[FFmpeg-devel] [PATCH v3 4/7] avformat/apm: use new extradata format
Zane van Iperen
zane at zanevaniperen.com
Fri Jun 12 14:46:33 EEST 2020
Signed-off-by: Zane van Iperen <zane at zanevaniperen.com>
---
libavformat/Makefile | 2 +-
libavformat/apm.c | 130 +++++++++++++++++++++++--------------------
2 files changed, 70 insertions(+), 62 deletions(-)
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 0658fa3710..bb09dc6563 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -93,7 +93,7 @@ OBJS-$(CONFIG_AMRWB_DEMUXER) += amr.o
OBJS-$(CONFIG_ANM_DEMUXER) += anm.o
OBJS-$(CONFIG_APC_DEMUXER) += apc.o
OBJS-$(CONFIG_APE_DEMUXER) += ape.o apetag.o img2.o
-OBJS-$(CONFIG_APM_DEMUXER) += apm.o riffdec.o
+OBJS-$(CONFIG_APM_DEMUXER) += apm.o
OBJS-$(CONFIG_APNG_DEMUXER) += apngdec.o
OBJS-$(CONFIG_APNG_MUXER) += apngenc.o
OBJS-$(CONFIG_APTX_DEMUXER) += aptxdec.o rawdec.o
diff --git a/libavformat/apm.c b/libavformat/apm.c
index dc59c16562..57d23200b0 100644
--- a/libavformat/apm.c
+++ b/libavformat/apm.c
@@ -21,12 +21,13 @@
*/
#include "avformat.h"
#include "internal.h"
-#include "riff.h"
#include "libavutil/internal.h"
#include "libavutil/intreadwrite.h"
-#define APM_FILE_HEADER_SIZE 20
-#define APM_VS12_CHUNK_SIZE 76
+#define APM_FILE_HEADER_SIZE 18
+#define APM_FILE_EXTRADATA_SIZE 80
+#define APM_EXTRADATA_SIZE 28
+
#define APM_MAX_READ_SIZE 4096
#define APM_TAG_CODEC 0x2000
@@ -43,34 +44,37 @@ typedef struct APMState {
int32_t saved_l;
} APMState;
-typedef struct APMVS12Chunk {
+typedef struct APMExtraData {
uint32_t magic;
uint32_t file_size;
uint32_t data_size;
uint32_t unk1;
uint32_t unk2;
APMState state;
- uint32_t pad[7];
-} APMVS12Chunk;
+ uint32_t unk3[7];
+ uint32_t data;
+} APMExtraData;
-static void apm_parse_vs12(APMVS12Chunk *vs12, const uint8_t *buf)
+static void apm_parse_extradata(APMExtraData *ed, const uint8_t *buf)
{
- vs12->magic = AV_RL32(buf + 0);
- vs12->file_size = AV_RL32(buf + 4);
- vs12->data_size = AV_RL32(buf + 8);
- vs12->unk1 = AV_RL32(buf + 12);
- vs12->unk2 = AV_RL32(buf + 16);
-
- vs12->state.has_saved = AV_RL32(buf + 20);
- vs12->state.predictor_r = AV_RL32(buf + 24);
- vs12->state.step_index_r = AV_RL32(buf + 28);
- vs12->state.saved_r = AV_RL32(buf + 32);
- vs12->state.predictor_l = AV_RL32(buf + 36);
- vs12->state.step_index_l = AV_RL32(buf + 40);
- vs12->state.saved_l = AV_RL32(buf + 44);
-
- for (int i = 0; i < FF_ARRAY_ELEMS(vs12->pad); i++)
- vs12->pad[i] = AV_RL32(buf + 48 + (i * 4));
+ ed->magic = AV_RL32(buf + 0);
+ ed->file_size = AV_RL32(buf + 4);
+ ed->data_size = AV_RL32(buf + 8);
+ ed->unk1 = AV_RL32(buf + 12);
+ ed->unk2 = AV_RL32(buf + 16);
+
+ ed->state.has_saved = AV_RL32(buf + 20);
+ ed->state.predictor_r = AV_RL32(buf + 24);
+ ed->state.step_index_r = AV_RL32(buf + 28);
+ ed->state.saved_r = AV_RL32(buf + 32);
+ ed->state.predictor_l = AV_RL32(buf + 36);
+ ed->state.step_index_l = AV_RL32(buf + 40);
+ ed->state.saved_l = AV_RL32(buf + 44);
+
+ for (int i = 0; i < FF_ARRAY_ELEMS(ed->unk3); i++)
+ ed->unk3[i] = AV_RL32(buf + 48 + (i * 4));
+
+ ed->data = AV_RL32(buf + 76);
}
static int apm_probe(const AVProbeData *p)
@@ -94,71 +98,75 @@ static int apm_read_header(AVFormatContext *s)
{
int64_t ret;
AVStream *st;
- APMVS12Chunk vs12;
- uint8_t buf[APM_VS12_CHUNK_SIZE];
+ APMExtraData extradata;
+ AVCodecParameters *par;
+ uint8_t buf[APM_FILE_EXTRADATA_SIZE];
if (!(st = avformat_new_stream(s, NULL)))
return AVERROR(ENOMEM);
- /* The header starts with a WAVEFORMATEX */
- if ((ret = ff_get_wav_header(s, s->pb, st->codecpar, APM_FILE_HEADER_SIZE, 0)) < 0)
- return ret;
-
- if (st->codecpar->bits_per_coded_sample != 4)
+ /*
+ * This is 98% a WAVEFORMATEX, but there's something screwy with the extradata
+ * that ff_get_wav_header() can't (and shouldn't) handle properly.
