Quoting Vittorio Giovara (2016-10-14 00:23:10)
> This matrix needs to be applied after all others have (currently only
> display matrix from trak), but cannot be handled in movie box, since
> streams are not allocated yet.
>
> So store it in main context and if not identity, apply it when appropriate,
> handling the case when trak display matrix is identity and when it is not.
>
> Fate tests are updated accordingly.
>
> Signed-off-by: Vittorio Giovara <vittorio.giov...@gmail.com>
> ---
> libavformat/isom.h | 2 ++
> libavformat/mov.c | 57
> +++++++++++++++++++++++++++++----------
> tests/ref/fate/mov-ar | 4 +--
> tests/ref/fate/mov-display-matrix | 2 +-
> 4 files changed, 48 insertions(+), 17 deletions(-)
>
> diff --git a/libavformat/isom.h b/libavformat/isom.h
> index 58f0a20..1aa2091 100644
> --- a/libavformat/isom.h
> +++ b/libavformat/isom.h
> @@ -167,6 +167,8 @@ typedef struct MOVContext {
> int export_all;
> int export_xmp;
> int enable_drefs;
> +
> + int32_t movie_display_matrix[3][3]; ///< display matrix from mvhd
> } MOVContext;
>
> int ff_mp4_read_descr_len(AVIOContext *pb);
> diff --git a/libavformat/mov.c b/libavformat/mov.c
> index 36e75d5..c082ee4 100644
> --- a/libavformat/mov.c
> +++ b/libavformat/mov.c
> @@ -950,6 +950,7 @@ static int mov_read_mdhd(MOVContext *c, AVIOContext *pb,
> MOVAtom atom)
>
> static int mov_read_mvhd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> {
> + int i;
> time_t creation_time;
> int version = avio_r8(pb); /* version */
> avio_rb24(pb); /* flags */
> @@ -973,7 +974,12 @@ static int mov_read_mvhd(MOVContext *c, AVIOContext *pb,
> MOVAtom atom)
>
> avio_skip(pb, 10); /* reserved */
>
> - avio_skip(pb, 36); /* display matrix */
> + /* movie display matrix, store it in main context and use it later on */
> + for (i = 0; i < 3; i++) {
> + c->movie_display_matrix[i][0] = avio_rb32(pb); // 16.16 fixed point
> + c->movie_display_matrix[i][1] = avio_rb32(pb); // 16.16 fixed point
> + c->movie_display_matrix[i][2] = avio_rb32(pb); // 2.30 fixed point
> + }
>
> avio_rb32(pb); /* preview time */
> avio_rb32(pb); /* preview duration */
> @@ -2747,17 +2753,34 @@ static int mov_read_meta(MOVContext *c, AVIOContext
> *pb, MOVAtom atom)
> return 0;
> }
>
> +// return 0 when matrix is identity, 1 otherwise
> +#define IS_MATRIX_FULL(matrix) \
nit: I'd flip the meaning and make it IS_MATRIX_ID(ENTITY), since "full"
is confusing in this context.
> + (matrix[0][0] != (1 << 16) || \
> + matrix[1][1] != (1 << 16) || \
> + matrix[2][2] != (1 << 30) || \
> + matrix[0][1] || matrix[0][2] || \
> + matrix[1][0] || matrix[1][2] || \
> + matrix[2][0] || matrix[2][1])
> +
> +// fixed point to double
> +#define CONV_FP(x, sh) ((double) (x)) / (1 << (sh))
> +
> +// double to fixed point
> +#define CONV_DB(x, sh) ((int32_t) ((x) * (1 << (sh))))
> +
> static int mov_read_tkhd(MOVContext *c, AVIOContext *pb, MOVAtom atom)
> {
> - int i;
> + int i, j, e;
> int width;
> int height;
> int64_t disp_transform[2];
> int display_matrix[3][3];
> + int res_display_matrix[3][3];
> AVStream *st;
> MOVStreamContext *sc;
> int version;
> int flags;
> + double val = 0;
>
> if (c->fc->nb_streams < 1)
> return 0;
> @@ -2803,15 +2826,21 @@ static int mov_read_tkhd(MOVContext *c, AVIOContext
> *pb, MOVAtom atom)
> sc->width = width >> 16;
> sc->height = height >> 16;
>
> - // save the matrix when it is not the default identity
> - if (display_matrix[0][0] != (1 << 16) ||
> - display_matrix[1][1] != (1 << 16) ||
> - display_matrix[2][2] != (1 << 30) ||
> - display_matrix[0][1] || display_matrix[0][2] ||
> - display_matrix[1][0] || display_matrix[1][2] ||
> - display_matrix[2][0] || display_matrix[2][1]) {
> - int i, j;
> + // apply the moov display matrix
> + for (i = 0; i < 3; i++) {
> + for (j = 0; j < 3; j++) {
> + int sh = j == 2 ? 30 : 16;
> + for (e = 0; e < 3; e++) {
> + val += CONV_FP(display_matrix[i][e], sh) *
> + CONV_FP(c->movie_display_matrix[e][j], sh);
> + }
> + res_display_matrix[i][j] = CONV_DB(val, sh);
> + val = 0;
This reinitialization is weird, just make val local to this block.
Making the multiplication floating point is unpleasant, but I guess
fixed point is more effort.
--
Anton Khirnov
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