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FFmpeg/libavformat/apetag.c

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/*
* APE tag handling
* Copyright (c) 2007 Benjamin Zores <ben@geexbox.org>
* based upon libdemac from Dave Chapman.
*
* 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 <inttypes.h>
#include "libavutil/dict.h"
#include "avformat.h"
#include "avio_internal.h"
#include "apetag.h"
#include "demux.h"
#include "internal.h"
#include "mux.h"
#define APE_TAG_FLAG_CONTAINS_HEADER (1U << 31)
#define APE_TAG_FLAG_LACKS_FOOTER (1 << 30)
#define APE_TAG_FLAG_IS_HEADER (1 << 29)
#define APE_TAG_FLAG_IS_BINARY (1 << 1)
static int ape_tag_read_field(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
uint8_t key[1024], *value;
int64_t size, flags;
int i, c;
size = avio_rl32(pb); /* field size */
flags = avio_rl32(pb); /* field flags */
for (i = 0; i < sizeof(key) - 1; i++) {
c = avio_r8(pb);
if (c < 0x20 || c > 0x7E)
break;
else
key[i] = c;
}
key[i] = 0;
if (c != 0) {
av_log(s, AV_LOG_WARNING, "Invalid APE tag key '%s'.\n", key);
return -1;
}
if (size > INT32_MAX - AV_INPUT_BUFFER_PADDING_SIZE) {
av_log(s, AV_LOG_ERROR, "APE tag size too large.\n");
return AVERROR_INVALIDDATA;
}
if (flags & APE_TAG_FLAG_IS_BINARY) {
uint8_t filename[1024];
enum AVCodecID id;
int ret;
AVStream *st = avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
ret = avio_get_str(pb, size, filename, sizeof(filename));
if (ret < 0)
return ret;
if (size <= ret) {
av_log(s, AV_LOG_WARNING, "Skipping binary tag '%s'.\n", key);
return 0;
}
size -= ret;
av_dict_set(&st->metadata, key, filename, 0);
if ((id = ff_guess_image2_codec(filename)) != AV_CODEC_ID_NONE) {
int ret = ff_add_attached_pic(s, st, s->pb, NULL, size);
if (ret < 0) {
av_log(s, AV_LOG_ERROR, "Error reading cover art.\n");
return ret;
}
lavf: replace AVStream.codec with AVStream.codecpar Currently, AVStream contains an embedded AVCodecContext instance, which is used by demuxers to export stream parameters to the caller and by muxers to receive stream parameters from the caller. It is also used internally as the codec context that is passed to parsers. In addition, it is also widely used by the callers as the decoding (when demuxer) or encoding (when muxing) context, though this has been officially discouraged since Libav 11. There are multiple important problems with this approach: - the fields in AVCodecContext are in general one of * stream parameters * codec options * codec state However, it's not clear which ones are which. It is consequently unclear which fields are a demuxer allowed to set or a muxer allowed to read. This leads to erratic behaviour depending on whether decoding or encoding is being performed or not (and whether it uses the AVStream embedded codec context). - various synchronization issues arising from the fact that the same context is used by several different APIs (muxers/demuxers, parsers, bitstream filters and encoders/decoders) simultaneously, with there being no clear rules for who can modify what and the different processes being typically delayed with respect to each other. - avformat_find_stream_info() making it necessary to support opening and closing a single codec context multiple times, thus complicating the semantics of freeing various allocated objects in the codec context. Those problems are resolved by replacing the AVStream embedded codec context with a newly added AVCodecParameters instance, which stores only the stream parameters exported by the demuxers or read by the muxers.
2014-06-18 21:42:52 +03:00
st->codecpar->codec_id = id;
} else {
if ((ret = ff_get_extradata(s, st->codecpar, s->pb, size)) < 0)
return ret;
lavf: replace AVStream.codec with AVStream.codecpar Currently, AVStream contains an embedded AVCodecContext instance, which is used by demuxers to export stream parameters to the caller and by muxers to receive stream parameters from the caller. It is also used internally as the codec context that is passed to parsers. In addition, it is also widely used by the callers as the decoding (when demuxer) or encoding (when muxing) context, though this has been officially discouraged since Libav 11. There are multiple important problems with this approach: - the fields in AVCodecContext are in general one of * stream parameters * codec options * codec state However, it's not clear which ones are which. It is consequently unclear which fields are a demuxer allowed to set or a muxer allowed to read. This leads to erratic behaviour depending on whether decoding or encoding is being performed or not (and whether it uses the AVStream embedded codec context). - various synchronization issues arising from the fact that the same context is used by several different APIs (muxers/demuxers, parsers, bitstream filters and encoders/decoders) simultaneously, with there being no clear rules for who can modify what and the different processes being typically delayed with respect to each other. - avformat_find_stream_info() making it necessary to support opening and closing a single codec context multiple times, thus complicating the semantics of freeing various allocated objects in the codec context. Those problems are resolved by replacing the AVStream embedded codec context with a newly added AVCodecParameters instance, which stores only the stream parameters exported by the demuxers or read by the muxers.
