avcodec/bsf/mp3_header_decompress: Remove BSF

This BSF is supposed to be used in conjunction with mp3_header_compress,
which has been removed more than ten years ago in commit
c6080d8900. 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.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

doc/bitstream_filters.texi

@@ -528,10 +528,6 @@ metadata header from each subtitle packet.
 
 See also the @ref{text2movsub} filter.
 
-@section mp3decomp
-
-Decompress non-standard compressed MP3 audio headers.
-
 @section mpeg2_metadata
 
 Modify metadata embedded in an MPEG-2 stream.

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
 

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;

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

libavcodec/bsf/mp3_header_decompress.c

@@ -1,130 +0,0 @@
-/*
- * copyright (c) 2006 Michael Niedermayer <michaelni@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,
-};

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #include "version_major.h"
 
-#define LIBAVCODEC_VERSION_MINOR  40
+#define LIBAVCODEC_VERSION_MINOR  41
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \