On Sat, 12 Apr 2014 18:25:43 +0200, Alessandro Ghedini <[email protected]>
wrote:
> ---
> libavformat/avio_internal.h | 2 +
> libavformat/aviobuf.c | 6 +++
> libavformat/mp3dec.c | 107
> +++++++++++++++++++++++++++++++++++++++-----
> 3 files changed, 105 insertions(+), 10 deletions(-)
>
> diff --git a/libavformat/avio_internal.h b/libavformat/avio_internal.h
> index fdc98ec..a8bcadd 100644
> --- a/libavformat/avio_internal.h
> +++ b/libavformat/avio_internal.h
> @@ -94,6 +94,8 @@ void ffio_init_checksum(AVIOContext *s,
> unsigned long ffio_get_checksum(AVIOContext *s);
> unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t
> *buf,
> unsigned int len);
> +unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf,
> + unsigned int len);
>
> /**
> * Open a write only packetized memory stream with a maximum packet
> diff --git a/libavformat/aviobuf.c b/libavformat/aviobuf.c
> index 0024f9e..cc79146 100644
> --- a/libavformat/aviobuf.c
> +++ b/libavformat/aviobuf.c
> @@ -414,6 +414,12 @@ unsigned long ff_crc04C11DB7_update(unsigned long
> checksum, const uint8_t *buf,
> return av_crc(av_crc_get_table(AV_CRC_32_IEEE), checksum, buf, len);
> }
>
> +unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf,
> + unsigned int len)
> +{
> + return av_crc(av_crc_get_table(AV_CRC_16_ANSI_LE), checksum, buf, len);
> +}
> +
> unsigned long ffio_get_checksum(AVIOContext *s)
> {
> s->checksum = s->update_checksum(s->checksum, s->checksum_ptr,
> diff --git a/libavformat/mp3dec.c b/libavformat/mp3dec.c
> index 1ab5159..a7ffea6 100644
> --- a/libavformat/mp3dec.c
> +++ b/libavformat/mp3dec.c
> @@ -21,10 +21,12 @@
>
> #include "libavutil/avstring.h"
> #include "libavutil/intreadwrite.h"
> +#include "libavutil/crc.h"
> #include "libavutil/dict.h"
> #include "libavutil/mathematics.h"
> #include "avformat.h"
> #include "internal.h"
> +#include "avio_internal.h"
> #include "id3v2.h"
> #include "id3v1.h"
> #include "replaygain.h"
> @@ -128,11 +130,21 @@ static void read_xing_toc(AVFormatContext *s, int64_t
> filesize, int64_t duration
> mp3->xing_toc = 1;
> }
>
> -
> static void mp3_parse_info_tag(AVFormatContext *s, AVStream *st,
> MPADecodeHeader *c, uint32_t spf)
> {
> +#define LAST_BITS(k, n) ((k) & ((1 << (n)) - 1))
> +#define MIDDLE_BITS(k, m, n) LAST_BITS((k) >> (m), ((n) - (m)))
> +
> + float f;
This shouldn't be float anymore.
> + uint16_t crc;
> uint32_t v;
> +
> + char version[10];
> +
> + uint32_t peak = 0;
> + int32_t r_gain = INT32_MIN, a_gain = INT32_MIN;
> +
> MP3DecContext *mp3 = s->priv_data;
> const int64_t xing_offtbl[2][2] = {{32, 17}, {17,9}};
>
> @@ -140,17 +152,90 @@ static void mp3_parse_info_tag(AVFormatContext *s,
> AVStream *st,
> avio_skip(s->pb, xing_offtbl[c->lsf == 1][c->nb_channels == 1]);
> v = avio_rb32(s->pb);
> mp3->is_cbr = v == MKBETAG('I', 'n', 'f', 'o');
> - if (v == MKBETAG('X', 'i', 'n', 'g') || mp3->is_cbr) {
> - v = avio_rb32(s->pb);
> - if (v & XING_FLAG_FRAMES)
> - mp3->frames = avio_rb32(s->pb);
> - if (v & XING_FLAG_SIZE)
> - mp3->size = avio_rb32(s->pb);
> - if (v & XING_FLAG_TOC && mp3->frames)
> - read_xing_toc(s, mp3->size,
> - av_rescale_q(mp3->frames,
> + if (v != MKBETAG('X', 'i', 'n', 'g') && !mp3->is_cbr)
> + return;
> +
> + v = avio_rb32(s->pb);
> + if (v & XING_FLAG_FRAMES)
> + mp3->frames = avio_rb32(s->pb);
> + if (v & XING_FLAG_SIZE)
> + mp3->size = avio_rb32(s->pb);
> + if (v & XING_FLAG_TOC && mp3->frames)
> + read_xing_toc(s, mp3->size, av_rescale_q(mp3->frames,
> (AVRational){spf, c->sample_rate},
> st->time_base));
> +
> + /* VBR quality */
> + avio_rb32(s->pb);
> +
> + /* Encoder short version string */
> + avio_get_str(s->pb, 9, version, sizeof(version));
It's probably better to init version to 0 and use avio_read() here, since the
string can contain zeroes which will cause avio_get_str() to terminate early,
breaking the rest of the tag.
> +
> + /* Info Tag revision + VBR method */
> + avio_r8(s->pb);
> +
> + /* Lowpass filter value */
> + avio_r8(s->pb);
> +
> + /* ReplayGain peak */
> + v = avio_rb32(s->pb);
> + peak = av_rescale(v, 100000, 1 << 23);
> +
> + /* Radio ReplayGain */
> + v = avio_rb16(s->pb);
> +
> + if (MIDDLE_BITS(v, 13, 15) == 1) {
> + f = MIDDLE_BITS(v, 0, 8);
> +
> + if (v & (1 << 9))
> + r_gain = f * -10000;
> + else
> + r_gain = f * 10000;
> + }
> +
> + /* Audiophile ReplayGain */
> + v = avio_rb16(s->pb);
> +
> + if (MIDDLE_BITS(v, 13, 15) == 2) {
> + f = MIDDLE_BITS(v, 0, 8);
> +
> + if (v & (1 << 9))
> + a_gain = f * -10000;
> + else
> + a_gain = f * 10000;
> + }
> +
> + /* Encoding flags + ATH Type */
> + avio_r8(s->pb);
> +
> + /* if ABR {specified bitrate} else {minimal bitrate} */
> + avio_r8(s->pb);
> +
> + /* Encoder delays */
> + avio_rb24(s->pb);
> +
> + /* Misc */
> + avio_r8(s->pb);
> +
> + /* MP3 gain */
> + avio_r8(s->pb);
> +
> + /* Preset and surround info */
> + avio_rb16(s->pb);
> +
> + /* Music length */
> + avio_rb32(s->pb);
> +
> + /* Music CRC */
> + avio_rb16(s->pb);
> +
> + /* Info Tag CRC */
> + crc = ffio_get_checksum(s->pb);
> + v = avio_rb16(s->pb);
> +
> + if (v == crc) {
> + ff_replaygain_export_raw(st, r_gain, peak, a_gain, 0);
> + av_dict_set(&st->metadata, "encoder", version, 0);
> }
> }
>
> @@ -235,6 +320,8 @@ static int mp3_read_header(AVFormatContext *s)
>
> off = avio_tell(s->pb);
>
> + ffio_init_checksum(s->pb, ff_crcA001_update, 0);
Why are you putting this call here?
Seems to be it'd be safer if it was at the top of mp3_parse_vbr_tags().
Otherwise it'll probably break at least on files with id3v1 tags.
--
Anton Khirnov
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