FFmpeg/libavformat/bit.c
Andreas Rheinhardt c1e439d7e9 avformat: Forward errors where possible
It is not uncommon to find code where the caller thinks to know better
what the return value should be than the callee. E.g. something like
"if (av_new_packet(pkt, size) < 0) return AVERROR(ENOMEM);". This commit
changes several instances of this to instead forward the actual error.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2019-12-12 19:25:33 +01:00

169 lines
4.4 KiB
C

/*
* G.729 bit format muxer and demuxer
* Copyright (c) 2007-2008 Vladimir Voroshilov
*
* 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 "avformat.h"
#include "internal.h"
#include "libavcodec/get_bits.h"
#include "libavcodec/put_bits.h"
#define MAX_FRAME_SIZE 10
#define SYNC_WORD 0x6b21
#define BIT_0 0x7f
#define BIT_1 0x81
#if CONFIG_BIT_DEMUXER
static int probe(const AVProbeData *p)
{
int i = 0, j, valid = 0;
while (2 * i + 3 < p->buf_size){
if (AV_RL16(&p->buf[2 * i++]) != SYNC_WORD)
return 0;
j = AV_RL16(&p->buf[2 * i++]);
if (j != 0 && j != 0x10 && j != 0x40 && j != 0x50 && j != 0x76)
return 0;
if (j)
valid++;
i += j;
}
if (valid > 10)
return AVPROBE_SCORE_MAX;
if (valid > 2)
return AVPROBE_SCORE_EXTENSION - 1;
return 0;
}
static int read_header(AVFormatContext *s)
{
AVStream* st;
st=avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
st->codecpar->codec_id=AV_CODEC_ID_G729;
st->codecpar->sample_rate=8000;
st->codecpar->block_align = 16;
st->codecpar->channels=1;
avpriv_set_pts_info(st, 64, 1, 100);
return 0;
}
static int read_packet(AVFormatContext *s,
AVPacket *pkt)
{
AVIOContext *pb = s->pb;
PutBitContext pbo;
uint16_t buf[8 * MAX_FRAME_SIZE + 2];
int packet_size;
uint16_t* src=buf;
int i, j, ret;
int64_t pos= avio_tell(pb);
if(avio_feof(pb))
return AVERROR_EOF;
avio_rl16(pb); // sync word
packet_size = avio_rl16(pb) / 8;
if(packet_size > MAX_FRAME_SIZE)
return AVERROR_INVALIDDATA;
ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t));
if(ret<0)
return ret;
if(ret != 8 * packet_size * sizeof(uint16_t))
return AVERROR(EIO);
if ((ret = av_new_packet(pkt, packet_size)) < 0)
return ret;
init_put_bits(&pbo, pkt->data, packet_size);
for(j=0; j < packet_size; j++)
for(i=0; i<8;i++)
put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0);
flush_put_bits(&pbo);
pkt->duration=1;
pkt->pos = pos;
return 0;
}
AVInputFormat ff_bit_demuxer = {
.name = "bit",
.long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
.read_probe = probe,
.read_header = read_header,
.read_packet = read_packet,
.extensions = "bit",
};
#endif
#if CONFIG_BIT_MUXER
static int write_header(AVFormatContext *s)
{
AVCodecParameters *par = s->streams[0]->codecpar;
if ((par->codec_id != AV_CODEC_ID_G729) || par->channels != 1) {
av_log(s, AV_LOG_ERROR,
"only codec g729 with 1 channel is supported by this format\n");
return AVERROR(EINVAL);
}
par->bits_per_coded_sample = 16;
par->block_align = (par->bits_per_coded_sample * par->channels) >> 3;
return 0;
}
static int write_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
GetBitContext gb;
int i;
if (pkt->size != 10)
return AVERROR(EINVAL);
avio_wl16(pb, SYNC_WORD);
avio_wl16(pb, 8 * pkt->size);
init_get_bits(&gb, pkt->data, 8 * pkt->size);
for (i = 0; i < 8 * pkt->size; i++)
avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0);
return 0;
}
AVOutputFormat ff_bit_muxer = {
.name = "bit",
.long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
.mime_type = "audio/bit",
.extensions = "bit",
.audio_codec = AV_CODEC_ID_G729,
.video_codec = AV_CODEC_ID_NONE,
.write_header = write_header,
.write_packet = write_packet,
};
#endif