+ */
+ if (avio_rl16(s->pb) != APM_TAG_CODEC)
return AVERROR_INVALIDDATA;
- if (st->codecpar->codec_tag != APM_TAG_CODEC)
+ par = st->codecpar;
+ par->channels = avio_rl16(s->pb);
+ par->sample_rate = avio_rl32(s->pb);
+ par->bit_rate = avio_rl32(s->pb) * 8;
+ par->block_align = avio_rl16(s->pb);
+ par->bits_per_coded_sample = avio_rl16(s->pb);
+
+ if (avio_rl16(s->pb) != APM_FILE_EXTRADATA_SIZE)
return AVERROR_INVALIDDATA;
- /* ff_get_wav_header() does most of the work, but we need to fix a few things. */
- st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_APM;
- st->codecpar->codec_tag = 0;
+ if (par->bits_per_coded_sample != 4)
+ return AVERROR_INVALIDDATA;
- if (st->codecpar->channels == 2)
- st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;
- else if (st->codecpar->channels == 1)
- st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
+ if (par->channels == 2)
+ par->channel_layout = AV_CH_LAYOUT_STEREO;
+ else if (par->channels == 1)
+ par->channel_layout = AV_CH_LAYOUT_MONO;
else
return AVERROR_INVALIDDATA;
- st->codecpar->format = AV_SAMPLE_FMT_S16;
- st->codecpar->bits_per_raw_sample = 16;
- st->codecpar->bit_rate = st->codecpar->channels *
- st->codecpar->sample_rate *
- st->codecpar->bits_per_coded_sample;
+ par->codec_type = AVMEDIA_TYPE_AUDIO;
+ par->codec_id = AV_CODEC_ID_ADPCM_IMA_APM;
+ par->format = AV_SAMPLE_FMT_S16;
+ par->bits_per_raw_sample = 16;
+
+ /* Now skip the pad that ruins everything. */
+ if ((ret = avio_skip(s->pb, 2)) < 0)
+ return ret;
- if ((ret = avio_read(s->pb, buf, APM_VS12_CHUNK_SIZE)) < 0)
+ if ((ret = avio_read(s->pb, buf, APM_FILE_EXTRADATA_SIZE)) < 0)
return ret;
- else if (ret != APM_VS12_CHUNK_SIZE)
+ else if (ret != APM_FILE_EXTRADATA_SIZE)
return AVERROR(EIO);
- apm_parse_vs12(&vs12, buf);
+ apm_parse_extradata(&extradata, buf);
- if (vs12.magic != APM_TAG_VS12) {
+ if (extradata.magic != APM_TAG_VS12 || extradata.data != APM_TAG_DATA)
return AVERROR_INVALIDDATA;
- }
- if (vs12.state.has_saved) {
+ if (extradata.state.has_saved) {
avpriv_request_sample(s, "Saved Samples");
return AVERROR_PATCHWELCOME;
}
- if (avio_rl32(s->pb) != APM_TAG_DATA)
- return AVERROR_INVALIDDATA;
-
- if ((ret = ff_alloc_extradata(st->codecpar, 16)) < 0)
+ if ((ret = ff_alloc_extradata(par, APM_EXTRADATA_SIZE)) < 0)
return ret;
- AV_WL32(st->codecpar->extradata + 0, vs12.state.predictor_l);
- AV_WL32(st->codecpar->extradata + 4, vs12.state.step_index_l);
- AV_WL32(st->codecpar->extradata + 8, vs12.state.predictor_r);
- AV_WL32(st->codecpar->extradata + 12, vs12.state.step_index_r);
+ /* Use the entire state as extradata. */
+ memcpy(par->extradata, buf + 20, APM_EXTRADATA_SIZE);
- avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
+ avpriv_set_pts_info(st, 64, 1, par->sample_rate);
st->start_time = 0;
- st->duration = vs12.data_size *
- (8 / st->codecpar->bits_per_coded_sample) /
- st->codecpar->channels;
+ st->duration = extradata.data_size *
+ (8 / par->bits_per_coded_sample) /
+ par->channels;
return 0;
}
--
2.25.1
More information about the ffmpeg-devel
mailing list