lavc/cbs: Add JPEG support

7 files changed, 851 insertions, 0 deletions

diff --git a/configure b/configure
index 42320de62b..709feffac7 100755
--- a/configure
+++ b/configure
@@ -2273,6 +2273,7 @@ CONFIG_EXTRA="
     cbs
     cbs_h264
     cbs_h265
+    cbs_jpeg
     cbs_mpeg2
     cbs_vp9
     dirac_parse
@@ -2536,6 +2537,7 @@ threads_if_any="$THREADS_LIST"
 # subsystems
 cbs_h264_select="cbs golomb"
 cbs_h265_select="cbs golomb"
+cbs_jpeg_select="cbs"
 cbs_mpeg2_select="cbs"
 cbs_vp9_select="cbs"
 dct_select="rdft"
diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 411c33da84..892ce233e9 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -65,6 +65,7 @@ OBJS-$(CONFIG_CABAC)                   += cabac.o
 OBJS-$(CONFIG_CBS)                     += cbs.o
 OBJS-$(CONFIG_CBS_H264)                += cbs_h2645.o h2645_parse.o
 OBJS-$(CONFIG_CBS_H265)                += cbs_h2645.o h2645_parse.o
+OBJS-$(CONFIG_CBS_JPEG)                += cbs_jpeg.o
 OBJS-$(CONFIG_CBS_MPEG2)               += cbs_mpeg2.o
 OBJS-$(CONFIG_CBS_VP9)                 += cbs_vp9.o
 OBJS-$(CONFIG_CRYSTALHD)               += crystalhd.o
diff --git a/libavcodec/cbs.c b/libavcodec/cbs.c
index be6c043b58..bb3ce95971 100644
--- a/libavcodec/cbs.c
+++ b/libavcodec/cbs.c
@@ -35,6 +35,9 @@ static const CodedBitstreamType *cbs_type_table[] = {
 #if CONFIG_CBS_H265
     &ff_cbs_type_h265,
 #endif
+#if CONFIG_CBS_JPEG
+    &ff_cbs_type_jpeg,
+#endif
 #if CONFIG_CBS_MPEG2
     &ff_cbs_type_mpeg2,
 #endif
@@ -50,6 +53,9 @@ const enum AVCodecID ff_cbs_all_codec_ids[] = {
 #if CONFIG_CBS_H265
     AV_CODEC_ID_H265,
 #endif
+#if CONFIG_CBS_JPEG
+    AV_CODEC_ID_MJPEG,
+#endif
 #if CONFIG_CBS_MPEG2
     AV_CODEC_ID_MPEG2VIDEO,
 #endif
diff --git a/libavcodec/cbs_internal.h b/libavcodec/cbs_internal.h
index 172b8a2515..e0e912e28e 100644
--- a/libavcodec/cbs_internal.h
+++ b/libavcodec/cbs_internal.h
@@ -88,6 +88,7 @@ int ff_cbs_write_unsigned(CodedBitstreamContext *ctx, PutBitContext *pbc,
 
 extern const CodedBitstreamType ff_cbs_type_h264;
 extern const CodedBitstreamType ff_cbs_type_h265;
+extern const CodedBitstreamType ff_cbs_type_jpeg;
 extern const CodedBitstreamType ff_cbs_type_mpeg2;
 extern const CodedBitstreamType ff_cbs_type_vp9;
 
diff --git a/libavcodec/cbs_jpeg.c b/libavcodec/cbs_jpeg.c
new file mode 100644
index 0000000000..5a72f0e2e7
--- /dev/null
+++ b/libavcodec/cbs_jpeg.c
@@ -0,0 +1,520 @@
+/*
+ * 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 "cbs.h"
+#include "cbs_internal.h"
+#include "cbs_jpeg.h"
+
+
+#define HEADER(name) do { \
+        ff_cbs_trace_header(ctx, name); \
