DEMUXER) += obu.o
>> OBJS-$(CONFIG_OGG_DEMUXER) += oggdec.o \
>> oggparsecelt.o \
>> oggparsedaala.o \
>> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
>> index f7fea32b45..152644e9f9 100644
>> --- a/libavformat/allformats.c
>> +++ b/libavformat/allformats.c
>> @@ -282,6 +282,7 @@ extern AVInputFormat ff_nut_demuxer;
>> extern AVOutputFormat ff_nut_muxer;
>> extern AVInputFormat ff_nuv_demuxer;
>> extern AVOutputFormat ff_oga_muxer;
>> +extern AVInputFormat ff_obu_demuxer;
>> extern AVInputFormat ff_ogg_demuxer;
>> extern AVOutputFormat ff_ogg_muxer;
>> extern AVOutputFormat ff_ogv_muxer;
>> diff --git a/libavformat/obu.c b/libavformat/obu.c
>> new file mode 100644
>> index 0000000000..55a9c7d55f
>> --- /dev/null
>> +++ b/libavformat/obu.c
>> @@ -0,0 +1,276 @@
>> +/*
>> + * AV1 Annex-B demuxer
>> + * Copyright (c) 2019 James Almer <jamr...@gmail.com>
>> + *
>> + * This file is part of FFmpeg.
>> + *
>> + * FFmpeg is free software; you can redistribute it and/or
>> + * modify it under the terms of the GNU Lesser General Public
>> + * License as published by the Free Software Foundation; either
>> + * version 2.1 of the License, or (at your option) any later version.
>> + *
>> + * FFmpeg is distributed in the hope that it will be useful,
>> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
>> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
>> + * Lesser General Public License for more details.
>> + *
>> + * You should have received a copy of the GNU Lesser General Public
>> + * License along with FFmpeg; if not, write to the Free Software
>> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301
>> USA
>> + */
>> +
>> +#include "config.h"
>> +
>> +#include "libavutil/common.h"
>> +#include "libavutil/opt.h"
>> +#include "libavcodec/av1_parse.h"
>> +#include "avformat.h"
>> +#include "avio_internal.h"
>> +#include "internal.h"
>> +
>> +typedef struct AnnexBContext {
>> + const AVClass *class;
>> + AVBSFContext *bsf;
>> + uint32_t temporal_unit_size;
>> + uint32_t frame_unit_size;
>> + AVRational framerate;
>> +} AnnexBContext;
>> +
>> +static int leb(AVIOContext *pb, uint32_t *len) {
>> + int more, i = 0;
>> + uint8_t byte;
>> + *len = 0;
>> + do {
>> + unsigned bits;
>> + byte = avio_r8(pb);
>> + more = byte & 0x80;
>> + bits = byte & 0x7f;
>> + if (i <= 3 || (i == 4 && bits < (1 << 4)))
>> + *len |= bits << (i * 7);
>> + else if (bits)
>> + return AVERROR_INVALIDDATA;
>> + if (++i == 8 && more)
>> + return AVERROR_INVALIDDATA;
>> + if (pb->eof_reached || pb->error)
>> + return pb->error ? pb->error : AVERROR(EIO);
>> + } while (more);
>> + return i;
>> +}
>> +
>> +static int read_obu(const uint8_t *buf, int size, int64_t *obu_size, int
>> *type)
>> +{
>> + int start_pos, temporal_id, spatial_id;
>> + int len;
>> +
>> + len = parse_obu_header(buf, size, obu_size, &start_pos,
>> + type, &temporal_id, &spatial_id);
>> + if (len < 0)
>> + return len;
>> +
>> + return 0;
>> +}
>> +
>> +static int annexb_probe(const AVProbeData *p)
>> +{
>> + AVIOContext pb;
>> + int64_t obu_size;
>> + uint32_t temporal_unit_size, frame_unit_size, obu_unit_size;
>> + int seq = 0, frame_header = 0;
>> + int ret, type, cnt = 0;
>> +
>> + ffio_init_context(&pb, p->buf, p->buf_size, 0,
>> + NULL, NULL, NULL, NULL);
>> +
>> + ret = leb(&pb, &temporal_unit_size);
>> + if (ret < 0)
>> + return 0;
>> + cnt += ret;
>> + ret = leb(&pb, &frame_unit_size);
>> + if (ret < 0 || (frame_unit_size + ret) > temporal_unit_size)
>> + return 0;
>> + cnt += ret;
>> + temporal_unit_size -= ret;
>> + ret = leb(&pb, &obu_unit_size);
>> + if (ret < 0 || (obu_unit_size + ret) >= frame_unit_size)
>> + return 0;
>> + cnt += ret;
>> +
>> + temporal_unit_size -= obu_unit_size + ret;
>> + frame_unit_size -= obu_unit_size + ret;
>> +
>> + avio_skip(&pb, obu_unit_size);
>> + if (pb.eof_reached || pb.error)
>> + return 0;
>> +
>> + // Check that the first OBU is a Temporal Delimiter.
