[FFmpeg-devel] [PATCH]Add an image3 demuxer with format autodetection
wm4
nfxjfg at googlemail.com
Thu May 29 14:21:51 CEST 2014
On Thu, 29 May 2014 11:38:51 +0200
Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 30e5d30..847c371 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -150,6 +150,7 @@ void av_register_all(void)
> REGISTER_DEMUXER (IMAGE2_ALIAS_PIX, image2_alias_pix);
> REGISTER_DEMUXER (IMAGE2_BRENDER_PIX, image2_brender_pix);
> REGISTER_DEMUXER (INGENIENT, ingenient);
> + REGISTER_DEMUXER (IMAGE3, image3);
> REGISTER_DEMUXER (IPMOVIE, ipmovie);
> REGISTER_MUXER (IPOD, ipod);
> REGISTER_MUXDEMUX(IRCAM, ircam);
> diff --git a/libavformat/img2dec.c b/libavformat/img2dec.c
> index dc962db..880e26f 100644
> --- a/libavformat/img2dec.c
> +++ b/libavformat/img2dec.c
> @@ -27,6 +27,7 @@
> #include "libavutil/opt.h"
> #include "libavutil/pixdesc.h"
> #include "libavutil/parseutils.h"
> +#include "libavutil/intreadwrite.h"
> #include "avformat.h"
> #include "internal.h"
> #include "img2.h"
> @@ -153,6 +154,107 @@ fail:
> return -1;
> }
>
> +static int bmp_probe(uint8_t *p)
> +{
> + if (AV_RB16(p) == 0x424d)
> + if (!AV_RN32(p + 6)) {
> + return AVPROBE_SCORE_EXTENSION + 1;
> + } else {
> + return AVPROBE_SCORE_EXTENSION / 2;
> + }
> + return 0;
> +}
> +
> +static int dpx_probe(uint8_t *p)
> +{
> + if (AV_RN32(p) == AV_RN32("SDPX") || AV_RN32(p) == AV_RN32("XPDS"))
> + return AVPROBE_SCORE_EXTENSION + 1;
> + return 0;
> +}
> +
> +static int exr_probe(uint8_t *p)
> +{
> + if (AV_RL32(p) == 20000630)
> + return AVPROBE_SCORE_EXTENSION + 1;
> + return 0;
> +}
> +
> +static int jpegls_probe(uint8_t *p)
> +{
> + if (AV_RB32(p) == 0xffd8fff7)
> + return AVPROBE_SCORE_EXTENSION + 1;
> + return 0;
> +}
> +
> +static int pictor_probe(uint8_t *p)
> +{
> + if (AV_RL16(p) == 0x1234)
> + return AVPROBE_SCORE_EXTENSION / 2;
> + return 0;
> +}
> +
> +static int png_probe(uint8_t *p)
> +{
> + if (AV_RB64(p) == 0x89504e470d0a1a0a)
> + return AVPROBE_SCORE_MAX - 1;
> + return 0;
> +}
> +
> +static int sgi_probe(uint8_t *p)
> +{
> + if (AV_RB16(p) == 474 &&
> + (p[2] & ~1) == 0 &&
> + (p[3] & ~3) == 0 && p[3] &&
> + (AV_RB16(p + 4) & ~6) == 0 && AV_RB16(p + 4))
> + return AVPROBE_SCORE_EXTENSION + 1;
> + return 0;
> +}
> +
> +static int sunrast_probe(uint8_t *p)
> +{
> + if (AV_RB32(p) == 0x59a66a95)
> + return AVPROBE_SCORE_EXTENSION + 1;
> + return 0;
> +}
> +
> +static int tiff_probe(uint8_t *p)
> +{
> + if (AV_RB32(p) == 0x49492a00)
> + return AVPROBE_SCORE_EXTENSION + 1;
> + return 0;
> +}
> +
> +struct image_probe {
> + int (*f)(uint8_t *p);
> + enum AVCodecID codec_id;
> +};
> +
> +static struct image_probe probe_functions[] = {
> + { bmp_probe, AV_CODEC_ID_BMP },
> + { dpx_probe, AV_CODEC_ID_DPX },
> + { exr_probe, AV_CODEC_ID_EXR },
> + { jpegls_probe, AV_CODEC_ID_JPEGLS},
> + { pictor_probe, AV_CODEC_ID_PICTOR },
> + { png_probe, AV_CODEC_ID_PNG },
> + { sgi_probe, AV_CODEC_ID_SGI },
> + { sunrast_probe, AV_CODEC_ID_SUNRAST },
> + { tiff_probe, AV_CODEC_ID_TIFF },
> + { NULL, 0}
> +};
> +
> +static int img3_read_probe(AVProbeData *p)
> +{
> + struct image_probe *probe;
> +
> + for (probe = probe_functions; probe->f; probe++) {
> + int ret;
> + ret = probe->f(p->buf);
> + if (ret > 0)
> + return ret;
> + }
> + return 0;
> +}
> +
OK, but why stuff it all into one "super"-demuxer?