+    } while (0)
+
+#define CHECK(call) do { \
+        err = (call); \
+        if (err < 0) \
+            return err; \
+    } while (0)
+
+#define SUBSCRIPTS(subs, ...) (subs > 0 ? ((int[subs + 1]){ subs, __VA_ARGS__ }) : NULL)
+
+#define u(width, name, range_min, range_max) \
+    xu(width, name, range_min, range_max, 0)
+#define us(width, name, sub, range_min, range_max) \
+    xu(width, name, range_min, range_max, 1, sub)
+
+
+#define READ
+#define READWRITE read
+#define RWContext GetBitContext
+#define FUNC(name) cbs_jpeg_read_ ## name
+
+#define xu(width, name, range_min, range_max, subs, ...) do { \
+        uint32_t value = range_min; \
+        CHECK(ff_cbs_read_unsigned(ctx, rw, width, #name, \
+                                   SUBSCRIPTS(subs, __VA_ARGS__), \
+                                   &value, range_min, range_max)); \
+        current->name = value; \
+    } while (0)
+
+#include "cbs_jpeg_syntax_template.c"
+
+#undef READ
+#undef READWRITE
+#undef RWContext
+#undef FUNC
+#undef xu
+
+#define WRITE
+#define READWRITE write
+#define RWContext PutBitContext
+#define FUNC(name) cbs_jpeg_write_ ## name
+
+#define xu(width, name, range_min, range_max, subs, ...) do { \
+        uint32_t value = current->name; \
+        CHECK(ff_cbs_write_unsigned(ctx, rw, width, #name, \
+                                    SUBSCRIPTS(subs, __VA_ARGS__), \
+                                    value, range_min, range_max)); \
+    } while (0)
+
+
+#include "cbs_jpeg_syntax_template.c"
+
+#undef READ
+#undef READWRITE
+#undef RWContext
+#undef FUNC
+#undef xu
+
+
+static void cbs_jpeg_free_application_data(void *unit, uint8_t *content)
+{
+    JPEGRawApplicationData *ad = (JPEGRawApplicationData*)content;
+    av_buffer_unref(&ad->Ap_ref);
+    av_freep(&content);
+}
+
+static void cbs_jpeg_free_comment(void *unit, uint8_t *content)
+{
+    JPEGRawComment *comment = (JPEGRawComment*)content;
+    av_buffer_unref(&comment->Cm_ref);
+    av_freep(&content);
+}
+
+static void cbs_jpeg_free_scan(void *unit, uint8_t *content)
+{
+    JPEGRawScan *scan = (JPEGRawScan*)content;
+    av_buffer_unref(&scan->data_ref);
+    av_freep(&content);
+}
+
+static int cbs_jpeg_split_fragment(CodedBitstreamContext *ctx,
+                                   CodedBitstreamFragment *frag,
+                                   int header)
+{
+    AVBufferRef *data_ref;
+    uint8_t *data;
+    size_t data_size;
+    int unit, start, end, marker, next_start, next_marker;
+    int err, i, j, length;
+
+    if (frag->data_size < 4) {
+        // Definitely too short to be meaningful.
