| /* |
| * Vp9 invisible (alt-ref) frame to superframe merge bitstream filter |
| * Copyright (c) 2016 Ronald S. Bultje <rsbultje@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 "libavutil/avassert.h" |
| |
| #include "bsf.h" |
| #include "bsf_internal.h" |
| #include "get_bits.h" |
| |
| #define MAX_CACHE 8 |
| typedef struct VP9BSFContext { |
| int n_cache; |
| AVPacket *cache[MAX_CACHE]; |
| } VP9BSFContext; |
| |
| static void stats(AVPacket * const *in, int n_in, |
| unsigned *_max, unsigned *_sum) |
| { |
| int n; |
| unsigned max = 0, sum = 0; |
| |
| for (n = 0; n < n_in; n++) { |
| unsigned sz = in[n]->size; |
| |
| if (sz > max) |
| max = sz; |
| sum += sz; |
| } |
| |
| *_max = max; |
| *_sum = sum; |
| } |
| |
| static int merge_superframe(AVPacket * const *in, int n_in, AVPacket *out) |
| { |
| unsigned max, sum, mag, marker, n, sz; |
| uint8_t *ptr; |
| int res; |
| |
| stats(in, n_in, &max, &sum); |
| mag = av_log2(max) >> 3; |
| marker = 0xC0 + (mag << 3) + (n_in - 1); |
| sz = sum + 2 + (mag + 1) * n_in; |
| res = av_new_packet(out, sz); |
| if (res < 0) |
| return res; |
| ptr = out->data; |
| for (n = 0; n < n_in; n++) { |
| memcpy(ptr, in[n]->data, in[n]->size); |
| ptr += in[n]->size; |
| } |
| |
| #define wloop(mag, wr) \ |
| do { \ |
| for (n = 0; n < n_in; n++) { \ |
| wr; \ |
| ptr += mag + 1; \ |
| } \ |
| } while (0) |
| |
| // write superframe with marker 110[mag:2][nframes:3] |
| *ptr++ = marker; |
| switch (mag) { |
| case 0: |
| wloop(mag, *ptr = in[n]->size); |
| break; |
| case 1: |
| wloop(mag, AV_WL16(ptr, in[n]->size)); |
| break; |
| case 2: |
| wloop(mag, AV_WL24(ptr, in[n]->size)); |
| break; |
| case 3: |
| wloop(mag, AV_WL32(ptr, in[n]->size)); |
| break; |
| } |
| *ptr++ = marker; |
| av_assert0(ptr == &out->data[out->size]); |
| |
| return 0; |
| } |
| |
| static int vp9_superframe_filter(AVBSFContext *ctx, AVPacket *pkt) |
| { |
| GetBitContext gb; |
| VP9BSFContext *s = ctx->priv_data; |
| int res, invisible, profile, marker, uses_superframe_syntax = 0, n; |
| |
| res = ff_bsf_get_packet_ref(ctx, pkt); |
| if (res < 0) |
| return res; |
| |
| marker = pkt->data[pkt->size - 1]; |
| if ((marker & 0xe0) == 0xc0) { |
| int nbytes = 1 + ((marker >> 3) & 0x3); |
| int n_frames = 1 + (marker & 0x7), idx_sz = 2 + n_frames * nbytes; |
| |
| uses_superframe_syntax = pkt->size >= idx_sz && pkt->data[pkt->size - idx_sz] == marker; |
| } |
| |
| if ((res = init_get_bits8(&gb, pkt->data, pkt->size)) < 0) |
| goto done; |
| |
| get_bits(&gb, 2); // frame marker |
| profile = get_bits1(&gb); |
| profile |= get_bits1(&gb) << 1; |
| if (profile == 3) profile += get_bits1(&gb); |
| |
| if (get_bits1(&gb)) { |
| invisible = 0; |
| } else { |
| get_bits1(&gb); // keyframe |
| invisible = !get_bits1(&gb); |
| } |
| |
| if (uses_superframe_syntax && s->n_cache > 0) { |
| av_log(ctx, AV_LOG_ERROR, |
| "Mixing of superframe syntax and naked VP9 frames not supported\n"); |
| res = AVERROR(ENOSYS); |
| goto done; |
| } else if ((!invisible || uses_superframe_syntax) && !s->n_cache) { |
| // passthrough |
| return 0; |
| } else if (s->n_cache + 1 >= MAX_CACHE) { |
| av_log(ctx, AV_LOG_ERROR, |
| "Too many invisible frames\n"); |
| res = AVERROR_INVALIDDATA; |
| goto done; |
| } |
| |
| av_packet_move_ref(s->cache[s->n_cache++], pkt); |
| |
| if (invisible) { |
| return AVERROR(EAGAIN); |
| } |
| av_assert0(s->n_cache > 0); |
| |
| // build superframe |
| if ((res = merge_superframe(s->cache, s->n_cache, pkt)) < 0) |
| goto done; |
| |
| res = av_packet_copy_props(pkt, s->cache[s->n_cache - 1]); |
| if (res < 0) |
| goto done; |
| |
| for (n = 0; n < s->n_cache; n++) |
| av_packet_unref(s->cache[n]); |
| s->n_cache = 0; |
| |
| done: |
| if (res < 0) |
| av_packet_unref(pkt); |
| return res; |
| } |
| |
| static int vp9_superframe_init(AVBSFContext *ctx) |
| { |
| VP9BSFContext *s = ctx->priv_data; |
| int n; |
| |
| // alloc cache packets |
| for (n = 0; n < MAX_CACHE; n++) { |
| s->cache[n] = av_packet_alloc(); |
| if (!s->cache[n]) |
| return AVERROR(ENOMEM); |
| } |
| |
| return 0; |
| } |
| |
| static void vp9_superframe_flush(AVBSFContext *ctx) |
| { |
| VP9BSFContext *s = ctx->priv_data; |
| int n; |
| |
| // unref cached data |
| for (n = 0; n < s->n_cache; n++) |
| av_packet_unref(s->cache[n]); |
| s->n_cache = 0; |
| } |
| |
| static void vp9_superframe_close(AVBSFContext *ctx) |
| { |
| VP9BSFContext *s = ctx->priv_data; |
| int n; |
| |
| // free cached data |
| for (n = 0; n < MAX_CACHE; n++) |
| av_packet_free(&s->cache[n]); |
| } |
| |
| static const enum AVCodecID codec_ids[] = { |
| AV_CODEC_ID_VP9, AV_CODEC_ID_NONE, |
| }; |
| |
| const AVBitStreamFilter ff_vp9_superframe_bsf = { |
| .name = "vp9_superframe", |
| .priv_data_size = sizeof(VP9BSFContext), |
| .filter = vp9_superframe_filter, |
| .init = vp9_superframe_init, |
| .flush = vp9_superframe_flush, |
| .close = vp9_superframe_close, |
| .codec_ids = codec_ids, |
| }; |