>> + ret = read_obu(p->buf + cnt, FFMIN(p->buf_size - cnt, obu_unit_size),
>> &obu_size, &type);
>> + if (ret < 0 || type != AV1_OBU_TEMPORAL_DELIMITER || obu_size > 0)
>> + return 0;
>> + cnt += obu_unit_size;
>> +
>> + do {
>> + ret = leb(&pb, &obu_unit_size);
>> + if (ret < 0 || (obu_unit_size + ret) > frame_unit_size)
>> + return 0;
>> + cnt += ret;
>> +
>> + avio_skip(&pb, obu_unit_size);
>> + if (pb.eof_reached || pb.error)
>> + return 0;
>> +
>> + ret = read_obu(p->buf + cnt, FFMIN(p->buf_size - cnt,
>> obu_unit_size), &obu_size, &type);
>> + if (ret < 0)
>> + return 0;
>> + cnt += obu_unit_size;
>> +
>> + if (type == AV1_OBU_SEQUENCE_HEADER)
>> + seq = 1;
>> + if (type == AV1_OBU_FRAME || type == AV1_OBU_FRAME_HEADER) {
>> + if (frame_header || !seq)
>> + return 0;
>> + frame_header = 1;
>> + break;
>> + }
>> + if (type == AV1_OBU_TILE_GROUP && !frame_header)
>> + return 0;
>> +
>> + temporal_unit_size -= obu_unit_size + ret;
>> + frame_unit_size -= obu_unit_size + ret;
>> + } while (!seq || !frame_header || frame_unit_size);
>> +
>> + return (seq && frame_header) ? AVPROBE_SCORE_EXTENSION + 1 : 0;
>> +}
>> +
>> +static int annexb_read_header(AVFormatContext *s)
>> +{
>> + AnnexBContext *c = s->priv_data;
>> + const AVBitStreamFilter *filter = av_bsf_get_by_name("av1_frame_merge");
>> + AVStream *st;
>> + int ret;
>> +
>> + if (!filter) {
>> + av_log(c, AV_LOG_ERROR, "av1_frame_merge bitstream filter "
>> + "not found. This is a bug, please report it.\n");
>> + return AVERROR_BUG;
>> + }
>> +
>> + st = avformat_new_stream(s, NULL);
>> + if (!st)
>> + return AVERROR(ENOMEM);
>> +
>> + st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
>> + st->codecpar->codec_id = AV_CODEC_ID_AV1;
>> + st->need_parsing = AVSTREAM_PARSE_HEADERS;
>> +
>> + st->internal->avctx->framerate = c->framerate;
>> + // taken from rawvideo demuxers
>> + avpriv_set_pts_info(st, 64, 1, 1200000);
>> +
>> + ret = av_bsf_alloc(filter, &c->bsf);
>> + if (ret < 0)
>> + return ret;
>> +
>> + ret = avcodec_parameters_copy(c->bsf->par_in, st->codecpar);
>> + if (ret < 0) {
>> + av_bsf_free(&c->bsf);
>> + return ret;
>> + }
>> +
>> + return av_bsf_init(c->bsf);
>
> Demuxers don't have a deinit function, so if av_bsf_init() fails, no
> one will clean up after you and free the bsf.