+        return AVERROR_INVALIDDATA;
+    }
+
+    for (i = 0; i + 1 < frag->data_size && frag->data[i] != 0xff; i++);
+    if (i > 0) {
+        av_log(ctx->log_ctx, AV_LOG_WARNING, "Discarding %d bytes at "
+               "beginning of image.\n", i);
+    }
+    for (++i; i + 1 < frag->data_size && frag->data[i] == 0xff; i++);
+    if (i + 1 >= frag->data_size && frag->data[i]) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid JPEG image: "
+               "no SOI marker found.\n");
+        return AVERROR_INVALIDDATA;
+    }
+    marker = frag->data[i];
+    if (marker != JPEG_MARKER_SOI) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid JPEG image: first "
+               "marker is %02x, should be SOI.\n", marker);
+        return AVERROR_INVALIDDATA;
+    }
+    for (++i; i + 1 < frag->data_size && frag->data[i] == 0xff; i++);
+    if (i + 1 >= frag->data_size) {
+        av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid JPEG image: "
+               "no image content found.\n");
+        return AVERROR_INVALIDDATA;
+    }
+    marker = frag->data[i];
+    start  = i + 1;
+
+    for (unit = 0;; unit++) {
+        if (marker == JPEG_MARKER_EOI) {
+            break;
+        } else if (marker == JPEG_MARKER_SOS) {
+            for (i = start; i + 1 < frag->data_size; i++) {
+                if (frag->data[i] != 0xff)
+                    continue;
+                end = i;
+                for (++i; i + 1 < frag->data_size &&
+                          frag->data[i] == 0xff; i++);
+                if (i + 1 >= frag->data_size) {
+                    next_marker = -1;
+                } else {
+                    if (frag->data[i] == 0x00)
+                        continue;
+                    next_marker = frag->data[i];
+                    next_start  = i + 1;
+                }
+                break;
+            }
+        } else {
+            i = start;
+            if (i + 2 > frag->data_size) {
+                av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid JPEG image: "
+                       "truncated at %02x marker.\n", marker);
+                return AVERROR_INVALIDDATA;
+            }
+            length = AV_RB16(frag->data + i);
+            if (i + length > frag->data_size) {
+                av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid JPEG image: "
+                       "truncated at %02x marker segment.\n", marker);
+                return AVERROR_INVALIDDATA;
+            }
+            end = start + length;
+
+            i = end;
+            if (frag->data[i] != 0xff) {
+                next_marker = -1;
+            } else {
+                for (++i; i + 1 < frag->data_size &&
+                          frag->data[i] == 0xff; i++);
+                if (i + 1 >= frag->data_size) {
+                    next_marker = -1;
+                } else {
+                    next_marker = frag->data[i];
+                    next_start  = i + 1;
+                }
+            }
+        }
+
+        if (marker == JPEG_MARKER_SOS) {
+            length = AV_RB16(frag->data + start);
+
+            data_ref = NULL;
+            data     = av_malloc(end - start +
+                                 AV_INPUT_BUFFER_PADDING_SIZE);
+            if (!data)
+                return AVERROR(ENOMEM);
+
+            memcpy(data, frag->data + start, length);
+            for (i = start + length, j = length; i < end; i++, j++) {
+                if (frag->data[i] == 0xff) {
+                    while (frag->data[i] == 0xff)
+                        ++i;
+                    data[j] = 0xff;
+                } else {
+                    data[j] = frag->data[i];
+                }
+            }
+            data_size = j;
+
+            memset(data + data_size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
+
+        } else {
+            data      = frag->data + start;
+            data_size = end - start;
+            data_ref  = frag->data_ref;
+        }
+
+        err = ff_cbs_insert_unit_data(ctx, frag, unit, marker,
+                                      data, data_size, data_ref);
+        if (err < 0) {
+            if (!data_ref)
+                av_freep(&data);
+            return err;
+        }
+
+        if (next_marker == -1)
+            break;
+        marker = next_marker;
+        start  = next_start;
+    }
+
+    return 0;
+}
+
+static int cbs_jpeg_read_unit(CodedBitstreamContext *ctx,
+                              CodedBitstreamUnit *unit)
+{
+    GetBitContext gbc;
