/* * Copyright (c) 2019 James Almer <jamrial@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 */ /** * @file * This bitstream filter splits AV1 Temporal Units into packets containing * just one frame, plus any leading and trailing OBUs that may be present at * the beginning or end, respectively. * * Temporal Units already containing only one frame will be passed through * unchanged. When splitting can't be performed, the Temporal Unit will be * passed through containing only the remaining OBUs starting from the first * one after the last successfully split frame. */ #include "libavutil/avassert.h" #include "bsf.h"#include "bsf_internal.h"#include "cbs.h"#include "cbs_av1.h" typedef struct AV1FSplitContext {    AVPacket *buffer_pkt;    CodedBitstreamContext *cbc;    CodedBitstreamFragment temporal_unit;     int nb_frames;    int cur_frame;    int cur_frame_idx;    int last_frame_idx;} AV1FSplitContext; static int av1_frame_split_filter(AVBSFContext *ctx, AVPacket *out){    AV1FSplitContext *s = ctx->priv_data;    CodedBitstreamFragment *td = &s->temporal_unit;    int i, ret;    int split = !!s->buffer_pkt->data;     if (!s->buffer_pkt->data) {        int nb_frames = 0;         ret = ff_bsf_get_packet_ref(ctx, s->buffer_pkt);        if (ret < 0)            return ret;         ret = ff_cbs_read_packet(s->cbc, td, s->buffer_pkt);        if (ret < 0) {            av_log(ctx, AV_LOG_WARNING, "Failed to parse temporal unit.\n");            goto passthrough;        }         for (i = 0; i < td->nb_units; i++) {            CodedBitstreamUnit *unit = &td->units[i];             if (unit->type == AV1_OBU_FRAME ||                unit->type == AV1_OBU_FRAME_HEADER)                nb_frames++;            else if (unit->type == AV1_OBU_TILE_LIST) {                av_log(ctx, AV_LOG_VERBOSE, "Large scale tiles are unsupported.\n");                goto passthrough;            }        }        if (nb_frames > 1) {            s->cur_frame = 0;            s->cur_frame_idx = s->last_frame_idx = 0;            s->nb_frames = nb_frames;            split = 1;        }    }     if (split) {        AV1RawFrameHeader *frame = NULL;        int cur_frame_type = -1, size = 0;         for (i = s->cur_frame_idx; i < td->nb_units; i++) {            CodedBitstreamUnit *unit = &td->units[i];             size += unit->data_size;            if (unit->type == AV1_OBU_FRAME) {                AV1RawOBU *obu = unit->content;                 if (frame) {                    av_log(ctx, AV_LOG_WARNING, "Frame OBU found when Tile data for a "                                                "previous frame was expected.\n");                    goto passthrough;                }                 frame = &obu->obu.frame.header;                cur_frame_type = obu->header.obu_type;                s->last_frame_idx = s->cur_frame_idx;                s->cur_frame_idx  = i + 1;                s->cur_frame++;                 // split here unless it's the last frame, in which case                // include every trailing OBU                if (s->cur_frame < s->nb_frames)                    break;            } else if (unit->type == AV1_OBU_FRAME_HEADER) {                AV1RawOBU *obu = unit->content;                 if (frame) {                    av_log(ctx, AV_LOG_WARNING, "Frame Header OBU found when Tile data for a "                                                "previous frame was expected.