2014-06-18 21:42:52 +03:00
st->codecpar->codec_type = AVMEDIA_TYPE_ATTACHMENT;
}
} else {
value = av_malloc(size+1);
if (!value)
return AVERROR(ENOMEM);
c = avio_read(pb, value, size);
if (c < 0) {
av_free(value);
return c;
}
value[c] = 0;
av_dict_set(&s->metadata, key, value, AV_DICT_DONT_STRDUP_VAL);
}
return 0;
}
int64_t ff_ape_parse_tag(AVFormatContext *s)
{
AVIOContext *pb = s->pb;
int64_t file_size = avio_size(pb);
uint32_t val, fields, tag_bytes;
uint8_t buf[8];
int64_t tag_start;
int i;
if (file_size < APE_TAG_FOOTER_BYTES)
return 0;
avio_seek(pb, file_size - APE_TAG_FOOTER_BYTES, SEEK_SET);
avio_read(pb, buf, 8); /* APETAGEX */
if (strncmp(buf, APE_TAG_PREAMBLE, 8)) {
return 0;
}
val = avio_rl32(pb); /* APE tag version */
if (val > APE_TAG_VERSION) {
av_log(s, AV_LOG_ERROR, "Unsupported tag version. (>=%d)\n", APE_TAG_VERSION);
return 0;
}
tag_bytes = avio_rl32(pb); /* tag size */
if (tag_bytes - APE_TAG_FOOTER_BYTES > (1024 * 1024 * 16)) {
av_log(s, AV_LOG_ERROR, "Tag size is way too big\n");
return 0;
}
if (tag_bytes > file_size - APE_TAG_FOOTER_BYTES) {
av_log(s, AV_LOG_ERROR, "Invalid tag size %"PRIu32".\n", tag_bytes);
return 0;
}
fields = avio_rl32(pb); /* number of fields */
if (fields > 65536) {
av_log(s, AV_LOG_ERROR, "Too many tag fields (%"PRIu32")\n", fields);
return 0;
}
val = avio_rl32(pb); /* flags */
if (val & APE_TAG_FLAG_IS_HEADER) {
av_log(s, AV_LOG_ERROR, "APE Tag is a header\n");
return 0;
}
avio_seek(pb, file_size - tag_bytes, SEEK_SET);
if (val & APE_TAG_FLAG_CONTAINS_HEADER)
tag_bytes += APE_TAG_HEADER_BYTES;
tag_start = file_size - tag_bytes;
for (i=0; i<fields; i++)
if (ape_tag_read_field(s) < 0) break;
return tag_start;
}
static int string_is_ascii(const uint8_t *str)
{
while (*str && *str >= 0x20 && *str <= 0x7e ) str++;
return !*str;
}
int ff_ape_write_tag(AVFormatContext *s)
{
const AVDictionaryEntry *e = NULL;
int size, ret, count = 0;
AVIOContext *dyn_bc;
uint8_t *dyn_buf;
if ((ret = avio_open_dyn_buf(&dyn_bc)) < 0)
return ret;
ff_standardize_creation_time(s);
while ((e = av_dict_iterate(s->metadata, e))) {
int val_len;
if (!string_is_ascii(e->key)) {
av_log(s, AV_LOG_WARNING, "Non ASCII keys are not allowed\n");
continue;
}
val_len = strlen(e->value);
avio_wl32(dyn_bc, val_len); // value length
avio_wl32(dyn_bc, 0); // item flags
avio_put_str(dyn_bc, e->key); // key
avio_write(dyn_bc, e->value, val_len); // value
count++;
}
if (!count)
goto end;
size = avio_get_dyn_buf(dyn_bc, &dyn_buf);
if (size <= 0)
goto end;
size += APE_TAG_FOOTER_BYTES;
// header
avio_write(s->pb, "APETAGEX", 8); // id
avio_wl32(s->pb, APE_TAG_VERSION); // version
avio_wl32(s->pb, size);
avio_wl32(s->pb, count);
// flags
avio_wl32(s->pb, APE_TAG_FLAG_CONTAINS_HEADER | APE_TAG_FLAG_IS_HEADER);
ffio_fill(s->pb, 0, 8); // reserved
avio_write(s->pb, dyn_buf, size - APE_TAG_FOOTER_BYTES);
// footer
avio_write(s->pb, "APETAGEX", 8); // id
avio_wl32(s->pb, APE_TAG_VERSION); // version
avio_wl32(s->pb, size); // size
avio_wl32(s->pb, count); // tag count
// flags
avio_wl32(s->pb, APE_TAG_FLAG_CONTAINS_HEADER);
ffio_fill(s->pb, 0, 8); // reserved
end:
ffio_free_dyn_buf(&dyn_bc);
return ret;
}