+    int err;
+
+    err = init_get_bits(&gbc, unit->data, 8 * unit->data_size);
+    if (err < 0)
+        return err;
+
+    if (unit->type >= JPEG_MARKER_SOF0 &&
+        unit->type <= JPEG_MARKER_SOF3) {
+        err = ff_cbs_alloc_unit_content(ctx, unit,
+                                        sizeof(JPEGRawFrameHeader),
+                                        NULL);
+        if (err < 0)
+            return err;
+
+        err = cbs_jpeg_read_frame_header(ctx, &gbc, unit->content);
+        if (err < 0)
+            return err;
+
+    } else if (unit->type >= JPEG_MARKER_APPN &&
+               unit->type <= JPEG_MARKER_APPN + 15) {
+        err = ff_cbs_alloc_unit_content(ctx, unit,
+                                        sizeof(JPEGRawApplicationData),
+                                        &cbs_jpeg_free_application_data);
+        if (err < 0)
+            return err;
+
+        err = cbs_jpeg_read_application_data(ctx, &gbc, unit->content);
+        if (err < 0)
+            return err;
+
+    } else if (unit->type == JPEG_MARKER_SOS) {
+        JPEGRawScan *scan;
+        int pos;
+
+        err = ff_cbs_alloc_unit_content(ctx, unit,
+                                        sizeof(JPEGRawScan),
+                                        &cbs_jpeg_free_scan);
+        if (err < 0)
+            return err;
+        scan = unit->content;
+
+        err = cbs_jpeg_read_scan_header(ctx, &gbc, &scan->header);
+        if (err < 0)
+            return err;
+
+        pos = get_bits_count(&gbc);
+        av_assert0(pos % 8 == 0);
+        if (pos > 0) {
+            scan->data_size = unit->data_size - pos / 8;
+            scan->data_ref  = av_buffer_ref(unit->data_ref);
+            if (!scan->data_ref)
+                return AVERROR(ENOMEM);
+            scan->data = unit->data + pos / 8;
+        }
+
+    } else {
+        switch (unit->type) {
+#define SEGMENT(marker, type, func, free) \
+        case JPEG_MARKER_ ## marker: \
+            { \
+                err = ff_cbs_alloc_unit_content(ctx, unit, \
+                                                sizeof(type), free); \
+                if (err < 0) \
+                    return err; \
+                err = cbs_jpeg_read_ ## func(ctx, &gbc, unit->content); \
+                if (err < 0) \
+                    return err; \
+            } \
+            break
+            SEGMENT(DQT, JPEGRawQuantisationTableSpecification, dqt, NULL);
+            SEGMENT(DHT, JPEGRawHuffmanTableSpecification,      dht, NULL);
+            SEGMENT(COM, JPEGRawComment,  comment, &cbs_jpeg_free_comment);
+#undef SEGMENT
+        default:
+            return AVERROR(ENOSYS);
+        }
+    }
+
+    return 0;
+}
+
+static int cbs_jpeg_write_scan(CodedBitstreamContext *ctx,
+                               CodedBitstreamUnit *unit,
+                               PutBitContext *pbc)
+{
+    JPEGRawScan *scan = unit->content;
+    int i, err;
+
+    err = cbs_jpeg_write_scan_header(ctx, pbc, &scan->header);
+    if (err < 0)
+        return err;
+
+    if (scan->data) {
+        if (scan->data_size * 8 > put_bits_left(pbc))
+            return AVERROR(ENOSPC);
+
+        for (i = 0; i < scan->data_size; i++)
+            put_bits(pbc, 8, scan->data[i]);
+    }
+
+    return 0;
+}
+
+static int cbs_jpeg_write_segment(CodedBitstreamContext *ctx,
+                                  CodedBitstreamUnit *unit,
+                                  PutBitContext *pbc)
+{
+    int err;
+
+    if (unit->type >= JPEG_MARKER_SOF0 &&
+        unit->type <= JPEG_MARKER_SOF3) {
+        err = cbs_jpeg_write_frame_header(ctx, pbc, unit->content);
+    } else if (unit->type >= JPEG_MARKER_APPN &&
+               unit->type <= JPEG_MARKER_APPN + 15) {
+        err = cbs_jpeg_write_application_data(ctx, pbc, unit->content);
+    } else {
+        switch (unit->type) {
+#define SEGMENT(marker, func) \
+            case JPEG_MARKER_ ## marker: \
+                err = cbs_jpeg_write_ ## func(ctx, pbc, unit->content); \
+                break;
+            SEGMENT(DQT, dqt);
+            SEGMENT(DHT, dht);
+            SEGMENT(COM, comment);
+        default:
+            return AVERROR_PATCHWELCOME;
+        }
+    }
+
+    return err;
+}
+
+static int cbs_jpeg_write_unit(CodedBitstreamContext *ctx,
+                                CodedBitstreamUnit *unit)
+{
+    CodedBitstreamJPEGContext *priv = ctx->priv_data;
+    PutBitContext pbc;
+    int err;
+
+    if (!priv->write_buffer) {
+        // Initial write buffer size is 1MB.
