[FFmpeg-devel] [PATCH] avcodec/bsf/mp3_header_decompress: Remove BSF
Andreas Rheinhardt
andreas.rheinhardt at outlook.com
Fri Mar 1 13:34:27 EET 2024
Andreas Rheinhardt:
> This BSF is supposed to be used in conjunction with mp3_header_compress,
> which has been removed more than ten years ago in commit
> c6080d89009056530119ab794ad02e4d515c7754. It mangled the headers
> by removing the CRC field as well as fields that are supposed
> to stay constant for the entirety of a stream (which are put into
> extradata). This made these files unplayable; they need to be
> decompressed with the BSF first (which does not happen automatically).
> Even in this case the CRC does not get restored.
>
> I am not aware that such compressed files exist at all; therefore
> this commit removes the BSF completely.
>
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>
> ---
> doc/bitstream_filters.texi | 4 -
> libavcodec/Makefile | 1 -
> libavcodec/bitstream_filters.c | 1 -
> libavcodec/bsf/Makefile | 1 -
> libavcodec/bsf/mp3_header_decompress.c | 130 -------------------------
> 5 files changed, 137 deletions(-)
> delete mode 100644 libavcodec/bsf/mp3_header_decompress.c
>
> diff --git a/doc/bitstream_filters.texi b/doc/bitstream_filters.texi
> index d5bac105ff..e06de1a73a 100644
> --- a/doc/bitstream_filters.texi
> +++ b/doc/bitstream_filters.texi
> @@ -528,10 +528,6 @@ metadata header from each subtitle packet.
>
> See also the @ref{text2movsub} filter.
>
> - at section mp3decomp
> -
> -Decompress non-standard compressed MP3 audio headers.
> -
> @section mpeg2_metadata
>
> Modify metadata embedded in an MPEG-2 stream.
> diff --git a/libavcodec/Makefile b/libavcodec/Makefile
> index 09ae5270b3..f28a6568de 100644
> --- a/libavcodec/Makefile
> +++ b/libavcodec/Makefile
> @@ -1240,7 +1240,6 @@ OBJS-$(CONFIG_EXTRACT_EXTRADATA_BSF) += av1_parse.o h2645_parse.o
> OBJS-$(CONFIG_H264_METADATA_BSF) += h264_levels.o h2645data.o
> OBJS-$(CONFIG_HAPQA_EXTRACT_BSF) += hap.o
> OBJS-$(CONFIG_HEVC_METADATA_BSF) += h265_profile_level.o h2645data.o
> -OBJS-$(CONFIG_MP3_HEADER_DECOMPRESS_BSF) += mpegaudiotabs.o
> OBJS-$(CONFIG_REMOVE_EXTRADATA_BSF) += av1_parse.o
> OBJS-$(CONFIG_TRUEHD_CORE_BSF) += mlp_parse.o mlp.o
>
> diff --git a/libavcodec/bitstream_filters.c b/libavcodec/bitstream_filters.c
> index 1bae113d92..12860c332b 100644
> --- a/libavcodec/bitstream_filters.c
> +++ b/libavcodec/bitstream_filters.c
> @@ -46,7 +46,6 @@ extern const FFBitStreamFilter ff_imx_dump_header_bsf;
> extern const FFBitStreamFilter ff_media100_to_mjpegb_bsf;
> extern const FFBitStreamFilter ff_mjpeg2jpeg_bsf;
> extern const FFBitStreamFilter ff_mjpega_dump_header_bsf;
> -extern const FFBitStreamFilter ff_mp3_header_decompress_bsf;
> extern const FFBitStreamFilter ff_mpeg2_metadata_bsf;
> extern const FFBitStreamFilter ff_mpeg4_unpack_bframes_bsf;
> extern const FFBitStreamFilter ff_mov2textsub_bsf;
> diff --git a/libavcodec/bsf/Makefile b/libavcodec/bsf/Makefile
> index 62609eb24e..fb70ad0c21 100644
> --- a/libavcodec/bsf/Makefile
> +++ b/libavcodec/bsf/Makefile
> @@ -25,7 +25,6 @@ OBJS-$(CONFIG_MEDIA100_TO_MJPEGB_BSF) += bsf/media100_to_mjpegb.o
> OBJS-$(CONFIG_MJPEG2JPEG_BSF) += bsf/mjpeg2jpeg.o
> OBJS-$(CONFIG_MJPEGA_DUMP_HEADER_BSF) += bsf/mjpega_dump_header.o
> OBJS-$(CONFIG_MOV2TEXTSUB_BSF) += bsf/movsub.o
> -OBJS-$(CONFIG_MP3_HEADER_DECOMPRESS_BSF) += bsf/mp3_header_decompress.o
> OBJS-$(CONFIG_MPEG2_METADATA_BSF) += bsf/mpeg2_metadata.o
> OBJS-$(CONFIG_MPEG4_UNPACK_BFRAMES_BSF) += bsf/mpeg4_unpack_bframes.o
> OBJS-$(CONFIG_NOISE_BSF) += bsf/noise.o
> diff --git a/libavcodec/bsf/mp3_header_decompress.c b/libavcodec/bsf/mp3_header_decompress.c
> deleted file mode 100644
> index a177029fe0..0000000000
> --- a/libavcodec/bsf/mp3_header_decompress.c
> +++ /dev/null
> @@ -1,130 +0,0 @@
> -/*
> - * copyright (c) 2006 Michael Niedermayer <michaelni at gmx.at>
> - *
> - * 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/common.h"
> -#include "libavutil/intreadwrite.h"
> -#include "bsf.h"
> -#include "bsf_internal.h"
> -#include "defs.h"
> -#include "mpegaudiodecheader.h"
> -#include "mpegaudiodata.h"
> -
> -
> -static int mp3_header_decompress(AVBSFContext *ctx, AVPacket *out)
> -{
> - AVPacket *in;
> - uint32_t header;
> - int sample_rate= ctx->par_in->sample_rate;
> - int sample_rate_index=0;
> - int lsf, mpeg25, bitrate_index, frame_size, ret;
> - uint8_t *buf;
> - int buf_size;
> -
> - ret = ff_bsf_get_packet(ctx, &in);
> - if (ret < 0)
> - return ret;
> -
> - buf = in->data;
> - buf_size = in->size;
> -
> - header = AV_RB32(buf);
> - if(ff_mpa_check_header(header) >= 0){
> - av_packet_move_ref(out, in);
> - av_packet_free(&in);
> -
> - return 0;
> - }
> -
> - if(ctx->par_in->extradata_size != 15 || strcmp(ctx->par_in->extradata, "FFCMP3 0.0")){
> - av_log(ctx, AV_LOG_ERROR, "Extradata invalid %d\n", ctx->par_in->extradata_size);
> - ret = AVERROR(EINVAL);
> - goto fail;
> - }
> -
> - header= AV_RB32(ctx->par_in->extradata+11) & MP3_MASK;
> -
> - lsf = sample_rate < (24000+32000)/2;
> - mpeg25 = sample_rate < (12000+16000)/2;
> - sample_rate_index= (header>>10)&3;
> - if (sample_rate_index == 3) {
> - ret = AVERROR_INVALIDDATA;
> - goto fail;
> - }
> -
> - sample_rate = ff_mpa_freq_tab[sample_rate_index] >> (lsf + mpeg25); //in case sample rate is a little off
> -
> - for(bitrate_index=2; bitrate_index<30; bitrate_index++){
> - frame_size = ff_mpa_bitrate_tab[lsf][2][bitrate_index>>1];
> - frame_size = (frame_size * 144000) / (sample_rate << lsf) + (bitrate_index&1);
> - if(frame_size == buf_size + 4)
> - break;
> - if(frame_size == buf_size + 6)
> - break;
> - }
> - if(bitrate_index == 30){
> - av_log(ctx, AV_LOG_ERROR, "Could not find bitrate_index.\n");
> - ret = AVERROR(EINVAL);
> - goto fail;
> - }
> -
> - header |= (bitrate_index&1)<<9;
> - header |= (bitrate_index>>1)<<12;
> - header |= (frame_size == buf_size + 4)<<16; //FIXME actually set a correct crc instead of 0
> -
> - ret = av_new_packet(out, frame_size);
> - if (ret < 0)
> - goto fail;
> - ret = av_packet_copy_props(out, in);
> - if (ret < 0) {
> - av_packet_unref(out);
> - goto fail;
> - }
> - memcpy(out->data + frame_size - buf_size, buf, buf_size + AV_INPUT_BUFFER_PADDING_SIZE);
> -
> - if (ctx->par_in->ch_layout.nb_channels == 2){
> - uint8_t *p= out->data + frame_size - buf_size;
> - if(lsf){
> - FFSWAP(int, p[1], p[2]);
> - header |= (p[1] & 0xC0)>>2;
> - p[1] &= 0x3F;
> - }else{
> - header |= p[1] & 0x30;
> - p[1] &= 0xCF;
> - }
> - }
> -
> - AV_WB32(out->data, header);
> -
> - ret = 0;
> -
> -fail:
> - av_packet_free(&in);
> - return ret;
> -}
> -
> -static const enum AVCodecID codec_ids[] = {
> - AV_CODEC_ID_MP3, AV_CODEC_ID_NONE,
> -};
> -
> -const FFBitStreamFilter ff_mp3_header_decompress_bsf = {
> - .p.name = "mp3decomp",
> - .p.codec_ids = codec_ids,
> - .filter = mp3_header_decompress,
> -};
Will apply tomorrow unless there are objections.
- Andreas
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