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"
25 #include "bsf_internal.h"
29 typedef struct VP9BSFContext {
31 AVPacket *cache[MAX_CACHE];
34 static void stats(AVPacket * const *in, int n_in,
35 unsigned *_max, unsigned *_sum)
38 unsigned max = 0, sum = 0;
40 for (n = 0; n < n_in; n++) {
41 unsigned sz = in[n]->size;
52 static int merge_superframe(AVPacket * const *in, int n_in, AVPacket *out)
54 unsigned max, sum, mag, marker, n, sz;
58 stats(in, n_in, &max, &sum);
59 mag = av_log2(max) >> 3;
60 marker = 0xC0 + (mag << 3) + (n_in - 1);
61 sz = sum + 2 + (mag + 1) * n_in;
62 res = av_new_packet(out, sz);
66 for (n = 0; n < n_in; n++) {
67 memcpy(ptr, in[n]->data, in[n]->size);
71 #define wloop(mag, wr) \
73 for (n = 0; n < n_in; n++) { \
79 // write superframe with marker 110[mag:2][nframes:3]
83 wloop(mag, *ptr = in[n]->size);
86 wloop(mag, AV_WL16(ptr, in[n]->size));
89 wloop(mag, AV_WL24(ptr, in[n]->size));
92 wloop(mag, AV_WL32(ptr, in[n]->size));
96 av_assert0(ptr == &out->data[out->size]);
101 static int vp9_superframe_filter(AVBSFContext *ctx, AVPacket *pkt)
104 VP9BSFContext *s = ctx->priv_data;
105 int res, invisible, profile, marker, uses_superframe_syntax = 0, n;
107 res = ff_bsf_get_packet_ref(ctx, pkt);
111 marker = pkt->data[pkt->size - 1];
112 if ((marker & 0xe0) == 0xc0) {
113 int nbytes = 1 + ((marker >> 3) & 0x3);
114 int n_frames = 1 + (marker & 0x7), idx_sz = 2 + n_frames * nbytes;
116 uses_superframe_syntax = pkt->size >= idx_sz && pkt->data[pkt->size - idx_sz] == marker;
119 if ((res = init_get_bits8(&gb, pkt->data, pkt->size)) < 0)
122 get_bits(&gb, 2); // frame marker
123 profile = get_bits1(&gb);
124 profile |= get_bits1(&gb) << 1;
125 if (profile == 3) profile += get_bits1(&gb);
127 if (get_bits1(&gb)) {
130 get_bits1(&gb); // keyframe
131 invisible = !get_bits1(&gb);
134 if (uses_superframe_syntax && s->n_cache > 0) {
135 av_log(ctx, AV_LOG_ERROR,
136 "Mixing of superframe syntax and naked VP9 frames not supported\n");
137 res = AVERROR(ENOSYS);
139 } else if ((!invisible || uses_superframe_syntax) && !s->n_cache) {
142 } else if (s->n_cache + 1 >= MAX_CACHE) {
143 av_log(ctx, AV_LOG_ERROR,
144 "Too many invisible frames\n");
145 res = AVERROR_INVALIDDATA;
149 av_packet_move_ref(s->cache[s->n_cache++], pkt);
152 return AVERROR(EAGAIN);
154 av_assert0(s->n_cache > 0);
157 if ((res = merge_superframe(s->cache, s->n_cache, pkt)) < 0)
160 res = av_packet_copy_props(pkt, s->cache[s->n_cache - 1]);
164 for (n = 0; n < s->n_cache; n++)
165 av_packet_unref(s->cache[n]);
170 av_packet_unref(pkt);
174 static int vp9_superframe_init(AVBSFContext *ctx)
176 VP9BSFContext *s = ctx->priv_data;
179 // alloc cache packets
180 for (n = 0; n < MAX_CACHE; n++) {
181 s->cache[n] = av_packet_alloc();
183 return AVERROR(ENOMEM);
189 static void vp9_superframe_flush(AVBSFContext *ctx)
191 VP9BSFContext *s = ctx->priv_data;
195 for (n = 0; n < s->n_cache; n++)
196 av_packet_unref(s->cache[n]);
200 static void vp9_superframe_close(AVBSFContext *ctx)
202 VP9BSFContext *s = ctx->priv_data;
206 for (n = 0; n < MAX_CACHE; n++)
207 av_packet_free(&s->cache[n]);
210 static const enum AVCodecID codec_ids[] = {
211 AV_CODEC_ID_VP9, AV_CODEC_ID_NONE,
214 const AVBitStreamFilter ff_vp9_superframe_bsf = {
215 .name = "vp9_superframe",
216 .priv_data_size = sizeof(VP9BSFContext),
217 .filter = vp9_superframe_filter,
218 .init = vp9_superframe_init,
219 .flush = vp9_superframe_flush,
220 .close = vp9_superframe_close,
221 .codec_ids = codec_ids,