+        priv->write_buffer_size = 1024 * 1024;
+
+    reallocate_and_try_again:
+        err = av_reallocp(&priv->write_buffer, priv->write_buffer_size);
+        if (err < 0) {
+            av_log(ctx->log_ctx, AV_LOG_ERROR, "Unable to allocate a "
+                   "sufficiently large write buffer (last attempt "
+                   "%"SIZE_SPECIFIER" bytes).\n", priv->write_buffer_size);
+            return err;
+        }
+    }
+
+    init_put_bits(&pbc, priv->write_buffer, priv->write_buffer_size);
+
+    if (unit->type == JPEG_MARKER_SOS)
+        err = cbs_jpeg_write_scan(ctx, unit, &pbc);
+    else
+        err = cbs_jpeg_write_segment(ctx, unit, &pbc);
+
+    if (err == AVERROR(ENOSPC)) {
+        // Overflow.
+        priv->write_buffer_size *= 2;
+        goto reallocate_and_try_again;
+    }
+    if (err < 0) {
+        // Write failed for some other reason.
+        return err;
+    }
+
+    if (put_bits_count(&pbc) % 8)
+        unit->data_bit_padding = 8 - put_bits_count(&pbc) % 8;
+    else
+        unit->data_bit_padding = 0;
+
+    unit->data_size = (put_bits_count(&pbc) + 7) / 8;
+    flush_put_bits(&pbc);
+
+    err = ff_cbs_alloc_unit_data(ctx, unit, unit->data_size);
+    if (err < 0)
+        return err;
+
+    memcpy(unit->data, priv->write_buffer, unit->data_size);
+
+    return 0;
+}
+
+static int cbs_jpeg_assemble_fragment(CodedBitstreamContext *ctx,
+                                       CodedBitstreamFragment *frag)
+{
+    const CodedBitstreamUnit *unit;
+    uint8_t *data;
+    size_t size, dp, sp;
+    int i;
+
+    size = 4; // SOI + EOI.