Note that for web stuff, the mime-type should also take part in
determining the format.
> static int img_read_probe(AVProbeData *p)
> {
> if (p->filename && ff_guess_image2_codec(p->filename)) {
> @@ -198,7 +300,8 @@ int ff_img_read_header(AVFormatContext *s1)
> s->is_pipe = 0;
> else {
> s->is_pipe = 1;
> - st->need_parsing = AVSTREAM_PARSE_FULL;
> + if (memcmp(s1->iformat->name, "image3", 6))
> + st->need_parsing = AVSTREAM_PARSE_FULL;
Why not strcmp or at least strncmp? Is iformat some kind of prefix that
has a guaranteed length at this point of the code?
> }
>
> if (s->ts_from_file == 2) {
> @@ -302,7 +405,21 @@ int ff_img_read_header(AVFormatContext *s1)
> const char *str = strrchr(s->path, '.');
> s->split_planes = str && !av_strcasecmp(str + 1, "y");
> st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
> - st->codec->codec_id = ff_guess_image2_codec(s->path);
> + if (s1->pb) {
> + struct image_probe *probe;
> + uint8_t probe_buffer[10] = {0};
> + int ret;
> +
> + ret = avio_read(s1->pb, probe_buffer, 8);
> + if (ret < 8)
> + return AVERROR(EINVAL);
> + avio_seek(s1->pb, -8, SEEK_CUR);
> + for (probe = probe_functions; probe->f; probe++)
> + if (probe->f(probe_buffer))
> + st->codec->codec_id = probe->codec_id;
> + }
> + if (st->codec->codec_id == AV_CODEC_ID_NONE)
> + st->codec->codec_id = ff_guess_image2_codec(s->path);
> if (st->codec->codec_id == AV_CODEC_ID_LJPEG)
> st->codec->codec_id = AV_CODEC_ID_MJPEG;
> if (st->codec->codec_id == AV_CODEC_ID_ALIAS_PIX) // we cannot distingiush this from BRENDER_PIX
> @@ -387,6 +504,8 @@ int ff_img_read_packet(AVFormatContext *s1, AVPacket *pkt)
> return AVERROR(EIO);
> if (s->frame_size > 0) {
> size[0] = s->frame_size;
> + } else if (!memcmp(s1->iformat->name, "image3", 6)) {
> + size[0] = avio_size(s1->pb);
Again...
Also, is it right to pass the whole file as packet, instead of trying
to parse and sanitize the size of the data somehow?
> } else {
> size[0] = 4096;
> }
> @@ -522,3 +641,22 @@ AVInputFormat ff_image2pipe_demuxer = {
> .priv_class = &img2pipe_class,
> };
> #endif
> +#if CONFIG_IMAGE3_DEMUXER
> +static const AVClass img3_class = {
> + .class_name = "image3 demuxer",
> + .item_name = av_default_item_name,
> + .option = options,
> + .version = LIBAVUTIL_VERSION_INT,
> +};
> +AVInputFormat ff_image3_demuxer = {
> + .name = "image3",
> + .long_name = NULL_IF_CONFIG_SMALL("single image"),
> + .priv_data_size = sizeof(VideoDemuxData),
> + .read_probe = img3_read_probe,
> + .read_header = ff_img_read_header,
> + .read_packet = ff_img_read_packet,
> + .read_close = img_read_close,
> + .read_seek = img_read_seek,
> + .priv_class = &img3_class,
> +};
> +#endif
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