1/*
2 * Copyright (c) 2019 James Almer <jamrial@gmail.com>
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include "bsf.h"
22#include "bsf_internal.h"
23#include "cbs.h"
24#include "cbs_av1.h"
25
26typedef struct AV1FMergeContext {
27    CodedBitstreamContext *input;
28    CodedBitstreamContext *output;
29    CodedBitstreamFragment frag[2];
30    AVPacket *pkt, *in;
31    int idx;
32} AV1FMergeContext;
33
34static void av1_frame_merge_flush(AVBSFContext *bsf)
35{
36    AV1FMergeContext *ctx = bsf->priv_data;
37
38    ff_cbs_fragment_reset(&ctx->frag[0]);
39    ff_cbs_fragment_reset(&ctx->frag[1]);
40    av_packet_unref(ctx->in);
41    av_packet_unref(ctx->pkt);
42}
43
44static int av1_frame_merge_filter(AVBSFContext *bsf, AVPacket *out)
45{
46    AV1FMergeContext *ctx = bsf->priv_data;
47    CodedBitstreamFragment *frag = &ctx->frag[ctx->idx], *tu = &ctx->frag[!ctx->idx];
48    AVPacket *in = ctx->in, *buffer_pkt = ctx->pkt;
49    int err, i;
50
51    err = ff_bsf_get_packet_ref(bsf, in);
52    if (err < 0) {
53        if (err == AVERROR_EOF && tu->nb_units > 0)
54            goto eof;
55        return err;
56    }
57
58    err = ff_cbs_read_packet(ctx->input, frag, in);
59    if (err < 0) {
60        av_log(bsf, AV_LOG_ERROR, "Failed to read packet.\n");
61        goto fail;
62    }
63
64    if (frag->nb_units == 0) {
65        av_log(bsf, AV_LOG_ERROR, "No OBU in packet.\n");
66        err = AVERROR_INVALIDDATA;
67        goto fail;
68    }
69
70    if (tu->nb_units == 0 && frag->units[0].type != AV1_OBU_TEMPORAL_DELIMITER) {
71        av_log(bsf, AV_LOG_ERROR, "Missing Temporal Delimiter.\n");
72        err = AVERROR_INVALIDDATA;
73        goto fail;
74    }
75
76    for (i = 1; i < frag->nb_units; i++) {
77        if (frag->units[i].type == AV1_OBU_TEMPORAL_DELIMITER) {
78            av_log(bsf, AV_LOG_ERROR, "Temporal Delimiter in the middle of a packet.\n");
79            err = AVERROR_INVALIDDATA;
80            goto fail;
81        }
82    }
83
84    if (tu->nb_units > 0 && frag->units[0].type == AV1_OBU_TEMPORAL_DELIMITER) {
85eof:
86        err = ff_cbs_write_packet(ctx->output, buffer_pkt, tu);
87        if (err < 0) {
88            av_log(bsf, AV_LOG_ERROR, "Failed to write packet.\n");
89            goto fail;
90        }
91        av_packet_move_ref(out, buffer_pkt);
92
93        // Swap fragment index, to avoid copying fragment references.
94        ctx->idx = !ctx->idx;
95    } else {
96        for (i = 0; i < frag->nb_units; i++) {
97            err = ff_cbs_insert_unit_content(tu, -1, frag->units[i].type,
98                                             frag->units[i].content, frag->units[i].content_ref);
99            if (err < 0)
100                goto fail;
101        }
102
103        err = AVERROR(EAGAIN);
104    }
105
106    /* Buffer packets with timestamps (there should be at most one per TU)
107     * or any packet if buffer_pkt is empty. The latter is needed to
108     * passthrough positions in case there are no timestamps like with
109     * the raw OBU demuxer. */
110    if (!buffer_pkt->data ||
111        in->pts != AV_NOPTS_VALUE && buffer_pkt->pts == AV_NOPTS_VALUE) {
112        av_packet_unref(buffer_pkt);
113        av_packet_move_ref(buffer_pkt, in);
114    } else
115        av_packet_unref(in);
116
117    ff_cbs_fragment_reset(&ctx->frag[ctx->idx]);
118
119fail:
120    if (err < 0 && err != AVERROR(EAGAIN))
121        av1_frame_merge_flush(bsf);
122
123    return err;
124}
125
126static int av1_frame_merge_init(AVBSFContext *bsf)
127{
128    AV1FMergeContext *ctx = bsf->priv_data;
129    int err;
130
131    ctx->in  = av_packet_alloc();
132    ctx->pkt = av_packet_alloc();
133    if (!ctx->in || !ctx->pkt)
134        return AVERROR(ENOMEM);
135
136    err =  ff_cbs_init(&ctx->input, AV_CODEC_ID_AV1, bsf);
137    if (err < 0)
138        return err;
139
140    return ff_cbs_init(&ctx->output, AV_CODEC_ID_AV1, bsf);
141}
142
143static void av1_frame_merge_close(AVBSFContext *bsf)
144{
145    AV1FMergeContext *ctx = bsf->priv_data;
146
147    ff_cbs_fragment_free(&ctx->frag[0]);
148    ff_cbs_fragment_free(&ctx->frag[1]);
149    av_packet_free(&ctx->in);
150    av_packet_free(&ctx->pkt);
151    ff_cbs_close(&ctx->input);
152    ff_cbs_close(&ctx->output);
153}
154
155static const enum AVCodecID av1_frame_merge_codec_ids[] = {
156    AV_CODEC_ID_AV1, AV_CODEC_ID_NONE,
157};
158
159const FFBitStreamFilter ff_av1_frame_merge_bsf = {
160    .p.name         = "av1_frame_merge",
161    .p.codec_ids    = av1_frame_merge_codec_ids,
162    .priv_data_size = sizeof(AV1FMergeContext),
163    .init           = av1_frame_merge_init,
164    .flush          = av1_frame_merge_flush,
165    .close          = av1_frame_merge_close,
166    .filter         = av1_frame_merge_filter,
167};
168