+    for (i = 0; i < frag->nb_units; i++) {
+        unit = &frag->units[i];
+        size += 2 + unit->data_size;
+        if (unit->type == JPEG_MARKER_SOS) {
+            for (sp = 0; sp < unit->data_size; sp++) {
+                if (unit->data[sp] == 0xff)
+                    ++size;
+            }
+        }
+    }
+
+    frag->data_ref = av_buffer_alloc(size + AV_INPUT_BUFFER_PADDING_SIZE);
+    if (!frag->data_ref)
+        return AVERROR(ENOMEM);
+    data = frag->data_ref->data;
+
+    dp = 0;
+
+    data[dp++] = 0xff;
+    data[dp++] = JPEG_MARKER_SOI;
+
+    for (i = 0; i < frag->nb_units; i++) {
+        unit = &frag->units[i];
+
+        data[dp++] = 0xff;
+        data[dp++] = unit->type;
+
+        if (unit->type != JPEG_MARKER_SOS) {
+            memcpy(data + dp, unit->data, unit->data_size);
+            dp += unit->data_size;
+        } else {
+            sp = AV_RB16(unit->data);
+            av_assert0(sp <= unit->data_size);
+            memcpy(data + dp, unit->data, sp);
+            dp += sp;
+
+            for (; sp < unit->data_size; sp++) {
+                if (unit->data[sp] == 0xff) {
+                    data[dp++] = 0xff;
+                    data[dp++] = 0x00;
+                } else {
+                    data[dp++] = unit->data[sp];
+                }
+            }
+        }
+    }
+
+    data[dp++] = 0xff;
+    data[dp++] = JPEG_MARKER_EOI;
+
+    av_assert0(dp == size);
+
+    memset(data + size, 0, AV_INPUT_BUFFER_PADDING_SIZE);
+    frag->data      = data;
+    frag->data_size = size;
+
+    return 0;
+}
+
+static void cbs_jpeg_close(CodedBitstreamContext *ctx)
+{
+    CodedBitstreamJPEGContext *priv = ctx->priv_data;
+
+    av_freep(&priv->write_buffer);
+}
+
+const CodedBitstreamType ff_cbs_type_jpeg = {
+    .codec_id          = AV_CODEC_ID_MJPEG,
+
+    .priv_data_size    = sizeof(CodedBitstreamJPEGContext),
+
+    .split_fragment    = &cbs_jpeg_split_fragment,
+    .read_unit         = &cbs_jpeg_read_unit,
+    .write_unit        = &cbs_jpeg_write_unit,
+    .assemble_fragment = &cbs_jpeg_assemble_fragment,
+
+    .close             = &cbs_jpeg_close,
+};
diff --git a/libavcodec/cbs_jpeg.h b/libavcodec/cbs_jpeg.h
new file mode 100644
index 0000000000..913d3f90f6
--- /dev/null
+++ b/libavcodec/cbs_jpeg.h
@@ -0,0 +1,130 @@
+/*
+ * 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
+ */
+
+#ifndef AVCODEC_CBS_JPEG_H
+#define AVCODEC_CBS_JPEG_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+#include "libavutil/buffer.h"
+
+
+enum {
+    JPEG_MARKER_SOF0    = 0xc0,
+    JPEG_MARKER_SOF1    = 0xc1,
+    JPEG_MARKER_SOF2    = 0xc2,
+    JPEG_MARKER_SOF3    = 0xc3,
+
+    JPEG_MARKER_DHT     = 0xc4,
+    JPEG_MARKER_SOI     = 0xd8,
+    JPEG_MARKER_EOI     = 0xd9,
+    JPEG_MARKER_SOS     = 0xda,
+    JPEG_MARKER_DQT     = 0xdb,
+
+    JPEG_MARKER_APPN    = 0xe0,
+    JPEG_MARKER_JPGN    = 0xf0,
+    JPEG_MARKER_COM     = 0xfe,
+};
+
+enum {
+    JPEG_MAX_COMPONENTS = 255,
+
+    JPEG_MAX_HEIGHT = 65535,
+    JPEG_MAX_WIDTH  = 65535,
