diff options
Diffstat (limited to 'media/ffvpx/libavcodec/vp9_superframe_split_bsf.c')
| -rw-r--r-- | media/ffvpx/libavcodec/vp9_superframe_split_bsf.c | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/media/ffvpx/libavcodec/vp9_superframe_split_bsf.c b/media/ffvpx/libavcodec/vp9_superframe_split_bsf.c new file mode 100644 index 000000000..9c4aa33dc --- /dev/null +++ b/media/ffvpx/libavcodec/vp9_superframe_split_bsf.c @@ -0,0 +1,147 @@ +/* + * 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 + */ + +/** + * @file + * This bitstream filter splits VP9 superframes into packets containing + * just one frame. + */ + +#include <stddef.h> + +#include "avcodec.h" +#include "bsf.h" +#include "bytestream.h" +#include "get_bits.h" + +typedef struct VP9SFSplitContext { + AVPacket buffer_pkt; + + int nb_frames; + int next_frame; + size_t next_frame_offset; + int sizes[8]; +} VP9SFSplitContext; + +static int vp9_superframe_split_filter(AVBSFContext *ctx, AVPacket *out) +{ + VP9SFSplitContext *s = ctx->priv_data; + AVPacket *in; + int i, j, ret, marker; + int is_superframe = !!s->buffer_pkt.data; + + if (!s->buffer_pkt.data) { + ret = ff_bsf_get_packet_ref(ctx, &s->buffer_pkt); + if (ret < 0) + return ret; + in = &s->buffer_pkt; + + marker = in->data[in->size - 1]; + if ((marker & 0xe0) == 0xc0) { + int length_size = 1 + ((marker >> 3) & 0x3); + int nb_frames = 1 + (marker & 0x7); + int idx_size = 2 + nb_frames * length_size; + + if (in->size >= idx_size && in->data[in->size - idx_size] == marker) { + GetByteContext bc; + int64_t total_size = 0; + + bytestream2_init(&bc, in->data + in->size + 1 - idx_size, + nb_frames * length_size); + + for (i = 0; i < nb_frames; i++) { + int frame_size = 0; + for (j = 0; j < length_size; j++) + frame_size |= bytestream2_get_byte(&bc) << (j * 8); + + total_size += frame_size; + if (frame_size < 0 || total_size > in->size - idx_size) { + av_log(ctx, AV_LOG_ERROR, + "Invalid frame size in a superframe: %d\n", frame_size); + ret = AVERROR(EINVAL); + goto fail; + } + s->sizes[i] = frame_size; + } + s->nb_frames = nb_frames; + s->next_frame = 0; + s->next_frame_offset = 0; + is_superframe = 1; + } + } + } + + if (is_superframe) { + GetBitContext gb; + int profile, invisible = 0; + + ret = av_packet_ref(out, &s->buffer_pkt); + if (ret < 0) + goto fail; + + out->data += s->next_frame_offset; + out->size = s->sizes[s->next_frame]; + + s->next_frame_offset += out->size; + s->next_frame++; + + if (s->next_frame >= s->nb_frames) + av_packet_unref(&s->buffer_pkt); + + ret = init_get_bits8(&gb, out->data, out->size); + if (ret < 0) + goto fail; + + get_bits(&gb, 2); // frame_marker + profile = get_bits1(&gb); + profile |= get_bits1(&gb) << 1; + if (profile == 3) + get_bits1(&gb); + if (!get_bits1(&gb)) { + get_bits1(&gb); + invisible = !get_bits1(&gb); + } + + if (invisible) + out->pts = AV_NOPTS_VALUE; + + } else { + av_packet_move_ref(out, &s->buffer_pkt); + } + + return 0; +fail: + if (ret < 0) + av_packet_unref(out); + av_packet_unref(&s->buffer_pkt); + return ret; +} + +static void vp9_superframe_split_uninit(AVBSFContext *ctx) +{ + VP9SFSplitContext *s = ctx->priv_data; + av_packet_unref(&s->buffer_pkt); +} + +const AVBitStreamFilter ff_vp9_superframe_split_bsf = { + .name = "vp9_superframe_split", + .priv_data_size = sizeof(VP9SFSplitContext), + .close = vp9_superframe_split_uninit, + .filter = vp9_superframe_split_filter, + .codec_ids = (const enum AVCodecID []){ AV_CODEC_ID_VP9, AV_CODEC_ID_NONE }, +}; |