True, will change.
>
>> +}
>> +
>> +static int annexb_read_packet(AVFormatContext *s, AVPacket *pkt)
>> +{
>> + AnnexBContext *c = s->priv_data;
>> + uint32_t obu_unit_size;
>> + int ret, len;
>> +
>> +retry:
>> + if (avio_feof(s->pb)) {
>> + if (c->temporal_unit_size || c->frame_unit_size)
>> + return AVERROR(EIO);
>> + av_bsf_send_packet(c->bsf, NULL);
>> + goto end;
>> + }
>> +
>> + if (!c->temporal_unit_size) {
>> + len = leb(s->pb, &c->temporal_unit_size);
>> + if (len < 0) return AVERROR_INVALIDDATA;
>> + }
>> +
>> + if (!c->frame_unit_size) {
>> + len = leb(s->pb, &c->frame_unit_size);
>> + if (len < 0 || (c->frame_unit_size + len) > c->temporal_unit_size)
>> + return AVERROR_INVALIDDATA;
>> + c->temporal_unit_size -= len;
>> + }
>> +
>> + len = leb(s->pb, &obu_unit_size);
>> + if (len < 0 || (obu_unit_size + len) > c->frame_unit_size)
>> + return AVERROR_INVALIDDATA;
>> +
>> + ret = av_get_packet(s->pb, pkt, obu_unit_size);
>> + if (ret < 0)
>> + return ret;
>> + if (ret != obu_unit_size) {
>> + av_packet_unref(pkt);
>
> This is unnecessary: ff_read_packet() will unref the packet if you
> return an error. You added this yourself. (You are btw relying on this
> by not unreferencing the packet if av_bsf_send_packet() fails.)
Will remove.
>
>> + return AVERROR(EIO);
>> + }
>> +
>> + c->temporal_unit_size -= obu_unit_size + len;
>> + c->frame_unit_size -= obu_unit_size + len;
>> +
>> + ret = av_bsf_send_packet(c->bsf, pkt);
>> + if (ret < 0) {
>> + av_log(s, AV_LOG_ERROR, "av1_frame_merge filter "
>> + "failed to send input packet\n");
>
> "Failed to send packet to av1_frame_merge filter\n" (av1_frame_merge
> does not send any input packet ever, it receives them; and this call
> does not call any av1_frame_merge internal functions.)
It's pretty much a copy paste log message from another module. I'll
change it and the one below.
>
>> + return ret;
>> + }
>> +
>> +end:
>> + ret = av_bsf_receive_packet(c->bsf, pkt);
>> +
>> + if (ret < 0 && ret != AVERROR(EAGAIN) && ret != AVERROR_EOF)
>> + av_log(s, AV_LOG_ERROR, "av1_frame_merge filter "
>> + "failed to receive output packet\n");
>
> "av1_frame_merge filter failed to send output packet\n"
>
>> +
>> + if (ret == AVERROR(EAGAIN))
>> + goto retry;
>> +
>> + return ret;
>> +}
>> +
>> +static int annexb_read_close(AVFormatContext *s)
>
> Side-note: Why does read_close() have to return an int? The return
> value is ignored in avformat_close_input(), the only place where
> read_close() is ever called.
I don't know. I also wondered about that. Every other close function is
a void (codecs, filters, etc).
It may have been done for a reason at some point, but in any case, it's
hardly important.
>
> I haven't looked at the rest (i.e. probe and leb) yet, in particular
> wrt overflows.
Things like "frame_unit_size + ret" could in theory overflow, with
frame_unit_size being of type uint32_t and possible values up to
UINT32_MAX. I could cast it to int64_t to workaround that.
>
> - Andreas
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