+};
+
+
+typedef struct JPEGRawFrameHeader {
+    uint16_t Lf;
+    uint8_t  P;
+    uint16_t Y;
+    uint16_t X;
+    uint16_t Nf;
+
+    uint8_t  C [JPEG_MAX_COMPONENTS];
+    uint8_t  H [JPEG_MAX_COMPONENTS];
+    uint8_t  V [JPEG_MAX_COMPONENTS];
+    uint8_t  Tq[JPEG_MAX_COMPONENTS];
+} JPEGRawFrameHeader;
+
+typedef struct JPEGRawScanHeader {
+    uint16_t Ls;
+    uint8_t  Ns;
+
+    uint8_t  Cs[JPEG_MAX_COMPONENTS];
+    uint8_t  Td[JPEG_MAX_COMPONENTS];
+    uint8_t  Ta[JPEG_MAX_COMPONENTS];
+
+    uint8_t  Ss;
+    uint8_t  Se;
+    uint8_t  Ah;
+    uint8_t  Al;
+} JPEGRawScanHeader;
+
+typedef struct JPEGRawScan {
+    JPEGRawScanHeader header;
+    uint8_t          *data;
+    size_t            data_size;
+    AVBufferRef      *data_ref;
+} JPEGRawScan;
+
+typedef struct JPEGRawQuantisationTable {
+    uint8_t  Pq;
+    uint8_t  Tq;
+    uint16_t Q[64];
+} JPEGRawQuantisationTable;
+
+typedef struct JPEGRawQuantisationTableSpecification {
+    uint16_t Lq;
+    JPEGRawQuantisationTable table[4];
+} JPEGRawQuantisationTableSpecification;
+
+typedef struct JPEGRawHuffmanTable {
+    uint8_t  Tc;
+    uint8_t  Th;
+    uint8_t  L[16];
+    uint8_t  V[224];
+} JPEGRawHuffmanTable;
+
+typedef struct JPEGRawHuffmanTableSpecification {
+    uint16_t Lh;
+    JPEGRawHuffmanTable table[8];
+} JPEGRawHuffmanTableSpecification;
+
+typedef struct JPEGRawApplicationData {
+    uint16_t     Lp;
+    uint8_t     *Ap;
+    AVBufferRef *Ap_ref;
+} JPEGRawApplicationData;
+
+typedef struct JPEGRawComment {
+    uint16_t     Lc;
+    uint8_t     *Cm;
+    AVBufferRef *Cm_ref;
+} JPEGRawComment;
+
+
+typedef struct CodedBitstreamJPEGContext {
+    // Write buffer.
+    uint8_t *write_buffer;
+    size_t write_buffer_size;
+} CodedBitstreamJPEGContext;
+
+
+#endif /* AVCODEC_CBS_JPEG_H */
diff --git a/libavcodec/cbs_jpeg_syntax_template.c b/libavcodec/cbs_jpeg_syntax_template.c
new file mode 100644
index 0000000000..d3cd9ff62e
--- /dev/null
+++ b/libavcodec/cbs_jpeg_syntax_template.c
@@ -0,0 +1,191 @@
+/*
+ * 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
+ */
+
+static int FUNC(frame_header)(CodedBitstreamContext *ctx, RWContext *rw,
+                              JPEGRawFrameHeader *current)
+{
+    int err, i;
+
+    HEADER("Frame Header");
+
+    u(16, Lf, 8, 8 + 3 * JPEG_MAX_COMPONENTS);
+
+    u(8,  P,  2, 16);
+    u(16, Y,  0, JPEG_MAX_HEIGHT);
+    u(16, X,  1, JPEG_MAX_WIDTH);
+    u(8,  Nf, 1, JPEG_MAX_COMPONENTS);
+
+    for (i = 0; i < current->Nf; i++) {
+        us(8, C[i],  i, 0, JPEG_MAX_COMPONENTS);
+        us(4, H[i],  i, 1, 4);
+        us(4, V[i],  i, 1, 4);
+        us(8, Tq[i], i, 0, 3);
+    }
+
+    return 0;
+}
+
+static int FUNC(quantisation_table)(CodedBitstreamContext *ctx, RWContext *rw,
+                                     JPEGRawQuantisationTable *current)
+{
+    int err, i;
+
+    u(4, Pq, 0, 1);
+    u(4, Tq, 0, 3);
+
+    if (current->Pq) {
+        for (i = 0; i < 64; i++)
+            us(16, Q[i], i, 1, 255);
+    } else {
