mirror of
https://github.com/librempeg/librempeg
synced 2024-11-22 18:49:58 +00:00
137 lines
4.0 KiB
C
137 lines
4.0 KiB
C
/*
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* VP9 compatible video decoder
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*
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* Copyright (C) 2013 Ronald S. Bultje <rsbultje gmail com>
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* Copyright (C) 2013 Clément Bœsch <u pkh me>
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "libavutil/intreadwrite.h"
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#include "parser.h"
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typedef struct VP9ParseContext {
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int n_frames; // 1-8
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int size[8];
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int64_t pts;
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} VP9ParseContext;
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static void parse_frame(AVCodecParserContext *ctx, const uint8_t *buf, int size)
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{
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VP9ParseContext *s = ctx->priv_data;
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if (buf[0] & 0x4) {
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ctx->pict_type = AV_PICTURE_TYPE_P;
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ctx->key_frame = 0;
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} else {
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ctx->pict_type = AV_PICTURE_TYPE_I;
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ctx->key_frame = 1;
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}
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if (buf[0] & 0x2) {
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if (ctx->pts == AV_NOPTS_VALUE)
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ctx->pts = s->pts;
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s->pts = AV_NOPTS_VALUE;
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} else {
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s->pts = ctx->pts;
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ctx->pts = AV_NOPTS_VALUE;
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}
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}
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static int parse(AVCodecParserContext *ctx,
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AVCodecContext *avctx,
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const uint8_t **out_data, int *out_size,
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const uint8_t *data, int size)
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{
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VP9ParseContext *s = ctx->priv_data;
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int full_size = size;
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int marker;
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if (size <= 0) {
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*out_size = 0;
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*out_data = data;
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return 0;
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}
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if (s->n_frames > 0) {
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*out_data = data;
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*out_size = s->size[--s->n_frames];
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parse_frame(ctx, *out_data, *out_size);
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return s->n_frames > 0 ? *out_size : size /* i.e. include idx tail */;
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}
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marker = data[size - 1];
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if ((marker & 0xe0) == 0xc0) {
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int nbytes = 1 + ((marker >> 3) & 0x3);
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int n_frames = 1 + (marker & 0x7), idx_sz = 2 + n_frames * nbytes;
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if (size >= idx_sz && data[size - idx_sz] == marker) {
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const uint8_t *idx = data + size + 1 - idx_sz;
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int first = 1;
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switch (nbytes) {
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#define case_n(a, rd) \
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case a: \
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while (n_frames--) { \
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unsigned sz = rd; \
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idx += a; \
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if (sz > size) { \
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s->n_frames = 0; \
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*out_size = size; \
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*out_data = data; \
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av_log(avctx, AV_LOG_ERROR, \
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"Superframe packet size too big: %u > %d\n", \
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sz, size); \
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return full_size; \
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} \
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if (first) { \
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first = 0; \
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*out_data = data; \
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*out_size = sz; \
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s->n_frames = n_frames; \
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} else { \
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s->size[n_frames] = sz; \
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} \
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data += sz; \
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size -= sz; \
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} \
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parse_frame(ctx, *out_data, *out_size); \
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return *out_size
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case_n(1, *idx);
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case_n(2, AV_RL16(idx));
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case_n(3, AV_RL24(idx));
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case_n(4, AV_RL32(idx));
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}
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}
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}
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*out_data = data;
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*out_size = size;
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parse_frame(ctx, data, size);
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return size;
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}
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AVCodecParser ff_vp9_parser = {
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.codec_ids = { AV_CODEC_ID_VP9 },
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.priv_data_size = sizeof(VP9ParseContext),
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.parser_parse = parse,
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};
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