From bdfae2a57572b37156fb5d46bdf26a4ad80c7715 Mon Sep 17 00:00:00 2001 From: Benoit Fouet Date: Thu, 6 Sep 2007 12:36:07 +0000 Subject: [PATCH] Add a bitstream filter for H.264. Originally committed as revision 10422 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/Makefile | 1 + libavcodec/allcodecs.c | 1 + libavcodec/allcodecs.h | 1 + libavcodec/h264_mp4toannexb_bsf.c | 154 ++++++++++++++++++++++++++++++++++++++ 4 files changed, 157 insertions(+) create mode 100644 libavcodec/h264_mp4toannexb_bsf.c diff --git a/libavcodec/Makefile b/libavcodec/Makefile index 9400bf0..84742d4 100644 --- a/libavcodec/Makefile +++ b/libavcodec/Makefile @@ -320,6 +320,7 @@ OBJS-$(CONFIG_PNM_PARSER) += pnm_parser.o pnm.o OBJS-$(CONFIG_VC1_PARSER) += vc1_parser.o OBJS-$(CONFIG_DUMP_EXTRADATA_BSF) += dump_extradata_bsf.o +OBJS-$(CONFIG_H264_MP4TOANNEXB_BSF) += h264_mp4toannexb_bsf.o OBJS-$(CONFIG_IMX_DUMP_HEADER_BSF) += imx_dump_header_bsf.o OBJS-$(CONFIG_MJPEGA_DUMP_HEADER_BSF) += mjpega_dump_header_bsf.o OBJS-$(CONFIG_MP3_HEADER_COMPRESS_BSF) += mp3_header_compress_bsf.o diff --git a/libavcodec/allcodecs.c b/libavcodec/allcodecs.c index 2b03001..1362451 100644 --- a/libavcodec/allcodecs.c +++ b/libavcodec/allcodecs.c @@ -278,6 +278,7 @@ void avcodec_register_all(void) /* bitstream filters */ REGISTER_BSF (DUMP_EXTRADATA, dump_extradata); + REGISTER_BSF (H264_MP4TOANNEXB, h264_mp4toannexb); REGISTER_BSF (IMX_DUMP_HEADER, imx_dump_header); REGISTER_BSF (MJPEGA_DUMP_HEADER, mjpega_dump_header); REGISTER_BSF (MP3_HEADER_COMPRESS, mp3_header_compress); diff --git a/libavcodec/allcodecs.h b/libavcodec/allcodecs.h index dc3ea6f..34efcb3 100644 --- a/libavcodec/allcodecs.h +++ b/libavcodec/allcodecs.h @@ -307,6 +307,7 @@ extern AVCodecParser vc1_parser; /* bitstream filters */ extern AVBitStreamFilter dump_extradata_bsf; +extern AVBitStreamFilter h264_mp4toannexb_bsf; extern AVBitStreamFilter imx_dump_header_bsf; extern AVBitStreamFilter mjpega_dump_header_bsf; extern AVBitStreamFilter mp3_header_compress_bsf; diff --git a/libavcodec/h264_mp4toannexb_bsf.c b/libavcodec/h264_mp4toannexb_bsf.c new file mode 100644 index 0000000..a4cbf87 --- /dev/null +++ b/libavcodec/h264_mp4toannexb_bsf.c @@ -0,0 +1,154 @@ +/* + * Copyright (c) 2007 Benoit Fouet + * + * 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 "avcodec.h" + +typedef struct H264BSFContext { + uint8_t length_size; + uint8_t first_idr; + uint8_t *sps_pps_data; + uint32_t size; +} H264BSFContext; + +static void alloc_and_copy(uint8_t **poutbuf, int *poutbuf_size, + const uint8_t *sps_pps, uint32_t sps_pps_size, + const uint8_t *in, uint32_t in_size) { + uint32_t offset = *poutbuf_size; + uint8_t nal_header_size = offset ? 