+        for (i = 0; i < 64; i++)
+            us(8,  Q[i], i, 1, 255);
+    }
+
+    return 0;
+}
+
+static int FUNC(dqt)(CodedBitstreamContext *ctx, RWContext *rw,
+                     JPEGRawQuantisationTableSpecification *current)
+{
+    int err, i, n;
+
+    HEADER("Quantisation Tables");
+
+    u(16, Lq, 2, 2 + 4 * 65);
+    n = current->Lq / 65;
+
+    for (i = 0; i < n; i++)
+        CHECK(FUNC(quantisation_table)(ctx, rw, &current->table[i]));
+
+    return 0;
+}
+
+static int FUNC(huffman_table)(CodedBitstreamContext *ctx, RWContext *rw,
+                               JPEGRawHuffmanTable *current)
+{
+    int err, i, j, ij;
+
+    u(4, Tc, 0, 1);
+    u(4, Th, 0, 3);
+
+    for (i = 0; i < 16; i++)
+        us(8, L[i], i, 0, 224);
+
+    ij = 0;
+    for (i = 0; i < 16; i++) {
+        for (j = 0; j < current->L[i]; j++) {
+            us(8, V[ij], ij, 0, 255);
+            ++ij;
+        }
+    }
+
+    return 0;
+}
+
+static int FUNC(dht)(CodedBitstreamContext *ctx, RWContext *rw,
+                     JPEGRawHuffmanTableSpecification *current)
+{
+    int err, i, j, n;
+
+    HEADER("Huffman Tables");
+
+    u(16, Lh, 2, 2 + 8 * (1 + 16 + 256));
+
+    n = 2;
+    for (i = 0; n < current->Lh; i++) {
+        CHECK(FUNC(huffman_table)(ctx, rw, &current->table[i]));
+
+        ++n;
+        for (j = 0; j < 16; j++)
+            n += 1 + current->table[i].L[j];
+    }
+
+    return 0;
+}
+
+static int FUNC(scan_header)(CodedBitstreamContext *ctx, RWContext *rw,
+                             JPEGRawScanHeader *current)
+{
+    int err, j;
+
+    HEADER("Scan");
+
+    u(16, Ls, 6, 6 + 2 * JPEG_MAX_COMPONENTS);
+
+    u(8, Ns, 1, 4);
+    for (j = 0; j < current->Ns; j++) {
+        us(8, Cs[j], j, 0, JPEG_MAX_COMPONENTS);
+        us(4, Td[j], j, 0, 3);
+        us(4, Ta[j], j, 0, 3);
+    }
+
+    u(8, Ss, 0, 63);
+    u(8, Se, 0, 63);
+    u(4, Ah, 0, 13);
+    u(4, Al, 0, 15);
+
+    return 0;
+}
+
+static int FUNC(application_data)(CodedBitstreamContext *ctx, RWContext *rw,
+                                  JPEGRawApplicationData *current)
+{
+    int err, i;
+
+    HEADER("Application Data");
+
+    u(16, Lp, 2, 65535);
+
+    if (current->Lp > 2) {
+#ifdef READ
+        current->Ap_ref = av_buffer_alloc(current->Lp - 2);
+        if (!current->Ap_ref)
+            return AVERROR(ENOMEM);
+        current->Ap = current->Ap_ref->data;
+#endif
+
+        for (i = 0; i < current->Lp - 2; i++)
+            us(8, Ap[i], i, 0, 255);
+    }
+
+    return 0;
+}
+
+static int FUNC(comment)(CodedBitstreamContext *ctx, RWContext *rw,
+                         JPEGRawComment *current)
+{
+    int err, i;
+
+    HEADER("Comment");
+
+    u(16, Lc, 2, 65535);
+
+    if (current->Lc > 2) {
+#ifdef READ
+        current->Cm_ref = av_buffer_alloc(current->Lc - 2);
+        if (!current->Cm_ref)
+            return AVERROR(ENOMEM);
+        current->Cm = current->Cm_ref->data;
+#endif
+
+        for (i = 0; i < current->Lc - 2; i++)
+            us(8, Cm[i], i, 0, 255);
+    }
+
+    return 0;
+}