| /* |
| * H.264 MP4 to Annex B byte stream format filter |
| * Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr> |
| * |
| * 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 <string.h> |
| |
| #include "libavutil/avassert.h" |
| #include "libavutil/intreadwrite.h" |
| #include "libavutil/mem.h" |
| |
| #include "avcodec.h" |
| #include "bsf.h" |
| #include "bytestream.h" |
| #include "h264.h" |
| |
| typedef struct H264BSFContext { |
| uint8_t *sps; |
| uint8_t *pps; |
| int sps_size; |
| int pps_size; |
| uint8_t length_size; |
| uint8_t new_idr; |
| uint8_t idr_sps_seen; |
| uint8_t idr_pps_seen; |
| int extradata_parsed; |
| } H264BSFContext; |
| |
| static void count_or_copy(uint8_t **out, uint64_t *out_size, |
| const uint8_t *in, int in_size, int ps, int copy) |
| { |
| uint8_t start_code_size = ps < 0 ? 0 : *out_size == 0 || ps ? 4 : 3; |
| |
| if (copy) { |
| memcpy(*out + start_code_size, in, in_size); |
| if (start_code_size == 4) { |
| AV_WB32(*out, 1); |
| } else if (start_code_size) { |
| (*out)[0] = |
| (*out)[1] = 0; |
| (*out)[2] = 1; |
| } |
| *out += start_code_size + in_size; |
| } |
| *out_size += start_code_size + in_size; |
| } |
| |
| static int h264_extradata_to_annexb(AVBSFContext *ctx, const int padding) |
| { |
| H264BSFContext *s = ctx->priv_data; |
| GetByteContext ogb, *gb = &ogb; |
| uint16_t unit_size; |
| uint32_t total_size = 0; |
| uint8_t *out = NULL, unit_nb, sps_done = 0; |
| static const uint8_t nalu_header[4] = { 0, 0, 0, 1 }; |
| int length_size, pps_offset = 0; |
| |
| bytestream2_init(gb, ctx->par_in->extradata, ctx->par_in->extradata_size); |
| |
| bytestream2_skipu(gb, 4); |
| |
| /* retrieve length coded size */ |
| length_size = (bytestream2_get_byteu(gb) & 0x3) + 1; |
| |
| /* retrieve sps and pps unit(s) */ |
| unit_nb = bytestream2_get_byteu(gb) & 0x1f; /* number of sps unit(s) */ |
| if (!unit_nb) { |
| goto pps; |
| } |
| |
| while (unit_nb--) { |
| int err; |
| |
| /* possible overread ok due to padding */ |
| unit_size = bytestream2_get_be16u(gb); |
| total_size += unit_size + 4; |
| av_assert1(total_size <= INT_MAX - padding); |
| if (bytestream2_get_bytes_left(gb) < unit_size + !sps_done) { |
| av_log(ctx, AV_LOG_ERROR, "Global extradata truncated, " |
| "corrupted stream or invalid MP4/AVCC bitstream\n"); |
| av_free(out); |
| return AVERROR_INVALIDDATA; |
| } |
| if ((err = av_reallocp(&out, total_size + padding)) < 0) |
| return err; |
| memcpy(out + total_size - unit_size - 4, nalu_header, 4); |
| bytestream2_get_bufferu(gb, out + total_size - unit_size, unit_size); |
| pps: |
| if (!unit_nb && !sps_done++) { |
| unit_nb = bytestream2_get_byteu(gb); /* number of pps unit(s) */ |
| pps_offset = total_size; |
| } |
| } |
| |
| if (out) |
| memset(out + total_size, 0, padding); |
| |
| if (pps_offset) { |
| s->sps = out; |
| s->sps_size = pps_offset; |
| } else { |
| av_log(ctx, AV_LOG_WARNING, |
| "Warning: SPS NALU missing or invalid. " |
| "The resulting stream may not play.\n"); |
| } |
| if (pps_offset < total_size) { |
| s->pps = out + pps_offset; |
| s->pps_size = total_size - pps_offset; |
| } else { |
| av_log(ctx, AV_LOG_WARNING, |
| "Warning: PPS NALU missing or invalid. " |
| "The resulting stream may not play.\n"); |
| } |
| |
| av_freep(&ctx->par_out->extradata); |
| ctx->par_out->extradata = out; |
| ctx->par_out->extradata_size = total_size; |
| |
| return length_size; |
| } |
| |
| static int h264_mp4toannexb_init(AVBSFContext *ctx) |
| { |
| H264BSFContext *s = ctx->priv_data; |
| int extra_size = ctx->par_in->extradata_size; |
| int ret; |
| |
| /* retrieve sps and pps NAL units from extradata */ |
| if (!extra_size || |
| (extra_size >= 3 && AV_RB24(ctx->par_in->extradata) == 1) || |
| (extra_size >= 4 && AV_RB32(ctx->par_in->extradata) == 1)) { |
| av_log(ctx, AV_LOG_VERBOSE, |
| "The input looks like it is Annex B already\n"); |
| } else if (extra_size >= 7) { |
| ret = h264_extradata_to_annexb(ctx, AV_INPUT_BUFFER_PADDING_SIZE); |
| if (ret < 0) |
| return ret; |
| |
| s->length_size = ret; |
| s->new_idr = 1; |
| s->idr_sps_seen = 0; |
| s->idr_pps_seen = 0; |
| s->extradata_parsed = 1; |
| } else { |
| av_log(ctx, AV_LOG_ERROR, "Invalid extradata size: %d\n", extra_size); |
| return AVERROR_INVALIDDATA; |
| } |
| |
