avformat: add an AV1 Annex B demuxer

Signed-off-by: James Almer <jamrial@gmail.com>

1 files changed, 277 insertions, 0 deletions

diff --git a/libavformat/av1dec.c b/libavformat/av1dec.c
new file mode 100644
index 0000000000..a0cad55668
--- /dev/null
+++ b/libavformat/av1dec.c
@@ -0,0 +1,277 @@
+/*
+ * AV1 Annex B demuxer
+ * Copyright (c) 2019 James Almer <jamrial@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 || ((int64_t)frame_unit_size + ret) > temporal_unit_size)
+        return 0;
+    cnt += ret;
+    temporal_unit_size -= ret;
+    ret = leb(&pb, &obu_unit_size);
+    if (ret < 0 || ((int64_t)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 || ((int64_t)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 (!frame_header && frame_unit_size);
+
+    return 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;
+    }
+
+    ret = av_bsf_init(c->bsf);
+    if (ret < 0)
+        av_bsf_free(&c->bsf);
+
+    return ret;
+}
+
+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 || ((int64_t)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 || ((int64_t)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)
+        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, "Failed to send packet to "
+                                "av1_frame_merge filter\n");
+        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 "
+                                "send output packet\n");
+
+    if (ret == AVERROR(EAGAIN))
+        goto retry;
+
+    return ret;
+}
+
+static int annexb_read_close(AVFormatContext *s)
+{
+    AnnexBContext *c = s->priv_data;
+
+    av_bsf_free(&c->bsf);
+    return 0;
+}
+
+#define OFFSET(x) offsetof(AnnexBContext, x)
+#define DEC AV_OPT_FLAG_DECODING_PARAM
+static const AVOption annexb_options[] = {
+    { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, DEC},
+    { NULL },
+};
+
+static const AVClass annexb_demuxer_class = {
+    .class_name = "AV1 Annex B demuxer",
+    .item_name  = av_default_item_name,
+    .option     = annexb_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+AVInputFormat ff_av1_demuxer = {
+    .name           = "av1",
+    .long_name      = NULL_IF_CONFIG_SMALL("AV1 Annex B"),
+    .priv_data_size = sizeof(AnnexBContext),
+    .read_probe     = annexb_probe,
+    .read_header    = annexb_read_header,
+    .read_packet    = annexb_read_packet,
+    .read_close     = annexb_read_close,
+    .extensions     = "obu",
+    .flags          = AVFMT_GENERIC_INDEX,
+    .priv_class     = &annexb_demuxer_class,
+};