\n");                    goto passthrough;                }                 frame = &obu->obu.frame_header;                cur_frame_type = obu->header.obu_type;                s->last_frame_idx = s->cur_frame_idx;                s->cur_frame++;                 // split here if show_existing_frame unless it's the last                // frame, in which case include every trailing OBU                if (frame->show_existing_frame &&                    s->cur_frame < s->nb_frames) {                    s->cur_frame_idx = i + 1;                    break;                }            } else if (unit->type == AV1_OBU_TILE_GROUP) {                AV1RawOBU *obu = unit->content;                AV1RawTileGroup *group = &obu->obu.tile_group;                 if (!frame || cur_frame_type != AV1_OBU_FRAME_HEADER) {                    av_log(ctx, AV_LOG_WARNING, "Unexpected Tile Group OBU found before a "                                                "Frame Header.\n");                    goto passthrough;                }                 if ((group->tg_end == (frame->tile_cols * frame->tile_rows) - 1) &&                    // include every trailing OBU with the last frame                    s->cur_frame < s->nb_frames) {                    s->cur_frame_idx = i + 1;                    break;                }            }        }        av_assert0(frame && s->cur_frame <= s->nb_frames);         ret = av_packet_ref(out, s->buffer_pkt);        if (ret < 0)            goto fail;         out->data = (uint8_t *)td->units[s->last_frame_idx].data;        out->size = size;         // skip the frame in the buffer packet if it's split successfully, so it's not present        // if the packet is passed through in case of failure when splitting another frame.        s->buffer_pkt->data += size;        s->buffer_pkt->size -= size;         if (!frame->show_existing_frame && !frame->show_frame)            out->pts = AV_NOPTS_VALUE;         if (s->cur_frame == s->nb_frames) {            av_packet_unref(s->buffer_pkt);            ff_cbs_fragment_reset(td);        }         return 0;    } passthrough:    av_packet_move_ref(out, s->buffer_pkt);     ret = 0;fail:    if (ret < 0) {        av_packet_unref(out);        av_packet_unref(s->buffer_pkt);    }    ff_cbs_fragment_reset(td);     return ret;} static const CodedBitstreamUnitType decompose_unit_types[] = {    AV1_OBU_TEMPORAL_DELIMITER,    AV1_OBU_SEQUENCE_HEADER,    AV1_OBU_FRAME_HEADER,    AV1_OBU_TILE_GROUP,    AV1_OBU_FRAME,}; static int av1_frame_split_init(AVBSFContext *ctx){    AV1FSplitContext *s = ctx->priv_data;    CodedBitstreamFragment *td = &s->temporal_unit;    int ret;     s->buffer_pkt = av_packet_alloc();    if (!s->buffer_pkt)        return AVERROR(ENOMEM);     ret = ff_cbs_init(&s->cbc, AV_CODEC_ID_AV1, ctx);    if (ret < 0)        return ret;     s->cbc->decompose_unit_types    = decompose_unit_types;    s->cbc->nb_decompose_unit_types = FF_ARRAY_ELEMS(decompose_unit_types);     if (!ctx->par_in->extradata_size)        return 0;     ret = ff_cbs_read_extradata(s->cbc, td, ctx->par_in);    if (ret < 0)        av_log(ctx, AV_LOG_WARNING, "Failed to parse extradata.\n");     ff_cbs_fragment_reset(td);     return 0;} static void av1_frame_split_flush(AVBSFContext *ctx){    AV1FSplitContext *s = ctx->priv_data;     av_packet_unref(s->buffer_pkt);    ff_cbs_fragment_reset(&s->temporal_unit);} static void av1_frame_split_close(AVBSFContext *ctx){    AV1FSplitContext *s = ctx->priv_data;     av_packet_free(&s->buffer_pkt);    ff_cbs_fragment_free(&s->temporal_unit);    ff_cbs_close(&s->cbc);} static const enum AVCodecID av1_frame_split_codec_ids[] = {    AV_CODEC_ID_AV1, AV_CODEC_ID_NONE,}; const FFBitStreamFilter ff_av1_frame_split_bsf = {    .p.name         = "av1_frame_split",    .p.codec_ids    = av1_frame_split_codec_ids,    .priv_data_size = sizeof(AV1FSplitContext),    .init           = av1_frame_split_init,    .flush          = av1_frame_split_flush,    .close          = av1_frame_split_close,    .filter         = av1_frame_split_filter,};