| return 0; |
| } |
| |
| static int h264_mp4toannexb_filter(AVBSFContext *ctx, AVPacket *opkt) |
| { |
| H264BSFContext *s = ctx->priv_data; |
| AVPacket *in; |
| uint8_t unit_type, new_idr, sps_seen, pps_seen; |
| const uint8_t *buf; |
| const uint8_t *buf_end; |
| uint8_t *out; |
| uint64_t out_size; |
| int ret; |
| |
| ret = ff_bsf_get_packet(ctx, &in); |
| if (ret < 0) |
| return ret; |
| |
| /* nothing to filter */ |
| if (!s->extradata_parsed) { |
| av_packet_move_ref(opkt, in); |
| av_packet_free(&in); |
| return 0; |
| } |
| |
| buf_end = in->data + in->size; |
| |
| #define LOG_ONCE(...) \ |
| if (j) \ |
| av_log(__VA_ARGS__) |
| for (int j = 0; j < 2; j++) { |
| buf = in->data; |
| new_idr = s->new_idr; |
| sps_seen = s->idr_sps_seen; |
| pps_seen = s->idr_pps_seen; |
| out_size = 0; |
| |
| do { |
| uint32_t nal_size = 0; |
| |
| /* possible overread ok due to padding */ |
| for (int i = 0; i < s->length_size; i++) |
| nal_size = (nal_size << 8) | buf[i]; |
| |
| buf += s->length_size; |
| |
| /* This check requires the cast as the right side might |
| * otherwise be promoted to an unsigned value. */ |
| if ((int64_t)nal_size > buf_end - buf) { |
| ret = AVERROR_INVALIDDATA; |
| goto fail; |
| } |
| |
| if (!nal_size) |
| continue; |
| |
| unit_type = *buf & 0x1f; |
| |
| if (unit_type == H264_NAL_SPS) { |
| sps_seen = new_idr = 1; |
| } else if (unit_type == H264_NAL_PPS) { |
| pps_seen = new_idr = 1; |
| /* if SPS has not been seen yet, prepend the AVCC one to PPS */ |
| if (!sps_seen) { |
| if (!s->sps_size) { |
| LOG_ONCE(ctx, AV_LOG_WARNING, "SPS not present in the stream, nor in AVCC, stream may be unreadable\n"); |
| } else { |
| count_or_copy(&out, &out_size, s->sps, s->sps_size, -1, j); |
| sps_seen = 1; |
| } |
| } |
| } |
| |
| /* If this is a new IDR picture following an IDR picture, reset the idr flag. |
| * Just check first_mb_in_slice to be 0 as this is the simplest solution. |
| * This could be checking idr_pic_id instead, but would complexify the parsing. */ |
| if (!new_idr && unit_type == H264_NAL_IDR_SLICE && (buf[1] & 0x80)) |
| new_idr = 1; |
| |
| /* prepend only to the first type 5 NAL unit of an IDR picture, if no sps/pps are already present */ |
| if (new_idr && unit_type == H264_NAL_IDR_SLICE && !sps_seen && !pps_seen) { |
| if (ctx->par_out->extradata) |
| count_or_copy(&out, &out_size, ctx->par_out->extradata, |
| ctx->par_out->extradata_size, -1, j); |
| new_idr = 0; |
| /* if only SPS has been seen, also insert PPS */ |
| } else if (new_idr && unit_type == H264_NAL_IDR_SLICE && sps_seen && !pps_seen) { |
| if (!s->pps_size) { |
| LOG_ONCE(ctx, AV_LOG_WARNING, "PPS not present in the stream, nor in AVCC, stream may be unreadable\n"); |
| } else { |
| count_or_copy(&out, &out_size, s->pps, s->pps_size, -1, j); |
| } |
| } |
| |
| count_or_copy(&out, &out_size, buf, nal_size, |
| unit_type == H264_NAL_SPS || unit_type == H264_NAL_PPS, j); |
| if (!new_idr && unit_type == H264_NAL_SLICE) { |
| new_idr = 1; |
| sps_seen = 0; |
| pps_seen = 0; |
| } |
| |
| buf += nal_size; |
| } while (buf < buf_end); |
| |
| if (!j) { |
| if (out_size > INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE) { |
| ret = AVERROR_INVALIDDATA; |
| goto fail; |
| } |
| ret = av_new_packet(opkt, out_size); |
| if (ret < 0) |
| goto fail; |
| out = opkt->data; |
| } |
| } |
| #undef LOG_ONCE |
| |
| av_assert1(out_size == opkt->size); |
| |
| s->new_idr = new_idr; |
| s->idr_sps_seen = sps_seen; |
| s->idr_pps_seen = pps_seen; |
| |
| ret = av_packet_copy_props(opkt, in); |
| if (ret < 0) |
| goto fail; |
| |
| fail: |
| if (ret < 0) |
| av_packet_unref(opkt); |
| av_packet_free(&in); |
| |
| return ret; |
| } |
| |
| static void h264_mp4toannexb_flush(AVBSFContext *ctx) |
| { |
| H264BSFContext *s = ctx->priv_data; |
| |
| s->idr_sps_seen = 0; |
| s->idr_pps_seen = 0; |
| s->new_idr = s->extradata_parsed; |
| } |
| |
| static const enum AVCodecID codec_ids[] = { |
| AV_CODEC_ID_H264, AV_CODEC_ID_NONE, |
| }; |
| |
| const AVBitStreamFilter ff_h264_mp4toannexb_bsf = { |
| .name = "h264_mp4toannexb", |
| .priv_data_size = sizeof(H264BSFContext), |
| .init = h264_mp4toannexb_init, |
| .filter = h264_mp4toannexb_filter, |
| .flush = h264_mp4toannexb_flush, |
| .codec_ids = codec_ids, |
| }; |
