tavenc: header support for extended dimensions (max(width,height) > 65535)

terranmon.txt

@@ -918,6 +918,7 @@ transmission capability, and region-of-interest coding.
             When motion coder is CDF 5/3, add 8 to the base version number.
     uint16 Width: picture width in pixels. Columns count for Videotex-only file.
     uint16 Height: picture height in pixels. Rows count for Videotex-only file.
+            If either width or height exceeds 65535 pixels, above two fields must be filled with zero and the dimension must be sourced from XDIM entry of the Extended Header
     uint8  FPS: frames per second. Use 0x00 for still pictures
     uint32 Total Frames: number of video frames
             - use 0 to denote not-finalised video stream
@@ -1091,8 +1092,9 @@ The encoder supports following presets:
     <if Value Type is Bytes>
     uint16 Length of bytes
     *      Bytes
-    <otherwise>
+    <else>
     type_t Value
+    <fi>
 
     ### List of Keys
     - Uint64 BGNT: Video begin time in nanoseconds (must be equal to the value of the first Timecode packet)
@@ -1100,6 +1102,7 @@ The encoder supports following presets:
     - Uint64 CDAT: Creation time in microseconds since UNIX Epoch (must be in UTC timezone)
     - Bytes  VNDR: Name and version of the encoder (for Reference encoder: "Encoder-TAV 20251014 (list,of,features)")
     - Bytes FMPG: FFmpeg version (typically "ffmpeg version 8.0 Copyright (c) 2000-2025 the FFmpeg developers"; the first line of text FFmpeg emits)
+    - Bytes XDIM: Video dimension in '<width>,<height>' format. Mandatory if either width or height exceeds 65535
 
 ## Extensible Packet Structure
     uint8  Packet Type
@@ -1108,8 +1111,9 @@ The encoder supports following presets:
     uint8  Identifier[4]
     <if 64-bit size>
     uint64 Length of the payload
-    <if not>
+    <else>
     uint32 Length of the payload
+    <fi>
     *      Payload
 
 ## Standard Metadata Payload Packet Structure
@@ -1178,7 +1182,7 @@ temporal compression.
     <if packet type is 0x13>
     uint32 Compressed Size
     *      Zstd-compressed Motion Data
-    <endif>
+    <fi>
     uint32 Compressed Size
     *      Zstd-compressed Unified Block Data
 
@@ -1192,6 +1196,7 @@ The entire GOP (width×height×N_frames×3_channels) is preprocessed as a single
     int16  Y Non-zero Values[variable length]                          // All Y non-zero coefficients
     int16  Co Non-zero Values[variable length]                         // All Co non-zero coefficients
     int16  Cg Non-zero Values[variable length]                         // All Cg non-zero coefficients
+    <fi>
 
     <if EZBC is used>
     uint32 EZBC Size for Y
@@ -1200,6 +1205,7 @@ The entire GOP (width×height×N_frames×3_channels) is preprocessed as a single
     *      EZBC Structure for Co
     uint32 EZBC Size for Cg
     *      EZBC Structure for Cg
+    <fi>
 
 This layout enables Zstd to find patterns across both spatial and temporal dimensions,
 resulting in superior compression compared to per-frame encoding.
@@ -2028,9 +2034,11 @@ A universal, simple cue designed to work as both playlist to cue up external fil
     <if external addressing mode>
     uint16 String Length for relative path
     *       Relative path
+    <fi>
 
     <if internal addressing mode>
     uint48 Offset to the file
+    <fi>
 
 --------------------------------------------------------------------------------
 

video_encoder/src/encoder_tav.c

@@ -464,11 +464,13 @@ static int write_tav_header(FILE *fp, const tav_encoder_params_t *params, int ha
     fputc(version, fp);
 
     // Width (uint16_t, 2 bytes)
-    uint16_t width = (uint16_t)params->width;
+    // Write 0 if width exceeds 65535 (extended dimensions will be in XDIM)
+    uint16_t width = (params->width > 65535) ? 0 : (uint16_t)params->width;
     fwrite(&width, sizeof(uint16_t), 1, fp);
 
     // Height (uint16_t, 2 bytes)
-    uint16_t height = (uint16_t)params->height;
+    // Write 0 if height exceeds 65535 (extended dimensions will be in XDIM)
+    uint16_t height = (params->height > 65535) ? 0 : (uint16_t)params->height;
     fwrite(&height, sizeof(uint16_t), 1, fp);
 
     // FPS (uint8_t, 1 byte) - simplified to just fps_num
@@ -529,15 +531,18 @@ static int write_tav_header(FILE *fp, const tav_encoder_params_t *params, int ha
  * Write Extended Header packet (0xEF) with metadata.
  * Returns the file offset of the ENDT value for later update, or -1 on error.
  */
-static long write_extended_header(cli_context_t *cli) {
+static long write_extended_header(cli_context_t *cli, int width, int height) {
     FILE *fp = cli->output_fp;
 
     // Write packet type (0xEF)
     uint8_t packet_type = TAV_PACKET_EXTENDED_HDR;
     if (fwrite(&packet_type, 1, 1, fp) != 1) return -1;
 
-    // Count key-value pairs: BGNT, ENDT, CDAT, VNDR, and optionally FMPG
+    // Count key-value pairs: BGNT, ENDT, CDAT, VNDR, optionally FMPG, and optionally XDIM
-    uint16_t num_pairs = cli->ffmpeg_version ? 5 : 4;
+    int has_xdim = (width > 65535 || height > 65535);
+    uint16_t num_pairs = 4;  // BGNT, ENDT, CDAT, VNDR
+    if (cli->ffmpeg_version) num_pairs++;  // FMPG
+    if (has_xdim) num_pairs++;  // XDIM
     if (fwrite(&num_pairs, sizeof(uint16_t), 1, fp) != 1) return -1;
 
     // Helper macros for writing key-value pairs
@@ -578,6 +583,13 @@ static long write_extended_header(cli_context_t *cli) {
         WRITE_KV_BYTES("FMPG", cli->ffmpeg_version, strlen(cli->ffmpeg_version));
     }
 
+    // XDIM: Extended dimensions (if width or height exceeds 65535)
+    if (has_xdim) {
+        char xdim_str[32];
+        snprintf(xdim_str, sizeof(xdim_str), "%d,%d", width, height);
+        WRITE_KV_BYTES("XDIM", xdim_str, strlen(xdim_str));
+    }
+
     #undef WRITE_KV_UINT64
     #undef WRITE_KV_BYTES
 
@@ -1460,7 +1472,7 @@ static int encode_video_mt(cli_context_t *cli) {
 
     // Write Extended Header (unless suppressed)
     if (!cli->suppress_xhdr) {
-        cli->extended_header_offset = write_extended_header(cli);
+        cli->extended_header_offset = write_extended_header(cli, cli->enc_params.width, cli->enc_params.height);
         if (cli->extended_header_offset < 0) {
             fprintf(stderr, "Warning: Failed to write Extended Header\n");
         }
@@ -1917,7 +1929,7 @@ static int encode_video(cli_context_t *cli) {
 
     // Write Extended Header (unless suppressed)
     if (!cli->suppress_xhdr) {
-        cli->extended_header_offset = write_extended_header(cli);
+        cli->extended_header_offset = write_extended_header(cli, cli->enc_params.width, cli->enc_params.height);
         if (cli->extended_header_offset < 0) {
             fprintf(stderr, "Warning: Failed to write Extended Header\n");
         }