3 : 4; + + *poutbuf_size += sps_pps_size+in_size+nal_header_size; + *poutbuf = av_realloc(*poutbuf, *poutbuf_size); + if (sps_pps) + memcpy(*poutbuf+offset, sps_pps, sps_pps_size); + memcpy(*poutbuf+sps_pps_size+nal_header_size+offset, in, in_size); + if (!offset) + AV_WB32(*poutbuf+sps_pps_size, 1); + else { + (*poutbuf+offset)[0] = (*poutbuf+offset)[1] = 0; + (*poutbuf+offset)[2] = 1; + } +} + +static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc, + AVCodecContext *avctx, const char *args, + uint8_t **poutbuf, int *poutbuf_size, + const uint8_t *buf, int buf_size, + int keyframe) { + H264BSFContext *ctx = bsfc->priv_data; + uint8_t unit_type; + uint32_t nal_size, cumul_size = 0; + + /* nothing to filter */ + if (!avctx->extradata || avctx->extradata_size < 6) { + *poutbuf = (uint8_t*) buf; + *poutbuf_size = buf_size; + return 0; + } + + /* retrieve sps and pps NAL units from extradata */ + if (!ctx->sps_pps_data) { + uint16_t unit_size; + uint32_t total_size = 0; + uint8_t *out = NULL, unit_nb, sps_done = 0; + const uint8_t *extradata = avctx->extradata+4; + static const uint8_t nalu_header[4] = {0, 0, 0, 1}; + + /* retrieve length coded size */ + ctx->length_size = (*extradata++ & 0x3) + 1; + if (ctx->length_size == 3) + return AVERROR(EINVAL); + + /* retrieve sps and pps unit(s) */ + unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */ + if (!unit_nb) { + unit_nb = *extradata++; /* number of pps unit(s) */ + sps_done++; + } + while (unit_nb--) { + unit_size = AV_RB16(extradata); + total_size += unit_size+4; + if (extradata+2+unit_size > avctx->extradata+avctx->extradata_size) { + av_free(out); + return AVERROR(EINVAL); + } + out = av_realloc(out, total_size); + if (!out) + return AVERROR(ENOMEM); + memcpy(out+total_size-unit_size-4, nalu_header, 4); + memcpy(out+total_size-unit_size, extradata+2, unit_size); + extradata += 2+unit_size; + + if (!unit_nb && !sps_done++) + unit_nb = *extradata++; /* number of pps unit(s) */ + } + + ctx->sps_pps_data = out; + ctx->size = total_size; + ctx->first_idr = 1; + } + + *poutbuf_size = 0; + *poutbuf = NULL; + do { + if (ctx->length_size == 1) + nal_size = buf[0]; + else if (ctx->length_size == 2) + nal_size = AV_RB16(buf); + else + nal_size = AV_RB32(buf); + + buf += ctx->length_size; + unit_type = *buf & 0x1f; + + /* prepend only to the first type 5 NAL unit of an IDR picture */ + if (ctx->first_idr && unit_type == 5) { + alloc_and_copy(poutbuf, poutbuf_size, + ctx->sps_pps_data, ctx->size, + buf, nal_size); + ctx->first_idr = 0; + } + else { + alloc_and_copy(poutbuf, poutbuf_size, + NULL, 0, + buf, nal_size); + if (!ctx->first_idr && unit_type == 1) + ctx->first_idr = 1; + } + + buf += nal_size; + cumul_size += nal_size + ctx->length_size; + } while (cumul_size < buf_size); + + return 1; +} + +static void h264_mp4toannexb_close(AVBitStreamFilterContext *bsfc) +{ + H264BSFContext *ctx = bsfc->priv_data; + av_freep(&ctx->sps_pps_data); +} + +AVBitStreamFilter h264_mp4toannexb_bsf = { + "h264_mp4toannexb", + sizeof(H264BSFContext), + h264_mp4toannexb_filter, + h264_mp4toannexb_close, +}; + -- 2.7.4