2 * Vp9 invisible (alt-ref) frame to superframe merge bitstream filter
3 * Copyright (c) 2016 Ronald S. Bultje <rsbultje@gmail.com>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
22 #include "libavutil/avassert.h"
28 typedef struct VP9BSFContext {
36 static void stats(const struct CachedBuf *in, int n_in,
37 unsigned *_max, unsigned *_sum)
40 unsigned max = 0, sum = 0;
42 for (n = 0; n < n_in; n++) {
43 unsigned sz = in[n].size;
54 static int merge_superframe(const struct CachedBuf *in, int n_in, AVPacket *out)
56 unsigned max, sum, mag, marker, n, sz;
60 stats(in, n_in, &max, &sum);
61 mag = av_log2(max) >> 3;
62 marker = 0xC0 + (mag << 3) + (n_in - 1);
63 sz = sum + 2 + (mag + 1) * n_in;
64 res = av_new_packet(out, sz);
68 for (n = 0; n < n_in; n++) {
69 memcpy(ptr, in[n].data, in[n].size);
73 #define wloop(mag, wr) \
75 for (n = 0; n < n_in; n++) { \
81 // write superframe with marker 110[mag:2][nframes:3]
85 wloop(mag, *ptr = in[n].size);
88 wloop(mag, AV_WL16(ptr, in[n].size));
91 wloop(mag, AV_WL24(ptr, in[n].size));
94 wloop(mag, AV_WL32(ptr, in[n].size));
98 av_assert0(ptr == &out->data[out->size]);
103 static int vp9_superframe_filter(AVBSFContext *ctx, AVPacket *out)
106 VP9BSFContext *s = ctx->priv_data;
108 int res, invisible, profile, marker, uses_superframe_syntax = 0, n;
110 res = ff_bsf_get_packet(ctx, &in);
114 marker = in->data[in->size - 1];
115 if ((marker & 0xe0) == 0xc0) {
116 int nbytes = 1 + ((marker >> 3) & 0x3);
117 int n_frames = 1 + (marker & 0x7), idx_sz = 2 + n_frames * nbytes;
119 uses_superframe_syntax = in->size >= idx_sz && in->data[in->size - idx_sz] == marker;
122 if ((res = init_get_bits8(&gb, in->data, in->size)) < 0)
125 get_bits(&gb, 2); // frame marker
126 profile = get_bits1(&gb);
127 profile |= get_bits1(&gb) << 1;
128 if (profile == 3) profile += get_bits1(&gb);
130 if (get_bits1(&gb)) {
133 get_bits1(&gb); // keyframe
134 invisible = !get_bits1(&gb);
137 if (uses_superframe_syntax && s->n_cache > 0) {
138 av_log(ctx, AV_LOG_ERROR,
139 "Mixing of superframe syntax and naked VP9 frames not supported");
140 res = AVERROR_INVALIDDATA;
142 } else if ((!invisible || uses_superframe_syntax) && !s->n_cache) {
144 av_packet_move_ref(out, in);
146 } else if (s->n_cache + 1 >= MAX_CACHE) {
147 av_log(ctx, AV_LOG_ERROR,
148 "Too many invisible frames");
149 res = AVERROR_INVALIDDATA;
153 s->cache[s->n_cache].size = in->size;
154 if (invisible && !uses_superframe_syntax) {
155 s->cache[s->n_cache].data = av_malloc(in->size);
156 if (!s->cache[s->n_cache].data) {
157 res = AVERROR(ENOMEM);
160 memcpy(s->cache[s->n_cache++].data, in->data, in->size);
161 res = AVERROR(EAGAIN);
164 av_assert0(s->n_cache > 0);
166 s->cache[s->n_cache].data = in->data;
169 if ((res = merge_superframe(s->cache, s->n_cache + 1, out)) < 0)
172 for (n = 0; n < s->n_cache; n++)
173 av_freep(&s->cache[n].data);
176 res = av_packet_copy_props(out, in);
182 av_packet_unref(out);
187 static void vp9_superframe_close(AVBSFContext *ctx)
189 VP9BSFContext *s = ctx->priv_data;
193 for (n = 0; n < s->n_cache; n++)
194 av_freep(&s->cache[n].data);
197 static const enum AVCodecID codec_ids[] = {
198 AV_CODEC_ID_VP9, AV_CODEC_ID_NONE,
201 const AVBitStreamFilter ff_vp9_superframe_bsf = {
202 .name = "vp9_superframe",
203 .priv_data_size = sizeof(VP9BSFContext),
204 .filter = vp9_superframe_filter,
205 .close = vp9_superframe_close,
206 .codec_ids = codec_ids,