diff options
Diffstat (limited to 'libavcodec/vp9_parser.c')
| -rw-r--r-- | libavcodec/vp9_parser.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/libavcodec/vp9_parser.c b/libavcodec/vp9_parser.c new file mode 100644 index 0000000000..ab33c33414 --- /dev/null +++ b/libavcodec/vp9_parser.c @@ -0,0 +1,136 @@ +/* + * VP9 compatible video decoder + * + * Copyright (C) 2013 Ronald S. Bultje <rsbultje gmail com> + * Copyright (C) 2013 Clément Bœsch <u pkh me> + * + * 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/intreadwrite.h" +#include "parser.h" + +typedef struct VP9ParseContext { + int n_frames; // 1-8 + int size[8]; + int64_t pts; +} VP9ParseContext; + +static void parse_frame(AVCodecParserContext *ctx, const uint8_t *buf, int size) +{ + VP9ParseContext *s = ctx->priv_data; + + if (buf[0] & 0x4) { + ctx->pict_type = AV_PICTURE_TYPE_P; + ctx->key_frame = 0; + } else { + ctx->pict_type = AV_PICTURE_TYPE_I; + ctx->key_frame = 1; + } + + if (buf[0] & 0x2) { + if (ctx->pts == AV_NOPTS_VALUE) + ctx->pts = s->pts; + s->pts = AV_NOPTS_VALUE; + } else { + s->pts = ctx->pts; + ctx->pts = AV_NOPTS_VALUE; + } +} + +static int parse(AVCodecParserContext *ctx, + AVCodecContext *avctx, + const uint8_t **out_data, int *out_size, + const uint8_t *data, int size) +{ + VP9ParseContext *s = ctx->priv_data; + int full_size = size; + int marker; + + if (size <= 0) { + *out_size = 0; + *out_data = data; + + return 0; + } + + if (s->n_frames > 0) { + *out_data = data; + *out_size = s->size[--s->n_frames]; + parse_frame(ctx, *out_data, *out_size); + + return s->n_frames > 0 ? *out_size : size /* i.e. include idx tail */; + } + + marker = data[size - 1]; + if ((marker & 0xe0) == 0xc0) { + int nbytes = 1 + ((marker >> 3) & 0x3); + int n_frames = 1 + (marker & 0x7), idx_sz = 2 + n_frames * nbytes; + + if (size >= idx_sz && data[size - idx_sz] == marker) { + const uint8_t *idx = data + size + 1 - idx_sz; + int first = 1; + + switch (nbytes) { +#define case_n(a, rd) \ + case a: \ + while (n_frames--) { \ + unsigned sz = rd; \ + idx += a; \ + if (sz > size) { \ + s->n_frames = 0; \ + *out_size = size; \ + *out_data = data; \ + av_log(avctx, AV_LOG_ERROR, \ + "Superframe packet size too big: %u > %d\n", \ + sz, size); \ + return full_size; \ + } \ + if (first) { \ + first = 0; \ + *out_data = data; \ + *out_size = sz; \ + s->n_frames = n_frames; \ + } else { \ + s->size[n_frames] = sz; \ + } \ + data += sz; \ + size -= sz; \ + } \ + parse_frame(ctx, *out_data, *out_size); \ + return *out_size + + case_n(1, *idx); + case_n(2, AV_RL16(idx)); + case_n(3, AV_RL24(idx)); + case_n(4, AV_RL32(idx)); + } + } + } + + *out_data = data; + *out_size = size; + parse_frame(ctx, data, size); + + return size; +} + +AVCodecParser ff_vp9_parser = { + .codec_ids = { AV_CODEC_ID_VP9 }, + .priv_data_size = sizeof(VP9ParseContext), + .parser_parse = parse, +}; |